GlaxoSmithKline (GSK) has agreed to acquire Affinivax, a Cambridge, Massachusetts-based bio/pharmaceutical company developing vaccines, in a $3.3-billion deal ($2.1 billion upfront and up to $1.2 billion in potential development milestones).

Affinivax’s most advanced vaccines are pneumococcal vaccines for which it applies its proprietary vaccine technology platform, Multiple Antigen Presenting System (MAPS). MAPS supports higher valency than conventional conjugation technologies to enable broader coverage against prevalent pneumococcal serotypes and potentially creating higher immunogenicity than current vaccines. Pneumococcal disease includes pneumonia, meningitis, bloodstream infections, and milder diseases such as sinusitis and otitis media. There are many different pneumococcal serotypes. The number of serotypes in current vaccines is limited due to the degree of immunological interference observed when using existing conjugation technologies, according to information from the companies.

Affinivax’s most advanced vaccine candidate, AFX3772, is in Phase II development and includes 24 pneumococcal polysaccharides plus two conserved pneumococcal proteins (compared to up to 20 serotypes in currently approved vaccines). The US Food and Drug Administration (FDA) granted breakthrough therapy designation for AFX3772 to prevent Streptococcus pneumoniae invasive disease and pneumonia in adults 50 years old and above. Phase III trials are expected to start in the short term (as reported on May 31, 2022). Phase I/II clinical trials for pediatric use are planned to begin later this year (2022). A 30-plus valent pneumococcal vaccine candidate is also in preclinical development.

Under the agreement, GSK will acquire 100% of the outstanding shares of Affinivax for an upfront payment of $2.1 billion to be paid upon closing and two potential milestone payments of $600 million to be paid upon the achievement of certain pediatric clinical development milestones. The transaction is subject to customary closing conditions, including the expiration or early termination of the waiting period under the Hart-Scott- Rodino Anti-Trust Improvements Act of 1976. The transaction is expected to close in the third quarter of 2022.

Source: GlaxoSmithKline and Affinivax