Roche's solo Tecentriq advances toward Keytruda showdown with 'priority' boost in lung cancer

The FDA is set to decide on Roche's Tecentriq as a lung cancer monotherapy by June 19. (Roche)

How much space has Merck powerhouse Keytruda left for rival Tecentriq to snap up share as a solo therapy in lung cancer? Industry watchers are one step closer to finding out after a Roche regulatory boost from the FDA.

The agency has granted Tecentriq a priority review in patients with previously untreated non-small cell lung cancer whose tumors bear high levels of biomarker PD-L1, it said Wednesday. The move sets up the Roche drug for an approval decision by June 19.

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Regulators based the decision on results from Roche’s phase 3 Impower110 study, which showed Tecentriq could cut patients’ risk of disease worsening or death by 41%. The checkpoint inhibitor extended patients’ lives by an additional 7.1 months compared with chemo, with those receiving the checkpoint inhibitor living a median 20.2 months versus chemo’s 13.1.

Those data raised eyebrows when they rolled out in September at the European Society for Medical Oncology annual meeting, where industry watchers were eager to pit them against Merck’s Keytrtuda results in the same setting. “For investors who have gotten used to an invincible Keytruda in NSCLC, these results may be jolting,” Leerink Partners analyst Daina Graybosch wrote to clients at the time.

The reason? Tecentriq posted a better hazard ratio than Keytruda did in either the Keynote-042 or the Keynote-024 study, she wrote, though “results are not directly comparable” because of differences between the study populations.

RELATED: Roche's Tecentriq scores solo win in lung cancer. But can it challenge Merck's Keytruda?

That said, Graybosch still only expects to see “limited to moderate uptake” for Tecentriq, which she predicts will poach less than 15% of Keytruda’s market share in the setting thanks to the Merck drug’s “substantial” headstart.

“Considering Keytruda’s 2+ year headstart in the setting, and its demonstrated survival benefit across PD-L1 expression levels, we see little risk to its continued dominance in PD-L1 high segment,” she wrote.