FDA Approves Tremelimumab With Durvalumab and Platinum Chemotherapy for mNSCLC

The FDA has granted approval to tremelimumab (Imjudo) in combination with durvalumab (Imfinzi) and platinum-based chemotherapy for the treatment of patients with metastatic non–small cell lung cancer (NSCLC).¹

Approval was granted based on results from the randomized, multicenter, active-controlled, open-label, phase 3 POSEIDON clinical trial (NCT03164616). After 4 years of follow-up in the study, the overall survival improvement was significant.

Approximately 675 patients in the POSEIDON were randomized 1:1:1 to receive tremelimumab in combination with durvalumab and platinum-based chemotherapy, durvalumab plus chemotherapy, or chemotherapy alone. Treatment in the triplet and doublet arm lasted for 4 cycles and was administered every 4 weeks. In the chemotherapy arm, patients were treated for 6 cycles before receiving maintenance therapy.

POSEIDON evaluated progression-free survival (PFS) and overall survival (OS) as primary end points. The secondary end points of the study were PFS, OS, objective response rate (ORR), duration of response, time from randomization to second progression, pharmacokinetics, and quality of life.

The median OS observed in the long-term analysis was 14.0 months (95% CI, 11.7-16.1) compared with 11.7 months (95% CI, 10.5-13.1) in chemotherapy alone arm (HR, 0.75; 95% CI, 0.63-0.88). The risk for death by was decreased by 25%. At the 36-month mark, the OS rate was 25% in the triplet arm vs 13.6% in the chemotherapy alone arm.

The triplet regimen also achieved a median PFS of 6.2 months (95% CI, 5.0-6.5) compared with 4.8 months (95% CI ,4.6-5.8) in chemotherapy-alone arm (HR, 0.72; 95% CI, 0.60-0.86; 2-sided P =.00031).

In terms of the secondary end point, the ORR observed with the triplet was 39% (95% CI, 34-44) vs 24% (95% CI, 20-29) in the chemotherapy arm. The median durations of response were 9.5 months (95% CI, 7.2-not reached) vs 5.1 months (95% CI, 4.4-6.0), respectively.

Safety results showed that nausea, fatigue, decreased appetite, musculoskeletal pain, rash, and diarrhea were common adverse events which occurred in more than 20% of patients treated with tremelimumab, durvalumab, and platinum-based chemotherapy. Moreover, grade 3/4 laboratory abnormalities that were observed in over 10% of patients included neutropenia, anemia, leukopenia, lymphocytopenia, lipase increased, hyponatremia, and thrombocytopenia.

The FDA recommends administering tremelimumab 75 mg intravenously (IV) to patients who weigh 30 kg or more, every 3 weeks with durvalumab 1500 mg IV and platinum-based chemotherapy for 4 cycles. This should be followed by durvalumab 1500 mg with maintenance chemotherapy every 4 week and a fifth administration of tremelimumab 75 mg at the 16-week mark. In patients who weigh less than 30 kg, the FDA recommends a 1mg/kg dose of tremelimumab and 20 mg/kg dose of durvalumab.

_REFERENCE:

_{FDA approves tremelimumab in combination with durvalumab and platinum-based chemotherapy for metastatic non-small cell lung cancer. News release. FDA. November 10, 2022. Accessed November 10, 2022. https://bit.ly/3thS69g}