Roche's Tecentriq-Avastin pairing fails to keep ovarian cancer at bay

Immune checkpoint inhibitors have gained a foothold in several tumor types, but not so much in ovarian cancer. Now, an early attempt by Roche to change that situation has failed.

Adding PD-L1 inhibitor Tecentriq to Roche’s own Avastin and chemotherapies paclitaxel and carboplatin didn’t help women with newly diagnosed ovarian cancer live longer without their disease progressing, the Swiss drugmaker said Sunday.

Despite that letdown on one of the two primary endpoints in the phase 3 IMagyn050 study, Roche is still following the patients for insight on whether the Tecentriq-Avastin-chemo cocktail can extend patients’ lives.

Back in 2018, the Avastin-chemo pairing—used after single-agent Avastin—won a hard-fought FDA nod to treat advanced ovarian cancer patients following initial surgery.

In the GOG-0218 study, the Avastin-chemo regimen cut the risk of progression or death by 38% versus chemo alone. There was also a numerical difference in overall survival in favor of Avastin-chemo, but it was not statistically significant.

Roche’s hope was that the addition of Tecentriq could provide even more benefit in the same ovarian cancer setting. But it looks unlikely for now.

RELATED: AstraZeneca, Merck's Lynparza wins bid to challenge GSK's Zejula in wider ovarian cancer pool

Immunotherapy progress in ovarian cancer is lagging behind that for other cancer types. So far, no PD-1/L1 agent is approved for the tough-to-treat tumor. Pfizer and Merck KGaA previously chalked up multiple failures for their anti-PD-L1 drug Bavencio in ovarian cancer, including in previously treated patients and in new patients.

Merck & Co.’s PD-1 king Keytruda showed limited benefit for women with advanced and recurrent ovarian cancer. According to results from the Keynote-100 trial, just unveiled at this year’s American Society of Clinical Oncology virtual meeting, solo Keytruda triggered a response in merely 8% of patients who had received between one and three prior lines of treatment.

But drugmakers are testing different combo approaches to improve response to immunotherapy in ovarian cancer. One such example is the combination of PD-1/L1 with PARP inhibitors, an ovarian cancer mainstay.

Clovis Oncology, for one, just completed enrollment in the phase 3 Athena trial that’s testing its PARP inhibitor Rubraca with Bristol Myers Squibb’s PD-1 inhibitor Opdivo as maintenance treatment to prevent cancer from returning after response to front-line treatment.

AstraZeneca, meanwhile, paired its PD-L1 Imfinzi with PARP market-leader Lynparza, a drug it shares with Merck. In the phase 2 Mediola trial, the combo shrank tumors in 71.9% of patients with a BRCA-mutant, platinum-sensitive disease.

Both GlaxoSmithKline’s Zejula and Lynparza—in tandem with Avastin—were recently granted FDA green lights to help keep disease at bay in ovarian cancer patients following a successful round of chemo, regardless of their BRCA mutation status.