ESMO 2025 preview – Junshi goes pivotal in PI3Kα

Lilly and Relay are attempting to improve PI3Kα inhibitors by sparing wild-type forms of the protein, and now Asian groups are getting involved here, too. The latest is China’s Junshi Biosciences, whose JS105 is set to go into a phase 3 trial in the country soon, according to a recent listing on clinicaltrials.gov. Little is known about JS105, but it appears to be another wild-type sparing agent, like Lilly’s tersolisib and Relay’s RLY-2608, which are already in, or about to go into, global pivotal trials. The new study, JS105-004-III-BC, is set to begin in November and will evaluate JS105 plus Faslodex and Jiangsu HengRui’s CDK4/6 inhibitor dalpiciclib in ER-positive, HER2-negative breast cancer with PI3KCA mutations. Junshi hasn’t presented any clinical data for the asset yet, but early results will feature in a poster at ESMO – presumably, the company must have seen encouraging signs to move straight from phase 1 to phase 3. Among Asian competitors, Haihe Biopharma is currently the most advanced with CYH33, now under regulatory review in Japan for ovarian cancer, an indication where no other pivotal PI3Kα studies are ongoing, though Lilly is testing tersolisib in ovarian cancer in the phase 1/2 Pikalo-1 trial.

Notable PI3Kalpha inhibitors developed by Asian companies

Source: OncologyPipeline.

ESMO will take place in Berlin on 17-21 October.