Key clinical point: Rupacarib did not show clinical benefits in the overall cohort of patients with metastatic breast cancer, but a small proportion of patients with high loss of heterozygosity (LOH) scores and no mutations in germline BReast CAncer genes 1 and 2 ( BRCA1/2) seemed to benefit.
Major finding: Investigator-assessed clinical benefit rate was 13.5% ( 95% CI, 4.5%-28.8%) in the overall cohort, which was below the clinically relevant 20% mark. However, 5 patients achieved clinical benefits with rucaparib, with 2 of them with high LOH scores and no somatic BRCA1/2 mutation achieving a complete response of 12 months and 28.5 months, respectively.
Study details: Findings are from a phase 2 RUBY study including 40 adult patients with progressive human epidermal growth factor receptor 2-negative breast cancer with high LOH or nongermline BRCA1/2 mutation, who received at least 1 dose of rucaparib.
Disclosures: This study was funded by Clovis. The authors declared serving as speaker and advisor and/or receiving research grants, travel fees, consulting fees, and personal fees from various pharmaceutical companies.
Source: Patsouris A et al. Eur J Cancer. 2021 Nov 25. doi: 10.1016/j.ejca.2021.09.028 .