Lurbinectedin Active in BRCA Mutation-positive Metastatic Breast Cancer

Lurbinectedin, a novel investigational drug that inhibits trans-activated transcription, induces DNA double-strand breaks, and  regulates the tumor microenvironment, displays anti-tumor activity in patients with BRCA1/2-associated metastatic breast cancer, according to a study presented at the European Society for Medical Oncology (ESMO) 2016 Congress.¹

Previous studies demonstrate activity with lurbinectedin in various tumor types, as well as in patients resistant to platinum-based chemotherapy. Researchers therefore assessed the activity of lurbinectedin among patients with metastatic breast cancer and deleterious germline BRCA mutations.

For the phase 2 clinical trial (ClinicalTrials.gov Identifier: NCT01525589), researchers enrolled 54 patients who received no more than 3 prior lines of chemotherapy for advanced or metastatic disease. Of those, 30 were BRCA1 mutation-positive and 31 had triple-negative disease.

Most had received prior treatment with anthracyclines and taxanes; half had received platinum agents and 9 were previously treated with PARP inhibitors.

The objective response rate was 39% (95% CI, 26-54), with 2% of the 51 evaluable patients achieving a complete response and 37% having partial responses. Among platinum pretreated patients, 23% (95% CI, 9-44) achieved an objective response.

Median duration of response was 4.6 months (95% CI, 3.4-11.3); median progression-free survival was 4.1 months (95% CI, 2.6-6.0).

The most frequently reported grade 3 to 4 treatment-related adverse events were neutropenia, febrile neutropenia, thrombocytopenia, fatigue, transaminase elevation, and nausea.

The findings suggest that further evaluation of lurbinectedin in a phase 3 clinical trial is warranted.                

Reference

1. Balmana J, Cruz C, Arun BK, et al. Anti-tumor activity of PM01183 (lurbinectedin) in BRCA1/2-associated metastatic breast cancer patients: results of a single-agent phase II trial. Paper presented at: European Society for Medical Oncology (ESMO) 2016 Congress; October 7-11, 2016; Copenhagen, Denmark.