A raft of City firms have landed roles advising pharmaceutical giants Pfizer and GlaxoSmithKline (GSK) on a joint venture that will see the creation of a new HIV and AIDS treatment company.

Allen & Overy (A&O), Slaughter and May, Clifford Chance (CC), Jones Day and Morgan Lewis & Bockius have all won instructions on the deal, which will see the drug companies merge their treatment companies into one entity.