Ivonescimab notched its third approval in China last week, but the label update has tempered expectations for the Summit Therapeutics/Akeso drug, showing that progression-free survival declines over time.
New data for Summit Therapeutics’ Akeso-partnered asset ivonescimab have soured analysts on the drug’s potential in a type of lung cancer, just as the companies celebrate a third approval in China.
Last Wednesday, ivonescimab was approved by China’s National Medical Products Administration (NMPA) in combination with chemotherapy for the first-line treatment of advanced squamous non-small cell lung cancer (NSCLC). The nod marked the third approval in the nation for the PD-1/VEGF bispecific antibody, which has built up plenty of hype for its prospects in the U.S.
But as part of the approval, the NMPA posted some new data on the drug’s label showing degradation of progression free survival (PFS) in the Phase 3 HARMONi-6 trial that underpinned the regulatory clearance.
The update spurred “increased pessimism” from Leerink Partners, as Summit works to confirm the benefit of ivonescimab in global clinical trials to secure an FDA approval. The firm is now concerned that the ongoing HARMONi-3 trial intended to support an accelerated approval in the U.S. will not show a “substantial benefit” when the final analysis is revealed sometime this half.
“FDA’s bar for [accelerated approval] based on PFS outcomes in 1L NSCLC is high, in our view,” Leerink wrote on Friday.
Summit’s shares closed Friday down more than 4% at $13.35, reflecting the update. The biotech’s shares could fall further with the HARMONi-3 readout, Leerink predicted, down to cash value of around $1 apiece.
Alternatively, Leerink added, “We also see potential for investor overreaction to the updated H-6 PFS analysis that may create a near-term opportunity to long SMMT.”
Summit has already revealed interim data from the study that suggested the early survival mark had not been met but Leerink remained optimistic given the benefit was trending in a positive direction. It’s possible, the firm suggested, that the VEGF antagonism provides an early benefit, and that the longer-term readout from HARMONi-3 could therefore fall short of the bar for statistical success. But this is an unlikely scenario, Leerink said, as other assets in the class have shown positive data and “supportive biologic plausibility.” Following the second-half PFS analysis for HARMONi-3, Leerink is expecting top-line overall survival outcomes from the late-stage program to arrive later in the first half of 2027.
The analysts now expect a delayed launch of ivonescimab given accelerated approval has become less likely. The chemo combination in squamous NSCLC launch is now more likely to occur in the fourth quarter of 2029 as compared to the fourth quarter of 2027. An approval in non-squamous disease could follow in the third quarter of 2030, instead of the third quarter of 2028.
All is not lost for Summit’s U.S. prospects, however. The biotech is awaiting a November FDA decision for ivonescimab in NSCLC with mutations in the gene for epidermal growth factor receptor (EGFR).
But the biotech needs a major win, as it had just $690 million in cash available as of June 30, enough to keep the lights on for less than a year, according to a second quarter earnings report last month.
