Full Year 2025 Results Call Corporate Update & Financial Results February 26, 2026 CONFIDENTIAL & PROPRIETARY Forward-looking statements This presentation contains forward-looking statements, including statements regarding, among other things, future results, performance or achievements, expectations regarding pipeline development, anticipated approval and commercialization of navenibart, pharmaceutical research and development, such as drug discovery, preclinical and clinical development activities and rel ...

Core Viewpoint - BioCryst Pharmaceuticals has agreed to acquire Astria Therapeutics for an implied value of $13 per share, totaling approximately $700 million in enterprise value, with the transaction expected to close in the first quarter of 2026 [1][2]. Acquisition Details - The acquisition will consist of $8.55 in cash and 0.59 shares of BioCryst stock for each share of Astria [1]. - Astria focuses on therapies for allergic and immunologic diseases, with its lead product candidate being Navenibart, an injectable monoclonal antibody for hereditary angioedema (HAE) prophylaxis [3][4]. Strategic Importance - Navenibart's clinical profile and administration schedule could significantly improve treatment options compared to existing therapies [3]. - BioCryst's established infrastructure in HAE is expected to enhance the market reach of Navenibart, which will complement its existing portfolio of oral and potential injectable therapies for HAE [4][5]. Market Potential - The addressable market for Navenibart includes over 5,000 patients currently treated with injectable prophylaxis, potentially driving double-digit revenue growth for BioCryst over the next decade [6]. - The transaction is anticipated to be accretive to adjusted operating profit in the first full year following Navenibart's expected launch [6]. Funding Mechanism - BioCryst has secured a debt commitment letter for a strategic financing facility with Blackstone, with a total capacity of up to $550 million to fund the acquisition [7][8]. - The cash portion of the acquisition will be financed through existing cash and a portion of the Blackstone facility [8]. Shareholder Impact - Following the acquisition, Astria stockholders will own approximately 15% of the pro forma equity in the combined company [8].

Navenibart (STAR-0215) for Hereditary Angioedema (HAE) - Navenibart is designed for a better patient experience with potential for Q3M and Q6M administration[9, 5] - The estimated HAE market is expected to grow from $3.2 billion in 2024 to $5.4 billion in 2030[14] - A global Phase 3 pivotal trial is ongoing to assess the efficacy and safety of Navenibart for Q3M and Q6M administration in HAE, with a 3:3:3:2 randomization (n=135)[17, 18] - ALPHA-STAR Phase 1b/2 results showed Navenibart achieved 91-95% attack rate reduction, 25-67% attack-free rate, 95-96% reduction in moderate and severe attack rate, and 91-94% reduction in attacks requiring rescue medication[29] - QSP model-predicted change in time-normalized monthly HAE attack rate shows 91-93% reduction with 600mg Q6M, 96-99% reduction with 600mg loading and 300mg Q3M, and 83-87% reduction with 600mg Q3M[41] - Market research indicates Navenibart Q3M & Q6M is expected to gain 46% total patient share from switches and 53% from newly initiating preventative therapies[50, 53] STAR-0310 for Atopic Dermatitis (AD) - The estimated moderate-to-severe AD market is expected to grow from $7 billion in 2023 to $26 billion in 2030[59] - STAR-0310 is a high affinity, next-generation anti-OX40 antibody with potential for low volume, infrequent SC delivery and a patent expiring in 2044[74, 75] - STAR-0310 has an estimated mean half-life of 26 days in cynomolgus monkeys, suggesting potential for administration as infrequently as once every 6 months in humans[87, 88] - A Phase 1a trial of STAR-0310 in healthy subjects has been initiated, with initial results expected in Q3 2025[91] Financial Position - As of March 31, 2025, the company had $295.1 million in cash, cash equivalents, and short-term investments[97] - The company expects its cash to fund operations into mid-2027[97]