Background: CheckMate 032 (NCT01928394) is an open-label, phase 1/2 trial evaluating the efficacy and safety of nivolumab monotherapy and nivolumab plus ipilimumab in patients with advanced or metastatic solid tumors. In this study, nivolumab alone or in combination with ipilimumab showed durable responses, encouraging survival, and manageable safety in patients with small cell lung cancer (SCLC) that progressed after ≥1 previous platinum-containing regimens.
Objectives: An exploratory objective of the study is to describe changes in patient-reported health status using the EuroQoL-5 Dimensions (EQ-5D) instrument.
Methods: The EQ-5D visual analog scale (VAS; scale: 0-100 [worst-best health]; minimally important difference [MID] = 7) was assessed in the treatment period at baseline (week 1 prior to study drug administration) and then every 2 weeks in the nivolumab (3 mg/kg) arm and at baseline and then every 3 weeks in the nivolumab (1 mg/kg) plus ipilimumab (3 mg/kg) arm through week 13, and in both arms at subsequent tumor assessments (every 6 weeks until week 24 and every 12 weeks thereafter). After treatment discontinuation, the EQ-5D was assessed at follow-up visits 1 and 2, and at survival visits. EQ-5D VAS mean and mean within-patient change from baseline were estimated at each assessment. Time to first deterioration (TTD) in health status was also evaluated.
Results: In the nivolumab (n = 245) and nivolumab plus ipilimumab (n = 156) arms, EQ-5D VAS completion rates were 90% and 85%, respectively, at baseline and remained ≥60% at the last assessment (≥5 patients/arm; weeks 97 and 121, respectively). Baseline mean EQ-5D VAS scores for the nivolumab and nivolumab plus ipilimumab arms were 67.1 and 65.2, respectively, and similar to a lung cancer population norm (68). With monotherapy, EQ-5D VAS mean within-patient changes from baseline suggested health status stability while on treatment (estimated changes <MID). With the combination, stability was suggested through week 37 (n = 24 at this time point); 4/6 subsequent assessments (through week 109) suggested improvements from baseline (estimated changes ≥MID). Mean EQ-5D VAS scores increased over time, approximating the general population norm (80.05) in the nivolumab and nivolumab plus ipilimumab arms from weeks 37 and 49 onward, respectively. Additional data, including TTD, will be presented.
Conclusions: Preliminary EQ-5D VAS results from CheckMate 032 showed that on-treatment health status in patients with recurrent SCLC remained stable with nivolumab and improved (ie, increases in scores exceeded the MID) with nivolumab plus ipilimumab. For patients remaining on treatment for ≥6 months, mean EQ-VAS scores in both arms trended toward the population norm.