Rifabutin

Ad hoc announcement pursuant to Art. 53 LR BASEL, Switzerland, March 18, 2026 (GLOBE NEWSWIRE) -- Significant clinical and regulatory progress across entire pipeline BV100: Initiated global registrational Phase 3 (RIV-TARGET) in HABP/VABP 1 program – US FDA green lights IND Phase 2b (RIV-CARE) to be conducted via Wellcome-funded trial network ADVANCE-ID First participants dosed in Phase 1 in China, preparing onboarding of China into RIV-TARGET BV100 patent granted in China, adding to BV100’s patent coverage in over 25 countries including the US and Europe Alpibectir: Our partner GSK reported first patient first visit for Phase 2b/c trial in pulmonary TB Phase 2a results published in New England Journal of Medicine Received EMA Orphan Designation Corporate: BV500: Entered global research collaboration with Shionogi for broad-spectrum non-tuberculous mycobacteria Successful IPO funding operations into 2028 with BV100 Phase 3 read-out by the end of 2027 Conference call on March 18, 2026 at 2.00 pm CET (9.00 am EST) 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 its audited financial results and corporate highlights for the full year 2025, as well as the publication of its 2025 Annual Report. Dr. Marc Gitzinger, Chief Executive Officer of BioVersys: “Our successful IPO in early 2025 provided us with the funding to progress our entire pipeline of novel antibacterial drugs, including our two lead assets BV100 and alpibectir. 2025 has been a year of substantial clinical and regulatory progress. We initiated a global Phase 3 program for BV100 in HABP/VABP 1 caused by carbapenem resistant Acinetobacter baumanni (CRAB), and entered into strategic partnerships with Shionogi for BV500 in non-tuberculous mycobacteria (NTM) infection, and with the ADVANCE-ID clinical trial network for the BV100 Phase 2b (RIV-CARE) study. These agreements validate our rich pipeline and extend our cash runway well beyond the BV100 Phase 3 read-out. In 2025, we also saw significant progress in policy change and reimbursement reforms for novel antibiotics, particularly in Europe, and we believe that BioVersys is ideally positioned to benefit from these long-awaited changes. 2026 has started very strongly with the publication of pre-clinical and clinical data on BV100 and alpibectir in prestigious journals, as well as the US FDA’s acceptance of the BV100 Phase 3 IND. As we continue to advance our pipeline, I would like to thank our shareholders, stakeholders and colleagues for supporting us in developing the next generation antibiotics.” Pipeline Highlights BV100: In 2025, the company’s lead candidate BV100 initiated its planned global Phase 3 registrational trial ( RIV-TARGET ) in HABP/VABP caused by carbapenem resistant Acinetobacter baumannii (CRAB) and received US FDA green light for its IND. The study aims to enroll approximately 300 HABP/VABP patients with suspected or confirmed CRAB infections. Patients will be randomized 1:1 to receive either [1] BV100 combined with low dose polymyxin B or [2] Colistin combined with high-dose ampicillin-sulbactam, with both arms allowing meropenem as background in case of polymicrobial infections. The primary efficacy endpoint is defined as 28-day all-cause mortality (ACM) in the CRABC microbiological modified intention-to-treat (CRABC m-MITT) population. Secondary efficacy endpoints will include clinical cure status at the test of cure (ToC) in CRABC m-MITT, ventilator free days, time spent in intensive care unit (ICU) and time in hospital. As part of the study protocol, data safety monitoring boards (DSMB) 2 will be convened at regular intervals to review trial progress. In parallel to the Phase 3 pivotal trial, an open-label Phase 2b differentiation trial ( RIV-CARE ) will be initiated in H1 2026, comparing BV100 with BAT in multiple geographies. The Phase 2b trial aims to provide real world evidence of clinical practices in settings with very high drug resistance levels. Interim analysis is planned for end of 2026. In November 2025, BioVersys announced that the ADVANCE-ID clinical trial network will support and collaborate with BioVersys in conducting the Phase 2b study. This support has been made possible thanks to the generous contribution of Wellcome who strengthened the ADVANCE-ID network with SGD 22 million (c. USD 17m or CHF 14m). A Phase 1 safety study in China was also initiated in 2025 prior to enrolling Chinese patients in the global Phase 3 study program in H2 2026. The Chinese Patent Office granted crucial IP protection to BV100, adding to BV100’s patent coverage in over 25 countries including the US, Europe and the UK. Alpibectir: In March 2025, BioVersys announced first patient first visit (FPFV) in part 1 of the alpibectir-ethionamide (AlpE) Phase 2 clinical trial in pulmonary tuberculosis (TB) in combination with 1 st line tuberculosis drugs. This part 1 of the study delivered top line data showed that alpibectir is generally safe and well tolerated warranting progression into part 2 of the study. Part 2 of the study is a Phase 2b in which AlpE is given for 2 months in combination with first-line TB drugs, followed by 18 weeks of Rifampicin and Isoniazid treatment. FPFV for the Phase 2b was reported in March 2026. Alongside the development in pulmonary TB, BioVersys has also submitted a Phase 2 trial for AlpE in meningeal TB to regulatory authorities. FPFV is expected in H1 2026. In August 2025, BioVersys received European Medicine Agency Orphan Designation for alpibectir combined with ethionamide for the treatment of tuberculosis. This Designation provides key incentives, including reduced fees, research and clinical protocol support, and 10-year EU market exclusivity, and follows alpibectir ethionamide receiving US FDA Orphan Drug Designation in 2023. Alpibectir is being developed in strategic partnership with GSK, who leads clinical development in Tuberculosis Pneumonia while BioVersys leads development in Tuberculosis Meningitis. Both partners share equal economics. BV500: In July 2025, BioVersys entered a global research collaboration with Shionogi for its broad-spectrum non-tuberculous mycobacteria (NTM) program BV500. The collaboration provides a research and exclusive license option agreement with Shionogi to jointly develop novel ansamycin leads from BioVersys’ BV500 program into clinical candidates. Under the terms of the agreement, BioVersys is eligible to receive upfront and near-term research payments of CHF 5.0 million and, upon exercise of the license option, regulatory and sales milestones of up to CHF 479 million as well as royalties on future sales. 2025 Financial Highlights For the year ended 31 December 2025, BioVersys recognized revenues of CHF 0.8 million (2024: nil) related to the Research Collaboration Agreement entered with Shionogi in July 2025 as well as CHF 2.5 million in other operating income made of research tax credits, grants and subsidies (2024: CHF 1.2 million) leading to a total operating income of CHF 3.3 million (2024: CHF 1.2 million). As a result of BioVersys pipeline progressing through the stages of development, operating expenses were CHF 23.2 million in 2025 compared to CHF 19.9 million in 2024 and leading to an operating loss of CHF 20 million (2024: CHF 18.7m) for the financial year 2025. Operating expenses in 2025 included CHF 16.5 million in R&D expenses, representing approximately 71% of operating expenses for the year (2024: 64.9%). The net loss in 2025 amounted to CHF 21.8 million (2024: Net loss of CHF 18.7 million). The net cash used in operating activities in 2025 was CHF 22.0 million (2024: CHF 16.1 million). The company raised approximately CHF 76.7 million as part of its February 2025 Initial Public Offering. The cash and cash equivalents position increased to CHF 82.5 million as of December 31, 2025 (December 31, 2024: CHF 26.6 million). Total shareholders’ equity stood at CHF 59.8 million as of December 31, 2025 (December 31, 2024: CHF 10.7 million). As of December 31, 2025, the company employed 33 FTE (full-time equivalents) (end 2024: 27). About 75% of the employees are employed in R&D-related functions. Key Figures as of December 31, 2025 CHF million FY 2025 FY 2024 Change Operating income 3.3 1.2 2.1 R&D expenses (16.5) (12.9) (3.6) G&A expenses (6.7) (7.0) 0.3 Operating loss (20.0) (18.7) (1.3) Net loss (21.8) (18.7) (3.1) Basic net loss per share (in CHF) (3.89) (5.62) 1.73 Net cash used in operating activities (22.0 ) (16.1 ) (5.9 ) Cash & cash equivalents 82.5 26.6 55.9 Total shareholders’ equity 59.8 10.7 49.1 Number of registered shares 5,848,011 3,692,285 2,155,726 Number of FTE 33 27 6 Initial Public Offering in Q1 2025 On the back of the promising advancement of the company’s pipeline and the related positive clinical data generated, BioVersys successfully completed its IPO on the SIX Swiss Exchange on February 7, 2025. Hernan Levett, CFO of BioVersys, comments: “In February 2025, we successfully completed an IPO on the Swiss Stock Exchange, which added proceeds of CHF 76.7 million, providing the necessary capital to advance our pipeline through key development milestones. Later in the year, we entered into a research collaboration agreement with Shionogi and added the partnership with ADVANCE-ID financially supported by Wellcome. These partnerships further strengthen our financial position and are of strategic importance to our pipeline. The accomplishments of 2025 are a testament to the robust clinical data and the strong team at BioVersys demonstrating potential to bring game-changing anti-infectives to market.” Outlook Following the initiation of the BV100 global Phase 3 registrational study in 2025, BioVersys plans to initiate the recruitment of patients based on regulatory green lights (e.g. US FDA IND) and the completion of the ongoing Phase 1 study in China, respectively. The study remains on track to report top-line data by the end of 2027, with DSMB reviews planned in H2 2026 and H1 2027. The Phase 2b for BV100 being conducted by the ADVANCE-ID network is expected to initiate recruiting patients in H1 2026 with a planned interim analysis expected to take place by end of this year. For alpibectir, BioVersys’ partner GSK is pursuing the Phase 2 program in pulmonary TB, expecting last patient last visit by end of 2026, while BioVersys is on track to initiate the Phase 2 in meningeal TB in H1 2026. For BV200 and BV500, BioVersys expects to generate additional pre-clinical data in the course of 2026. In addition, the BioVersys team will continue to engage with industry alliances and will be working with global regulatory and political leaders towards a sustainable policy framework ensuring adequate reimbursement and access mechanisms for novel antibiotics. Financial Outlook 2026 For the full year 2026, the company expects total operating loss to be in the range of CHF 40.0 to CHF 45.0 million. Full Year 2025 Documents This press release, the Annual Report 2025 as well as the webcast presentation are available under the investors section of . Full Year 2025 Conference Call & Audio Webcast BioVersys will host a conference call and webcast at 2.00 pm CET (9.00 am EST) to discuss the financial results, provide an update on the company’s performance, outline its strategic outlook, and share insights into BioVersys' therapeutic pipeline. Event details for Investors, Media and Interested Parties: Conference Call Registration: Link (Participants will receive dial-in details upon registration) Financial calendar April 30, 2026 Annual General Meeting September 3, 2026 Half-year Statement 2026 The scheduled events for BioVersys are also available on the investor section of the company’s website. About BioVersys BioVersys AG is a multi-asset, clinical stage biopharmaceutical company focused on identifying, developing and commercializing novel antibacterial products for serious life-threatening infections caused by multi-drug resistant (“MDR”) bacteria. Derived from the company’s two internal technology platforms (TRIC and Ansamycin Chemistry), candidates are designed and developed to overcome resistance mechanisms, block virulence production and directly affect the pathogenesis of harmful bacteria towards the identification of new treatment options in the antimicrobial and microbiome fields. This enables BioVersys to address the high unmet medical need for new treatments against life-threatening resistant bacterial infections and bacteria-exacerbated chronic inflammatory microbiome disorders. The company’s most advanced research and development programs address nosocomial infections of Acinetobacter baumannii (BV100, Phase 3), and tuberculosis (alpibectir, Phase 2, in collaboration with GlaxoSmithKline (GSK) and a consortium of the University of Lille, France). BioVersys is located in the biotech hub of Basel, Switzerland. BioVersys contact Hernan Levett , CFO, Tel. +41 61 633 22 50; Mail: hernan.levett@bioversys.com For media: media@bioversys.com Website: Disclaimer This communication expressly or implicitly contains certain forward-looking statements, such as "believe", "assume", "expect", "forecast", "project", "may", "could", "might", "will" or similar expressions concerning BioVersys and its business, including with respect to the progress, timing and completion of research, development and clinical studies for product candidates. Such statements involve certain known and unknown risks, uncertainties and other factors, which could cause the actual results, financial condition, performance or achievements of BioVersys to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. BioVersys is providing this communication as of this date and does not undertake to update any forward-looking statements contained herein as a result of new information, future events or otherwise. __________________________________ 1 HABP: Hospital-Acquired Bacterial Pneumonia; VABP: Ventilator-Associated Bacterial Pneumonia. 2 The DSMB review is the periodic evaluation of unblinded or partially unblinded clinical trial data by an independent committee of experts to determine whether the study should continue, be modified, or be stopped based on safety, efficacy, or futility considerations.

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) or ventilator-associated bacterial pneumonia (VABP), caused by carbapenem-resistant Acinetobacter baumannii (CRAB). US FDA confirms that the BV100 global pivotal Phase 3 HABP/VABP trial may proceed, based on the initial IND submission. BV100 global pivotal Phase 3 is on track to read-out by the end of 2027. BASEL, Switzerland, March 16, 2026 (GLOBE NEWSWIRE) -- 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 that the US Food and Drug Administration (US FDA) has confirmed that the global Phase 3 pivotal trial to recruit US patients into the RIV-TARGET clinical trial (NCT07326540) can proceed. The Phase 3 trial will recruit patients with hospital-acquired or ventilator-associated bacterial pneumonia (HABP or VABP), due to carbapenem-resistant Acinetobacter baumannii-calcoaceticus Complex (CRABC). CRABC is a highly-drug resistant Gram-negative pathogen that is recognized as a critical priority by global health authorities. BV100 is a novel intravenous formulation of rifabutin based on the newly identified mode of action for the active uptake of rifabutin into the Acinetobacter baumannii-calcoaceticus complex. BV100 is being developed for MDR hospital infections caused by Acinetobacter baumannii, including carbapenem-resistant Acinetobacter baumannii (CRAB) strains. BV100 has Qualified Infectious Disease Product (QIDP) Designation from the U.S. FDA, making BV100 eligible for priority FDA review, Fast Track designation, and a five-year extension of market exclusivity. Dr. Glenn E Dale, Chief Development Officer: “This is a significant step towards our goal of completing the BV100 global Phase 3 trial by the end of 2027. HABP and VABP infections remain a leading cause of infectious disease hospital mortality and represent a substantial burden on healthcare systems. Our teams have already gathered interest from US-based clinical sites to participate in the trial, and this successful IND application will allow us to activate the clinical sites prior to enrolling US patients in the coming months.” Dr. Marc Gitzinger, Chief Executive Officer of BioVersys: “ We are excited about this regulatory development. Enrolling US patients into the trial is an important contribution towards the global nature of the study. This follows closely behind our announcement in December 2025 that we had initiated the BV100 global Phase 3 trial. I am incredibly proud of our team’s multi-pronged efforts in ensuring that this trial can proceed simultaneously in all the key regions of the world. We will bring this much-needed treatment option to patients in dire need.” Phase 3 trial design The global Phase 3 trial, is a randomized, active-controlled two-part parallel-group trial to evaluate the efficacy and safety of BV100 plus low-dose polymyxin B in patients with HABP or VABP suspected or confirmed to be due to CRABC infection ( RIV-TARGET ). Part A is the pivotal, randomized, comparative portion of the trial, employing a partially blinded design aiming to enroll approximately 300 HABP/VABP patients with suspected or confirmed CRABC infections. Patients will be randomized 1:1 to receive either [1] BV100 combined with low dose polymyxin B or [2] colistin combined with high-dose ampicillin-sulbactam, with both arms allowing meropenem as background in case of polymicrobial infections. The primary efficacy endpoint is defined as 28-day all-cause mortality (ACM) in the CRABC microbiological modified intention-to-treat (CRABC m-MITT) population. Secondary efficacy endpoints will include clinical cure status at the test of cure (ToC) in CRABC m-MITT, ventilator free days, time spent in intensive care unit (ICU) and time in hospital. As part of the study protocol, data safety monitoring boards (DSMB) 1 will be convened at regular intervals to review trial progress. The Phase 3 trial also includes an open-label, non-randomized, additional single group (Part B) to evaluate the efficacy and safety of BV100 plus low-dose polymyxin B in patients with HABP or VABP due to CRABC known to be resistant to colistin or polymyxin B prior to study entry and patients where colistin or polymyxin B regimen has failed prior to study entry. Approximately 25 patients are expected to be enrolled in Part B. This pivotal Phase 3 trial follows the successful completion of a Phase 2 trial in documented Acinetobacter VABP patients. BV100 combined with polymyxin B demonstrated a clear survival benefit, resulting in a 50% relative reduction in 28-day ACM compared with best available therapy (BAT), in VABP patients suffering from confirmed CRAB infections (28-day ACM: 60% for BAT vs 25% for BV100), and was generally safe and well tolerated. The current Phase 3 trial mimics the successful study design of the positive Phase 2 trial and is expected to read-out towards the end of 2027. Subsequent regulatory submissions aimed at commercial approval are planned in 2028, initially for the US, Europe and China. In parallel to the Phase 3 pivotal trial an open-label Phase 2b differentiation trial ( RIV-CARE ) will be initiated in H1 2026 comparing BV100 with BAT in multiple geographies. The Phase 2b trial aims to provide real world evidence of clinical practices in settings with very high drug resistance levels. Interim analysis is planned for end of 2026. About BV100 BV100 is a novel formulation of rifabutin suitable for intravenous administration, with a recently discovered novel mode of action showing an active uptake of rifabutin into the Gram-negative bacterial species, Acinetobacter baumannii . For the first time, BV100 allows for the targeting of the RNA-polymerase enzyme in Gram-negative bacteria with a human-suitable dose. BV100 is being developed for the treatment of infections caused by Acinetobacter baumannii calcoaceticus complex (ABC), including carbapenem-resistant ABC (CRABC) in critically important indications of ventilator associated bacterial pneumonia (VABP), hospital-acquired bacterial pneumonia (HABP) and bloodstream infections (BSI). BV100 was granted QIDP Designation by the U.S. FDA in May 2019 for use in the treatment of VABP, HABP and BSI, making BV100 eligible for priority FDA review, Fast Track designation, and a five-year extension of market exclusivity upon approval of the first QIDP indication. About Acinetobacter baumannii Acinetobacter baumannii calcoaceticus complex (ABC) are Gram-negative bacteria found in the environment (e.g., in soil and water) and an opportunistic pathogen in humans, typically infecting critically ill and immunocompromised patients, that can result in severe pneumonia and bloodstream infections in addition to affecting other parts of the body. ABC is considered a significant worldwide threat in the healthcare setting given its ability to survive for prolonged periods on surfaces, combined with its ability to develop or acquire resistance to standard of care antibiotics, e.g. carbapenems. Carbapenem-resistance as well as multi-drug resistance (MDR) rates for ABC are among the highest recorded for any bacteria in current times (The Lancet 2022; 399: 629–55). Incidence and resistance rates for ABC are trending upwards and COVID-19 has exacerbated this significantly. BioVersys forecasts the annual number of carbapenem-resistant A. baumannii infections in hospitals to have surpassed one million globally and due to the limited treatment options, such infections come with high (up to 50%) mortality rates. About BioVersys BioVersys AG is a multi-asset, clinical stage biopharmaceutical company focused on identifying, developing and commercializing novel antibacterial products for serious life-threatening infections caused by multi-drug resistant (“MDR”) bacteria. Derived from the company’s two internal technology platforms (TRIC and Ansamycin Chemistry), candidates are designed and developed to overcome resistance mechanisms, block virulence production and directly affect the pathogenesis of harmful bacteria towards the identification of new treatment options in the antimicrobial and microbiome fields. This enables BioVersys to address the high unmet medical need for new treatments against life-threatening resistant bacterial infections and bacteria-exacerbated chronic inflammatory microbiome disorders. The company’s most advanced research and development programs address nosocomial infections of Acinetobacter baumannii (BV100, Phase 3), and tuberculosis (alpibectir, Phase 2, in collaboration with GlaxoSmithKline (GSK) and a consortium of the University of Lille, France). BioVersys is located in the biotech hub of Basel, Switzerland. BioVersys contact Hernan Levett , CFO, Tel. +41 61 633 22 50; Mail: hernan.levett@bioversys.com For media: media@bioversys.com Website: X: LinkedIn: Disclaimer This communication expressly or implicitly contains certain forward-looking statements, such as "believe", "assume", "expect", "forecast", "project", "may", "could", "might", "will" or similar expressions concerning BioVersys and its business, including with respect to the progress, timing and completion of research, development and clinical studies for product candidates. Such statements involve certain known and unknown risks, uncertainties and other factors, which could cause the actual results, financial condition, performance or achievements of BioVersys to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. BioVersys is providing this communication as of this date and does not undertake to update any forward-looking statements contained herein as a result of new information, future events or otherwise. ___________________________________ 1 The DSMB review is the periodic evaluation of unblinded or partially unblinded clinical trial data by an independent committee of experts to determine whether the study should continue, be modified, or be stopped based on safety, efficacy, or futility considerations.