Case series of patients under biweekly treatment with laronidase: a report of a single center experience / Série de casos de pacientes em tratamento com laronidase quinzenal: relato da experiência de um centro

ABSTRACT Objective: To report the stabilization of urinary glycosaminoglicans (GAG) excretion and clinical improvements in patients with mucopolysaccharidosis type I (MPS I) under an alternative dose regimen of laronidase of 1.2 mg/kg every other week. Methods: We participated in a dose-optimization trial for laronidase in MPS-I patients using four alternative regimens: 0.58 mg/kg every week, 1.2 mg/kg every two weeks, 1.2 mg/kg every week and 1.8 mg/kg every other week (EOW). After the trial ended, the patients resumed the recommended dose and regimen of 0.58 mg/kg every week. Under this regimen, some patients presented difficulties in venous access and were unable to commute weekly to the treatment center. Therefore, we used an alternative regimen that consisted of 1.2 mg/kg EOW in eight patients. A retrospective study of medical records of MPS-I patients who underwent both enzyme replacement therapy (ERT) regimens, of 0.58 mg/kg every week and 1.2 mg/kg EOW, was done. Results: Patients remained clinically stable under the alternative regimen, did not present elevation of urinary GAG nor any adverse event. Conclusions: The switch of dose regimen to 1.2 mg/kg EOW of laronidase was safe, and did not cause any clinical worsening in patients who had been previously under standard dose ERT.

RESUMO Objetivo: Descrever a manutenção dos níveis de glicosaminoglicano (GAG) excretados na urina e da estabilização clínica em pacientes com mucopolissacaridose do tipo I (MPS I) com o uso da laronidase num regime de dose alternativo de 1,2 mg/kg a cada duas semanas. Método: Alguns pacientes do nosso serviço participaram de um estudo de otimização de dose da laronidase para o tratamento da MPS I no qual foram comparados quatro esquemas terapêuticos: 0,58 mg/kg/semana, 1,2 mg/kg a cada duas semanas, 1,2 mg/kg/semana e 1,8 mg/kg a cada duas semanas. Após o término do estudo, todos os pacientes passaram a receber a terapia de reposição enzimática (TRE) na dose padrão de bula, que é de 0,58 mg/kg/semana, e nesse regime alguns pais se queixaram da dificuldade em comparecer ao centro todas as semanas, além da dificuldade de se obter acesso para punção venosa. Com base nessas queixas, oito pacientes passaram a receber a TRE no regime alternativo de 1,2 mg/kg a cada duas semanas. Foi feito o estudo retrospectivo de dados de prontuário de pacientes com MPS I que fizeram TRE com laronidase nas doses 0,58 mg/kg/semana e 1,2 mg/kg a cada duas semanas. Resultados: Os pacientes mantiveram-se clinicamente estáveis, não apresentaram aumento dos níveis de GAG urinários nem eventos adversos durante o regime alternativo de dose. Conclusões: A mudança para o esquema de 1,2 mg/kg de laronidase a cada duas semanas foi segura e não acarretou piora clínica nos pacientes que já estavam em TRE na dose padrão.

Clinical and laboratorial study of 19 cases of mucopolysaccharidoses

The mucopolysaccharidoses (MPS) are a heterogeneous group of inborn errors of lysosomal glycosaminoglycan (GAG) metabolism. The importance of this group of disorders among the inborn errors of metabolism led us to report 19 cases. METHOD: We performed clinical, radiological, and biochemical evaluations of the suspected patients, which allowed us to establish a definite diagnosis in 19 cases. RESULTS: Not all patients showed increased GAG levels in urine; enzyme assays should be performed in all cases with strong clinical suspicion. The diagnosis was made on average at the age of 48 months, and the 19 MPS cases, after a full clinical, radiological, and biochemical study, were classified as follows: Hurler -- MPS I (1 case); Hunter -- MPS II (2 cases); Sanfilippo -- MPS III (2 cases); Morquio -- MPS IV (4 cases); Maroteaux-Lamy -- MPS VI (9 cases); and Sly -- MPS VII (1 case). DISCUSSION: The high relative frequency of Maroteaux-Lamy disease contrasts with most reports in the literature and could express a population variability