Armed with new phase III data, GlaxoSmithKline (GSK) has said it is on course to file for approval of its rheumatoid arthritis candidate sirukumab in 2016.
Sirukumab is an interleukin-6 (IL-6) inhibitor, and one of a crop of new drugs that GSK has said could add at least £6bn to its revenues in 2020. The drug has been partnered with Johnson & Johnson’s Janssen Biologics unit since 2011.
GSK has not revealed details of the clinical results of the phase III trials, but said the data showed “no unexpected safety findings relative to the known effects of anti-IL-6 inhibitors”, and positive efficacy data.
There are still questions about the potential for new biologic therapies in rheumatoid arthritis, which is already fairly well served with drugs and according to some commentators may have peaked.
Other drugs on the market for RA include TNF inhibitors such as AbbVie’s Humira (adalimumab), anti-CD20 antibodies like Roche/Genentech/Biogen’s MabThera/Rituxan (rituximab) and Roche’s IL-6-targeting Actemra (tocilizumab) with biosimilars of first-generation biologics starting to reach the market.
GSK said at its recent R&D day however that the anti-IL-6 class is the fastest growing of the biological classes in RA. In addition to Actemra, Sanofi and Regeneron are developing an IL-6-targeting drug – called sarilumab – that has already been filed for approval with the FDA.
In the phase III SIRROUND programme, sirukumab given subcutaneously at dosages of 100mg every two weeks or 50mg every four weeks, and is being compared to both placebo and adalimumab as an active control. The trials involve both treatment-naïve patients and those with prior exposure to disease-modifying anti-rheumatic drugs (DMARDs) and anti-TNF drugs.
Sirukumab is also in a phase III trial involving patients with giant cell arteritis – a form of vasculitis – as well as earlier-stage trials in severe asthma where it addresses a different population to GSK’s recently-approved severe asthma therapy Nucala (mepolizumab).
While mepolizumab is indicated for severe asthma with high levels of eosinophils – a type of white blood cell, sirukumab seems to be a promising treatment for non-eosinophilic asthma.