GlaxoSmithKline has begun a couple of late-stage trials, one evaluating its new muscle loss drug, plus a study comparing an intravenous version of Relenza and Roche's Tamiflu.

First up, GSK and Dutch partner Prosensa have announced that the first patient has commenced treatment in the Phase III study investigating GSK2402968, in ambulant boys with Duchenne muscular dystrophy. The trial will enrol 180 patients, from up to 18 countries, and GSK noted that it is "currently the most advanced ongoing study for this rare, severely debilitating, neuromuscular disease".

The trial is an important milestone said Philippe Monteyne, chief medical officer for GSK Rare Diseases. He noted that there is no approved treatment to alter the course of DMD, "a disease that puts boys in wheelchairs and often leads to death in early adulthood". DMD affects one in 3,500 live male births and is caused by mutations in the dystrophin gene.

GSK linked up with Prosensa to develop DMD drugs in October 2009, an agreement that could be worth £428 million to the Leiden-headquartered company. The deal included an upfront payment of £16 million.

The UK drugs giant also noted that the first patient has received treatment in a Phase III study of hospitalised patients with influenza which compares intravenous zanamivir, sold in an inhaled version as Relenza, to oral Tamiflu (oseltamivir). The trial has a target enrolment of 462 patients planned in over 20 countries that take into account flu seasons in the northern and southern hemispheres and will take three years.

Intravenous zanamivir is not approved for sale in any country but GSK believes it could be a valuable addition to treatment, especially in severe cases.