Original source text
Key Takeaways Summit sold ridinilazole rights to Biossil for upfront cash, milestones and royalties.SMMT's phase III ridinilazole program missed its primary endpoint despite encouraging exploratory benefits.Summit said the divestiture supports its strategic focus on developing ivonescimab in oncology. Summit Therapeutics (SMMT - Free Report) has entered into an agreement with Toronto-based Biossil Inc. to divest its investigational antibiotic candidate, ridinilazole. The late-stage asset was being developed for the treatment of patients with clostridioides difficile infection (CDI), a serious bacterial infection of the colon.
Financial Terms of Summit’s Deal With BiossilPer the agreement, Biossil will assume responsibility for the further development and commercialization of ridinilazole.
In return, Summit will receive an upfront payment of $500,000 and will be eligible for up to $104.5 million in regulatory and commercial milestone payments. The company is eligible to receive tiered royalties on future net sales of the product.
Year to date, Summit's shares have lost 11.6% compared with the industry’s 2.8% decline.
Image Source: Zacks Investment Research
Ridinilazole's Clinical ProfileSummit evaluated ridinilazole in the phase III Ri-CoDIFy program, combining the Ri-CoDIFy 1 and Ri-CoDIFy 2 studies for patients with CDI, versus vancomycin, the standard of care in 2021, with a twice-daily dosing regimen.
Although the primary endpoint of these studies was not met, the antibiotic showed several clinically encouraging exploratory benefits. These include better preservation of the gut microbiome, lower recurrence rates, reduced toxin production, favorable tolerability and a convenient dosing regimen compared with the current standard of care.
Summit held a Type C meeting with the FDA in 2022 to discuss a possible pathway to advance ridinilazole with the goal of achieving marketing authorization. Following the meeting, the company determined that ridinilazole would likely require at least one additional phase III study to support regulatory approval. Conducting another large-scale CDI study would have required significant time and financial resources, with an uncertain likelihood of success. As a result, the company decided to seek a development partner or divest the asset rather than continue its development independently.
Clostridioides difficile infection is a contagious bacterial infection of the colon that causes severe diarrhea and inflammation and can lead to serious complications such as sepsis, bowel perforation and death. It is a major healthcare-associated infection, causing nearly 500,000 cases and contributing to more than 29,000 deaths annually in the United States.
Summit Shifts Strategic Focus to OncologySummit believes Biossil's AI-driven drug development platform is well-positioned to further advance the ridinilazole program. The divestiture also enables Summit to sharpen its strategic focus on oncology, particularly the development of its lead investigational oncology drug, ivonescimab.
Ivonescimab is currently being evaluated in multiple late-stage clinical studies across several treatment settings in non-small cell lung cancer (NSCLC) and colorectal cancer. Summit is developing the therapy in partnership with China-based Akeso. In January, the FDA accepted Summit’s biologics license application (BLA), seeking approval of ivonescimab plus chemotherapy for patients with EGFR-mutated, locally advanced or metastatic non-squamous NSCLC who have progressed after treatment with third-generation EGFR-TKIs. The BLA filing was based on encouraging results from the phase III HARMONi study. The FDA decision is expected by Nov. 14, 2026.
SMMT’s Zacks Rank & Stocks to ConsiderSummit currently carries a Zacks Rank #3 (Hold).
Some better-ranked stocks in the biotech sector are Neurocrine Biosciences (NBIX - Free Report) , Amarin Corporation (AMRN - Free Report) and Liquidia Corporation (LQDA - Free Report) , each currently sporting a Zacks Rank #1 (Strong Buy). You can see the complete list of today’s Zacks #1 Rank stocks here.
Over the past 60 days, estimates for Neurocrine Biosciences’ 2026 earnings per share have risen from $9.15 to $9.48. Over the same period, EPS estimates for 2027 have increased from $10.23 to $10.79. NBIX shares have gained 21.3% year to date.
Neurocrine Biosciences’ earnings beat estimates in three of the trailing four quarters and missed in the remaining one, the average surprise being 9.08%.
Over the past 60 days, loss-per-share estimates for Amarin Corporation have narrowed from $15.20 to 65 cents for 2026. Over the same period, estimates for loss per share have also narrowed from $13.00 to 51 cents for 2027. AMRN shares have risen 3% year to date.
Amarin Corporation’s earnings beat estimates in three of the trailing four quarters and missed in the remaining one, the average surprise being 50.02%.
Over the past 60 days, estimates for Liquidia’s 2026 earnings per share have increased to $3.02 from $2.97. Over the same period, EPS estimates for 2027 have risen to $4.92 from $4.81. LQDA shares have gained 121.8% year to date.
Liquidia’s earnings beat estimates in three of the trailing four quarters and missed in the remaining one, with the average surprise being 54.40%.
