Merck announced that first-line treatment with KEYTRUDA, Merck’s anti-PD-1 therapy, in combination with chemotherapy demonstrated improvements in overall survival (OS), progression-free survival (PFS) and objective response rate (ORR) in a pooled analysis of a subgroup of patients with advanced nonsquamous and squamous non-small cell lung cancer (NSCLC) whose tumors do not express PD-L1 (tumor proportion score [TPS] <1%) from three randomized trials. Patients with nonsquamous NSCLC with EGFR or ALK genomic tumor aberrations were ineligible. Results – from KEYNOTE-189, KEYNOTE-407 and KEYNOTE-021 (Cohort G) – were consistent with those observed in the overall study populations across all three trials. Findings were featured in an oral presentation at the IASLC 2019 World Conference on Lung Cancer (WCLC) hosted by the International Association for the Study of Lung Cancer in Barcelona, Spain (Abstract #MA25.01). Findings from the pooled subgroup analysis of 428 patients showed that KEYTRUDA in combination with chemotherapy reduced the risk of death by 44% (HR=0.56 [95% CI, 0.43-0.73]) compared to chemotherapy alone. The KEYTRUDA-chemotherapy combinations also reduced the risk of disease progression or death by 33% (HR=0.67 [95% CI, 0.54-0.84]) compared to chemotherapy alone. The ORR was 46.9% for patients treated with the KEYTRUDA-chemotherapy combinations versus 28.6% for those treated with chemotherapy alone. The safety profile of KEYTRUDA was consistent with what has been seen in previously reported studies among patients with advanced NSCLC. Additional Data from Pooled Subgroup Analysis of KEYNOTE-189, KEYNOTE-407 and KEYNOTE-021 (Cohort G). Data presented at WCLC are from a pooled subgroup of 428 previously untreated patients whose tumors do not express PD-L1 (TPS <1%) from the KEYNOTE-189 (nonsquamous NSCLC; n=190), KEYNOTE-407 (squamous NSCLC; n=194) and KEYNOTE-021 (nonsquamous NSCLC; n=44 [Cohort G]) trials. Patients were randomized to receive KEYTRUDA 200 mg every three weeks plus chemotherapy (n=243) or chemotherapy alone (n=185). Patients with nonsquamous NSCLC received pemetrexed (ALIMTA®) and platinum chemotherapy; patients with squamous NSCLC received carboplatin and either paclitaxel or nab-paclitaxel. Patients with nonsquamous NSCLC with EGFR or ALK genomic tumor aberrations were ineligible. Key efficacy outcome measures include OS, PFS and ORR. With a median follow-up of 10.2 months, KEYTRUDA in combination with chemotherapy reduced the risk of death by 44% (HR=0.56 [95% CI, 0.43-0.73]) compared to chemotherapy alone. Estimated 12-month OS rates were 66% with the KEYTRUDA-chemotherapy combinations compared to 47% with chemotherapy alone; the 18-month OS rates were 52% and 29%, respectively. Median OS was 19.0 months (95% CI, 15.2-24.0) with the KEYTRUDA-chemotherapy combinations compared to 11.0 months (95% CI, 9.2-13.5) with chemotherapy alone. The KEYTRUDA-chemotherapy combinations also reduced the risk of disease progression or death by 33% (HR=0.67 [95% CI, 0.54-0.84]) compared to chemotherapy alone. Estimated 12-month PFS rates were 29% with the KEYTRUDA-chemotherapy combinations compared to 17% with chemotherapy alone; the 18-month PFS rates were 22% and 9%, respectively. Median PFS was 6.5 months (95% CI, 6.2-8.5) with the KEYTRUDA-chemotherapy combinations compared to 5.4 months (95% CI, 4.7-6.2) with chemotherapy alone. The ORR was 46.9% (n=114) for patients who received the KEYTRUDA-chemotherapy combinations and 28.6% (n=53) for those who received chemotherapy alone. Median DOR was 7.9 months (range, 1.1+ to 28.4+) with the KEYTRUDA-chemotherapy combinations and 6.7 months (range, 1.4+ to 30.1+) with chemotherapy alone. For patients receiving the KEYTRUDA- chemotherapy combinations, 42.4% experienced a response lasting 12 months or longer compared to 35.3% of those receiving chemotherapy alone. Among patients who received KEYTRUDA in combination with chemotherapy, 68% (n=165) experienced a Grade 3-5 adverse event (AE) compared to 72% (n=131) of those who received chemotherapy alone. Grade 3-5 AEs that led to death occurred in 9% (n=23) of patients who received the KEYTRUDA-chemotherapy combinations and 6% (n=11) of those who received chemotherapy alone. Grade 3-5 immune-mediated AEs and infusion reactions occurred in 11% (n=27) of patients who received the KEYTRUDA-chemotherapy combinations compared to 3% (n=5) of those who received chemotherapy alone. Deaths resulting from immune-mediated AEs and infusion reactions occurred in 1% (n=2) of patients who received the KEYTRUDA-chemotherapy combinations compared to no deaths among patients who received chemotherapy alone.