Myasthenia Gravis Cell Therapy Granted Fast Track Designation
The therapy’s IND has been cleared and a first in-human trial is expected to begin later this year.
The FDA has granted fast track designation to Cabaletta Bio's muscle-specific kinase (MuSK) chimeric autoantibody receptor T (MuSK-CAART) cell therapy for improving activities of daily living and muscle strength in patients with myasthenia gravis (MG).1
“Anti-MuSK autoantibodies are observed in a subset of patients diagnosed with MG, and the limited treatment options for these patients underscore the need for a new and more effective standard of care,” David J. Chang, MD, chief medical officer, Cabaletta, said in a statement.1
Cabaletta Bio also announced that the FDA had cleared their investigational new drug application for MuSK-CAART. The company plans to initiate their first in-human trial of the cell therapy later in 2022.
The open-label, dose-escalation trial will start with a 100 million cell dose cohort that will receive the full dose as a single infusion. In the absence of any dose-limiting toxicities, each cohort is expected to enroll 2 patients. The second part of the trial will be a cohort expansion trial at a selected dose and Cabaletta plans to enroll around 20 patients in this part.
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“We believe the FDA’s decision to grant Fast Track Designation highlights the need for a treatment capable of potentially delivering deep and durable responses for patients living with MuSK-associated MG,” Chang added.1
MuSK-CAART's trial design builds off of Cabaletta’s other ongoing phase 1 DesCAARTes trial (NCT04422912) of DSG3-CAART in patients with mucosal Pemphigus Vulgaris (mPV). Cabaletta announced top-line data on biologic activity in 6 patients dosed in the 2 lowest dose cohorts in December 2021 that demonstrated some dose-dependent improvements in DSG3 autoantibody levels.2
“As the first targeted cell therapy clinical trial for patients with a B cell-mediated autoimmune disease, the DesCAARTes™ trial was designed with patient safety as the top priority. By starting with these low-dose cohorts, we have been able to administer the product to autoimmune patients, with no dose-limiting toxicities or clinically relevant adverse events observed to date,” Chang said in a previous statement.2 “While clear signs of DSG3-CAART biologic activity were not observed to date in the two lowest cell dose cohorts, the emerging clinical and serological data in one of the six patients who has improved since DSG3-CAART infusion is notable.”
The DesCAARTes trial is currently dosing patients in the fourth cohort with a dose of 2.5 billion cells and the third cohort has been dosed with no safety concerns. Cabaletta plans to further expand the trial to additional high dose cohorts.
"Our engagements and interactions with patients, investigators, and advocacy groups have given us confidence that patients with mPV are highly interested in a deep, durable, and potentially curative therapy, and we look forward to advancing the trial to potentially identify an optimal dose regimen that maximizes the opportunity for patients to achieve those goals, while maintaining a favorable safety profile,” Chang added.2
