Category: Meeting Updates

Platinum Chemotherapy Inferior to XELODA® in Triple Negative Breast Cancer Following Neoadjuvant Chemotherapy

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SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. Approximately 284,200 new cases of breast cancer will be diagnosed in 2021 and about 44,130 individuals will die of the disease, largely due to metastatic recurrence.

Breast cancer is heterogeneous malignancy and using global gene expression analyses, 6 breast cancer intrinsic subtypes have been established. They include Luminal A, Luminal B, HER2-enriched, Claudin-low, Basal-like, and a Normal breast-like group. Triple Negative Breast Cancer (TNBC) is a heterogeneous, molecularly diverse group of breast cancers and are ER (Estrogen Receptor), PR (Progesterone Receptor) and HER2 (Human Epidermal Growth Factor Receptor-2) negative. TNBC accounts for 15-20% of invasive breast cancers, with a higher incidence noted in young patients and African American females. It is a surrogate for the inherently aggressive Basal-like breast cancer subtype. This group has the worse prognosis compared to other breast cancer subtypes and is usually aggressive, and tumors tend to be high grade. Patients with TNBC are at a higher risk for both local and distant recurrence and often develop visceral metastases. Those with metastatic disease have one of the worst prognoses of all cancers, with a median Overall Survival of 13 months. The majority of patients with TNBC who develop metastatic disease do so within the first 3 years after diagnosis, whereas those without recurrence during this period of time have survival rates similar to those with ER-positive breast cancers. Basal-like breast cancer subtype is also a marker of hereditary breast cancer susceptibility. Multiparity may increase the risk of TNBC and reduce the likelihood of developing ER-positive breast cancer. The lack of known recurrent oncogenic drivers in patients with metastatic TNBC, presents a major therapeutic challenge.Molecular-Subtypes-of-Breast-Cancer

Nonetheless, patients with TNBC often receive chemotherapy in the neoadjuvant, adjuvant or metastatic settings and approximately 30-40% of patients achieve a pathological Complete Response (pCR) in the neoadjuvant setting. In addition to increasing the likelihood of tumor resectability and breast preservation, patients achieving a pCR following neoadjuvant chemotherapy have a longer Event Free Survival (EFS) and Overall Survival (OS). Those who do not achieve a pathological Complete Response tend to have a poor prognosis. For all these reasons, pCR is considered a valid endpoint for clinical testing of neoadjuvant therapy in patients with early stage TNBC. Patients with TNBC are at a high risk for recurrence if they have residual invasive disease, following completion of standard neoadjuvant chemotherapy.

In the Phase III CREATE-X trial, the addition of adjuvant XELODA® (Capecitabine) therapy was found to be safe and effective in prolonging Disease Free Survival (DFS) and Overall Survival (OS) among patients with HER2-negative breast cancer, who had residual invasive disease on pathological evaluation, following neoadjuvant chemotherapy (N Engl J Med 2017;376:2147-2159).

Based on the preclinical models supporting the use of platinum agents in the TNBC Basal-like subtype, the EA1131 trial was conducted to test the hypothesis that adjuvant platinum chemotherapy would improve invasive DFS compared with XELODA®, in patients with clinical Stage II-III TNBC, who had Basal-like subtype invasive residual disease in the breast, following neoadjuvant chemotherapy. The aim of this study was to assess whether platinum chemotherapy would be as effective, or more effective than XELODA® (noninferiority design with superiority alternative – Hybrid design).

In this study, 410 patients with clinical Stage II or III TNBC who had completed at least one full cycle of taxane with or without anthracycline-containing neoadjuvant chemotherapy were randomly assigned to receive XELODA® 1000 mg/m2 orally twice daily, days 1-14, every 3 weeks, for a total of six cycles, or a platinum agent (treating physician choice of Cisplatin 75 mg/m2 or Carboplatin AUC 6 on day 1) IV, once every 3 weeks, for a total of four cycles. Radiation Therapy before or after study treatment completion, was required for all patients after breast-conservation surgery. Postmastectomy Radiation Therapy was required for patients with primary tumors more than 5 cm or those with 4 or more positive axillary lymph nodes. TNBC subtype (Basal versus non-Basal) was determined by PAM50 in the residual disease. The Primary end point was invasive DFS (time from random assignment to the earliest disease recurrence, invasive contralateral cancer, second primary cancer, or death) in patients with Basal subtype TNBC.

After a recent interim analysis, the Data and Safety Monitoring Committee recommended stopping the trial, as it was unlikely that further follow up would show noninferiority or superiority of platinum chemotherapy. After a median follow up of 20 months, the 3-year invasive DFS among the 308 patients with Basal subtype TNBC for platinum chemotherapy was 42% versus 49% for XELODA®. Further, Grade 3 and 4 toxicities were more common in the platinum chemotherapy group. The 3-year Relapse Free Survival as well as Overall Survival was also in favor of XELODA® group versus Platinum group. There was no benefit noted with platinum chemotherapy in any of the subsets of randomized patients.

It was concluded from this study that platinum agents do not improve outcomes in patients with Basal subtype TNBC, who have residual disease following neoadjuvant chemotherapy, and are associated with more severe toxicities, when compared with XELODA®. All participants in this study had a lower than expected 3-year invasive DFS regardless of study treatment, highlighting the need for better therapies in this high-risk population. The authors added that these study findings have an immediate impact in clinical practice, and adjuvant use of platinum agents in this patient population should only be considered in the context of a clinical trial.

Randomized Phase III Postoperative Trial of Platinum-Based Chemotherapy Versus Capecitabine in Patients With Residual Triple-Negative Breast Cancer Following Neoadjuvant Chemotherapy: ECOG-ACRIN EA1131. Mayer IA, Zhao F, Arteaga CL, et al. DOI: 10.1200/JCO.21.00976 Journal of Clinical Oncology. Published online June 06, 2021.

Late Breaking Abstract – ASCO 2021: PSMA Targeted Radioligand Therapy Improves Progression Free Survival and Overall Survival in Metastatic Prostate Cancer

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SUMMARY: Prostate cancer is the most common cancer in American men with the exclusion of skin cancer, and 1 in 8 men will be diagnosed with prostate cancer during their lifetime. It is estimated that in the United States, about 248,530 new cases of prostate cancer will be diagnosed in 2021 and 34,130 men will die of the disease.

The development and progression of prostate cancer is driven by androgens. Androgen Deprivation Therapy (ADT) or testosterone suppression has therefore been the cornerstone of treatment of advanced prostate cancer, and is the first treatment intervention. Approximately 10-20% of patients with advanced Prostate cancer will progress to Castration Resistant Prostate Cancer (CRPC) within five years during ADT, and over 80% of these patients will have metastatic disease at the time of CRPC diagnosis. Among those patients without metastases at CRPC diagnosis, 33% are likely to develop metastases within two years. Progression to Castration Resistant Prostate Cancer (CRPC) often manifests itself with a rising PSA (Prostate Specific Antigen) and the estimated mean survival of patients with CRPC is 9-36 months, and there is therefore an unmet need for new effective therapies.

Prostate-Specific Membrane Antigen (PSMA) is a type II cell membrane glycoprotein that is selectively expressed in prostate cells, with higher levels of expression in prostatic adenocarcinoma. PSMA is a therefore an excellent target for molecular imaging and therapeutics, due to its high specificity for prostate cancer.

Lu-177-PSMA-617 is a radiopharmaceutical that targets PSMA. It is comprised of Lutetium-177, linked to the ligand PSMA-617, a small molecule designed to bind with high affinity to PSMA. Radioligand therapy with Lu-177-PSMA-617 targets PSMA and releases its payload of lethal beta radiation into the prostate cancer cell. The antitumor activity and safety of Lu-177-PSMA-617 have been established previously in a Phase II study (Lancet Oncol. 2018;19:825-833).

VISION is an international, randomized, open-label Phase III study in which the benefit of Lu-177-PSMA-617 was evaluated in men with PSMA-positive mCRPC, previously treated with second generation Androgen Receptor signaling pathway inhibitor (XTANDI®-Enzalutamide or ZYTIGA®-Abiraterone acetate), and 1-2 taxane chemotherapy regimens. In this trial, 831 patients were randomized 2:1 to receive Lu-177-PSMA-617, 7.4 GBq every 6 weeks for 6 cycles plus Standard of Care as determined by the treating physician (N=551), or Standard of Care only (N=280). Both treatment groups were well balanced and this trial excluded patients treated with XOFIGO® (Radium-223). Enrolled patients had a castrate level or serum/plasma testosterone of lower than 50 ng/dL, and PET imaging with 68Ga-PSMA-11 was used to determine PSMA positivity by central review. The Primary endpoints were radiographic Progression Free Survival (rPFS) by Independent Central Review (ICR) and Overall Survival (OS). Secondary endpoints included Objective Response Rate (ORR), Disease Control Rate (DCR), and time to first Symptomatic Skeletal Event (SSE). The median study follow up was 20.9 months.

Lu-177-PSMA-617 plus Standard of Care significantly improved rPFS by 60%, compared to Standard of Care alone (median rPFS 8.7 versus 3.4 months, HR=0.40; P<0.001). The median OS was also significantly improved by 38% with Lu-177-PSMA-617 plus Standard of Care compared to Standard of Care alone (median OS 15.3 versus 11.3 months, HR=0.62; P<0.001). All key secondary endpoints including Objective Response Rate, Disease Control Rate, and time to first Symptomatic Skeletal Event were statistically significant, and in favor of Lu-177-PSMA-617 plus Standard of Care.

It was concluded that radioligand therapy with Lutetium-177–PSMA-617 significantly improved radiographic Progression Free Survival and Overall Survival when added to Standard of Care, compared with Standard of Care alone, in men with PSMA-positive metastatic Castration Resistant Prostate Cancer.

Phase 3 study of lutetium-177-PSMA-617 in patients with metastatic castration-resistant prostate cancer (VISION). Morris MJ, De Bono JS, Chi KN, et al. J Clin Oncol. 2021;39(suppl 15):LBA4.

Late Breaking Abstract – ASCO 2021: Adjuvant KEYTRUDA® Improves Disease Free Survival in Renal Cell Carcinoma

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SUMMARY: The American Cancer Society estimates that 76,080 new cases of kidney cancers will be diagnosed in the United States in 2021 and about 13,780 people will die from the disease. Renal Cell Carcinoma (RCC) is by far the most common type of kidney cancer and is about twice as common in men as in women. Modifiable risk factors include smoking, obesity, workplace exposure to certain substances and high blood pressure. The five year survival of patients with advanced RCC is less than 10% and there is a significant unmet need for improved therapies for this disease.

The prognosis for patients with Renal Cell Carcinoma (RCC) is dependent on the stage of disease and risk factors. Two validated models, the University of California Los Angeles Integrated Staging System (UISS) and the Stage, Size, Grade, and Necrosis (SSIGN) score were developed, to assess the risk for relapse. UISS is based on ECOG Performance Status, Fuhrman nuclear grading and TNM pathological stage, whereas the SSIGN score takes Stage, Size, Grade and Necrosis into consideration. Approximately 16% of patients with RCC present with Locoregional disease, and up to 40% of these patients relapse with metastatic disease, following nephrectomy. The 5-year survival for locoregional (stage III) disease is 53%, and 8% for metastatic disease. The standard management of high risk patients following nephrectomy has been surveillance, as there has been limited data demonstrating the benefit of adjuvant therapy in reducing the risk of relapse. Adjuvant therapy with immune check point inhibitors therapy is a potentially attractive treatment strategy for this patient group.

KEYNOTE-564 is a multicenter, double-blind, Phase III trial in which the benefit of adjuvant therapy with KEYTRUDA® was compared with placebo, following nephrectomy, in patients with clear cell RCC. In this study, 994 patients were randomized 1:1 to receive either KEYTRUDA® or placebo at least 12 weeks after surgery. Enrolled patients had histologically confirmed clear cell RCC, with Intermediate-High risk (pT2, Grade 4 or Sarcomatoid, N0 M0; or pT3, any Grade, N0 M0), High risk (pT4, any Grade, N0 M0; or pT any Stage, any Grade, N+ M0), or M1 with No Evidence of Disease after primary tumor and soft tissue metastases were completely resected, 1 year or less from nephrectomy. Treatment consisted of KEYTRUDA® 200 mg IV every 3 weeks (N=496) or placebo (N=498), every 3 weeks, for approximately 1 year. Both treatment groups were well balanced. The Primary end point of the trial was Disease Free Survival (DFS) assessment in all randomized patients and Secondary end points included Overall Survival (OS) and Safety. The median follow up at the time of data cut-off was 24.1 months.

At first prespecified interim analysis, the Primary endpoint of DFS was met. The median DFS was not reached for both treatment groups. KEYTRUDA® reduced the risk of recurrence or death by 32% compared with placebo, and this difference was statistically significant (HR=0.68; P=0.0010). The estimated DFS rate at 24 months was 77.3% with KEYTRUDA® versus 68.1% with placebo and this DFS benefit was consistent across subgroups. The estimated OS rate at 24 months was 96.6% with KEYTRUDA® versus 93.5% with placebo. Survival data are premature and additional follow up is planned for OS.

It was concluded that KEYTRUDA® demonstrated a statistically significant and clinically meaningful improvement in Disease Free Survival compared to placebo, in patients with Renal Cell Carcinoma, with a high risk of recurrence. The authors added that this is the first positive Phase III study with a checkpoint inhibitor, in adjuvant Renal Cell Carcinoma, and these practice changing results support KEYTRUDA® as a potential new standard of care for this patient group.

Pembrolizumab versus placebo as post-nephrectomy adjuvant therapy for patients with renal cell carcinoma: Randomized, double-blind, phase III KEYNOTE-564 study. Choueiri TK, Tomczak P, Park SH, et al. J Clin Oncol 2021; 39: (suppl 15; abstr LBA5) DOI: 10.1200/JCO.2021.39.15_suppl.LBA5

Late Breaking Abstract – ASCO 2021: Adjuvant LYNPARZA® Improves Disease Free Survival in BRCA Positive Breast Cancer

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SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. Approximately 284,200 new cases of breast cancer will be diagnosed in 2021 and about 44,130 individuals will die of the disease, largely due to metastatic recurrence.

DNA can be damaged due to errors during its replication or as a result of environmental exposure to ultraviolet radiation from the sun or other toxins. The tumor suppressor genes such as BRCA1 (Breast Cancer 1) and BRCA2 help repair damaged DNA and thus play an important role in maintaining cellular genetic integrity, failing which these genetic aberrations can result in malignancies. The BRCA1 gene is located on the long (q) arm of chromosome 17 whereas BRCA2 is located on the long arm of chromosome 13. Mutations in BRCA1 and BRCA2 account for about 20 to 25 percent of hereditary breast cancers and about 5 to 10 percent of all breast cancers. These mutations can be inherited from either of the parents and a child has a 50 percent chance of inheriting this mutation, and the deleterious effects of the mutations are seen even when an individual’s second copy of the gene is normal. Patients with BRCA mutations can present with aggressive, high-risk disease and are at a high risk of recurrence following completion of multimodality therapy including surgery, radiation, and chemotherapy. This is an area of unmet need, warranting identification of additional novel and effective therapies.

BRCA1 and BRCA2 are tumor suppressor genes and they recognize and repair double strand DNA breaks via Homologous Recombination (HR) pathway. Homologous Recombination is a DNA repair pathway utilized by cells to accurately repair DNA double-stranded breaks during the S and G2 phases of the cell cycle, and thereby maintain genomic integrity. The PARP (Poly ADP Ribose Polymerase) family of enzymes include PARP1 and PARP2, and is a related enzymatic pathway that repairs single strand breaks in DNA. In a BRCA mutant, the cancer cell relies solely on PARP pathway for DNA repair to survive.

LYNPARZA® is a PARP inhibitor, that traps PARP onto DNA at sites of single-strand breaks, thereby preventing their repair and generate double-strand breaks. These breaks cannot be repaired accurately in tumors harboring defects in Homologous Recombination Repair pathway genes, such as BRCA1 or BRCA2 mutations, and this leads to cumulative DNA damage and tumor cell death. LYNPARZA® is presently approved by the FDA for metastatic HER2-negative breast cancer with BRCA1/2 germline mutation. The researchers in this study evaluated the benefit of LYNPARZA® in patients with germline BRCA-mutated, HER2-negative, early stage breast cancer.MOA-of-LYNPARZA

OlympiA is a multicenter, randomized, placebo-controlled, double-blind, Phase III trial of adjuvant LYNPARZA® after neoadjuvant/adjuvant chemotherapy, in patients with germline BRCA1/2 mutations, and high-risk HER2-negative early breast cancer. This trial enrolled 1836 patients, including triple negative and hormone receptor positive breast cancer. All enrolled patients had already received standard adjuvant or neoadjuvant chemotherapy, surgery and if needed, radiation therapy, for early stage breast cancer (Stage II-III). Inclusion criteria also required that patients have a high risk of disease recurrence and those with lower risk of invasive disease recurrence were excluded. For example, patients with hormone receptor positive breast cancer had 4 or more positive lymph nodes prior to adjuvant chemotherapy. Patients were randomized 1:1 to receive LYNPARZA® 300 mg PO BID continuously for 1 year (N=921) or placebo (N=915). Endocrine therapy and bisphosphonates were allowed. The Primary endpoint was invasive Disease Free Survival (IDFS) and Secondary endpoints included distant DFS (DDFS), Overall Survival (OS) and Safety. The study results were reported early, at a median follow up of 2.5 years, after a planned interim analysis was reviewed by an Independent Data Monitoring Committee.

At the pre-specified interim analysis (2.5 years), the estimated 3-year invasive DFS (IDFS) was 85.9% for patients who received LYNPARZA® compared with 77.1% for those who received placebo (HR=0.58; P<0.001), representing a 42% reduction in the risk of IDFS with LYNPARZA® compared to placebo. The estimated 3-year distant DFS (DDFS) was 87.5% versus 80.4% respectively (HR=0.57; P<0.001). This represented a 43% reduction in DDFS with adjuvant LYNPARZA® compared to placebo. At the time of this interim analysis, Overall Survival data were considered immature. The side effects were consistent with the known safety profile of LYNPARZA®, and no new safety signals were noted during the trial.

The authors concluded that adjuvant LYNPARZA® following adjuvant or neoadjuvant chemotherapy significantly improved invasive DFS and distant DFS with acceptable toxicity, in patients with germline BRCA mutated, and high risk HER-2 negative early stage breast cancer. The authors added that this is the first study to report the benefit of a PARP inhibitor given as adjuvant therapy on survival endpoints, in this patient group. Overall Survival data are awaited, as follow up data matures.

Adjuvant Olaparib for Patients with BRCA1- or BRCA2-Mutated Breast Cancer. Tutt AJ, Garber JE, Kaufman B, et al. June 3, 2021, DOI: 10.1056/NEJMoa2105215.

2021 ASCO GU Cancers Symposium: Apalutamide and Abiraterone plus Prednisone Improves PFS in Chemo-Naive mCRPC Patients

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SUMMARY: Prostate cancer is the most common cancer in American men with the exclusion of skin cancer, and 1 in 8 men will be diagnosed with prostate cancer during their lifetime. It is estimated that in the United States, about 248,530 new cases of prostate cancer will be diagnosed in 2021 and 34,130 men will die of the disease. The development and progression of prostate cancer is driven by androgens. Androgen Deprivation Therapy (ADT) or testosterone suppression has therefore been the cornerstone of treatment of advanced prostate cancer, and is the first treatment intervention. Androgen Deprivation Therapies have included bilateral orchiectomy or Gonadotropin Releasing Hormone (GnRH) analogues, with or without first generation Androgen Receptor (AR) inhibitors such as CASODEX® (Bicalutamide), NILANDRON® (Nilutamide) and EULEXIN® (Flutamide) or with second generation anti-androgen agents, which include ZYTIGA® (Abiraterone), XTANDI® (Enzalutamide), ERLEADA® (Apalutamide) and NUBEQA® (Darolutamide). Approximately 10-20% of patients with advanced Prostate cancer will progress to Castration Resistant Prostate Cancer (CRPC) within five years during ADT, and over 80% of these patients will have metastatic disease at the time of CRPC diagnosis. Among those patients without metastases at CRPC diagnosis, 33% are likely to develop metastases within two years. Progression to Castration Resistant Prostate Cancer (CRPC) often manifests itself with a rising PSA (Prostate Specific Antigen), and watchful waiting is often recommended in men with non-metastatic CRPC. However, those with a rapidly rising PSA on ADT (doubling time of less than 8-10 months), are at significantly greater risk of developing metastases and death. The estimated mean survival of patients with CRPC is 9-36 months, and there is therefore an unmet need for new effective therapies.MOA-of-Androgen-Receptor-Targeted-Agents

Expression of Androgen Receptor (AR) in prostate cancer is heterogeneous and this AR heterogeneity is accentuated in advanced metastatic and relapsed prostate cancer with varying degrees of AR resistance and sensitivity. Both single agent ERLEADA® (Apalutamide) and ZYTIGA® (Abiraterone acetate) in combination with Prednisone, are approved for the treatment of metastatic CRPC. They have distinct mechanisms of action on the Androgen Receptors. Apalutamide is an Androgen Receptor (AR) inhibitor that binds directly to the ligand-binding domain of the AR. Apalutamide inhibits AR nuclear translocation, inhibits DNA binding, and impedes AR-mediated transcription. Abiraterone acetate is an androgen biosynthesis inhibitor that inhibits CYP17, an enzyme expressed in testicular, adrenal, and prostatic tumor tissues, and is required for androgen biosynthesis. The ACIS trial was conducted to study the benefit of androgen annihilation by combining these two drugs (dual inhibition), for the first-line treatment of metastatic CRPC.

ACIS is a randomized, double-blind, placebo-controlled, multicenter study Phase III trial in which the efficacy and safety of single agent Apalutamide and Abiraterone acetate along with Prednisone plus ADT, was compared to placebo and Abiraterone acetate with Prednisone plus ADT, in patients with chemotherapy-naïve mCRPC. This study enrolled 982 chemo naïve patients with metastatic CRPC, who had disease progression on ADT, and were on no other life-prolonging treatment since diagnosis. Patients were randomized 1:1 to receive Apalutamide 240 mg daily along with Abiraterone acetate 1000 mg daily plus Prednisone 5 mg twice daily, all given orally (N=492) versus Placebo along with Abiraterone Acetate plus Prednisone (N=490). All patients were also on Androgen Deprivation Therapy. The median patient age was 71 years, 53% of patients had a Gleason score of 7 or more at initial diagnosis, about 85% had bone metastases, 48% had lymph node metastases and 15% had visceral metastases. Baseline characteristics were comparable in both treatment groups.
The Primary end point was radiographic Progression Free Survival (rPFS), defined from randomization date to radiographic progression date or death. Secondary end points included PSA response, Overall Survival (OS), initiation of cytotoxic chemotherapy, and pain progression.

This trial met its Primary endpoint of rPFS benefit with androgen annihilation, and the Apalutamide plus Abiraterone combination prolonged rPFS from 16.6 months to 22.6 months (HR=0.69, P<0.0001), suggesting a 31% reduction in the risk of radiographic disease progression and death. However, after 54.8 months of median follow-up, Overall Survival was numerically higher but not statistically significantly higher with Apalutamide plus Abiraterone combination (36.2 months versus 33.7 months, P=0.498). In the pre-specified subgroup analysis, the Apalutamide plus Abiraterone combination was more favorable in patients 75 years and older and in those with visceral metastases. More patients receiving Apalutamide plus Abiraterone combination had a PSA decline greater than 50%. In an exploratory analysis of biomarkers of response, tumors classified as luminal by the PAM50 signature score, or those having high AR activity expression signatures, trended towards improved rPFS and OS with the Apalutamide plus Abiraterone combination. There were no new safety signals noted with the Apalutamide plus Abiraterone combination, and based on FACT (Functional Assessment of Cancer Therapy-Prostate) -P score, Quality of Life was comparable between treatment groups.

It was concluded that the ACIS trial met its Primary endpoint, and when compared to Abiraterone with ADT, a combination of Apalutamide plus Abiraterone along with ADT demonstrated a 31% reduction in risk of radiographic progression or death, in chemo-naive mCRPC patients.

Final results from ACIS, a randomized, placebo (PBO)-controlled double-blind phase 3 study of apalutamide (APA) and abiraterone acetate plus prednisone (AAP) versus AAP in patients (pts) with chemo-naive metastatic castration-resistant prostate cancer (mCRPC). Rathkopf DE, Efstathiou E, Attard G, et al. On behalf of the ACIS investigators. J Clin Oncol 39, 2021 (suppl 6; abstr 9)

FDA Approves UKONIQ® for Relapsed or Refractory Marginal Zone and Follicular Lymphomas

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SUMMARY: The FDA on February 5, 2021 granted accelerated approval to UKONIQ® (Umbralisib), a kinase inhibitor including PI3K-delta and Casein Kinase CK1-epsilon, for adult patients with Relapsed or Refractory Marginal Zone Lymphoma (MZL) who have received at least one prior anti-CD20-based regimen and adult patients with Relapsed or Refractory Follicular Lymphoma (FL) who have received at least three prior lines of systemic therapy. The American Cancer Society estimates that in 2021, about 81,560 people will be diagnosed with Non Hodgkin Lymphoma (NHL) in the United States and about 20,720 individuals will die of this disease. Indolent Non Hodgkin Lymphomas are mature B cell lymphoproliferative disorders and include Follicular Lymphoma, Nodal Marginal Zone Lymphoma (NMZL), Extranodal Marginal Zone Lymphoma (ENMZL) of Mucosa-Associated Lymphoid Tissue (MALT), Splenic Marginal Zone Lymphoma (SMZL), LymphoPlasmacytic Lymphoma (LPL) and Small Lymphocytic Lymphoma (SLL). Follicular Lymphoma is the most indolent form and second most common form of all NHLs and they are a heterogeneous group of lymphoproliferative malignancies. Approximately 20% of all NHLs are Follicular Lymphomas (FL).

Advanced stage indolent NHL is not curable and as such, prolonging Progression Free Survival (PFS) and Overall Survival (OS), while maintaining Quality of Life, have been the goals of treatment intervention. Asymptomatic patients with indolent NHL are generally considered candidates for “watch and wait” approach. Patients with advanced stage symptomatic Follicular Lymphoma are often treated with induction chemoimmunotherapy followed by maintenance RITUXAN® (Rituximab). This can result in a median PFS of 6-8 yrs and a median OS of 12-15 yrs. However, approximately 30% of the patients will relapse in 3 years and treatment options are limited for patients with relapses, after multiple treatments.

UKONIQ® is an oral, once-daily, dual inhibitor of Phosphatidylinositol-3-Kinase-delta (PI3Kδ) and Casein Kinase 1-epsilon (CK1-epsilon) that exhibits improved selectivity for the delta isoform of PI3K. In contrast with other PI3K inhibitors, there was a low incidence of immune-mediated toxicities with UKONIQ® possibly attributable to enhanced selectivity for the PI3Kδ isoform as well as inhibition of CK1-epsilon.

The present FDA approval was based on the UNITY-NHL trial (NCT02793583), which is global, multicenter, open-label, multicohort, Phase IIb registration study, designed to evaluate the safety and efficacy of UKONIQ® in previously treated NHL patients. This study had a total 208 patients with indolent NHL and included 69 patients with MZL (splenic, nodal, extranodal), 117 patients with FL (grade 1, 2, 3a), and 22 patients with Small Lymphocytic Lymphoma (SLL). MZL patients were Relapsed/Refractory to 1 or more prior lines of treatment, which included an anti-CD20, while FL and SLL patients were Relapsed/Refractory to 2 or more prior lines of therapy, which included an anti-CD20 and an alkylating agent. UKONIQ® was administered at 800 mg orally once daily in 28-day treatment cycles until disease progression or unacceptable tolerability. The median age was 66 years and the median duration of treatment exposure was 8.4 months. Pneumocystis jiroveci Pneumonia (PCP) and anti-viral prophylaxis were mandated for all patients. The Primary endpoint of the study was Overall Response Rate (ORR) as assessed by an Independent Review Committee (IRC) and Secondary endpoints included Duration of Response (DoR), Progression Free Survival (PFS), Time To Response (TTR), and Safety.

With a median follow up of 27.8 months, the ORR for patients with MZL was 49%, with a 16% Complete Response (CR) rate and a Disease Control Rate (CR+PR+SD) of 82.6%. The ORR was consistent amongst MZL subtypes and no patients who achieved CR had experienced disease progression to date. Additionally, the median DoR and median PFS was not reached for this patient population.

Among patients with FL, with a median follow up of 27.5 months, the ORR was 45%, with 5% achieving a CR, and a DCR of 79.5%. The median TTR was 4.6 months and the median DoR was 11.1 months. The median PFS was 10.6 months.

Among SLL patients, with a median follow up of 29.3 months, the ORR was 50%, with 4.5% achieving a CR, and a DCR of 86.4%. The median TTR was 2.7 months and the median DoR was 18.3 months. The median PFS was 20.9 months.

The most common toxicities included increased creatinine, diarrhea/colitis, fatigue, transaminase elevation, musculoskeletal pain, neutropenia, anemia, thrombocytopenia, upper respiratory tract infection, nausea, vomiting, abdominal pain, reduced appetite, and cutaneous reactions.

It was concluded from this study that UKONIQ® has a favorable benefit-risk profile and achieved meaningful clinical activity in a heavily pretreated population of patients with indolent NHL. The authors added that the safety profile was manageable, with a relatively low incidence of immune-mediated toxicities and treatment discontinuations.

Umbralisib, the Once Daily Dual Inhibitor of PI3Kδ and Casein Kinase-1ε Demonstrates Clinical Activity in Patients with Relapsed or Refractory Indolent Non-Hodgkin Lymphoma: Results from the Phase 2 Global Unity-NHL Trial. Zinzani PL, Samaniego F, Jurczak W, et al. Presented at the 62nd ASH Annual Meeting and Exposition, December 5-8, 2020. Abstract # 2934.

TIBSOVO® Improves Survival in IDH1 Mutated Advanced Cholangiocarcinoma

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SUMMARY: Bile Duct cancer (Cholangiocarcinoma), comprise about 30% of all primary liver tumors and includes both intrahepatic and extrahepatic bile duct cancers. Klatskin tumor is a type of Cholangiocarcinoma that begins in the hilum, at the junction of the left and right bile ducts. It is the most common type of Cholangiocarcinoma, accounting for more than half of all cases. About 8,000 people in the US are diagnosed with Cholangiocarcinoma each year and approximately 20% of the cases are suitable for surgical resection. The 5-year survival is less than 10%, with limited progress made over the past two decades. There is therefore an unmet need for new effective therapies.

Isocitrate DeHydrogenase (IDH) is a metabolic enzyme that helps generate energy from glucose and other metabolites, by catalyzing the conversion of Isocitrate to Alpha-Ketoglutarate. Alpha-ketoglutarate is required to properly regulate DNA and histone methylation, which in turn is important for gene expression and cellular differentiation. IDH mutations lead to aberrant DNA methylation and altered gene expression thereby preventing cellular differentiation, with resulting immature undifferentiated cells. IDH mutations can thus promote leukemogenesis in Acute Myeloid Leukemia (AML) and tumorigenesis in solid tumors and can result in inferior outcomes. There are three isoforms of IDH. IDH1 is mainly found in the cytoplasm, as well as in peroxisomes, whereas IDH2 and IDH3 are found in the mitochondria, and are a part of the Krebs cycle. Approximately 20% of patients with AML, 70% of patients with Low-grade Glioma and secondary Glioblastoma, 50% of patients with Chondrosarcoma, 20% of patients with Intrahepatic Cholangiocarcinoma, 30% of patients with Angioimmunoblastic T-cell lymphoma and 8% of patients with Myelodysplastic syndromes/Myeloproliferative neoplasms, are associated with IDH mutations.

TIBSOVO® (Ivosidenib) is an oral, targeted, small-molecule inhibitor of mutant IDH1. The FDA in July, 2018, approved TIBSOVO® for adult patients with relapsed or refractory AML with a susceptible IDH1 mutation. A previously published Phase I study demonstrated the safety and activity of TIBSOVO® in patients with IDH1 mutated advanced Cholangiocarcinoma.MOA-of-Ivosidenib

ClarIDHy is an international, randomized, double-blind, Phase III study, in which 187 previously treated patients with advanced Cholangiocarcinoma with an IDH1 mutation were randomly assigned 2:1 to receive TIBSOVO® 500 mg orally once daily (N=126) or matched placebo (N=61). All patients had advanced unresectable Cholangiocarcinoma. The median age was 62 years, 91% had intrahepatic Cholangiocarcinoma, 93% of patients had metastatic disease and 47% had received two prior therapies. The Primary endpoint was Progression Free Survival (PFS) and Secondary endpoints included Safety, Objective Response Rate (ORR) and Overall Survival (OS). Crossover from placebo to TIBSOVO® was permitted upon radiographic disease progression.

This study met its Primary endpoint and the median PFS was 2.7 months for patients treated with TIBSOVO® compared to 1.4 months with placebo (HR=0.37; P<0.0001). More importantly, the median PFS at 6 and 12 months were 32% and 22% in the TIBSOVO® group, whereas no patients randomized to the placebo group were progression-free for 6 or more months, at the time of data cutoff.

The authors now reported the results of final analysis which showed an improvement in the secondary endpoint of OS, favoring patients randomized to TIBSOVO® compared to those randomized to placebo. However, statistical significance was not reached. The median OS for patients in the TIBSOVO® arm was 10.3 months compared to 7.5 months for patients in the placebo arm (HR=0.79; 1-sided P=0.093). A high proportion of patients in the placebo arm (70.5%) crossed over to TIBSOVO®. After adjusting for crossover from placebo to TIBSOVO®, the median OS for patients in the placebo arm was 5.1 months (HR=0.49; 1-sided P<0.0001).

The 6-month survival rate for patients in the TIBSOVO® arm was 69% compared to 57% of patients in the placebo arm, not adjusted for crossover. The 12-month survival rate for patients in the TIBSOVO® arm was 43% compared to 36% for patients in the placebo arm, not adjusted for crossover. Treatment with TIBSOVO® preserved patients’ physical functioning from baseline, as assessed by the EORTC QLQ-C30 questionnaire, whereas patients in the placebo arm experienced decline from baseline starting cycle 2. The most common Adverse Events of any grade for TIBSOVO® were nausea (38%), diarrhea (33.1%) and fatigue (28.9%). Adverse Events leading to discontinuation were more common with placebo compared with total TIBSOVO® (8.5% versus 6.6%).

It was concluded that treatment with TIBSOVO® in patients with advanced Cholangiocarcinoma with an IDH1 mutation, resulted in significant improvement in Progression Free Survival as well as favorable Overall Survival trend, when compared to Placebo, despite a high rate of crossover. This is the first pivotal study demonstrating the clinical benefit of targeting IDH1 mutation in this patient group. This new oral, non-cytotoxic, targeted treatment option, with a tolerable safety profile, will be a welcome addition to treat this aggressive disease, for which there is an unmet need for new therapies.

Final results from ClarIDHy, a global, phase III, randomized, double-blind study of ivosidenib (IVO) versus placebo (PBO) in patients (pts) with previously treated cholangiocarcinoma (CCA) and an isocitrate dehydrogenase 1 (IDH1) mutation. Zhu A, Macarulla T, Javle MM, et al. J Clin Oncol 39, 2021 (suppl 3; abstr 266)

SABCS 2020: Ongoing Benefit with VERZENIO® in High Risk Early Stage Breast Cancer

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SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women 12%) will develop invasive breast cancer during their lifetime. Approximately 279,100 new cases of invasive breast cancer will be diagnosed in 2020 and about 42,690 individuals will die of the disease largely due to metastatic recurrence. About 70% of breast tumors express Estrogen Receptors and/or Progesterone Receptors, and Hormone Receptor (HR)-positive/HER2-negative breast cancer is the most frequently diagnosed molecular subtype. Majority of these patients are diagnosed with early stage disease and are often cured with a combination of surgery, radiotherapy, chemotherapy, and hormone therapy. However approximately 20% of patients will experience local recurrence or distant relapse during the first 10 years of treatment. This may be more relevant for those with high risk disease, among whom the risk of recurrence is even greater during the first 2 years while on adjuvant endocrine therapy, due to primary endocrine resistance. More than 75% of the early recurrences are seen at distant sites.

Cyclin Dependent Kinases (CDKs) play a very important role to facilitate orderly and controlled progression of the cell cycle. Genetic alterations in these kinases and their regulatory proteins have been implicated in various malignancies. CDK 4 and 6 phosphorylate RetinoBlastoma protein (RB), and initiate transition from the G1 phase to the S phase of the cell cycle. RetinoBlastoma protein has antiproliferative and tumor-suppressor activity and phosphorylation of RB protein nullifies its beneficial activities. CDK4 and CDK6 are activated in hormone receptor positive breast cancer, promoting breast cancer cell proliferation. Further, there is evidence to suggest that endocrine resistant breast cancer cell lines depend on CDK4 for cell proliferation. The understanding of the role of Cyclin Dependent Kinases in the cell cycle, has paved the way for the development of CDK inhibitors.Cell-Cycle-Inhibition-by-ABEMACICLIB-A-CDK4-and-CDK6-Inhibitor

VERZENIO® (Abemaciclib) is an oral, selective inhibitor of CDK4 and CDK6 kinase activity, and prevents the phosphorylation and subsequent inactivation of the Rb tumor suppressor protein, thereby inducing G1 cell cycle arrest and inhibition of cell proliferation. VERZENIO® is structurally distinct from other CDK 4 and 6 inhibitors (such as Ribociclib and Palbociclib) and is 14 times more potent against cyclin D1/CDK 4 and cyclin D3/CDK 6, in enzymatic assays, but potentially less toxic than earlier pan-CDK inhibitors. At higher doses, only VERZENIO® causes significant cancer cell death, compared with other CDK4/6 inhibitors, suggesting that this drug may be affecting proteins, other than CDK4/6. Additionally, preclinical studies have demonstrated that VERZENIO® may have additional therapeutic benefits for a subset of tumors that are unresponsive to treatment or have grown resistant to other CDK4/6 inhibitors. It has also been shown to cross the blood-brain barrier.

VERZENIO® is presently approved by the FDA as monotherapy as well as in combination with endocrine therapy for patients with HR-positive, HER2- negative advanced breast cancer. The addition of VERZENIO® to FASLODEX® resulted in a statistically significant improvement in Overall Survival among patients with HR-positive, HER2-negative advanced breast cancer, who had progressed on prior endocrine therapy. The goal of monarchE was to evaluate the additional benefit of adding a CDK4/6 inhibitor to endocrine therapy in the adjuvant setting, for patients with HR-positive, HER2-negative, high risk early breast cancer.

The International monarchE trial, is an open-label, randomized, Phase III study, which included 5637 patients, who were pre- and postmenopausal, with HR-positive, HER2-negative early breast cancer, and with clinical and/or pathologic risk factors that rendered them at high risk for relapse. The researchers defined high risk as the presence of four or more positive axillary lymph nodes, or 1-3 three positive axillary lymph nodes, with either a tumor size of 5 cm or more, histologic Grade 3, or centrally tested high proliferation rate (Ki-67 of 20% or more). Following completion of primary therapy which included both adjuvant and neoadjuvant chemotherapy and radiotherapy, patients were randomly assigned (1:1) to VERZENIO® 150 mg orally twice daily for 2 years plus 5 to 10 years of physicians choice of endocrine therapy as clinically indicated (N=2808), or endocrine therapy alone (N=2829). The median patient age was 51 years, about 43% of the patients were premenopausal, and 95% of patients had prior chemotherapy. Approximately 60% of patients had 4 or more positive lymph nodes. The Primary endpoint was Invasive Disease Free Survival (IDFS), and Secondary end points included distant Relapse Free Survival, Overall Survival, and safety. At a preplanned interim analysis, the addition of VERZENIO® to endocrine therapy resulted in a 25% reduction in the risk of developing a Invasive Disease Free Survival (IDFS) event, relative to endocrine therapy alone. Following the positive interim analysis, patients continued to be followed for IDFS, distant recurrence, and Overall Survival. The current study describes outcomes following an extended follow up of this trial, with a median follow up time of 19 months.

At the time of this primary outcome analysis, 1,437 patients (25.5%) had completed the two-year treatment period and 3,281 patients (58.2%) were in the two-year treatment period. The combination of VERZENIO® plus endocrine therapy continued to demonstrate superior Invasive Disease Free Survival (IDFS) compared to endocrine therapy alone, with a 28.7% reduction in the risk of developing invasive disease (P=0.0009; HR=0.713). The 2-year IDFS in the combination group was 92.3% and 89.3% in the endocrine therapy alone treatment group. This IDFS benefit with VERZENIO® was consistently noted in all prespecified subgroups. Further, there was an improvement in the 2-year distant Relapse Free Survival rate among patients who received the combination treatment compared with those who received endocrine therapy alone (93.8% versus 90.8%, respectively). Overall Survival data was immature at the time of analysis.

The researchers also evaluated outcomes among 2,498 patients with centrally assessed high tumor Ki-67 status. Among patients in this cohort, those who received the combination treatment had a 30.9% decreased risk of invasive disease compared with those who received endocrine therapy alone (P=0.01; HR=0.691) and the 2-year IDFS rates in the combination group and the endocrine therapy alone group were 91.6% and 87.1%, respectively. There were no new safety signals observed with VERZENIO®.

It was concluded that at the time of this primary outcome analysis, VERZENIO® combined with endocrine therapy continued to demonstrate a clinically meaningful improvement in Invasive Disease Free Survival, among patients with HR-positive, HER2-negative, node-positive, high risk, early breast cancer.

Primary outcome analysis of invasive disease-free survival for monarchE: abemaciclib combined with adjuvant endocrine therapy for high risk early breast cancer. O’Shaughnessy JA, Johnston S, Harbeck N, et al. Presented at the 2020 San Antonio Breast Cancer Symposium, December 8-11. Abstract. GS1-01.

ASH 2020: Subcutaneous DARZALEX® Plus Pomalidomide and Dexamethasone in Relapsed or Refractory Multiple Myeloma

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SUMMARY: Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 32,270 new cases will be diagnosed in 2020 and 12,830 patients are expected to die of the disease. Multiple Myeloma (MM) in 2020 remains an incurable disease. The therapeutic goal therefore is to improve Progression Free Survival (PFS) and Overall Survival (OS). Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients eventually will relapse, and patients with a high-risk cytogenetic profile or refractory disease have the worst outcomes. The median survival for patients with Myeloma is over 10 years.Mechanism-of-Action-of-Daratumumab

DARZALEX® is a human IgG1 antibody that targets CD38, a transmembrane glycoprotein abundantly expressed on malignant plasma cells and with low levels of expression on normal lymphoid and myeloid cells. DARZALEX® exerts its cytotoxic effect on myeloma cells by multiple mechanisms, including Antibody Dependent Cellular Cytotoxicity (ADCC), Complement Mediated Cytotoxicity and direct apoptosis. Additionally, DARZALEX® may have a role in immunomodulation by depleting CD38-positive regulator Immune suppressor cells, and thereby expanding T cells, in patients responding to therapy. DARZALEX® has activity as both a single agent and when combined with other standard regimens. POMALYST® (Pomalidomide) is a novel, oral, immunomodulatory drug which is far more potent than THALOMID® (Thalidomide) and REVLIMID®, and has been shown to be active in REVLIMID® and VELCADE® refractory patients. In the EQUULEUS Phase Ib study, intravenous DARZALEX® in combination with POMALYST® and Dexamethasone in relapsed or refractory Multiple Myeloma resulted in an Overall Response Rate (ORR) of 59% with Very Good Partial Response (VGPR) noted in 28% of patients, and Complete Response (CR) achieved in 6% of patients.

Recently published studies have concluded that the subcutaneous formulation of DARZALEX® resulted in non-inferior pharmacokinetics and efficacy compared to the current IV formulation, and also importantly offers the potential for a fixed-dose administration, shorter administration times and a lower rate of infusion-related reactions with improved safety profile.

APOLLO study is an open-label, randomized, multicenter, Phase III trial, conducted by the European Myeloma Network investigators, to evaluate SubCutaneous (SC) formulation of DARZALEX® in combination with POMALYST® (Pomalidomide) and Dexamethasone (D-Pd; N=151) versus POMALYST® (Pomalidomide) and Dexamethasone (Pd; N=153) alone in relapsed/refractory Multiple Myeloma patients who have received one or more prior lines of therapy including REVLIMID® (Lenalidomide) and a Proteasome Inhibitor. This study enrolled 304 patients with relapsed or refractory Multiple Myeloma, and prior treatment with anti-CD38 antibody or Pomalidomide was not permitted. Treatment for all patients consisted of POMALYST® 4 mg orally daily plus Dexamethasone 40 mg orally on days 1, 8, 15, and 22 (20 mg for patients aged 75 years or older), given every 28 days. Patients in the D-Pd group additionally received DARZALEX® 1800 mg SC co-formulated with recombinant human hyaluronidase PH20 (rHuPH20; ENHANZE® drug delivery technology, Halozyme, Inc.), given weekly for cycles 1 to 2, every 2 weeks for cycles 3 to 6, and every 4 weeks thereafter. The median age was 67 years, and 35% had high cytogenetic risk (presence of del17p, t[14;16], or t[4;14]). The median prior lines of therapy were 2, approximately 80% of patients were refractory to REVLIMID®, 48% of patients were refractory to a Proteosome Inhibitor, and 42% of patients were refractory to both agents. Treatment was continued until disease progression or unacceptable toxicity. The median duration of treatment was 11.5 months with D-Pd, compared with 6.6 months with Pd. The Primary endpoint was Progression Free Survival (PFS). Secondary endpoints included Overall Response Rate (ORR), Very Good Partial Response (VGPR), Complete Response (CR), MRD negativity rate, Overall Survival (OS), and Safety.

The study met its Primary endpoint of improved PFS in the primary analysis. The median PFS for the D-Pd group was 12.4 months versus 6.9 months for Pd group (HR=0.63; P=0.0018). This represented a 37% reduction in the risk of progression or death in patients treated with D-Pd. Among patients who were refractory to REVLIMID®, median PFS was 9.9 months in the D-Pd group versus 6.5 months in the Pd group. This benefit was seen across all subgroups of patients, regardless of age, stage, prior line of therapy, REVLIMID® refractoriness and cytogenetic risk. D-Pd regimen was also superior to Pd regimen in terms of other endpoints, including ORR (69% versus 46%), VGPR or better (51% versus 20%), CR (25% versus 4%), and MRD negativity (9% versus 2%). Survival data are immature and follow up is ongoing. Infusion-related events were rare, and seen in 6% of patients treated with D-Pd, and local injection-site reactions which were all Grade 1 were seen in 2% of patients in the D-Pd group. Treatment discontinuation due to treatment-related adverse events, were similar for the D-Pd and Pd groups (2% versus 3%).

It was concluded that Subcutaneous DARZALEX® given along with POMALYST® and Dexamethasone significantly reduced the risk of progression or death by 37% in patients with relapsed/refractory Multiple Myeloma, compared to POMALYST® and Dexamethasone alone. The infusion-related reaction rate was very low and median duration of injection administration was short at 5 minutes. Subcutaneous DARZALEX® thus has a high likelihood of changing clinical practice, increasing convenience for patients and decreasing treatment burden.

Apollo: Phase 3 Randomized Study of Subcutaneous Daratumumab Plus Pomalidomide and Dexamethasone (D-Pd) Versus Pomalidomide and Dexamethasone (Pd) Alone in Patients (Pts) with Relapsed/Refractory Multiple Myeloma (RRMM). Dimopoulos MA, Terpos E, Boccadoro M, et al. Presented at the 62nd ASH Annual Meeting and Exposition, 2020. Abstract 412.

ASH 2020: CRISPR-Cas9 Gene-Editing Technique May Cure Sickle Cell Disease and Beta Thalassemia

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SUMMARY: Sickle Cell Disease or Sickle Cell anemia is an Autosomal Recessive disorder and affects approximately 100,000 Americans. It is estimated that it affects 1 out of every 365 African-American births and 1 out of every 16,300 Hispanic-American births. The average life expectancy for patients with Sickle Cell Disease in the United States is approximately 40-60 years. Beta thalassemia affects at least 1000 Americans and according to the WHO, more than 300,000 babies are born worldwide each year with hemoglobin disorders such as Transfusion-Dependent beta-Thalassemia (TDT) and Sickle Cell Disease (SCD). Both diseases are caused by mutations in the hemoglobin beta-globin gene.

HbSS disease or Sickle Cell anemia is the most common Sickle Cell Disease genotype and is associated with the most severe manifestations. HbSS disease is caused by a mutation substituting thymine for adenine in the sixth codon of the beta-globin chain gene. This in turn affects the hemoglobin’s ability to carry oxygen and causes it to polymerize. This results in decreased solubility thereby distorting the shape of the red blood cells, increasing their rigidity and resulting in red blood cells that are sickle shaped rather than biconcave. These sickle shaped red blood cells limit oxygen delivery to the tissues by restricting the flow in blood vessels, leading to severe pain and organ damage (Vaso-Occlusive Crises). Oxidative stress is an important contributing factor to hemoglobin polymerization with polymer formation occurring only in the deoxy state. HbS/b-0 Thalassemia (double heterozygote for HbS and b-0 Thalassemia) is clinically indistinguishable from HbSS disease. Thalassemia is an inherited hemoglobinopathy associated with an erythroid maturation defect and is characterized by ineffective erythropoiesis and impaired RBC maturation. Mutations in the hemoglobin beta-globin gene result in reduced (B+) or absent (B0) beta-globin synthesis creating an imbalance between the alpha and beta globin chains of hemoglobin, resulting in ineffective erythropoiesis. Management of Sickle Cell Disease includes pain control, transfusion support and Hydroxyurea, whereas management of beta Thalassemia include transfusion support and iron chelation therapy. None of the presently available therapies addresses the underlying cause of these diseases nor do they fully ameliorate disease manifestations. Allogeneic bone marrow transplantation can cure both these genetic disorders, but less than 20% of eligible patients have a related HLA-matched donor. There is therefore a great unmet need to find new therapies for beta-Thalassemia and Sickle Cell Disease.

Fetal hemoglobin which consists of two alpha and two gamma chains is produced in utero, but the level of gamma-globulin decreases postnatally as the production of beta-globin and adult hemoglobin which consists of two alpha and two beta chains increases. It has been noted that elevated levels of fetal hemoglobin are associated with decreased morbidity and mortality in patients with Sickle Cell Disease and Thalassemia. BCL11A gene is a repressor of gamma-globin expression and fetal hemoglobin production in adult red blood cells. Downregulating BCL11A can therefore reactivate gamma-globin expression and increase fetal hemoglobin in RBC.CRISPR-Cas9-Nuclease-Gene-Editing-Technique

The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9 nuclease gene editing technique cuts the DNA at the targeted location. The authors in this study used this gene-editing technique in Hematopoietic Stem and Progenitor Cells at the erythroid-specific enhancer region of BCL11A to down-regulate BCL11A expression in erythroid-lineage cells, restore gamma-globin synthesis, and reactivate production of fetal hemoglobin.

The authors reported the interim safety and efficacy data from 10 patients who received the investigational CRISPR-Cas9 nuclease gene-editing based therapy, following enrollment in CLIMB THAL-111 and CLIMB SCD-121 studies. These patients were infused with CTX001 (autologous CRISPR-Cas9-edited CD34+ Hematopoietic Stem and Progenitor Cells (HSPCs) that were genetically edited to reactivate the production of fetal hemoglobin. In the CLIMB THAL-111 and CLIMB SCD-121 open-label, PhaseI/II trials, patients with Transfusion-Dependent beta-Thalassemia and sickle cell disease , respectively, received a single intravenous infusion of CTX001. The production of CTX001 involved collection of CD34+ Hematopoietic Stem and Progenitor Cells (HSPCs) from patients by apheresis, following stem cell mobilization with either NEUPOGEN filgrastim and/or MOZOBIL® (plerixafor), after a minimum of 8 weeks of transfusions of packed red cells, to achieve a level of sickle hemoglobin of less than 30% in the patient with SCD. CTX001 was then manufactured from these CD34+ cells by editing with CRISPR-Cas9 with the use of a single-guide RNA molecule, following preclinical studies of BCL11A editing. Patients received myeloablation with pharmacokinetically adjusted, single-agent Busulfan, before the infusion of CTX001.

Eligible patients were between ages 18 and 35 years. In the CLIMB THAL-111 trial, eligible patients had a diagnosis of beta-Thalassemia (including the hemoglobin E genotype) with either homozygous or compound heterozygous mutations and had received transfusions of PRBC consisting of at least 100 ml/kg of body weight (or 10 units) per year during the previous 2 years. In the open-label CLIMB SCD-121 trial, eligible patients had a documented BS/BS or BS/B0 genotype and had a history of two or more severe vaso-occlusive episodes per year during the previous 2 years. Patients were monitored for engraftment, adverse events, total hemoglobin, hemoglobin fractions on high-performance liquid chromatography, F-cell expression (defined as the percentage of circulating erythrocytes with detectable levels of fetal hemoglobin), laboratory signs of hemolysis, requirements for transfusion support with PRBC, and occurrence of vaso-occlusive episodes in the patient with SCD. Bone marrow aspirates were obtained at 6 and 12 months after infusion, and DNA sequencing was used to measure the fraction of total DNA that was edited at the on-target site in CD34+ bone marrow cells and in nucleated peripheral-blood cells.

The Primary endpoint of the CLIMB THAL-111 trial was the proportion of patients with a transfusion reduction of 50% for at least six months, starting three months after CTX001 infusion. The Primary endpoint of CLIMB SCD-121 Sickle Cell Disease trial was the proportion of patients with fetal hemoglobin of 20% or more, sustained for at least three months, starting six months after CTX001 infusion.

CLIMB THAL-111 trial: Data was reported on 7 patients enrolled in the CLIMB THAL-111 trial, as they had reached at least three months of follow up after CTX001 infusion and therefore could be assessed for initial safety and efficacy. All seven showed a similar pattern of response, with rapid and sustained increases in total hemoglobin, fetal hemoglobin, and transfusion independence at last analysis. All 7 patients were transfusion independent with follow up ranging from 3-18 months after CTX001 infusion, with normal to near normal total hemoglobin levels at last visit. Their total hemoglobin levels ranged from 9.7 to 14.1 g/dL, and fetal hemoglobin ranged from 40.9% to 97.7%. Bone marrow allelic editing data collected from 4 patients with 6 months of follow up, and from one patient with 12 months of follow-up after CTX001 infusion showed the treatment resulted in a durable response. The safety data from all seven patients were generally consistent with an Autologous Stem Cell Transplant (ASCT) and myeloablative conditioning. There were four Serious Adverse Events (SAEs) considered related or possibly related to CTX001 reported in one patient and included headache, Hemophagocytic LymphoHistiocytosis (HLH), Acute Respiratory Distress Syndrome, and Idiopathic Pneumonia Syndrome. All four SAEs occurred in the context of HLH and resolved. Most of the non-SAEs were considered mild to moderate. CLIMB-111 is an ongoing trial and will enroll up to 45 patients and follow patients for approximately two years after infusion.

CLIMB SCD-121: Data was reported on 3 patients enrolled in the CLIMB SCD-121 sickle cell disease trial as they had reached at least three months of follow up after CTX001 infusion, and therefore could be assessed for initial safety and efficacy. Again, all 3 patients showed a similar pattern of response, with rapid and sustained increases in total hemoglobin and fetal hemoglobin, as well as elimination of Vaso-Occlusive Crises through last analysis. All 3 patients remained Vaso Occlusive Crises-free with follow up ranging from 3-15 months after CTX001 infusion and had hemoglobin levels in the normal to near normal range, including total hemoglobin from 11.5 to 13.2 g/dL and Fetal hemoglobin levels from 31.3% to 48.0%. Bone marrow allelic editing data collected from one patient with six months of follow-up and from one patient with 12 months of follow-up after CTX001 infusion demonstrated a durable response. Again the safety data were consistent with an ASCT and myeloablative conditioning. There were no Serious Adverse Events noted, thought to be related to CTX001, and the majority of non-SAEs were considered mild to moderate. CLIMB-121 is an ongoing open-label trial and will enroll up to 45 patients and follow patients for approximately two years after infusion.

It was concluded from this initial follow up that, CTX001 manufactured from Hematopoietic Stem Cells, edited of BCL11A with CRISPR-Cas9, has shown durable engraftment, with high levels of fetal hemoglobin expression, and the elimination of vaso-occlusive episodes or need for transfusion. The authors added that these preliminary results support further testing of CRISPR-Cas9 gene-editing approaches to treat other genetic diseases.

Safety and Efficacy of CTX001 in Patients with Transfusion-Dependent β- Thalassemia and Sickle Cell Disease: Early Results from the Climb THAL-111 and Climb SCD-121 Studies of Autologous CRISPR-CAS9–Modified CD34+ Hematopoietic Stem and Progenitor Cells. Frangoul H, Bobruff Y, Cappellini MD, et al. Presented at the 62nd ASH Annual Meeting and Exposition, 2020. Abstract#4