Phase II single-arm study of nivolumab and ipilimumab (Nivo/Ipi) in previously treated classical Kaposi sarcoma (cKS).

BACKGROUND: Classical Kaposi sarcoma (cKS) is a rare human herpesvirus 8-associated sarcoma with limited treatment options. We evaluated the efficacy and safety of nivolumab in combination with ipilimumab in patients with previously treated progressive cKS. PATIENTS AND METHODS: cKS patients with progressive disease after one or more lines of systemic therapy and measurable disease by positron emission tomography/computed tomography and/or physical examination received nivolumab 240 mg every 2 weeks and ipilimumab 1 mg/kg every 6 weeks until progression or toxicity for a maximum of 24 months. The primary endpoint was overall response rate; secondary endpoints included 6-month progression-free survival (PFS) rate and safety. Immune correlates were explored using immunohistochemistry, DNA sequencing (596/648 genes) and RNA sequencing (whole transcriptome hybrid capture) of tumor specimens and matched blood. RESULTS: Eighteen male patients (median age 76.5 years) were enrolled between April 2018 and December 2020. At a median follow up of 24.4 months, overall response rate by RECIST v1.1 was 87%. Metabolic complete response as assessed by positron emission tomography/computed tomography was observed in 8 of 13 (62%) assessable patients. Some 6/13 achieved pathological complete response after treatment. In two patients, palliative limb amputation was prevented. Median PFS was not reached. The 6- month and 12-month PFS rate was 76.5% and 58.8%, respectively. Only four patients (22%) experienced grade 3-4 adverse events. The most frequent genomic alteration was biallelic copy number loss of the FOX1A gene. The majority of tumors carried a low tumor mutational burden, were microsatellite stable, mismatch repair proficient, did not express programmed death-ligand 1, and displayed only low lymphocytic infiltrates, rendering them immunologically 'cold'. CONCLUSIONS: This prospectively designed phase II study of nivolumab and ipilimumab demonstrates promising activity of this combination in progressive cKS representing a new treatment option in this population.

Discrepancies between biomarkers of primary breast cancer and subsequent brain metastases: an international multicenter study.

PURPOSE: Discordances between the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), expression between primary breast tumors and their subsequent brain metastases (BM) were investigated in breast cancer patients. METHODS: We collected retrospective data from 11 institutions in 8 countries in a predefined-standardized format. Receptor status (positive or negative) was determined according to institutional guidelines (immunohistochemically and/or fluorescence in situ hybridization). The study was subject to each institution's ethical research committee. RESULTS: A total of 167 breast cancer patients with BM were included. 25 patients out of 129 with a complete receptor information from both primary tumor and BM (ER, PR, HER2) available, had a change in receptor status: 7 of 26 (27%) ER/PR-positive/HER2-negative primaries (3 gained HER2; 4 lost expression of ER/PR); 10 of 31 (32%) ER/PR-positive/HER2-positive primaries (4 lost ER/PR only; 3 lost HER2 only; 3 lost both ER/PR and HER2); one of 33 (3%) ER/PR-negative receptor/HER2-positive primaries (gained ER); and 7 of 39 (18%) triple-negative primaries (5 gained ER/PR and 2 gained HER2). CONCLUSIONS: The majority of breast cancer patients with BM in this series had primary HER2-enriched tumors, followed by those with a triple-negative profile. One out of 5 patients had a receptor discrepancy between the primary tumor and subsequent BM. Therefore, we advise receptor status assessment of BM in all breast cancer patients with available histology as it may have significant implications for therapy.