Late Breaking Abstract – ASCO 2015 OPDIVO® Improves Overall Survival in Non- Squamous NSCLC Patients

SUMMARY: Lung cancer is the second most common cancer in both men and women and accounts for about 13% of all new cancers and 27% of all cancer deaths. It is the leading cause of cancer death among both men and women. The American Cancer Society estimates that over 221,200 new cases of lung cancer will be diagnosed in the United States in 2015 and over 158,000 patients will die of the disease. Non Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers. Of the three main subtypes of Non Small Cell Lung Cancer (NSCLC), 25% are Squamous cell carcinomas, 40% are Adenocarcinomas and 10% are Large cell carcinomas. The treatment paradigm for solid tumors has been rapidly evolving with a better understanding of the Immune checkpoints. 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. Survival of cancer cells in the human body may be to a significant extent, related to their ability to escape immune surveillance, by inhibiting T lymphocyte activation. The T cells of the immune system therefore play a very important role in modulating the immune system. Under normal circumstances, inhibition of an intense immune response and switching off the T cells of the immune system, is an evolutionary mechanism and is accomplished by Immune checkpoints or gate keepers. 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), etc. By doing so, one would expect to unleash the T cells, resulting in T cell proliferation, activation and a therapeutic response. The first Immune checkpoint protein to be clinically targeted was CTLA-4. YERVOY® (Ipilimumab) , an antibody that blocks Immune checkpoint protein/receptor CTLA- 4, has been shown to prolong overall survival in patients with previously treated, unresectable or metastatic melanoma. OPDIVO® (Nivolumab) is a fully human, immunoglobulin G4 monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, thereby undoing PD-1 pathway-mediated inhibition of the immune response and unleashing the T cells. The U. S. Food and Drug Administration granted approval to OPDIVO®, for the treatment of patients with metastatic Squamous Non-Small Cell Lung Cancer (NSCLC), with progression on or after platinum based chemotherapy. CheckMate 057 is a randomized, international, phase 3 study designed to evaluate the benefit of OPDIVO® for patients with Non-Squamous (NSQ) NSCLC who had progressed after platinum-based doublet chemotherapy. A total of 582 patients were randomized to receive OPDIVO® 3 mg/kg IV every 2 weeks (n=292) or TAXOTERE® 75 mg/m2 IV every 3 weeks (n=290). Eligible patients included those with advanced Non-Squamous NSCLC who had progressed after platinum-based doublet chemotherapy and a Tyrosine Kinase Inhibitor (TKI), if deemed eligible for a TKI. Treatment was continued until disease progression or unacceptable toxicity. The primary clinical endpoint was Overall Survival (OS). Secondary endpoints included Objective Response Rate (ORR), Progression Free Survival (PFS), Efficacy based on PD-L1 expression, Quality of Life, and Safety. The study was stopped earlier than expected following assessment by the independent Data Monitoring Committee (DMC) which concluded that the study met its endpoint, demonstrating superior overall survival, in patients receiving OPDIVO®, compared to the control group. Patients in the OPDIVO®, group had a significantly higher median OS compared to those in the TAXOTERE® group (12.2 months versus 9.4 months, Hazard Ratio [HR] 0.73, P=0.0015). This meant a 27% reduction in the risk of death in the OPDIVO® group and this survival benefit was seen in all predefined subgroup of patients. The Objective Response Rate (ORR) was also significantly higher for patients receiving OPDIVO® compared to TAXOTERE® (19% versus 12%, P=0.0246) and the median duration of response (DOR) was significantly higher for the OPDIVO® group (17.2 months) vs the TAXOTERE® group (5.6 months). More importantly, when tumor PD-L1 expression was correlated with Overall Survival, the median OS for OPDIVO® was 17.2 months, 18.2 months, and 19.4 months for patients with tumors having 1% or higher, 5% or higher, and 10% or higher of cells staining positive for PD-L1, respectively, compared with 9.0 months, 8.1 months, and 8.0 months with TAXOTERE® treatment. Even though this study showed significant survival outcomes for patients expressing any level of PD-L1, the magnitude of benefit was even more so, in patients with tumors expressing higher levels of PD-L1. PD-L1 expression may therefore be a predictor of response, although this should not yet be used for patient selection. Grade 3-5 adverse events occurred more often in the TAXOTERE® group compared to the OPDIVO® group (54% vs 10%). Based on this compelling data, the authors concluded that OPDIVO® significantly improves Overall Survival when compared to TAXOTERE®, in patients with advanced non-Squamous NSCLC, after failure of platinum based doublet therapy. Phase III, randomized trial (CheckMate 057) of nivolumab (NIVO) versus docetaxel (DOC) in advanced non-squamous cell (non-SQ) non-small cell lung cancer (NSCLC). Paz-Ares L, Horn L, Borghaei H, et al. J Clin Oncol 33, 2015 (suppl; abstr LBA109)</s