Phase 3 Study of Raxone on Respiratory Health of DMD Patients Using Glucocorticoids Opening in US, Europe

Santhera Pharmaceuticals is recruiting patients for a new Phase 3 clinical trial evaluating its lead candidate Raxone (idebenone) in slowing respiratory decline in Duchenne muscular dystrophy (DMD) patients being treated with glucocorticoids.

Raxone is an experimental drug designed to improve energy production in the mitochondria (the cell’s powerhouse) of muscle cells.

In the Phase 3 SIDEROS trial (NCT02814019), 266 DMD patients on glucocorticoid treatment will be randomly assigned to receive either Raxone (900 mg/day; two tablets, three times a day) or a placebo for 78 weeks (18 months).

Efficacy will be measured by the change in the forced vital capacity percent predicted (FVC % p), a measure of how much a person can exhale, from study’s start to week 78, the study’s primary endpoint.

As secondary outcome measures, researchers will also analyze respiratory parameters that include the change in percent predicted peak expiratory flow (PEF % p, maximum speed of expiration), time to first 10 percent decline in FVC, and change in inspiratory flow reserve (IFR).

Patients who complete the trial will be eligible to enroll in an extension study where all patients receive Raxone. Results for the SIDEROS trial are expected to be known in mid-to-late summer 2019. (Trial sites throughout the U.S. and Europe are currently, or soon will be, enrolling eligible DMD patients of all ages; more information is available on the study’s clinical trial.gov website or by writing Jodi Wolff at [email protected].)

Raxone was previously assessed in a Phase 3 clinical trial with DMD patients not under glucocorticoid treatment. The DELOS trial (NCT01027884) enrolled 64 patients (ages 10 to 18) that were randomly assigned to receive Raxone (900 mg, three times a day) or a placebo. Patients on Raxone demonstrated a slower loss of respiratory function, measured by the PEF%p from study’s start to week 52, and fewer bronchopulmonary complications compared to placebo.

The FDA, however, denied Santhera’s request for an accelerated review of Raxone as a DMD treatment last year, and asked for more confirmatory evidence of efficacy. Santhera believes the results from the SIDEROS trial will demonstrate Raxone’s potential in treating DMD patients with respiratory decline regardless of whether they use glucocorticoids or not.

The European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) and Swiss regulatory authorities are currently reviewing a Marketing Authorization Application (MAA) for Raxone’s approval as a treatment for DMD patients with loss of respiratory function who are not taking glucocorticoid treatment. If approved, this indication would also include patients previously treated with glucocorticoids or in whom glucocorticoid treatment is ineffective or contraindicated.

Santhera also announced the opening of a new office in Burlington, Massachusetts, to facilitate its operations in the U.S.

“[Raxone] is generating a significant interest among researchers, physicians and the patient community. In slowing the loss of respiratory function in all patients irrespective of their mutational status, this drug candidate has the potential to expand the current treatment paradigm for DMD,” Thomas Meier, PhD and Santhera’s chief executive officer, said in a press release. “Our presence here in the U.S. will enable us to expand our engagement with physicians, their patients, and families as the SIDEROS trial moves forward while we continue our efforts to find a regulatory path for early approval.”