Hwu, Wen‐Jen

9009 Background: Programmed death-1 (PD-1) is an inhibitory T-cell co-receptor that may lead to suppression of antitumor immunity. Lambrolizumab is a humanized monoclonal IgG4 antibody against PD-1. This study explored the safety and clinical activity of lambrolizumab in patients (pts) with advanced melanoma (MEL). Methods: In this ongoing phase 1b expansion study of MEL pts with or without previous ipilimumab (IPI) treatment, lambrolizumab was administered IV every 2 or 3 weeks until disease progression or unacceptable toxicity. Tumor response was assessed every 12 weeks by independent, central, blinded radiographic review per immune-related response criteria and RECIST 1.1. Results: As of December 1, 2012, 294 pts with MEL were enrolled, including 179 IPI-naive and 115 IPI-pretreated. Pts received lambrolizumab 10 mg/kg (n = 183) or 2 mg/kg (n = 111). Preliminary data from the first 85 consecutive pts dosed before April 25, 2012, who had independent radiologic review available as of December 3, 2012, indicate a confirmed overall response rate per RECIST 1.1 of greater than 35%, pooled across all doses and schedules and including both IPI-naive and IPI-pretreated patients. The median duration of response has not been reached as only 2 pts who had initial response discontinued due to disease progression, but the duration of confirmed responses range from 28+ to 240+ days (up to 8+ months). Among 133 pts who were dosed with lambrolizumab before July 31, 2012, and evaluable for adverse events (AEs) as of September 28, 2012, fatigue (22%), rash (18%), and pruritus (14%) were the most common drug-related AEs (mostly grade 1/2). The incidence of drug-related grade 3/4 AEs was 10% (24% regardless of attribution). Four drug-related cases of pneumonitis were reported, all of grade 1/2. Grade 3/4 drug-related hypothyroidism (n = 1) and hyperthyroidism (n = 1) were noted. Conclusions: Preliminary data suggest that lambrolizumab has significant antitumor activity and is well tolerated with manageable side effects in both IPI-naive and IPI-pretreated MEL pts. These data have led to an ongoing, international, randomized study of lambrolizumab versus chemotherapy in IPI-pretreated MEL. Clinical trial information: NCT01295827.

2510 Background: Blocking the interaction between programmed death-1 (PD-1), a co-inhibitory receptor expressed by activated T cells, and its ligand PD-L1 may enhance T-cell function. Here we describe the safety and activity from the first clinical study of BMS-936559 in patients (pts) with advanced solid tumors, further validating the importance of the PD-1/PD-L1 pathway as a target for cancer therapy. Methods: BMS-936559 was given Q2 wk IV in a 6-wk cycle at doses of 0.3−10.0 mg/kg during dose escalation and/or cohort expansion; pts could receive up to 16 cycles (48 doses). Results: As of August 1, 2011, 162 pts with melanoma (MEL, n=53), non-small-cell lung (NSCLC, n=50), colorectal (n=18), renal cell (RCC, n=17), ovarian (n=17), and pancreatic (n=7) cancer were treated. Median therapy duration was 11 wks (max 99 wks). Common related adverse events (rAEs; ≥5% pts) included fatigue, diarrhea, infusion reaction, arthralgia, rash, and pruritus. The incidence of grade 3-4 rAEs was 8.6%. AEs of special interest included hypothyroidism, hepatitis, sarcoidosis, endophthalmitis, and myasthenia gravis; there were no drug-related deaths. Clinical activity was observed in MEL, RCC, and NSCLC. Objective responses (ORs; RECIST 1.0) were observed in heavily pretreated pts. ORs were durable; among 16 pts with ORs, 7 had responses lasting ≥1 yr. Two other pts had ongoing ORs with durations of 2.3 and 8.5 mo at data lock. Several pts had prolonged stable disease. Some pts had a persistent reduction in overall tumor burden in the presence of new lesions but were not categorized as responders. In NSCLC, ORs were observed irrespective of histology. Conclusions: BMS-936559 was active and generally well tolerated in pts with NSCLC, RCC, and MEL. In conjunction with data from anti-PD-1/BMS-936558 trials, this study concurrently validates the importance of the PD-1/PD-L1 pathway for cancer immunotherapy and supports further clinical development of anti-PD-1/PD-L1 directed therapy. [Table: see text]