Biopharmaceutical company GSK plc (LSE:GSK) (NYSE:GSK) confirmed on Tuesday that it has completed the acquisition of Affinivax Inc, a US clinical-stage biopharmaceutical company.

Based in Cambridge, Boston, Massachusetts, Affinivax has developed a novel class of vaccines, the most advanced of which are next-generation pneumococcal vaccines.

GSK acquired 100% of the outstanding shares of Affinivax for an upfront payment of USD2.1bn plus two potential milestone payments of USD0.6bn, depending on the achievement of certain paediatric clinical development milestones.

According to GSK, this acquisition aligns with the company's strategy of building a strong portfolio of specialty medicines and vaccines. It includes a next-generation 24-valent pneumococcal vaccine candidate (AFX3772), currently in phase II development, which is based on Affinivax's vaccine technology platform, Multiple Antigen Presenting System (MAPS). A 30-plus valent pneumococcal candidate vaccine is also in pre-clinical development.

The MAPS technology supports higher valency than conventional conjugation technologies, potentially enabling broader coverage against prevalent pneumococcal serotypes and generating higher antibody responses against many individual serotypes than current pneumococcal vaccines, GSK said.

Pneumococcal disease is an umbrella term used to describe any infection caused by the bacteria Streptococcus pneumoniae, a leading cause of acute bacterial infections worldwide. It has a broad clinical spectrum including bloodstream infections (sepsis), pneumonia, meningitis, and other milder diseases such as sinusitis and otitis media.