Novo tratamento para a esclerose múltipla, estudo publicado no "New England Journal of Medicine"
Efeitos colaterais a curto prazo não foram verificadosHá um novo tratamento clínico que se revelou eficaz no combate à esclerose múltipla, pois reduz o agravamento e as recaídas desta doença inflamatória do sistema nervoso central.
De acordo com o estudo publicado no "New England Journal of Medicine", trata-se do Cladribine, o primeiro tratamento experimental que pode ser administrado por via oral para combater esta doença neurológica crónica, de causa ainda desconhecida.
Este medicamento desenvolvido pelo grupo farmacêutico Merck Serono neutraliza o sistema imunitário, impedindo que este ataque o sistema nervoso central.
ABSTRACT Background Cladribine provides immunomodulation through selective targeting of lymphocyte subtypes. We report the results of a 96-week phase 3 trial of a short-course oral tablet therapy in patients with relapsing–remitting multiple sclerosis. Methods We randomly assigned 1326 patients in an approximate 1:1:1 ratio to receive one of two cumulative doses of cladribine tablets (either 3.5 mg or 5.25 mg per kilogram of body weight) or matching placebo, given in two or four short courses for the first 48 weeks, then in two short courses starting at week 48 and week 52 (for a total of 8 to 20 days per year). The primary end point was the rate of relapse at 96 weeks. Results Among patients who received cladribine tablets (either 3.5 mg or 5.25 mg per kilogram), there was a significantly lower annualized rate of relapse than in the placebo group (0.14 and 0.15, respectively, vs. 0.33; P<0.001 for both comparisons), a higher relapse-free rate (79.7% and 78.9%, respectively, vs. 60.9%; P<0.001 for both comparisons), a lower risk of 3-month sustained progression of disability (hazard ratio for the 3.5-mg group, 0.67; 95% confidence interval [CI], 0.48 to 0.93; P=0.02; and hazard ratio for the 5.25-mg group, 0.69; 95% CI, 0.49 to 0.96; P=0.03), and significant reductions in the brain lesion count on magnetic resonance imaging (MRI) (P<0.001 for all comparisons). Adverse events that were more frequent in the cladribine groups included lymphocytopenia (21.6% in the 3.5-mg group and 31.5% in the 5.25-mg group, vs. 1.8%) and herpes zoster (8 patients and 12 patients, respectively, vs. no patients). Conclusions Treatment with cladribine tablets significantly reduced relapse rates, the risk of disability progression, and MRI measures of disease activity at 96 weeks. The benefits need to be weighed against the risks. (ClinicalTrials.gov number, NCT00213135 [ClinicalTrials.gov] .) Published at www.nejm.org January 20, 2010 (10.1056/NEJMoa0902533) A Placebo-Controlled Trial of Oral Cladribine for Relapsing Multiple Sclerosis Gavin Giovannoni, M.B., B.Ch., Ph.D., Giancarlo Comi, M.D., Stuart Cook, M.D., Kottil Rammohan, M.D., Peter Rieckmann, M.D., Per Soelberg Sørensen, M.D., D.M.Sc., Patrick Vermersch, M.D., Ph.D., Peter Chang, Ph.D., Anthony Hamlett, Ph.D., Bruno Musch, M.D., Ph.D., Steven J. Greenberg, M.D., for the CLARITY Study Group |
Deste modo, é suficiente tomar os comprimidos num período de oito a dez dias por ano, evitando-se assim as injecções intravenosas às quais são submetidos actualmente os pacientes ao longo de todo o ano.
Os participantes do ensaio clínico que tomaram Cladribine tiveram menos 55 por cento de risco de recaída e menos 30 por cento de probabilidades de que a sua condição se agravasse do que o grupo tratado com placebos, fármacos inertes.
"A chegada do Cladribine, que não produz efeitos colaterais a curto prazo e é muito fácil de tomar, terá um importante impacto sobre o tratamento da esclerose em placas", afirma Gavin Giovannoni, da London School of Medicine and Dentistry, principal autor da investigação.
Fonte: cienciahoje.pt | 22-01-2010
