Eribulin and Pembrolizumab Combination in Triple-Negative Breast Cancer
Posted: Thursday, May 20, 2021
Sami Diab, MD, of Rocky Mountain Cancer Centers, Aurora, Colorado, and colleagues investigated the efficacy of eribulin plus pembrolizumab in patients with metastatic triple-negative breast cancer. Although these drugs have been effective as monotherapies, the researchers stated that their combination was well tolerated, with “promising” antitumor activity. Their results were published in Clinical Cancer Research.
The phase Ib/II ENHANCE 1 trial focused on 167 patients with metastatic triple-negative breast cancer who received at most two prior systemic therapies. Patients were stratified based on how many therapies had been received in the metastatic setting (stratum 1: 0; stratum 2: 1–2), as well as PD-L1 tumor status. Participants were intravenously administered 1.4 mg/m2 of eribulin on days 1 and 8 and 200 mg of pembrolizumab on day 1, of 21-day cycles.
At the time of data cutoff, 158 patients discontinued treatment, whereas 9 remained on therapy. A total of 44% of patients had PD-L1–positive tumors, 45% had PD-L1–negative tumors, and the rest had an unknown tumor status. No dose-limiting toxicities occurred in any patient. The most frequent treatment-emergent adverse events were fatigue (66%), nausea (58%), peripheral sensory neuropathy (41%), alopecia (40%), and constipation (37%). Fatal adverse events affected 15 patients, yet none were considered to be treatment-related.
Patients in stratum 1 had an objective response rate of 25.8%, and those in stratum 2 had a rate of 21.8%. Complete and partial responses were observed in 8 and 31 individuals, respectively. Additionally, a higher objective response rate was observed in patients with PD-L1–positive tumors (28.4%) versus those with PD-L1–negative tumors (17.3%).
The overall median progression-free survival and overall survival were 4.1 months and 16.1 months, respectively; patients in stratum 1 had a higher median overall survival (17.4 months) than those in stratum 2 (15.5 months). Of note, patients who had PD-L1–positive tumors were reported to have longer progression-free and overall survival (4.2 and 16.3 months) than those with PD-L1–negative tumors (3.9 and 15.2 months), respectively.
Disclosure: For full disclosures of the study authors, visit clincancerres.aacrjournals.org.