SUMMARY: The FDA on February 2, 2017 granted accelerated approval to OPDIVO® (Nivolumab), for the treatment of patients with locally advanced or metastatic urothelial carcinoma, who have disease progression during or following platinum containing chemotherapy, or have disease progression within 12 months of neoadjuvant or adjuvant treatment with a platinum-containing chemotherapy. Urothelial carcinoma accounts for 90 percent of all bladder cancers and can originate in the renal pelvis, ureter and urethra. The American Cancer Society’s estimates that in 2017, approximately 79,030 new cases of Bladder Cancer will be diagnosed and 16,870 patients will die of the disease. Treatment options for patients who progress after platinum based chemotherapy are limited, with poor outcomes. The response rates with standard chemotherapy in this patient population, is about 10%.
The treatment paradigm for solid tumors has been rapidly evolving, with a better understanding of the Immune checkpoints or gate keepers. Immune checkpoints are cell surface inhibitory proteins/receptors that are expressed on activated T cells. They harness the immune system and prevent uncontrolled immune reactions. With the recognition of Immune checkpoint proteins and their role in suppressing antitumor immunity, antibodies are being developed that target the membrane bound inhibitory Immune checkpoint proteins/receptors such as CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4, also known as CD152), PD-1(Programmed cell Death 1), as well as Programmed cell Death Ligands (PD-L1) that are expressed by cells in the tumor micro environment. By inhibiting checkpoint proteins and their ligands, T cells are unleashed, resulting in T cell proliferation, activation and a therapeutic response.
OPDIVO® is an immune checkpoint PD-1 (Programmed cell Death 1) targeted, fully human, immunoglobulin G4 monoclonal antibody that has demonstrated antitumor efficacy in multiple tumor types. The FDA approval of OPDIVO® for patients with previously treated locally advanced or metastatic urothelial carcinoma, was based on CheckMate-275 trial which is an international, multicenter, phase II study, in which 270 patients with metastatic or surgically unresectable locally advanced urothelial carcinoma received OPDIVO® 3 mg/kg IV every 2 weeks until disease progression or unacceptable toxicity. All patients had prior platinum based therapy. The median age was 66 years. The primary endpoint was overall Objective Response Rate confirmed by blinded independent review committee, in all treated patients and by tumor PD-L1 expression (5% or more and 1% or more). The follow up for this study is still ongoing. The median follow up for overall survival was 7 months.
The Objective Response Rate across all treated patients was 19.6% and the responses were durable and the median duration of response has not been reached. There was a higher likelihood of response with increasing tumor PD-L1 expression. The Objective Response Rate was 28.4% in patients with PD-L1 expression of 5% or greater, 23.8% in patients with PD-L1 expression of 1% or greater and 16.1% in those with PD-L1 expression of less than 1%. The most common adverse events were fatigue, musculoskeletal pain, nausea, and decreased appetite.
The authors concluded that single agent therapy with OPDIVO® in previously treated patients with metastatic or surgically unresectable urothelial carcinoma, resulted in durable response rate, irrespective of PD-L1 expression and was associated with an acceptable safety profile. Nivolumab in metastatic urothelial carcinoma after platinum therapy (CheckMate 275): a multicentre, single-arm, phase 2 trial. Sharma P, Retz M, Siefker-Radtke A, et al. The Lancet Oncology. Published: 25 January 2017, DOI: http://dx.doi.org/10.1016/S1470-2045(17)30065-7
