Ambroxol therapy for patients with Gaucher disease type 1, either poor responders to enzyme replacement therapy/substrate reduction therapy (ERT/SRT) or untreated

ABSTRACT

Ambroxol hydrochloride is an oral mucolytic drug, available over-the-counter for many years as cough medicine, which was found to also act as a pharmacological chaperone for mutant glucocerebrosidase, albeit in a several-fold higher dose. Proof-of-concept reports have been published over the past decade in all three forms of Gaucher disease (GD). The current study aimed to assess the safety and efficacy of 12-months ambroxol 600 mg/day in 3 groups of type 1 GD patients with sub-optimal response, after a minimum of 3 years, to enzyme replacement therapy (ERT)/substrate reduction therapy (SRT) defined as lumbar spine bone density <−2.0 t-score, or platelet count<100 × 10−3/L, or LysoGb1 > 200 ng/ml, and for a group of naïve patients, i.e., never treated or stopped therapy >12 months prior to enrollment, who had abnormal values in 2 of the 3 above-mentioned parameters. Forty patients were enrolled 28 ERT/SRT treated and 12 naïve;21 (52%) males, mean age 52 years (range 24–84). Safety aspects included several adverse effects (mainly gastrointestinal, excessive saliva, and vertigo) all mild and transient in nature, but led to drug discontinuation in 14 patients, additional dropouts were 7 patients due to COVID19 pandemic and 3 due to personal reasons. Of the remaining 16 patients, 14 have completed 12 months, and 2 are ongoing. Of the 14 completers, 5 (~36%) achieved significant improvement in at least one of the three parameters, and nine did not demonstrate any improvement nor deterioration. The interpretation of the results must take into account the fact that most of the enrolled patients have had poor response to ERT/SRT (including 10 of the 12 naïve patients) and therefore may not represent the majority of the patients. Further studies are needed in never-treated patients as well as an oral, less expensive, alternative to unselected stable patients currently treated with ERT/SRT with a favorable response.