The PREMIER trial, initiated in March 2021, is an international, randomized, double-blind, two-arm placebo-controlled, pivotal Phase III study, where the primary objective is to evaluate the efficacy and safety of PXT3003 versus placebo in mild-to-moderate CMT1A patients, over a 15-month period. The dose of PXT3003 tested in the PREMIER trial corresponds to the high dose (HD) tested in the prior Phase III clinical study, the PLEO-CMT trial, and its ongoing open-label extension Phase III study, the PLEOCMT-FU trial. As agreed with regulatory agencies, the primary efficacy endpoint will be the Overall Neuropathy Limitations Scale (‘ONLS’) which measures functional motor disability. A total of 387 patients with mild-to-moderate CMT1A, was enrolled in the PREMIER trial (exceeding the initial enrolment target of 350 subjects as defined in the study protocol): 153 in the United States, 183 in Europe, 39 in Canada and 12 in Israel.
The 15-month double-blind phase of the PREMIER trial is followed by an open-label extension phase named PREMIEROLE (Open Label Extension). All patients who completed the double-blind phase of the PREMIER trial are eligible to join the open-label extension phase, PREMIER-OLE, and have the opportunity to receive PXT3003 HD until the treatment is commercially available, should PXT3003 be approved in the US and Europe, respectively by the FDA and the EMA. The first patient entered the PREMIER-OLE phase in September 2022.
Furthermore, Pharnext successfully completed the manufacturing transfer and scale-up of PXT3003 from Unither’s facility in Colomiers, France, to Unither’s U.S.A. facility in Rochester, New York to prepare for potential marketing authorization of PXT3003. PXT3003 is now able to be manufactured in batches of up to 3,500 liters of oral solution, a volume potentially compatible with a commercial supply chain of PXT3003 enabling a more convenient and flexible form for CMT1A patients to use, allowing for better compliance.
The topline results announcement of this study is planned in Q4 2023