Basilea announces start of first‑in‑human study of novel antibiotic BAL2420

Allschwil, Switzerland, March 23, 2026

Basilea Pharmaceutica Ltd, Allschwil (SIX: BSLN), a commercial-stage biopharmaceutical company committed to meeting the needs of patients with severe bacterial and fungal infections, announced today the dosing of the first healthy volunteer in the first-in-human phase 1 study of BAL2420, evaluating the safety, tolerability and pharmacokinetics of this lipopolysaccharide transport protein A (LptA) inhibitor.

BAL2420 belongs to a novel class of antibiotics. It targets LptA, which is part of the lipopolysaccharide transport bridge, an essential structure in Gram-negative bacteria. LptA inhibitors have shown potent and rapid bactericidal activity in vitro and in vivo against Gram-negative bacteria of the Enterobacteriaceae family, such as E. coli and K. pneumoniae, including strains resistant to beta-lactams and colistin, an antibiotic regarded as last-resort therapy.¹ The Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) have identified Enterobacteriaceae, including carbapenem-resistant strains, as high priority pathogens for which new and effective antibiotic treatments are urgently needed.^2,3

Dr. Marc Engelhardt, Chief Medical Officer of Basilea, said: “BAL2420 offers a novel mode of action to address serious Gram‑negative bacterial infections, which remain of particular concern because of intrinsic and acquired resistance. The first dosing in this study marks a key milestone for the program and reflects our confidence in the underlying science and its clinical potential.”

This single-center, randomized, dose-escalation, double-blind and placebo-controlled phase 1 study assesses intravenous administration of BAL2420 using a single‑ and multiple‑ascending dose study design. Data from this study will support the further clinical development of BAL2420 as a potential treatment option for serious infections caused by Gram‑negative bacteria, including multidrug-resistant bacteria.

CARB-X has supported the development of BAL2420 since 2020, advancing the project from the Hit-to-Lead stage to the first-in-human study. CARB-X’s funding for this project is provided by federal funds from the US Department of Health and Human Services; Administration for Strategic Preparedness and Response; Biomedical Advanced Research and Development Authority; under agreement number: 75A50122C00028, and by awards from Wellcome (WT224842) and Germany’s Federal Ministry of Research, Technology and Space (BMFTR). The content of this press release is solely the responsibility of the authors and does not necessarily represent the official views of CARB-X or any of its funders.

About Basilea

Basilea is a commercial-stage biopharmaceutical company founded in 2000 and headquartered in Switzerland. We are committed to discovering, developing and commercializing innovative drugs to meet the needs of patients with severe bacterial and fungal infections. We have successfully launched two hospital brands, Cresemba for the treatment of invasive fungal infections and Zevtera for the treatment of bacterial infections. In addition, we have preclinical and clinical anti-infective assets in our portfolio. Basilea is listed on the SIX Swiss Exchange (SIX: BSLN). Please visit basilea.com.

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 Basilea Pharmaceutica Ltd, Allschwil 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 Basilea Pharmaceutica Ltd, Allschwil to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. Basilea Pharmaceutica Ltd, Allschwil 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.

For further information, please contact:

Peer Nils Schröder, PhD Head of Corporate Communications & Investor Relations Basilea Pharmaceutica International Ltd, Allschwil Hegenheimermattweg 167b 4123 Allschwil Switzerland
Phone	+41 61 606 1102
E-mail	media_relations@basilea.com investor_relations@basilea.com

This press release can be downloaded from www.basilea.com.

References

1. M. Schuster, E. Brabet, K. K. Oi et al. Peptidomimetic antibiotics disrupt the lipopolysaccharide transport bridge of drug-resistant Enterobacteriaceae. Science Advances 2023 (9), eadg3683
2. https://www.who.int/news/item/27-02-2017-who-publishes-list-of-bacteria-for-which-new-antibiotics-are-urgently-needed (Accessed: March 22, 2026)
   (Accessed: March 22, 2026) 
   
3. https://www.who.int/news/item/13-10-2025-who-warns-of-widespread-resistance-to-common-antibiotics-worldwide
   (Accessed: March 22, 2026) 
   

Attachment

• Press release (PDF)