CLARITY Extension Study
Condition: Relapsing-Remitting Multiple Sclerosis
MeSH terms: Multiple Sclerosis; Multiple Sclerosis, Relapsing-Remitting; Sclerosis
Intervention: Cladribine; Placebo; Cladribine; Cladribine; Placebo
Intervention description: Participants who received Cladribine 3.5 mg/kg in the previous study 25643 (NCT00213135) and completed will be re-randomized in this extension study and receive cladribine tablet orally as cumulative dose of 0.875 mg/kg over a course of 4 or 5 consecutive days of 28-day period at Week 1, 5, 48, and 52 resulting in total cladribine dose of 3.5 mg/kg during the treatment period of 96 weeks.; Participants who received Cladribine 3.5 mg/kg in the previous study 25643 (NCT00213135) and completed will be re-randomized in this extension study and receive placebo matched to cladribine tablet 0.875 mg/kg orally administered over a course of 4 or 5 consecutive days of 28-day period at Week 1, 5, 48, and 52 during the treatment period of 96 weeks.; Participants who received Cladribine 5.25 mg/kg in the previous study 25643 (NCT00213135) and completed will be re-randomized in this extension study and receive cladribine tablet orally as cumulative dose of 0.875 mg/kg over a course of 4 or 5 consecutive days of 28-day period at Week 1, 5, 48, and 52 resulting in total cladribine dose of 3.5 mg/kg during the treatment period of 96 weeks.; Participants who received placebo in the previous study 25643 (NCT00213135) and completed will be re-randomized in this extension study and receive cladribine tablet orally as cumulative dose of 0.875 mg/kg over a course of 4 or 5 consecutive days of 28-day period at Week 1, 5, 48, and 52 resulting in total cladribine dose of 3.5 mg/kg during the treatment period of 96 weeks.; Participants who received Cladribine 5.25 mg/kg in the previous study 25643 (NCT00213135) and completed will be re-randomized in this extension study and receive placebo matched to cladribine tablet 0.875 mg/kg orally administered over a course of 4 or 5 consecutive days of 28-day period at Week 1, 5, 48, and 52 during the treatment period of 96 weeks.
Intervention MeSH terms: Cladribine
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 867.0
Sex: All
Minimum age: 18 Years
Maximum age: 65 Years
Healthy volunteers: No

Summary:

      The purpose of this extension trial was to further evaluate the safety and tolerability of
      oral cladribine in subjects who have previously completed treatment within Trial 25643
      (CLARITY). This trial also explored clinical benefit of prolonged 192-week versus 96-week
      treatment.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Randomized in Trial 25643 and satisfied one of the following:

               -  Completed randomized treatment course and scheduled visits for the full 96 weeks;
                  or

               -  Did not complete the randomized treatment course in Trial 25643 but elected to
                  receive rescue treatment with Rebif®, another beta-interferon, or glatiramer
                  acetate and completed scheduled clinic visits for the full 96 weeks; or

               -  Did not complete the randomized treatment course in Trial 25643, declined rescue
                  with Rebif®, another beta-interferon, or glatiramer acetate and still completed
                  scheduled clinic visits for the full 96 weeks; or

               -  Did not complete the randomized treatment course in Trial 25643, were not
                  eligible for rescue option with Rebif®, and still completed scheduled clinic
                  visits for the full 96 weeks

          -  Male or female, between 18 and 65 years of age (inclusive, at time of informed consent
             for Trial 25643)

          -  No medical history or evidence of latent tuberculosis infection (LTBI) or tuberculosis
             (TB), as evidenced by TB skin test or chest X-ray

          -  All of the following laboratory hematologic parameters evaluated as normal (as define
             below, inclusively) within 28 days of first dosing of blinded study medication at
             study Day 1:

               -  Hemoglobin = 11.6 to 16.2 gram per deciliter (g/dL)

               -  Leukocytes (total white blood cell) = 4.1 to 12.3*10^3 per microliter

               -  Absolute lymphocyte count (ALC) = 1.02 to 3.36*10^3 per microliter

               -  Absolute neutrophil count (ANC) = 2.03 to 8.36*10^3 per microliter

               -  Platelet count = 140 to 450*10^3 per microliter

          -  Other protocol-defined inclusion/exclusion criteria may apply

        Exclusion Criteria:

          -  Participants who were not enrolled in Trial 25643

          -  Participant has moderate to severe renal impairment

          -  Use of mitoxantrone, total lymphoid irradiation, myelosuppressive therapy, campath-1h,
             cyclophosphamide, azathioprine, methotrexate or natalizumab at any time during and
             since Trial 25643

          -  Use of cytokine or anti-cytokine therapy, intravenous immunoglobulin (IVIG) or
             plasmapheresis at any time during and since Trial 25643

          -  Treatment with oral or systemic corticosteroids or adrenocorticotropic hormone within
             28 days before Study Day 1