Sanofi has reported positive data from the first pivotal trial of its rheumatoid arthritis candidate sarilumab, setting it on course for regulatory filings
Sarilumab is an interleukin-6 blocking antibody originally developed by Regeneron and works via a similar mechanism to Roche’s Actemra/RoActemra (tocilizumab), which is growing at a healthy rate, with sales up by a third in the first nine months of the year to 763m Swiss francs ($834m).
The results of the phase III SARIL-RA MOBILITY trial – involving 1,200 RA patients who did not respond to methotrexate therapy – showed that after one year’s treatment sarilumab was able to improve symptoms and physical function, as well as reducing the progression of joint damage.
The new antibody was superior to placebo at both doses tested (150mg or 200mg given by subcutaneous injection every other week), according to Sanofi, which indicated it was particularly pleased with the data on disease progression.
“Irreversible joint damage [remains] a major concern for RA patients,” said Sanofi’s sarilumab project head Tanya Momtahen. “We are encouraged by these phase III results and the impact sarilumab demonstrated on inhibition of progression of structural damage assessed radiographically.”
Actemra also has a claim for reducing structural damage on the label, as does AbbVie’s tumour necrosis factor (TNF) inhibitor Humira (adalimumab), which remains the biggest-selling biologic drug for RA with sales of $7.6bn in the first nine months of this year.
TNF blockers still dominate RA treatment but there remains a sizeable market opportunity for new entrants as the disease remains uncontrolled despite treatment in up to 40 per cent of patients who receive them.
Analysts suggest that Actemra might have made greater headway in the market but was held back until recently by the need for a 60-minute infusion every four weeks. Roche recent got approval for subcutaneous dosing every other week, which is more manageable for both patients and doctors.
Meanwhile, Sanofi is emphasising the fact that sarilumab is the first fully-human monoclonal antibody to target IL-6 (Actemra is a recombinant human mAb), which could theoretically improve tolerability and reduce immunogenicity.
Also vying to develop a more patient friendly IL-6 blocker is Bristol-Myers Squibb, whose clazakinumab was recently found equivalent in efficacy to Humira in a phase IIb trial, with a trend towards higher remission rates, and AbbVie which licensed ALX-0061 from Belgian biotech Ablynx in an $840m deal signed in September. ALX-0061 has just cleared a phase IIa study.