Pharma BD Deal Intelligence
GSK's $3.3B acquisition of Affinivax delivered a bust: the MAPS vaccine platform's lead pneumococcal candidate, AFX3772, was meant to challenge Pfizer's Prevnar franchise, but GSK discontinued the 24-valent adult program in October 2024 and pivoted to a preclinical successor still years from the clinic.
GSK acquired clinical-stage Affinivax for $2.1B cash upfront plus up to $1.2B in development milestones (up to ~$3.3B total), closing 23 Aug 2022, to obtain the Multiple Antigen Presenting System (MAPS) vaccine platform and lead candidate AFX3772, a 24-valent pneumococcal vaccine, as a challenge to Pfizer's Prevnar franchise. On its Q3 2024 update (30 Oct 2024) GSK discontinued the 24-valent adult program (AFX3772), citing increased competition, and pivoted to a preclinical 30-plus-valent MAPS successor targeted to enter the clinic in 2025; a 24-valent pediatric program continued in Phase 2. The platform bet on MAPS remains in development; the originally acquired lead asset has been superseded.
31K US cases/yr · $9.6B Global Market · 3,500 Annual US Deaths from IPD
Pneumococcal disease caused by Streptococcus pneumoniae ranges from non-invasive infections (otitis media, sinusitis) to invasive disease (bacteremia, meningitis, pneumonia). Despite existing vaccines, serotype replacement and incomplete coverage drive demand for higher-valency next-generation vaccines.
The pneumococcal vaccine market was dominated by Pfizer's Prevnar franchise (~$6.4B in 2022) and Merck's Vaxneuvance. GSK acquired Affinivax's MAPS platform to develop a higher-valency next-generation vaccine. In Oct 2024, after Vaxcyte reported Phase 1/2 data on its 31-valent candidate, GSK discontinued the acquired 24-valent adult asset (AFX3772) and shifted to a preclinical 30-plus-valent MAPS successor (clinic targeted 2025) to keep pace on serotype coverage.
GSK completed up to $3.3B acquisition of Affinivax, gaining MAPS vaccine technology platform and lead pneumococcal vaccine candidate AFX3772.
GSK discontinued the lead acquired asset AFX3772 (24-valent adult pneumococcal vaccine), removing it from the Phase 2 pipeline at the Q3 2024 update (30 Oct 2024) over increased competition; a 24-valent pediatric program continued in Phase 2.
MAPS platform is a long-term bet on next-gen vaccines. AFX3772 advancing but several years from approval. Strategic fit with GSK vaccine franchise is clear.
| Deal | Year | Value | Outcome |
|---|---|---|---|
| GSK plc / Affinivax Inc. (this deal) | 2022 | $3.3B | 48 |
| GSK plc / SmithKline Beecham | 2000 | $12.0B | 79 |
| GSK plc / Pfizer Inc. | 2018 | $0.0M | 77 |
| GSK plc / Novartis AG | 2014 | $16.0B | 76 |
| GSK plc / Hansoh Pharmaceutical Group Co. Ltd. | 2023 | $1.7B | 74 |
| GSK plc / Nuvalent, Inc. | 2026 | $10.6B | 70 |
| GSK plc / Sierra Oncology Inc. | 2022 | $1.9B | 70 |
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