As Bristol Myers reveals trial failure, AstraZeneca's Imfinzi stays king in stage 3 lung cancer

Another attempt at improving upon AstraZeneca’s Imfinzi in stage 3, unresectable non-small cell lung cancer (NSCLC) has gone up in flames.

The latest failure comes from a phase 3 trial conducted by Bristol Myers Squibb. The company’s Opdivo, used with concurrent chemoradiotherapy, followed by Opdivo plus BMS’ Yervoy, failed to beat Imfinzi maintenance in unresectable stage 3 NSCLC, BMS said Friday.

The Imfinzi regimen features chemoradiation alone followed by Imfinzi during the maintenance phase of treatment. Approved by the FDA in early 2018, unresectable stage 3 NSCLC has been Imfinzi’s main indication, and it’s where the AZ PD-L1 inhibitor is the standard of care for patients whose cancer has not progressed after chemoradiation.

BMS tried to challenge AZ’s dominance by launching the phase 3 CheckMate-73L trial in 2019. The company figured that because chemoradiotherapy increases PD-L1 expression, concurrent immune checkpoint inhibition may improve outcomes.

But, now, the study found the Opdivo-Yervoy-concurrent-chemoradiation regimen couldn’t extend the time before tumor progression or death versus the Imfinzi maintenance approach. The adverse events observed were generally consistent with the known profiles of each component in the combination, BMS said.

The CheckMate-73L study features another arm testing Opdivo monotherapy during the maintenance phase. But because its primary endpoint measures progression-free survival for the Opdivo-Yervoy arm, the entire study is now considered negative. The study’s many secondary endpoints include overall survival for either experimental arm against Imfinzi and for the two Opdivo arms against each other.

The BMS setback follows another similar one by Imfinzi itself. Because the current Imfinzi regimen is given only to patients who have not progressed after initial chemoradiotherapy, AZ had tried to expand the drug’s patient base by giving Imfinzi and chemoradiation concurrently. However, that regimen recently failed to beat Imfinzi maintenance in the phase 3 PACIFIC-2 trial.

Besides those regimens, China’s CStone Pharmaceuticals in 2022 reported positive phase 3 results from the GEMSTONE-301 trial for its China-approved PD-L1 inhibitor Cejemly (sugemalimab) when used after chemoradiotherapy in unresectable stage 3 NSCLC. However, that study was conducted solely in China, and the drug was pitted against placebo, not Imfinzi, so the results are not considered meaningful for the U.S. market.

Now, market watchers are turning their attention to Merck & Co.’s PD-1 king Keytruda. The phase 3 KEYLYNK-012 trial is testing concurrent use of chemoradiation and Keytruda, followed by Keytruda with or without AZ and Merck’s PARP inhibitor Lynparza, versus Imfinzi maintenance in unresectable stage 3 NSCLC. However, the regimen doesn’t look very promising after a pair of phase 3 flops for the PD-1/PARP combo in metastatic NSCLC.

There’s also Roche’s PD-L1 inhibitor Tecentriq. The Swiss pharma is running the phase 3 SKYSCRAPER-03 trial pairing Tecentriq with the company’s closely watched TIGIT inhibitor tiragolumab in the maintenance setting following concurrent platinum-based chemoradiation. The trial finished enrollment about a year ago and bears a primary completion date this October, according to Roche.

AZ isn’t giving up its expansion efforts, either. The PACIFIC-9 trial is evaluating Imfinzi together with either the company’s anti-CD73 antibody oleclumab or Innate Pharma-partnered anti-NKG2A antibody monalizumab as a maintenance therapy. A readout from that phase 3 study could be two years away.