Collecting worldwide experience with ambroxol

Ambroxol hydrochloride is an oral mucolytic drug available over-the-counter for many years as cough medicine. In 2009 it was found to also act as a pharmacological chaperone (PC) for mutant glucocerebrosidase, albeit in a several-fold higher dose. Unfortunately, due to its low cost, there have been no pharma-driven clinical trials to establish the use of ambroxol. Thus, data are needed on the safety and efficacy of ambroxol for patients with Gaucher disease (GD).

The three decades of success of enzyme replacement therapy (ERT) for patients with type 1 Gaucher disease (GD1) have been just a partial success to those patients with the more severe neuronopathic forms, particularly the children with myoclonic epilepsy or the infants with type 2 GD. Ambroxol hydrochloride is an oral mucolytic drug, available over-the-counter (OTC) for many years as cough medicine. In 2009 it was found (in-vitro) to also act as a pharmacological chaperone (PC) for mutant glucocerebrosidase (GCase), albeit in a several-fold higher dose . Unfortunately, due to its low cost, there have been no pharma-driven clinical trials to establish the use of ambroxol. In an attempt to provide the proof of concept to the potential use of Ambroxol as PC for patients with GD, the Gaucher Clinic at Shaare Zedek Medical Center in Jerusalem, Israel, has treated 12 adult patients with GD1, all untreated with any specific treatment for GD \[whether ERT or substrate reduction therapy (SRT),\] with Ambroxol at the OTC dose of 150mg/day for a period of 6 months; this was not a formal clinical trial, but rather an audit of a series of patients receiving this drug via the employment of the Israeli Ministry of Health Form 29c to prescribe it for an off-label indication. A single patient, the thinnest of the group with a BMI of 17.1, achieved a robust response relative to baseline similar to ERT. In 2016, a group from Japan has demonstrated impressive neurological response using high-dose Ambroxol (a marked decrease in seizure frequency, improvement of myoclonus, ability to walk for a bedridden patient, improvement in the latency of I-V waves and threshold of ABR) with dramatic change in daily activities and quality of life (QOL). These encouraging results, that were confirmed in a larger series, yet unpublished, have further led to the conduction of an investigator-initiated-research (IIR) clinical trial in London by Prof A Schapira, which has recently been published (January 13, 2020 JAMA Neurology), wherein newly diagnosed Parkinson patients received high dose Ambroxol, with good safety results