BIOPHYTIS DISCLOSURECurrent Reports (8-K / ad hoc)

Biophytis to evaluate BIO101’s potential to limit weight regain in its OBA clinical study in obesity

Press release Page 1 sur 2 Biophytis to evaluate BIO101’s potential to limit weight regain in its OBA clinical study in obesity • Regulatory protocol amendment filed in Brazil, with submissions planned in the United States and Europe • “Rebound effect”: expansion of the scope of BIO101 evaluation following semaglutide discontinuation • A new follow-up phase to assess weight regain and the role of BIO101 Paris (France) and Cambridge (Massachusetts, U.S.), September 9, 2026, at 07:00am CET – Biophytis SA (Euronext Growth Paris: ALBPS), (“Biophytis” or the “Company”), a pioneering company in the development of transformative therapies impacting longevity, today announces that it has submitted to the Brazilian Health Regulatory Agency (ANVISA) an amendment to the protocol of the phase 2 OBA clinical study in obesity. This protocol amendment includes the evaluation of BIO101's potential to limit weight regain, or "rebound effect," observed after discontinuation of treatment with semaglutide, a GLP-1 receptor agonist. Submission of the same amendment to the U.S. Food and Drug Administration (FDA) is expected in the coming days. This new evaluation complements the initial objective of the OBA study, which is to measure the effect of BIO101 on muscle function and mobility in obese or overweight patients treated with a GLP-1 agonist. In particular, the study aims to determine whether BIO101 can preserve lower-limb muscle strength during semaglutide-induced weight loss. A new dimension in the evaluation of BIO101 The amended protocol provides for the evaluation of the rebound effect under BIO101 following discontinuation of the 21-week semaglutide treatment. While GLP-1 receptor agonist–based treatments enable significant weight loss, their discontinuation may be followed by weight regain. The addition of an evaluation period therefore addresses an important clinical issue for patients treated with semaglutide. The follow-up period added to the OBA study protocol, which follows semaglutide treatment, extends over 12 weeks: it will make it possible to characterize any weight regain and to explore the role of BIO101 in maintaining the benefits achieved during the semaglutide treatment phase. Preventing or reducing this rebound effect represents a new therapeutic opportunity for BIO101, complementing its potential in p