Long-term effects of cladribine tablets on MRI activity outcomes in patients with relapsing-remitting multiple sclerosis: the CLARITY Extension study

TY - JOUR

T1 - Long-term effects of cladribine tablets on MRI activity outcomes in patients with relapsing-remitting multiple sclerosis

T2 - the CLARITY Extension study

AU - Comi, Giancarlo

AU - Cook, Stuart

AU - Rammohan, Kottil

AU - Soelberg Sorensen, Per

AU - Vermersch, Patrick

AU - Adeniji, Abidemi K

AU - Dangond, Fernando

AU - Giovannoni, Gavin

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Background: The CLARITY and CLARITY Extension studies demonstrated that treatment of relapsing-remitting multiple sclerosis (RRMS) with cladribine tablets (CT) results in significant clinical improvements, compared with placebo. This paper presents the key magnetic resonance imaging (MRI) findings from the CLARITY Extension study. Methods: Patients who received a cumulative dose of either CT 3.5 or 5.25 mg/kg in CLARITY were rerandomized to either placebo or CT 3.5 mg/kg in CLARITY Extension. Patients from the arm that received placebo in CLARITY were assigned to CT 3.5 mg/kg. MRI assessments were carried out when patients entered CLARITY Extension and after Weeks 24, 48, 72 and 96, and in a supplemental follow-up period. Results: At CLARITY Extension baseline, patients who received placebo during CLARITY had more T1 gadolinium-enhanced (Gd+) lesions than patients who received CT during CLARITY. These patients, who were then exposed to cladribine 3.5 mg/kg during the extension, experienced a 90.4% relative reduction (median difference -0.33, 97.5% confidence interval -0.33-0.00; p < 0.001) in T1 Gd+ lesions at the end of the extension compared with the end of CLARITY. Overall, the majority of patients in each treatment group remained free from T1 Gd+ lesions throughout CLARITY Extension. However, a small proportion of patients who were treated with cladribine in CLARITY and received placebo in CLARITY Extension showed evidence of increased MRI activity, and this was associated with a prolonged treatment gap between CLARITY and CLARITY Extension. Conclusion: A 2-year treatment with CT 3.5 mg/kg has a durable effect on MRI outcomes in the majority of patients, an effect that was sustained in patients who were not retreated in the subsequent 2 years after initial treatment.

AB - Background: The CLARITY and CLARITY Extension studies demonstrated that treatment of relapsing-remitting multiple sclerosis (RRMS) with cladribine tablets (CT) results in significant clinical improvements, compared with placebo. This paper presents the key magnetic resonance imaging (MRI) findings from the CLARITY Extension study. Methods: Patients who received a cumulative dose of either CT 3.5 or 5.25 mg/kg in CLARITY were rerandomized to either placebo or CT 3.5 mg/kg in CLARITY Extension. Patients from the arm that received placebo in CLARITY were assigned to CT 3.5 mg/kg. MRI assessments were carried out when patients entered CLARITY Extension and after Weeks 24, 48, 72 and 96, and in a supplemental follow-up period. Results: At CLARITY Extension baseline, patients who received placebo during CLARITY had more T1 gadolinium-enhanced (Gd+) lesions than patients who received CT during CLARITY. These patients, who were then exposed to cladribine 3.5 mg/kg during the extension, experienced a 90.4% relative reduction (median difference -0.33, 97.5% confidence interval -0.33-0.00; p < 0.001) in T1 Gd+ lesions at the end of the extension compared with the end of CLARITY. Overall, the majority of patients in each treatment group remained free from T1 Gd+ lesions throughout CLARITY Extension. However, a small proportion of patients who were treated with cladribine in CLARITY and received placebo in CLARITY Extension showed evidence of increased MRI activity, and this was associated with a prolonged treatment gap between CLARITY and CLARITY Extension. Conclusion: A 2-year treatment with CT 3.5 mg/kg has a durable effect on MRI outcomes in the majority of patients, an effect that was sustained in patients who were not retreated in the subsequent 2 years after initial treatment.

U2 - 10.1177/1756285617753365

DO - 10.1177/1756285617753365

M3 - Journal article

C2 - 29399054

SN - 1756-2856

VL - 11

SP - 1

EP - 11

JO - Therapeutic Advances in Neurological Disorders

JF - Therapeutic Advances in Neurological Disorders

ER -