It’s safe to say that Solid Bio really needed some good news for the troubled Duchenne muscular dystrophy (DMD) gene therapy SGT-001 after a clinical hold and safety mishaps nearly broke the biotech.
The company will present new biopsy results Thursday for three patients that show “durable expression and function of microdystrophin protein” at 1.5 years after dosing at the World Muscle Society 2021 Virtual Congress.
DMD is a rare, incurable disease caused by mutations in the DMD gene that reduce production of a protein called dystrophin, leading to progressive muscle degeneration. Drug developers have zeroed in on boosting dystrophin production in an attempt to treat the disease, which primarily affects young boys.
In plain English, Solid is reporting it believes its therapy is successfully delivering a synthetic dystrophin gene to patients, which in turn is expected to show a benefit. The company also said the data show “encouraging evidence of functional benefit” and that patients have reported “meaningful improvement.” This is a small, early study with just eight patients, and Solid Bio is now only reporting data for patients four through six.
SGT-001 has struggled after adverse events forced a clinical shutdown of the phase 1/2 IGNITE trial in 2019. One patient who received a higher dose of the therapy showed signs of liver damage, while others experienced a decline in platelet counts and other side effects. These developments, along with manufacturing concerns, have erased Solid’s value at the stock market.
But Solid was finally able to get things back on track this year, reporting in March that the therapy had been administered to a handful of patients without causing any of the adverse events that had cropped up earlier. The company believed it had finally gotten the manufacturing right, and a clinical mitigation strategy had rescued the program.
Now, six months later, the new data are bringing a bit of green back to Solid’s share price—but there’s a lot of recovery to go. Solid was worth around $9.52 in March but had dropped to around $3 Thursday with a slow climb in premarket trading around 2%.
The bottom line is, we need more data, and one of Solid’s clinical investigators agrees.
“Data from additional patients should enhance our understanding of the role that SGT-001 may play in improving outcomes for patients with Duchenne,” said Vamshi Rao, M.D., a neurology physician from the Lurie Children’s Hospital of Chicago and assistant professor of pediatrics at the Northwestern University Feinberg School of Medicine.
Another hurdle for all companies developing DMD treatments—and it’s a full pipeline—is that while early data have proven treatments can boost dystrophin, actual efficacy data have not materialized. This has been a challenge for leading DMD treatment maker Sarepta Therapeutics, which has plenty of biomarker data but not a lot on whether patients actually benefit from treatment.
Sarepta has also been plagued by difficult side effects in clinical trials, but patients may be willing to accept certain adverse events given the challenging nature of the disease itself.
Meanwhile, Solid has been working to get on track after having to reduce its workforce by a third in January 2020. The company partnered with Ultragenyx in October 2020 for a $40 million infusion into the DMD program to develop new therapies—the same month the clinical hold was lifted for the IGNITE trial.
For now, we'll wait for more information. Additional analyses are expected after patients are two years out from dosing.