BioVersys announces first patient first visit in Phase 2b RIV-CARE trial of BV100

Ad hoc announcement pursuant to Art. 53 LR

• BV100 is a potential best-in-class anti-infective agent in treating hospital-acquired bacterial pneumonia (HABP), ventilator-associated bacterial pneumonia (VABP) and bloodstream infections (BSI) caused by carbapenem-resistant Acinetobacter baumannii-calcoaceticus complex (CRABC).
• RIV-CARE (NCT07431307), an open label Phase 2b clinical trial, aims to compare BV100 plus low-dose polymyxin B plus ceftazidime/avibactam, or plus cefiderocol to best-available-therapy (BAT) in multiple geographies with very high drug resistance levels.
• RIV-CARE complements the ongoing Phase 3 RIV-TARGET trial of BV100, and is expected to broaden evidence based treatment in clinical practices, ahead of potential commercialisation.
• RIV-CARE is conducted by ADVANCE-ID clinical trial network with funding support from Wellcome
• Interim read-out is expected in H1 2027.

BASEL, SWITZERLAND – EQS Newswire – 29 October 2026 – BioVersys AG (SIX: BIOV), a multi-asset, clinical stage biopharmaceutical company focusing on research and development of novel antibacterial products for serious life-threatening infections caused by multi-drug resistant (MDR) bacteria, announced today the first patient first visit in RIV-CARE, an open label Phase 2b differentiation trial of BV100.

RIV-CARE will enrol approximately 100 patients with suspected or confirmed hospital-acquired bacterial pneumonia (HABP), ventilator-associated bacterial pneumonia (VABP) and bloodstream infections (BSI) caused by carbapenem-resistant Acinetobacter baumannii-calcoaceticus complex (CRABC). RIV-CARE aims to compare BV100 plus low-dose polymyxin B in combination with different background antibiotics (ceftazidime/avibactam or Cefiderocol) versus best available therapy across multiple geographies, to provide real-world evidence of clinical practice in settings with very high levels of drug resistance.

Dr. Glenn E Dale, Chief Development Officer of BioVersys: “CRABC remains amongst the most difficult to treat bacterial pathogens in hospitalized patients, with mortality reaching up to 50% globally due to very limited treatment options. Our RIV-CARE study allows us to bring a promising and novel treatment option, BV100, to patients who need it most. Importantly, RIV-CARE allows us to generate evidence exactly in settings with the highest resistance and greatest need.”

Professor David Paterson, Director of ADVANCE-ID, said: “Half of people with serious CRAB infections will die. Doctors desperately need new antibiotic options for treating these infections so we can lower the death rate. We hope that the RIV-CARE trial will help determine if BV100 plus low-dose polymyxin B is a safe and effective option for these infections.”

The last patient enrolled is anticipated towards end of 2027. RIV-CARE is conducted by the ADVANCE-ID clinical trial network, thanks to the generous contribution of Wellcome with SGD 22 million (c. USD 17m or CHF 14m). The non-dilutive funding from Wellcome offsets approximately 2/3 of the trial cost.

Dr. Florian von Groote-Bidlingmaier, Head of Clinical Research, Infectious Disease at Wellcome, said: “Antimicrobial resistance remains an urgent global health threat, and accelerating the development of new antibiotics into clinical use is a high priority. Partnerships like the one for this trial, that bring together industry, academia, clinical expertise and philanthropy, are vital for accelerating antibiotic R&D. The enrolment of the first patient in RIV-CARE is an important milestone, and it is exciting a potential new treatment is being evaluated in settings and communities already bearing a high burden of drug resistance.”

In September 2026, BV100 was granted Fast Track Designation by the US FDA, under the Qualified Infectious Disease Product (QIDP) Designation received in 2019. These designations make BV100 eligible for priority FDA review, increased communication on clinical trial design and data requirements, and a five-year extension of market exclusivity in the US.

BV100 is currently being studied in two clinical trials: the pivotal Phase 3 global registration trial, RIV-TARGET, which announced first patient first visit in April 2026, and the open-label Phase 2b differentiation trial, RIV-CARE. First submissions for regulatory approval are anticipated by mid-2028.

Dr. Marc Gitzinger, Chief Executive Officer of BioVersys, said: “We are pleased to report first patient first visit in RIV-CARE, our Phase 2b differentiation trial which is now recruiting in parallel with our RIV-TARGET Phase 3 trial. Together, RIV-TARGET and RIV-CARE represent a focused dual-trial strategy intended to support both regulatory approval and future commercial uptake of BV100. RIV-Target will deliver the pivotal data for registration, while RIV-CARE is designed to help answer the questions physicians will ask at the bed side, providing evidence on how BV100 performs in comparison with best available therapies in multiple geographies. The interim analysis of RIV-CARE, anticipated for H1 2027, will provide an important early read-out.”

RIV-CARE Phase 2b study design

RIV-CARE aims to evaluate the safety and efficacy of BV100 in combination with low dose polymyxin B plus ceftazidime/avibactam or cefiderocol in patients with suspected or confirmed CRABC nosocomial pneumonia (VABP and HABP) and BSI of non-urinary tract origin. This is an open-label study, and therefore, no blinding will be done.

The study is divided into two parts (Part A and Part B), recruiting in parallel. Approximately 90 patients will be recruited in Part A, and approximately 10 subjects will be recruited in Part B, with enrolment ending once Part A enrolment is complete.

In Part A, patients will be randomized 1:1:1, to one of the three treatment groups until the CRABC m-MITT population includes 30 evaluable subjects per group:

• Group 1: 300 mg BV100 in combination with 500,000 IU (50 mg) polymyxin B infused over 2 hours every 12 hours (q12h), plus 2 g/0.5 g ceftazidime/avibactam, infused over 2 hours every 8 hours (q8h).
• Group 2: 300 mg BV100 in combination with 500,000 IU (50 mg) polymyxin B infused over 2 hours every 12 hours (q12h), plus 2 g cefiderocol infused over 3 hours every 8 hours (q8h).
• Group 3: Best Available Therapy, which is determined by the site for each individual patient according to local epidemiology and the patient’s antibiotic history.

Part B is a prospective multicentre, open label, non-randomized, additional single cohort to evaluate the PK, safety, and efficacy BV100 in combination with both low dose polymyxin B and cefiderocol in patients with CRABC ventriculitis or meningitis. After 14 days of treatment with BV100 and low dose polymyxin B, the BV100 therapy must be stopped, but patients may continue therapy with cefiderocol and best available additional therapy at the discretion of the investigator and as needed.

This study follows the successful completion of a Phase II study that showed that BV100 plus polymyxin B halved all-cause mortality compared with best available therapy, meaning 28-day mortality of 25% compared to 28-day mortality of 60% in best available therapy. In vitro, the combination of BV100 with low-dose polymyxin B and cefiderocol showed synergy and a reduction in the emergence of resistance, suggesting improved treatment outcomes in patients.