The prospects of US approval for Akeso (HKG:9926) and Summit Therapeutics' ivonescimab lung cancer drug appear to be dimming after analysts identified discrepancies in its latest findings, Bloomberg reported Monday.

Akeso's shares in Hong Kong were down nearly 3% in Tuesday's trade.

New data released showed North American and European patients lived longer on the drug, but the results failed to impress analysts, the report said.

A Leerink analyst noted the data failed to validate positive signals from research in China, while analysts at Piper Sandler & Co said the reading on the Asian vs. non-Asian subgroups was "worse" than they expected, according to the report.

The results were also "uninterpretable" due to the fragmented subgroup data on North America and Europe patients, Bloomberg Intelligence analysts Javier Manso Polo and Sam Fazeli reportedly said.

The latest development marks a second setback for the companies, after earlier data showed the drug improved progression-free survival but did not demonstrate a sufficient overall survival benefit.

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