GlaxoSmithKline has said that it plans to buy long-term vaccines partner Corixa for $300 million, sparking a 40% rise in the latter’s Nasdaq-listed shares.

The acquisition will further bolster GSK’s position in the vaccine market and bring in-house technologies that underpin several of the UK-headquartered drugmaker’s vaccine products, including the novel adjuvant MPL (monophosphoryl lipid A).

MPL is a constituent of GSK Biologicals’ Fendrix, approved in February for the treatment of patients at particularly high risk of developing hepatitis B virus, such as those receiving dialysis for kidney failure [[09/02/05e]]. It is also used in several other vaccines in GSK’s pipeline, including one that could be the first effective vaccine for malaria - according to clinical studies reported last year [[15/10/04d]] - and Cervarix, a candidate for protecting against cervical cancer [[15/11/04d]].

In addition MPL is a key component in the adjuvant system GSK Bio is testing in a number of its investigational cancer immunotherapeutic vaccine approaches for the treatment of breast, lung, melanoma or prostate cancers. Corixa and GSK have also been collaborating on other vaccine projects including one for tuberculosis.

GSK and Corixa have had a manufacturing and supply agreement, running to the end of 2012, that grants GSK access to the current maximum output of Corixa’s MPL manufacturing facility of around 2kg a year. Under the terms of the acquisition agreement, GSK will acquire this facility outright, guaranteeing supply and doing away with the need to pay royalties on future sales of their vaccines containing the adjuvant. The transaction is expected to close in the third quarter of this year.