- CLARITY Extension data published in the MS Journal shows 75% of patients who received 2 annual short courses of Mavenclad (Cladribine Tablets) remained relapse free over 4 years
- The majority of patients who experienced Grade 3 lymphopenia in Years 1 and 2 recovered to Grade 0-1 by the end of the study
Merck announced on 5th September 2017 the publication of the results of the CLARITY Extension study in Multiple Sclerosis Journal. The trial, an extension of the Phase III CLARITY study, demonstrated that treatment of patients with relapsing remitting multiple sclerosis (MS) with MAVENCLAD®(Cladribine Tablets) for two years, followed by two years of treatment with placebo, had clinical benefits similar to those seen with four years of treatment with MAVENCLAD®, with a low risk of severe lymphopenia.
The CLARITY Extension study included 806 patients out of 1,184 patients who completed the CLARITY study. The CLARITY Extension study assessed several clinical efficacy endpoints including annualised relapse rate (ARR) and confirmed 3-month Expanded Disability Status Scale (EDSS) progression. The proportion of patients who remained relapse-free at the end of four years was similar to the patients who received Cladribine Tablets 3.5 mg/kg in CLARITY followed by placebo in CLARITY Extension (75.6%), and those who received Cladribine Tablets 3.5 mg/kg in both studies (81.2%). The proportion of patients who remained free of 3-month EDSS progression was also similar between the treatment groups (72.4% vs 77.4%).
Today’s publication further strengthens the evidence for the use of MAVENCLAD® in MS, demonstrating significant, durable benefits in patients not receiving active treatment after the two short courses. The data from this publication and other recent articles suggest that MAVENCLAD® selectively targets the adaptive immune system, particularly the B-cell compartment, and therefore allows the immune system to reconstitute while still preventing MS disease activity in the majority of treated patients.
Prof. Gavin Giovannoni
A lead investigator in the CLARITY studies &
Chair of Neurology, Barts and The London School of Medicine and Dentistry.
The safety outcomes were comparable to those seen in CLARITY; adverse event rates were similar in patients who received Cladribine Tablets in CLARITY followed by placebo in CLARITY Extension, and those who received Cladribine Tablets in both studies. In CLARITY, patients with active relapsing-remitting multiple sclerosis were randomized to placebo or 1 of 2 cumulative doses of Cladribine Tablets (3.5 or 5.25 mg/kg body weight) for 2 years. In CLARITY Extension, patients were administered placebo or a cumulative dose of Cladribine Tablets 3.5 mg/kg body weight. In patients who received Cladribine Tablets 3.5 mg/kg in CLARITY and placebo in CLARITY Extension, the majority of those who experienced Grade >3 lymphopenia recovered to Grade 0-1 by the completion of CLARITY Extension. Most AEs were classified as mild or moderate.
In the patient group receiving placebo in CLARITY Extension following Cladribine Tablets 3.5 mg/kg in CLARITY, 3.1% of patients discontinued because of AEs. The most frequent AE in patients receiving Cladribine Tablets in the CLARITY Extension study was lymphopenia. The majority of lymphopenia events were classified as mild or moderate, and the majority of patients who experienced lymphopenia Grade ≥3 actually experienced Grade 3 only. In CLARITY Extension, herpes zoster infections were most frequent in patients receiving the highest cumulative dose of Cladribine Tablets (4.8%), however the incidence of herpes zoster in all other treatment groups was similar irrespective of cumulative dose (1.1-2.0%).
Today’s data add to the growing evidence for the use of MAVENCLAD® in patients with relapsing MS. At Merck we are very excited about the difference MAVENCLAD®could make in the lives of patients with this debilitating condition.
Head of Global R&D for the biopharma business of Merck.
In August, the European Commission (EC) granted Marketing Authorisation for MAVENCLAD® for the treatment of adults with highly active relapsing MS* in the 28 countries of the European Union (EU) in addition to Norway, Liechtenstein and Iceland. Merck plans additional filings for regulatory approval in other countries, including the United States.
*Defined as: patients with 1 relapse during the previous year and ≥ 1 T1 Gd+ lesion or ≥ 9 T2 lesions while on therapy with other DMDs; OR patients with ≥ 2 or more relapses in the previous year, whether on DMD treatment or not.
CLARITY Extension Study Design
The CLARITY Extension study involved 806 patients out of 1,184 patients from the CLARITY study, allowing assessment of the effects of 2 years’ additional treatment with Cladribine Tablets beyond the 2-year CLARITY regimen. Patients who received Cladribine Tablets 3.5 mg/kg or 5.25 mg/kg in the CLARITY study were randomised to receive either Cladribine Tablets 3.5 mg/kg or placebo in CLARITY Extension, and patients who received placebo in the original CLARITY study received Cladribine Tablets 3.5 mg/kg in CLARITY Extension.
MAVENCLAD® (cladribine tablets) is approved in the European Union for the treatment of highly active relapsing multiple sclerosis[*] (RMS). MAVENCLAD® is a short-course oral therapy that selectively and periodically targets lymphocytes thought to be integral to the pathological process of relapsing MS (RMS). MAVENCLAD® is currently under clinical investigation and not yet approved for the treatment for any use in the United States or Canada. In August 2017, the European Commission (EC) granted marketing authorisation for MAVENCLAD® for the treatment of relapsing forms of multiple sclerosis (RMS) in the 28 countries of the European Union (EU) in addition to Norway, Liechtenstein and Iceland.
The clinical development programme for MAVENCLAD® includes:
- The CLARITY (Cladribine Tablets Treating MS Orally) study: a two-year Phase III placebo-controlled study designed to evaluate the efficacy and safety of MAVENCLAD® as a monotherapy in patients with RRMS.
- The CLARITY extension study: a two-year Phase III placebo-controlled study following on from the CLARITY study, designed to evaluate the safety and efficacy of MAVENCLAD® over an extended administration for four years.
- The ORACLE MS (Oral Cladribine in Early MS) study: a two-year Phase III placebo-controlled study designed to evaluate the efficacy and safety of MAVENCLAD® as a monotherapy in patients at risk of developing MS (patients who have experienced a first clinical event suggestive of MS).
- The ONWARD (Oral Cladribine Added ON To Interferon beta-1a in Patients With Active Relapsing Disease) study: a Phase II placebo-controlled study designed primarily to evaluate the safety and tolerability of adding MAVENCLAD® treatment to patients with relapsing forms of MS, who have experienced breakthrough disease while on established interferon-beta therapy.
- PREMIERE (Prospective Observational Long-term Safety Registry of Multiple Sclerosis Patients Who Have Participated in Cladribine Clinical Studies) study: interim long-term follow-up data from the prospective registry, PREMIERE, to evaluate the safety and efficacy of MAVENCLAD®. This includes more than 10,000 patient years of data with over 2,700 patients included in the clinical trial program, and more than 10 years of observation in some patients.
MAVENCLAD® (cladribine tablets) is indicated for the treatment of adult patients with highly active relapsing multiple sclerosis (RMS) as defined by clinical or imaging features.
Important EU Safety Information
MAVENCLAD® is contraindicated in patients with hypersensitivity to the active substance, human immunodeficiency virus (HIV), active chronic infection (tuberculosis or hepatitis), active malignancy, moderate to severe renal impairment (creatinine clearance <60 mL/min), and those who are pregnant and breast-feeding. MAVENCLAD® is also contraindicated in immunocompromised patients, including patients currently receiving immunosuppressive or myelosuppressive therapy.
Special warnings and precautions for use:
The most clinically relevant adverse reactions were lymphopenia and herpes zoster.
Decreases in neutrophil count, red blood cell count, haematocrit, haemoglobin or platelet count compared to baseline values have been observed in clinical studies, although these parameters usually remain within normal limits.
Additive haematological adverse reactions may be expected if cladribine is administered prior to or concomitantly with other substances that affect the haematological profile
Lymphocyte counts must be determined
- before initiating MAVENCLAD® in year 1,
- before initiating MAVENCLAD® in year 2,
- 2 and 6 months after start of treatment in each treatment year. If the lymphocyte count is below 500 cells/mm³, it should be actively monitored until values increase again.
Cladribine can reduce the body’s immune defence and may increase the likelihood of infections. HIV infection, active tuberculosis and active hepatitis must be excluded before initiation of cladribine.
The incidence of herpes zoster was increased in patients on cladribine. If lymphocyte counts drop below 200 cells/mm³, anti-herpes prophylaxis according to local standard practice should be considered during the time of grade 4 lymphopenia. Interruption or delay of MAVENCLAD® may be considered until proper resolution of the infection.
Cases of progressive multifocal leukoencephalopathy (PML) have been reported for parenteral cladribine in patients treated for hairy cell leukaemia with a different treatment regimen.
In the clinical study data base of cladribine in MS (1,976 patients, 8,650 patient years) no case of PML has been reported. However, a baseline magnetic resonance imaging (MRI) should be performed before initiating MAVENCLAD® (usually within 3 months).