Adding Tremelimumab and Durvalumab to Chemo Improves PFS, OS in mNSCLC

Adding tremelimumab and durvalumab to platinum-based chemotherapy can improve outcomes in patients with metastatic non-small cell lung cancer (mNSCLC), according to research published in the Journal of Clinical Oncology.

In the phase 3 POSEIDON trial, adding durvalumab to chemotherapy improved progression-free survival (PFS), and adding tremelimumab and durvalumab to chemotherapy improved both PFS and overall survival (OS). 

The POSEIDON trial (ClinicalTrials.gov Identifier: NCT03164616) included 1013 patients with mNSCLC who were naïve to systemic treatment.

The patients were randomly assigned to receive 1 of the following regimens:

• Tremelimumab (75 mg) plus durvalumab (1500 mg) plus platinum-based chemotherapy for up to four 21-day cycles, followed by durvalumab every 4 weeks until progression and an additional tremelimumab dose at week 16 (n=338)
• Durvalumab (1500 mg) plus platinum-based chemotherapy for up to four 21-day cycles, followed by durvalumab every 4 weeks until progression (n=338)
• Platinum-based chemotherapy for up to six 21-day cycles (n=337). 

The median PFS was 5.5 months in the durvalumab-chemotherapy arm and 4.8 months in the chemotherapy-alone arm (hazard ratio [HR], 0.74; 95% CI, 0.62-0.89; P =.0009). The 12-month PFS rate was 24.4% and 13.1%, respectively. 

The median PFS was 6.2 months in the tremelimumab-durvalumab-chemotherapy arm, compared with 4.8 months in the chemotherapy-alone arm (HR, 0.72; 95% CI, 0.60-0.86; P =.0003). The 12-month PFS rate was 26.6% and 13.1%, respectively. 

The median OS was 13.3 months in the durvalumab-chemotherapy arm and 11.7 months in the chemotherapy-alone arm (HR, 0.86; 95% CI, 0.72-1.02; P =.0758). The 24-month OS rate was 29.6% and 22.1%, respectively.

The median OS was 14.0 months in the tremelimumab-durvalumab-chemotherapy arm, compared with 11.7 months in the chemotherapy-alone arm (HR, 0.77; 95% CI, 0.65-0.92; P =.0030). The 24-month OS rate was 32.9% and 22.1%, respectively.

The rate of treatment-related adverse events (TRAEs) was 92.7% in the tremelimumab-durvalumab arm, 88.6% in the durvalumab arm, and 89.5% in the chemotherapy-alone arm. The rates of serious TRAEs were 27.6%, 19.5%, and 17.7%, respectively. 

The rate of treatment-related death was 3.3% in the tremelimumab-durvalumab arm, 2.1% in the durvalumab arm, and 2.4% in the chemotherapy-alone arm.

These data supported the recent approval of tremelimumab for use in combination with durvalumab and platinum-based chemotherapy to treat adults with mNSCLC who do not have sensitizing EGFR mutations or ALK genomic tumor aberrations. 

Disclosures: This research was supported by AstraZeneca. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

This article originally appeared on Cancer Therapy Advisor