Photo Credit: Lars Neumann

The addition of nivolumab to rucaparib maintenance therapy did not improve progression-free survival (PFS) in patients with ovarian cancer, outcomes of the phase 3 ATHENA-COMBO trial demonstrated.

Results from the ATHENA-MONO substudy (NCT03522246) previously showed that maintenance therapy with rucaparib monotherapy significantly improved survival in patients with stage III–IV, high-grade ovarian cancer, compared with placebo¹. Concurrently, ATHENA-COMBO evaluated the safety and efficacy of maintenance therapy with rucaparib plus nivolumab in this population. Bradley Monk, MD, from the University of Arizona, presented the results².

In ATHENA-COMBO, the rucaparib arm of ATHENA-MONO (n=427) was used as control arm. In the rucaparib plus nivolumab arm, 436 participants were treated with rucaparib plus nivolumab up to 24 months.

The addition of nivolumab to maintenance rucaparib did not improve outcomes. The median PFS was 15.0 months on doublet therapy versus 20.2 months in the rucaparib alone arm (HR 1.29; 95% CI 1.08–1.53). The 4-year PFS rate was 33% versus 26%. Monotherapy favored PFS in all prespecified subgroups, e.g. stratified by BRCA or PD-L1 status. In addition, no benefit of doublet maintenance therapy was seen in overall survival (OS). Median OS was 49.4 and 58.0 months in both doublet and monotherapy arms.

Moreover, doublet maintenance therapy came with more AEs, more dose interruptions, more discontinuations, and deaths due to AEs.

To explain the inferiority of the doublet maintenance therapy, Dr. Monk pointed out that in the doublet arm, the median exposure to rucaparib was 8.4 months, and 14.7 months in the monotherapy arm.

“Nivolumab in combination with rucaparib was associated with increased toxicity and did not extend the PFS benefit of rucaparib monotherapy as first-line maintenance treatment in patients with ovarian cancer,” concluded Dr. Monk.

Medical writing support was provided by Marten Dooper.

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