Merck KGaA is launching another late-stage trial of its investigational oral drug cladribine for the treatment of multiple sclerosis.

The Darmstadt-based company said that its Merck Serono unit has initiated the Phase III trial, called ORACLE MS, which will evaluate the safety and efficacy of two dosage regimens of cladribine tablets versus placebo in patients who have experienced a first clinical event suggestive of MS. Around 200 centres worldwide will be involved in the trial.

The ORACLE study follows Merck Serono’s CLARITY trial which is looking at cladribine for treatment of relapsing forms of MS. That study “was the first pivotal trial among all Phase III oral compounds in development for MS to complete enrolment”, the company said, noting that cladribine has been granted a fast-track designation by the US Food and Drug Administration.

Thomas Leist of the Thomas Jefferson University in Philadelphia and an investigator on the ORACLE MS study, said there is “increasing evidence supporting the initiation of treatment with a disease-modifying drug in patients who have experienced a first clinical event suggestive of MS”. This is “an initial stage of the disease when clinical manifestations are not necessarily pronounced but where the potential exists for irreversible neurological damage to take place".

Merck, which is already a major player in the MS market through Rebif (interferon beta-1a) is hoping that cladribine will be the first oral, as opposed to injected, treatment for the disease. Other oral treatments in late-stage development include Sanofi-Aventis’ teriflunomide, Teva/Active Biotech’s laquinimod and Novartis’ fingolimod.