Phase II study of durvalumab and tremelimumab in pulmonary sarcomatoid carcinoma: KCSG-LU16-07

Background: Pulmonary sarcomatoid carcinoma (PSC) is rare with a poor outcome and is resistant to conventional cytotoxic chemotherapy. The efficacy and safety of durvalumab and tremelimumab for treating recurrent or metastatic PSCs were assessed by a nonrandomized, open-label, phase II study.

Methods: A total of 18 patients with recurrent or metastatic PSC received 1500 mg of durvalumab and 75 mg of tremelimumab every four weeks, followed by 750 mg of durvalumab every two weeks until the disease progressed, or an unacceptable toxicity level was reached. The primary endpoint was the objective response rate (ORR). The secondary endpoints were progression-free survival (PFS), overall survival (OS), and toxicity. Genomic profiling of PSC by next-generation sequencing (NGS) and determination of peripheral blood lymphocyte subsets using flow cytometry were performed for exploratory analysis.

Results: A total of 15 out of 18 patients were evaluated for the analysis of the primary endpoint. At the data cutoff point, the ORR of 26.7% (95% confidence interval [CI]: 7.8-55.1) was achieved with the median follow-up duration of 12.0 months (range, 8.4-16.1). Median PFS and OS were 5.9 months (95% CI: 1.1-11.9) and 15.4 months (95% CI: 11.1-not reached), respectively. Treatment-related adverse events (AEs) of any grade were reported in 16 patients; the most common AEs were pruritus (n = 5), pneumonitis (n = 4), and rash (n = 4). Treatment was discontinued in two patients due to AEs of grade ≥ 3.

Conclusions: Durvalumab and tremelimumab demonstrated clinical benefit with a prolonged survival and manageable toxicity profile in patients with recurrent or metastatic PSC.