05/13/2020

A Phase II Single-Arm Study of Nivolumab and Ipilimumab (Nivo/Ipi) in Previously Treated Classical Kaposi Sarcoma (CKS)

American Society of Clinical Oncology Annual Meeting 2020 Presentation
Authors Alona Zer, Oded Icht, Lilach Joseph, Dana Avram, Oded Jacobi, Eyal Fenig, Noga Kurman, Idit Peretz, Sivan Shamai, Ofer Merimsky, Eitan Ben-Ami, Roni Shapira, Anna Ewa Schwarzbach, Hanna Bernstine, Rony Weitzen, Olga Vornicova, Gil Bar-Sela, Salomon M. Stemmer, and Michal Lotem

Background: CKS is a mesenchymal neoplasm associated with HHV8 infection. Though recombinant INFa is approved for treatment of AIDS-related KS, data is limited regarding the role of immune modulation in CKS therapy. Based on favorable responses in viral-induced cancers, we hypothesized that CTLA-4 and PD-1 blockade can induce tumor regression in CKS. We present pre-planned interim analysis of a phase II study of Nivo/Ipi in previously treated progressive CKS.

Methods: CKS pts with progressive disease after > 1 line of systemic therapy and measurable disease received nivolumab 240mg d1,15,28 and ipilimumab 1mg/kg d1 q42 days until progression or toxicity. The primary endpoint was overall response rate (ORR) evaluated clinically, radiologically (RECIST) and metabolically (FDG-PET). Secondary endpoints include 6-months progression free survival rate (PFS) and safety. Exploratory endpoints included PD-L1/MMR by IHC, DNAseq (596 genes)/RNAseq (whole transcriptome) of tumor and matched blood specimens to explore CKS genomic traits and IO correlates: TMB and MSI status, MMR and PD-L1 protein expression, and immune gene transcript expression (PD-1, PD-L1, CTLA-4, and others) (Tempus Labs, Chicago, IL, USA).

Results: Fifteen patients were enrolled and evaluable (Apr18-Jan20). Median age 72.5 (61-81), all male. At a median FU of 15.7 mo ORR as per RECIST was 66% (9 pts PR, 1 pt CR, 2 pts SD, 3 pts NE). Clinical ORR was 87% and metabolic ORR was 60%. Median PFS was not reached, 6mo PFS rate was 85% and 1y PFS rate was 75%. The safety profile was as expected with all pts experiencing G1 toxicity, 3 pts with G2 toxicity (1 hepatic, 2 asymptomatic lipase increase) and 2 pts with G3 toxicity (1 colitis, 1 asymptomatic lipase increase). One SAE was reported (TIA considered not related to therapy) and treatment was discontinued in 3 pts. Correlative results are available for 8 pts showing a trend for copy number loss in genes with tumor-suppressive activity (FOXA1, ELF3), no PDL1 expression, low TMB, microsatellite stability, but marked overexpression of CTLA-4, PD-1, PDL-1, CD40, OX40 and LAG3 RNA immune transcripts.

Conclusions: The interim analysis of this prospective phase II study of nivolumab and low-dose ipilimumab demonstrates promising activity in progressive CKS, with 66% ORR and a 6mo PFS rate of 85%. Toxicity profile is as expected in this class of drugs. Correlative studies are preliminary, but warrant further investigation into genomic traits and immune gene expression profiles. Clinical trial information: NCT03219671. Clinical trial information: NCT03219671.

VIEW THE PUBLICATION