Summit Therapeutics Stock Draws Cautious Retail Mood After Barclays ‘Underweight’ Call: ‘Added To The Biotech Graveyard’

Retail traders kept a cautious stance on Summit Therapeutics on Tuesday after Barclays initiated coverage of the biotech with an ‘Underweight’ rating and a $13 price target. 

The stock fell 4.3% to $18.12 on Tuesday and slipped another 0.4% after hours.

Barclays flagged a long regulatory path, stiff competition in lung cancer, and a rival backed by a major pharma partner as key risks.

The brokerage said it still sees a “high likelihood” of approval for ivonescimab, Summit’s experimental bispecific antibody, but its models suggest only modest improvements over the current standard of care. 

The note contrasted with Guggenheim’s initiation earlier this month at ‘Buy’ with a $40 price target, which argued the company’s late-stage trials could offer multi-fold upside if successful.

The cautious call comes just days after Summit presented new follow-up data from its Phase III HARMONi trial at the World Conference on Lung Cancer in Barcelona. Patients with advanced non-small cell lung cancer on ivonescimab plus chemotherapy lived a median of 16.8 months versus 14 months on chemo alone, with hazard ratios pointing to survival benefits across Western and Asian cohorts. 

Earlier results showed the study met its main goal, cutting the risk of progression or death by 48% compared with chemotherapy alone.

Ivonescimab, licensed from China’s Akeso and already approved there as SMT112, has been tested in more than 2,800 patients worldwide and carries a U.S. FDA Fast Track designation. 

Summit is running additional late-stage trials, HARMONi-3 and HARMONi-7, comparing ivonescimab against Merck’s blockbuster PD-1 drug Keytruda in first-line lung cancer, with readouts expected between 2027 and 2028.

On Stocktwits, retail sentiment was ‘bearish’ amid ‘low’ message volume.

One user remarked that they would only consider buying Summit Therapeutics if it returned to penny-stock levels, calling it “another one added to the biotech graveyard.”

Another user said they were holding their shares following the updated brokerage reports, waiting for what they described as a future payday.

Summit’s stock has risen 1.5% so far in 2025.

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