Solid Bio clears partial hold, but DMD gene therapy trial is still on hold

Illustration of three DNA helices
Solid Biosciences waited until the day of its IPO to announce the partial clinical hold on the higher-dose portion of the study. (Darwin Laganzon)

Solid Biosciences halted the phase 1/2 trial of its Duchenne muscular dystrophy treatment in March, after being hit with a pair of FDA clinical holds. The biotech has now fixed the manufacturing issue that led to a partial clinical hold on the study, but the program remains at a standstill because of a full clinical hold imposed for safety concerns.

The Cambridge, Massachusetts-based company announced the partial hold, on the high-dose part of the IGNITE DMD trial, on the day of its IPO in January. The hold, relating to its manufacturing process for the gene therapy SGT-001, was placed in November, but Solid Bio failed to include it in its prospectus in December. It had planned to price its shares at $18 to $19 but dropped that to $16, ending up pricing a downsized IPO of $125 million.

While the partial hold and the company's initial handling of it was a setback, Solid Bio was allowed to carry on with the lower-dose portion of the trial until March, when the FDA slapped it with a full clinical hold because the first patient dosed in the trial was hospitalized "several days" after treatment. His lab tests showed a lowered platelet count and decreased red blood cell count, as well as complement activation, a type of immune response, which the FDA deemed a "Suspected Unexpected Serious Adverse Reaction." When Solid Bio announced the hold, the patient had been treated and did not have symptoms. The company's stock tanked 54% in after-hours trading.

In a new letter about the full clinical hold, the FDA ordered Solid Bio to provide additional information, including the underlying cause of the event, the patient's clinical status and laboratory parameters, and any new measures that will address patient safety.

“We believe SGT-001 has the potential to significantly benefit patients with DMD,” said Solid Bio CEO Ilan Ganot in the statement. “We are working with the FDA to better understand the unexpected event that resulted in the clinical hold and put a plan in place to monitor and manage potential events in the future. I am happy to share that the treating physician has reported the patient is doing well. “We are also pleased that we were able to lift the earlier partial clinical hold on the high dose of SGT-001 through our existing manufacturing process, which is an important ongoing development effort for our company.”