This is a guest post, kindly authored by Giulia Balconi of Adjuvant Capital.
Earlier this month, Valneva (NASDAQ: VALN) and LimmaTech Biologics announced a strategic partnership to accelerate the development of a quadrivalent vaccine against Shigella, known as Shigella4V (S4V). Under this collaboration, LimmaTech will complete a Phase II Controlled Human Infection Model and a Phase II pediatric study in low- and middle-income countries, while Valneva will take over future clinical development, as well as CMC, regulatory approval, and commercialization. Thanks to this collaboration, S4V is poised to enter Phase III studies later in 2027.
Shigella is the second-leading cause of diarrheal mortality globally, with an estimated 80-165 million cases and up to 600,000 fatalities every year. Despite the high incidence, there is currently no approved vaccine widely available for Shigella, and current treatment remains symptomatic and mainly relies on oral replacement of fluids and salts, as well as administration of antibiotics. Over the past few years, an increase in antibiotic resistant infections has raised the attention of the global health community. Shigella was identified by the World Health Organization as one of the top priority pathogens for the development of a new vaccine and was also included in the most recent Gavi Vaccine Investment Strategy.
With a vaccine for Shigella potentially on the horizon, a step back in time might help illuminate how this vaccine—once considered a long-shot—has advanced to late-stage development. In 2015, GSK acquired GlycoVaxyn, a Swiss biotech focused on bioconjugation technology with a promising vaccine candidate targeting Shigella, which generated positive Phase I data in 2010. Following the acquisition, GlycoVaxyn’s operational research business spun-out into LimmaTech Biologics, a new entity designed to collaborate with GSK on future bacterial vaccine development.
In partnership with GSK, and with support from the Wellcome Trust, LimmaTech continued development, refining a 4-valent construct (S4V) targeting the most prevalent serotypes, which entered a Phase I/II clinical trial in Kenya in 2019, and secured non-dilutive funding from the Bill & Melinda Gates Foundation in December 2022.
With the Phase I/II study in Kenya ongoing, LimmaTech announced an in-licensing agreement with GSK last year to further develop and commercialize S4V for the target pediatric population as well as for travelers and military personnel in endemic regions. Shortly thereafter, LimmaTech closed a Series A financing led by renowned global health impact funds to support S4V development in addition to the company’s earlier stage pipeline, which aims to address the growing threat of antimicrobial resistance. In a matter of just over a year, a flurry of dealmaking has brought S4V into the spotlight.
Although there is much work left to do, the story of S4V reflects the difficulties and opportunities in developing vaccines for global health. Consequently, the recent activity surrounding the program highlights the need for closer collaboration among big pharma, biotech, global health funders, and institutional investors to ultimately drive the development of much needed vaccines for diseases that disproportionately burden low- and middle-income countries. Almost 15 years after the initial Phase I study, there appears to be a path forward for a Shigella vaccine that could have a tremendous global impact and bring hope for millions of patients in underserved markets.
Giulia Balconi, M.P.H., supports research efforts at Adjuvant Capital, an impact investment firm supporting life sciences technology companies focused on historically neglected diseases and maternal/child health. Note, Adjuvant Capital has provided funding to LimmaTech Biologics.
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