• Mitazalimab momentum: Final OPTIMIZE‑1 outcomes were presented at ASCO GI 2026, with additional investigator‑initiated data accepted for AACR 2026.
• External portfolio progress: The first patient was dosed in Henlius’ Phase 2/3 study of HLX22 in recurrent breast cancer.
• Capital structure update: The TO 14 warrant program was completed in line with previously communicated terms, with gross proceeds of approx. 19 MSEK.

Lund, Sweden – Alligator Bioscience (Nasdaq Stockholm: ATORX), a clinical-stage biotechnology company developing tumor-directed immuno-oncology antibody drugs, today announced its interim results for the first quarter of 2026 and provided a business update.

"During the first quarter of 2026, we continued to execute against our strategic priorities in a challenging biotech environment. We strengthened the clinical and translational foundation of mitazalimab through new data presentations, while maintaining clear focus on advancing the program toward late‑stage development under disciplined strategic and financial conditions. In parallel, HLX22 progress in our external portfolio, supports additional long‑term value potential without development cost exposure for Alligator."
Søren Bregenholt, CEO of Alligator Bioscience

BUSINESS UPDATE
Mitazalimab

• Additional data dissemination: Updated and final outcomes data from the OPTIMIZE 1 study were presented at the ASCO Gastrointestinal Cancers Symposium 2026, further strengthening the clinical and translational foundation of the program.
• Continued scientific visibility: New data from an investigator initiated trial evaluating mitazalimab were accepted for presentation at the AACR Annual Meeting 2026, providing additional insight into the antibody’s mechanism of action and tumor directed immune activation.

Technology

• Strengthened intellectual property position: Alligator strengthened the intellectual property protection for its bispecific antibody technology RUBY™, reinforcing the scientific and commercial foundation for future pipeline development and partnering opportunities.

HLX22

• Progress in partnered development: The first patient was dosed in Henlius’ Phase 2/3 study of HLX22 in recurrent breast cancer, marking an additional step in the late stage development of the program.

Company / Financial position

• Capital structure updates following the rights issue: Alligator announced the outcome of the exercise of warrants of series TO 14, resulting in gross proceeds of approximately 19 MSEK and changes in the number of shares and votes, as well as related directed issues to guarantors and Fenja Capital, in accordance with previously communicated terms. Alligator’s management further announced their intention to subscribe pro rata in the TO 14 warrant program, aligning management interests with those of shareholders.
• Nomination Committee proposal ahead of the AGM: The Nomination Committee presented its proposal for the Board of Directors ahead of the Annual General Meeting, including the nomination of two new Board members.

FINANCIAL SUMMARY FOR Q1 2026
The financial summaries for the quarterly periods ending 31 March 2026 and 31 March 2025 are presented below.

The full report is attached as a PDF, and is also available on the company’s website: https://alligatorbioscience.se/en/investors/financial-reports/

Alligator will host a webinar on Tuesday, 5 May 2026, at 1 p.m. CEST/ 7 a.m. EDT for investors, analysts and media, where CEO Søren Bregenholt and CFO Johan Giléus will present and comment on the interim report, which will be followed by a Q&A session.

The call will be held in English. Attendees need to register by following >>this link<<.