Single-agent anti-PD-1 or combined with ipilimumab in patients with mucosal melanoma: an international, retrospective, cohort study.

BACKGROUND: Mucosal melanoma (MM) is a rare melanoma subtype with distinct biology and poor prognosis. Data on the efficacy of immune checkpoint inhibitors (ICIs) are limited. We determined the efficacy of ICIs in MM, analyzed by primary site and ethnicity/race. PATIENTS AND METHODS: A retrospective cohort study from 25 cancer centers in Australia, Europe, USA and Asia was carried out. Patients with histologically confirmed MM were treated with anti-programmed cell death protein 1 (PD-1) ± ipilimumab. Primary endpoints were response rate (RR), progression-free survival (PFS), overall survival (OS) by primary site (naso-oral, urogenital, anorectal, other), ethnicity/race (Caucasian, Asian, Other) and treatment. Univariate and multivariate Cox proportional hazards model analyses were conducted. RESULTS: In total, 545 patients were included: 331 (63%) Caucasian, 176 (33%) Asian and 20 (4%) Other. Primary sites included 113 (21%) anorectal, 178 (32%) urogenital, 206 (38%) naso-oral and 45 (8%) other. Three hundred and forty-eight (64%) patients received anti-PD-1 and 197 (36%) anti-PD-1/ipilimumab. RR, PFS and OS did not differ by primary site, ethnicity/race or treatment. RR for naso-oral was numerically higher for anti-PD-1/ipilimumab [40%, 95% confidence interval (CI) 29% to 54%] compared with anti-PD-1 (29%, 95% CI 21% to 37%). Thirty-five percent of patients who initially responded progressed. The median duration of response (mDoR) was 26 months (95% CI 18 months-not reached). Factors associated with short PFS were Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≥3 (P < 0.01), lactate dehydrogenase (LDH) more than the upper limit of normal (ULN) (P = 0.01), lung metastases (P < 0.01) and ≥1 previous treatments (P < 0.01). Factors associated with short OS were ECOG PS ≥1 (P < 0.01), LDH >ULN (P = 0.03), lung metastases (P < 0.01) and ≥1 previous treatments (P < 0.01). CONCLUSIONS: MM has poor prognosis. Treatment efficacy of anti-PD-1 ± ipilimumab was similar and did not differ by ethnicity/race. Naso-oral primaries had numerically higher response to anti-PD-1/ipilimumab, without difference in survival. The addition of ipilimumab did not show greater benefit over anti-PD-1 for other primary sites. In responders, mDoR was short and acquired resistance was common. Other factors, including site and number of metastases, were associated with survival.

Clinical activity of programmed cell death 1 (PD-1) blockade in never, light, and heavy smokers with non-small-cell lung cancer and PD-L1 expression ≥50.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are standard therapies for patients with advanced non-small-cell lung cancer (NSCLC) and a programmed death-ligand 1 (PD-L1) tumor proportion score (TPS) ≥50%. Tumor mutation burden (TMB) also predicts response to ICIs but is often not available in real time for decision making in the first-line setting. Smoking exposure can be a proxy for TMB in NSCLC. The impact of smoking status on efficacy of PD-1 blockade in NSCLC patients with PD-L1 TPS ≥50% has not been well defined. PATIENTS AND METHODS: To investigate the relationship between smoking and activity of ICIs in NSCLC, we retrospectively studied 315 patients with NSCLC and PD-L1 TPS ≥50% at five USA academic medical centers. Objective response rates (ORRs), progression-free survival (PFS), and duration of response (DOR) were compared between never (<100 lifetime cigarettes), light (≤10 pack-years), and heavy (>10 pack-years) smokers. A subset of patients underwent next-generation sequencing to estimate TMB. RESULTS: We identified 36 (11%) never, 42 (13%) light, and 237 (75%) heavy smokers with NSCLC and PD-L1 TPS ≥50% treated with ICIs. Objective responses were observed in 27%, 40%, and 40% of never, light, and heavy smokers, respectively (P = 0.180 never versus heavy; P = 1.000 light versus heavy). Median PFS and median DOR were numerically shorter in never and light smokers compared with heavy smokers (PFS 3.0 versus 4.0 versus 5.4 months; median DOR 6.9 versus 10.8 versus 17.8 months), but were not statistically different [PFS: hazard ratio (HR) 1.37, P = 0.135 and HR 1.24, P = 0.272; DOR: HR 1.92, P = 0.217 and HR 1.79, P = 0.141]. CONCLUSIONS: PD-(L)1 inhibitors are associated with antitumor activity in NSCLC with PD-L1 TPS ≥50% regardless of smoking status. Nevertheless, there is a signal of potentially decreased durability among never and light smokers that should be further evaluated. Distinct immunobiologic features may affect initial response versus durability of antitumor immunity to programmed cell death 1 (PD-1) blockade.