Summit And Akeso Win Third China Approval For Ivonescimab, As HARMONi-6 Survival Signal Weakens

Summit Therapeutics and partner Akeso are celebrating a third approval in China for ivonescimab, but the market reaction has centered on what the newly posted trial data may mean for the drug’s U.S. trajectory.

Last Wednesday, China’s National Medical Products Administration approved the PD-1/VEGF bispecific antibody in combination with chemotherapy for the first-line treatment of advanced squamous non-small cell lung cancer. But the label also included updated results from the Phase 3 HARMONi-6 trial that underpinned the clearance, and those data showed degradation of progression free survival.

That update prompted Leerink Partners to express “increased pessimism” about the drug’s prospects in this lung cancer setting. Summit shares closed Friday down more than 4% at $13.35.

The regulatory read-through

The core strategic question is whether China approval momentum can still translate into an FDA path based on progression-free survival. Leerink now doubts that the ongoing HARMONi-3 study, which is intended to support an accelerated approval in the U.S., will show a “substantial benefit” when its final analysis arrives sometime this half.

Leerink’s concern is specific to the standard for accelerated approval in first-line NSCLC. The firm wrote that the FDA’s bar for that route based on PFS outcomes in 1L NSCLC is high in its view, making any sign of benefit erosion more consequential than the China approval is supportive.

Summit had already disclosed interim findings suggesting the early survival mark had not been met, though Leerink had remained constructive at that stage because benefit was still trending in a positive direction. The new HARMONi-6 label update changed that balance.

What This Changes For Summit

Leerink now expects a delayed U.S. launch timeline. The firm said the chemo combination in squamous NSCLC is more likely to launch in the fourth quarter of 2029, compared with its prior expectation of the fourth quarter of 2027. It also pushed its expectation for a non-squamous approval to the third quarter of 2030 from the third quarter of 2028.

The investment risk is amplified by Summit’s cash position. As of June 30, the biotech had $690 million in cash available, which the source said was enough to keep the lights on for less than a year, citing a second quarter earnings report last month. That means a weaker-than-hoped HARMONi-3 outcome would not just affect label timing; it would tighten financing pressure around the rest of the program.

Leerink said Summit’s shares could fall further with the HARMONi-3 readout, potentially to cash value of around $1 apiece. At the same time, the firm added that investor reaction to the updated HARMONi-6 PFS analysis could become excessive and create a near-term trading opportunity.

The remaining near-term support for the franchise is separate from this squamous setting. Summit is awaiting a November FDA decision for ivonescimab in NSCLC with mutations in the gene for epidermal growth factor receptor.