Oral Molecule Trial Shows Promise in MS Relapse Reduction

A remitting-relapsing multiple sclerosis (RRMS) investigative oral treatment showed a significant drop in MS patient relapse rates in a 4-year multi-study shared at the annual Consortium of Multiple Sclerosis Centers (CMSC).

Cladribine Tablets, a small molecule treatment developed by EMD Serono, showed reductions in relapse rates versus placebo treatment for patient groups in two clinical trials — the CLARITY and CLARITY EXTENSION studies.

The CLARITY study — a 2-year trial in which patients were either administered a 3.5 or 5.25 mg dosage of Cladribine Tabelts, or a placebo —reported a .14 and .15 relapse rate in the two tablet groups at 96 weeks, opposed to the placebo group’s .33 relapse rate.

The 3.5 and 5.25 mg patient groups’ relative reductions were 57.6% and 54.5%, respectively. Additionally, a respective 73% and 89.9% of patients in each group reported no new gadolinium (Gd)-enhancing lesions in the CLARITY EXTENSION trial.

However, patients receiving Cladribine Tablets were prone to an increased rate of lymphopenia — the study’s most commonly reported adverse event (AE). The study reported a 48.3% rate of infection among Cladribine Tablets patients, as opposed to just 42.5% in the placebo group — with nearly all infections being classed as mild to moderate.

In extension of the CLARITY trial, patients who had received placebo treatment were re-randomized to receive 3.5 mg Cladribine Tablets treatment, and patients who already received the treatment at either were re-randomized 2:1 to 3.5 Cladribine Tablets treatment or placebo for the next 2 years.

Researchers wished to better understand the tablet’s duration efficacy through separate 2-year studies.

“It's important that we saw similar results replicated in the CLARITY EXTENSION trial, which further supports the overall efficacy profile of Cladribine Tablets,” Kottil Rammohan, MD, CLARITY studies investigator, and Director of the Multiple Sclerosis Center at the University of Miami, said. “Rates of clinical and MRI disease activity-free status were consistent with Cladribine Tablets across all subsets of MS patients for the duration in both trials.”

A separate investigative study was conducted on the effect of 3.5 mg of bodyweight or 5.25 mg on conversion to clinically definite MS. Named the ORACLE-MS study, its data show annualized relapse rates in the open-label period were lower in patients originally randomized to receive either dose of Cladribine Tablets versus placebo.

In the ORACLE-MS trial, the most commonly reported AE with Cladribine Tablets patients was again lymphopenia. Patients previously exposed the 5.25 mg dosage reported an infection rate of 8.3%. Patients exposed to the 3.5 mg dosage reported a 4% infection rate, and placebo patients reported a 3.3% infection rate.

Joseph Leveque, MD, Chief Medical Officer of EMD Serono, said the ongoing research underscores his company’s commitment to creating new MS therapy options.

“Data presented at CMSC add to the body of research evaluating the efficacy and safety of Cladribine Tablets as a potential treatment option for patients with relapsing MS,” Leveque said.

While under clinical investigation, Cladribine Tablets are not yet approved for any use in any countries.