Biopharma deal value reached $79.22 billion in the first quarter (Q1) 2026, marking a strong start to the year and an increase of about 17% from $67.6 billion in Q1 2025 and similar to $78.93 billion in Q4 2025. The total is the highest first-quarter tally in recent years, and the highest quarter since Q4 2025 brought $80.65 billion.
Biopharma deal value reached $79.22 billion in the first quarter (Q1) 2026, marking a strong start to the year and an increase of about 17% from $67.6 billion in Q1 2025 and similar to $78.93 billion in Q4 2025. The total is the highest first-quarter tally in recent years, and the highest quarter since Q4 2025 brought $80.65 billion.
Infectious disease-focused biopharma companies continued their rebound into year-end, with the BioWorld Infectious Disease Index finishing 2025 up 68.55% after standing at a collective 28.98% at the end of October. The rally underscores a sharp reversal from earlier in the year, when the index had declined 17.83% by the end of April before recovering to a 4.34% gain by July.
Biopharma dealmaking continued its momentum into 2026, with January logging $31.16 billion in total value. That figure outpaced January 2025’s $28.63 billion and exceeded the 2025 monthly average of $24.38 billion. In addition, January 2026 ranks as the highest first month in the past eight years.
Biopharma companies focused on infectious disease extended their stock recoveries through the third quarter (Q3), with the BioWorld Infectious Disease Index closing October up 28.98%. The gain marks a strong turnaround from earlier in the year, when the index had fallen 17.83% by the end of April before rebounding to a 4.34% gain by July’s close.
Merck & Co. Inc. is buying Cidara Therapeutics Inc. for $9.2 billion to acquire a late-stage flu candidate and also to outrace blockbuster Keytruda’s looming patent expiration. CD-388, Cidara’s lead candidate, is in a phase III study of adolescents and adults for preventing influenza A and B in those who are at a high risk of developing complications.
Infectious disease biopharma stocks bounced back in June and July, with the BioWorld Infectious Disease Index (BIDI) closing July up 4.34%. This marked a sharp reversal from earlier in the year, as the BIDI had dropped 17.83% by the end of April and 21.04% by the end of May.
Cidara Therapeutics Inc. will meet with the FDA to discuss strongly favorable phase IIb results from its randomized, double-blind, placebo-controlled phase IIb Navigate trial testing CD-388 for the prevention of seasonal influenza in healthy, unvaccinated adults aged 18-64. Meanwhile, shares of the San Diego-based firm (NASDAQ:CDTX) closed June 23 at $44.95, up $23.93, or 113.8%, as Wall Street learned that the study met its primary endpoint, turning up a statistically significant prevention efficacy for each of three dose groups in people given a single shot at the beginning of the flu season.
The ability of influenza virus to rapidly undergo antigenic shift to evade immunity raises the need for effective influenza antivirals with a broad spectrum. In a recent Nature Microbiology article, Cidara Therapeutics Inc. provided preclinical data for their drug-Fc conjugate compound CD-388, which has the potential to be a robust therapeutic option for the universal prevention of both seasonal and pandemic influenza.
The BioWorld Infectious Disease Index (BIDI) faced challenges throughout the year but narrowed its losses, ending down 6.28% after hitting a low of -25.12% in late April. By October, the index was down 12.07% and had declined 8.86% for the year as of Nov. 22. However, in January, the BIDI rebounded slightly, gaining 1.85%.
