Tertiary lymphoid structures potential biomarker for pembrolizumab in STS
The presence of tertiary lymphoid structures (TLS) in patients with advanced soft-tissue sarcomas (STS) may act as a potential predictive biomarker for treatment with pembrolizumab, potentially improving patient selection, according to a study.
Limited clinical activity has been demonstrated using immune checkpoint inhibitors in patients with advanced STS.
In the multicohort phase 2 study (PEMBROSARC) of pembrolizumab combined with low-dose cyclophosphamide in patients with advanced STS,
A cohort of patients (n = 30) from the multicohort phase 2 study (PEMBROSARC) of pembrolizumab combined with low-dose cyclophosphamide, was selected based on the presence of TLSs.
In this cohort, the 6-month non-progression rate (NPR) and the objective response rate (ORR) were 40% and 30%, respectively compared to 4.9% and 2.4%, respectively, for cohorts in the PEMBROSARC trial enrolling all comers.
The most frequent toxicities were grade 1 or 2 fatigue, nausea, dysthyroidism, diarrhea, and anemia.
Further exploratory analyses found that the abundance of intratumoral plasma cells was significantly associated with improved outcomes.
Reference
Italiano A, Bessede A, Pulido M, et al. Pembrolizumab in soft-tissue sarcomas with tertiary lymphoid structures: a phase 2 PEMBROSARC trial cohort. Nat Med. 2022 May 26. doi: 10.1038/s41591-022-01821-3. Epub ahead of print. PMID: 35618839.
