Median overall survival of patients with BRCA-related relapsed ovarian cancer improved by more than 1 year when they were treated with olaparib maintenance compared with placebo, according to the results of the SOLO2 trial.1

The final analysis showed a median overall survival of 51.7 months with olaparib compared with 38.8 months with placebo (hazard ratio [HR], 0.74; 95% CI, 0.54-1.00; P =.0537).

“This analysis did not adjust for the 39% of patients in the placebo group who crossed over to subsequent PARP inhibitor therapy,” said lead author Andres Poveda, MD, of Initia Oncology, Hospital Quironsalud, in Valencia, Spain, who presented the results at a press conference ahead of the ASCO20 Virtual Scientific Program.

With 5 years’ follow-up, 42.1% of women assigned to receive the PARP inhibitor olaparib were alive, compared with 33.2% of patients who were assigned to receive placebo.

Commenting on the results of the study in a press release,2 American Society if Clinical Oncology (ASCO) Chief Medical Officer and Executive Vice President Richard L. Schilsky, MD, said, “This study confirms that the PARP inhibitor olaparib should be the standard maintenance therapy for patients with BRCA-related relapsed ovarian cancer responding to platinum-based chemotherapy — a significant advance for women with a cancer that has a historically poor prognosis.”

The double-blind trial included 196 patients with relapsed BRCA-related ovarian cancer who had responded to platinum-based chemotherapy. All patients had previously received at least two lines of chemotherapy. Patients were assigned in a 2:1 ratio to receive olaparib 300 mg twice daily or placebo, and continued on study until disease progression. The primary endpoint was investigator-assessed progression-free survival; overall survival was a secondary endpoint.

Among those patients with germline BRCA mutation, the median overall survival with olaparib was 52.4 months compared with 37.4 months (HR, 0.71; 95% CI, 0.52-0.97; P =.0306).  

SOLO2 was the first phase 3 trial to provide final overall survival data on maintenance PARP inhibitor therapy.

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“With the addition of overall survival data, this study helps usher in a new era of personalized medicine for women with this difficult-to-treat cancer,” Dr Poveda said.

The most common treatment-emergent adverse event grade 3 or worse was anemia. Half of patients assigned to be administered olaparib had a dose interruption as a result of an adverse event, compared with 19% of patients who were assigned to receive placebo. Dose reductions occurred in 28% of patients who got olaparib compared with 3% of patients who were assigned placebo.

In all, 17% of patients assigned to get the PARP inhibitor had to discontinue treatment because of adverse events.

Olaparib is currently approved in numerous countries as maintenance therapy for patients with platinum-sensitive relapsed ovarian cancer regardless of BRCA mutation status.

References

  1. Poveda A. A phase III trial assessing survival after maintenance treatment with the PARP inhibitor olaparib in patients with platinum-sensitive, relapsed ovarian cancer and a BRCA mutation. Presented at: ASCO20 Annual Meeting. J Clin Oncol. 2020;38(suppl):abstr 6002.
  2. American Society of Clinical Oncology (ASCO). https://www.asco.org/about-asco/press-center/news-releases/maintenance-therapy-parp-inhibitor-olaparib-extends-survival [press release]. Published May 13, 2020. Accessed May 19, 2020.

This article originally appeared on Cancer Therapy Advisor