SUMMARY: Thrombotic Thrombocytopenic Purpura (TTP), Hemolytic Uremic Syndrome (HUS) and Atypical Hemolytic Uremic Syndrome (aHUS) are Thrombotic Microangiopathies (TMA’s) associated with MicroAngiopathic Hemolytic Anemia and thrombocytopenia. Even though their clinical presentation has some similarities, they are distinct entities with different pathophysiology and hence managed differently. With the identification of von Willebrand Factor (vWF) cleaving protease ADAMTS13 (A disintegrin and metalloprotease with thrombospondin type 1 repeats, member 13) in 1996, we are now able to better understand and appropriately manage these TMA’s. Patients with TTP are deficient in ADAMTS13 and therefore develop platelet microthrombin in small blood vessels due to uninhibited propagation of platelet aggregates bound to ultra high molecular weight VWF multimers. Approximately 10% or less of Shiga-Toxin producing Escherichia Coli (STEC) infections may be associated with HUS. aHUS is caused by a genetic deficiency of one or more complement regulatory proteins which results in uncontrolled activity of the alternate complement pathway. Plasma Exchange in TTP restores the protease activity of ADAMTS13 whereas aHUS is treated with SOLIRIS® (Eculizumab) to inhibit complement mediated TMA. Once a diagnosis of STEC-HUS is confirmed, hospitalization and intensive care with transfusions and kidney dialysis may become necessary. George JN. Blood 2010:116; 4060-4069
Author: RR
Efficacy and safety of regorafenib for advanced gastrointestinal stromal tumours after failure of imatinib and sunitinib (GRID) an international, multicentre, randomised, placebo-controlled, phase 3 trial
SUMMARY: STIVARGA® (Regorafenib) is an oral multikinase inhibitor. In this international trial, 199 patients with advanced GIST who had progressed on both GLEEVEC® (Imatinib) and SUTENT® (Sunitinib) were randomized in a 2:1 ratio to receive either STIVARGA® or placebo. The primary endpoint was progression-free survival (PFS). Patients in the STIVARGA® group had a statistically significant 3.9 month improvement in progression-free survival (PFS) compared to placebo (4.8 months vs 0.9 months; Hazard Ratio = 0.27; P<.0001). Following progression, 85% of the patients assigned to the placebo group crossed over to the STIVARGA® group. Treatment was well tolerated and the most common adverse events included hypertension, hand-foot syndrome and diarrhea. There is now a new treatment option for patients with GIST who progress on GLEEVEC® and SUTENT®. Demetri GD, Reichardt P, Kang Y, et al. The Lancet. 2013;381:295-302
STIVARGA® (Regorafenib)
The FDA on February 25, 2013 approved the use of STIVARGA® for the treatment of patients with advanced GastroIntestinal Stromal Tumors (GIST) that are unresectable or metastatic and are no longer responding to GLEEVEC® (Imatinib) and SUTENT® (Sunitinib). The FDA initially approved STIVARGA® in 2012 for the treatment of patients with metastatic colorectal cancer (mCRC) who have been previously treated with fluoropyrimidine, ELOXATIN® (Oxaliplatin), and CAMPTOSAR® (Irinotecan) based chemotherapy, an anti-VEGF therapy, and, if KRAS wild type, an anti-EGFR therapy. STIVARGA® is a product of Bayer HealthCare Pharmaceuticals, Inc.
STIVARGA® (Regorafenib) for advanced GIST
STIVARGA® is an oral multikinase inhibitor. In a study published in the January 2013 issue of THE LANCET, treatment with STIRVAGA® in patient population resistant or refractory to GLEEVEC® and SUTENT® resulted in significant improvement in progression free survival. This is the third agent approved by the FDA for advanced GIST. As patients with advanced GIST live longer, newer agents with unique mechanism of action will take center stage.
KADCYLA® (Ado-Trastuzumab Emtansine, T-DM1):
The FDA on February 22, 2013 approved KADCYLA® for the treatment of patients with HER2-positive metastatic breast cancer who have received prior treatment with HERCEPTIN® (Trastuzumab) and a Taxane chemotherapy. KADCYLA® is marketed by Genentech U.S., Inc.
Primary results from EMILIA, a phase III study of trastuzumab emtansine (T-DM1) versus capecitabine (X) and lapatinib (L) in HER2-positive locally advanced or metastatic breast cancer (MBC) previously treated with trastuzumab (T) and a taxane.
SUMMARY: The HER or erbB family of receptors consist of HER1,HER2,HER3 and HER4. Overexpression of HER2 in breast cancer has been associated with higher risk for relapse as well as overall survival. HERCEPTIN® (Trastuzumab) is a humanized monoclonal antibody targeting HER2. It binds to the extracellular domain of the receptor and blocks the downstream cell signaling pathways. KADCYLA® (Ado-Trastuzumab Emtansine, T-DM1) is an antibody-drug conjugate (ADC) comprised of the antibody Trastuzumab and the chemotherapy agent Emtansine, linked together. It inhibits HER2 signaling and destroys the HER2-positive tumor cells by delivering the chemotherapy agent Emtansine which binds to tubulin, directly inside the tumor cells. The EMILIA trial is a phase III study in which 991 patients with HER2-positive locally advanced or metastatic breast cancer who had previously received treatment with HERCEPTIN® and a Taxane chemotherapy, were enrolled. Patient received either KADCYLA® or XELODA® (Capecitabine) and TYKERB® (Lapatinib) doublet. The primary endpoints were Progression Free Survival (PFS), Overall Survival (OS) and safety. Patients receiving KADCYLA® had an improved PFS compared to XELODA® and TYKERB® (9.6 months vs 6.4 months, HR=0.65, P <0.0001). The median overall survival was 30.9 months in the KADCYLA® group and 25.1 months with the XELODA® and TYKERB® doublet. KADCYLA® is the fourth drug approved by the FDA, that targets the HER2 oncogene. The other FDA-approved drugs used to treat HER2-positive breast cancer include HERCEPTIN® (1998), TYKERB® (2007) and PERJETA® (Pertuzumab) (2012). Blackwell KL, Miles D, Gianni L, et al. J Clin Oncol 30, 2012 (suppl; abstr LBA1)
KADCYLA® (Ado-Trastuzumab Emtansine, T-DM1) now approved
The FDA today approved KADCYLA® for the treatment of patients with HER2-positive metastatic breast cancer who have received prior treatment with HERCEPTIN® (Trastuzumab) and a taxane chemotherapy. In a large Phase III trial, KADCYLA® improved Progression Free Survival as well as Overall Survival compared to XELODA® (Capecitabine) and TYKERB® (Lapatinib). KADCYLA® is the fourth drug approved by the FDA, that targets the HER2 oncogene. The other FDA-approved drugs used to treat HER2-positive breast cancer include HERCEPTIN® (1998), TYKERB® (2007) and PERJETA® (Pertuzumab) (2012).
Proton Versus Intensity-Modulated Radiotherapy for Prostate Cancer Patterns of Care and Early Toxicit
SUMMARY: Proton Radiotherapy (PRT) unlike external beam radiotherapy uses energy from positively charged particles called protons and has the ability to precisely localize the radiation dose to the tumor site, minimizing collateral damage. In this retrospective analysis, data on 27,647 Medicare beneficiaries who received PRT or IMRT (Intensity-Modulated RadioTherapy) for prostate cancer, was reviewed, during 2008 and/or 2009. At 12 months post-treatment, there was no statistical difference in genitourinary and gastrointestinal toxicity for patients who had received PRT compared to those who were treated with IMRT. With PRT almost twice as expensive as IMRT, it remains to be seen if PRT will be reimbursed by third party payors. It is interesting to note that in this study, patients receiving PRT were relatively younger, healthier, and lived in more affluent areas than patients receiving IMRT. Yu JB, Soulos PR, Herrin J, et al. J. Natl. Cancer Inst. 2013;105:25-32
Vitamin D deficiency and Bladder Cancer
The active metabolite of Vitamin D is Vitamin D3. In a recent study published in the JNCI, September 2012 issue, the authors noted a statistically significant increase in the risk of Bladder Cancer in individuals with low plasma concentrations of Vitamin D3. It is felt that Vitamin D3 favorably upregulates Fibroblast Growth Factor Receptor 3 (FGFR3). Mutations in FGFR3 are known to be associated with urothelial carcinoma. Urine samples evaluating for FGFR3 mutations, to diagnose urothelial carcinoma, has a positive predictive value of 95% when detected in patients with no history of Bladder Cancer. It appears that patients with aggressive bladder cancer have low expression of wild- type FGFR3 in association with low plasma concentrations of Vitamin D3. Therefore, it is possible that low plasma concentrations of Vitamin D3 may predict increased risk for bladder cancer, with more aggressive types of bladder cancer manifesting in those with significantly low Vitamin D3 levels.
POMALYST® (Pomalidomide)
The FDA on February 8, 2013 granted accelerated approval to POMALYST® for the treatment of patients with multiple myeloma who have received at least two prior therapies, including REVLIMID® (Lenalidomide) and VELCADE® (Bortezomib), and have demonstrated disease progression on or within 60 days of completion of the last therapy. POMALYST® capsules are a product of Celgene Corporation.