Today Solid Bio shared an update on their gene therapy programs for SGT-001 and SGT-003. SGT-001 is Solid’s AAV9 microdystrophin gene therapy investigational product that is currently being evaluated in boys with Duchenne. SGT-003 is Solid’s next generation capsid (the vector that delivers a microdystrophin transgene) that they are developing to improve on current AAV capsids.

As shard in the community letter, Solid has closed enrollment in their Phase I/II IGNITE clinical trial with SGT-001. To-date 9 participants have received SGT-001, those participants will continue to be followed for 5 years to understand the impact of SGT-001. Solid made the decision to close enrollment to advance their gene therapy program and begin the process of commercial manufacture, which is a necessary step along the pathway of drug development for gene therapies. Solid is targeting a return to the clinic in 2023 with commercial product.

Solid also shared promising data on their novel SGT-003 capsid from pre-clinical studies. The data aligns with previous pre-clinical data which indicates that SGT-003 may increase delivery of microdystrophin transgenes to muscle, decrease the amount of virus that impacts the liver, and ultimately increase the expression of microdystrophin. They hope to submit an IND submission in early 2023 which would enable investigating the product in clinical trials.

Read the Community Letter

Dear Duchenne Community,

In a press release issued this morning, we shared an update to our company’s strategy and reiterated our commitment to advancing both of our gene therapy programs for Duchenne: SGT-001 and SGT-003. We wanted to provide you with a bit more context and what this means for the future of these ongoing programs.

SGT-001

Last month, we provided an update on patients dosed with SGT-001 two years after treatment. These data show sustained benefit two years after treatment compared with natural history trajectories across functional, pulmonary, and patient reported outcomes.

In the update provided this morning, we announced that we have decided to conclude enrollment in the IGNITE DMD Phase I/II clinical trial in order to transition to FDA engagement and planning for future clinical activities. Per study protocol, all patients dosed will continue with their scheduled follow-up visits 5 years post-infusion. As part of the clinical activities for IGNITE DMD, we will be developing a primary analysis of data from all nine patients who were treated in IGNITE DMD through the primary end point at one year. We plan to make information related to the full study, as well as individual patient data, available to all study participants.

We will also be making the shift to a commercially scaled transient transfection-based manufacturing process for SGT-001. Following a robust manufacturing analysis, we believe that by transitioning to a transient-based process, we will be able to produce a high-quality drug product and see improvements to manufacturability and clinical supply capabilities.

This was a natural opportunity for the company to complete enrollment in the study. We will be moving aggressively through the transition process and have already contacted the FDA to determine how we can rapidly return to the clinic with SGT-001. We expect to resume dosing with SGT-001 in the first half of 2023.

We would like to take this opportunity to express our immense gratitude for the patients who have participated in IGNITE DMD, and for all patients and families who choose to participate in clinical trials. Without your bravery and willingness to participate in clinical trials, we would not be able to advance this important science in our pursuit to develop meaningful therapies for Duchenne.

SGT-003

We also shared new data that support SGT-003, a novel, next generation capsid candidate that we believe may have meaningful advantages for the delivery of muscle-related gene therapies. New data from a non-human primate study using a reporter transgene in our novel capsid demonstrated increased muscle tropism, decreased liver biodistribution and improved efficiency compared with AAV9. These results are consistent with earlier in vitro and in vivo studies in mouse models, which suggested improved muscle tropism with our novel capsid as well as improved expression of Solid’s microdystrophin compared with AAV9. In the SGT-003 program for Duchenne, we combine this novel, muscle tropic capsid with our differentiated microdystrophin. We are excited about these compelling new data and remain on track for an anticipated early 2023 IND submission.

As a result of our decision to align Solid behind these two promising gene therapy programs, we had to make some tough choices to re-focus our resources. As part of the organizational changes, we will reduce our work force by approximately thirty five percent and curtail activities on our other research and development programs unrelated to SGT-001, SGT-003 and next generation capsids. We are grateful for the efforts and contributions of every employee who has worked tirelessly to advance our mission.

Thank you for your continued support of Solid. As always, our commitment to the Duchenne community is unwavering. We will continue to work every day with resolve and urgency towards the unified goal of developing meaningful treatments and improving the lives of patients with Duchenne.

Read the full community letter.

Read the Press Release:

Solid Biosciences Announces Updated Corporate Strategy to Develop SGT-001 and SGT-003 Pipeline Programs for Patients with Duchenne Muscular Dystrophy

April 27, 2022 at 7:30 AM EDT

– IGNITE DMD functional and durability patient data support advancement of SGT-001; Program transitioning to a commercially scaled transient transfection-based manufacturing process –

– Novel capsid development to continue, supported by new preclinical data; Company anticipates early-2023 Investigational New Drug (IND) submission for SGT-003 for Duchenne –

– Strategy and resource alignment support funding of operations through important clinical milestones and into Q2 2024 –

– Solid Biosciences reports first quarter 2022 financial results; Company to hold conference call at 8:00am ET today –

CAMBRIDGE, Mass., April 27, 2022 (GLOBE NEWSWIRE) — Solid Biosciences Inc. (Nasdaq: SLDB), a life sciences company focused on advancing meaningful therapies for Duchenne muscular dystrophy (Duchenne), today announced an update to its strategic priorities to focus on developing SGT-001 and SGT-003. The company also announced financial results for the first quarter ended March 31, 2022.

“Today, we are sharing changes to our corporate strategy to better align our resources behind Solid’s core values of innovation and patient centricity, with a focus on bringing our differentiated microdystrophin gene therapy to more patients. We will be transitioning SGT-001 to a commercially scaled manufacturing process, advancing SGT-003 toward an anticipated IND submission in early 2023, and aligning our organization behind these two programs,” said Ilan Ganot, Chief Executive Officer, President and Co-Founder of Solid Biosciences.

Mr. Ganot continued, “Recent data suggest that our lead program, SGT-001, holds meaningful promise as a potential treatment option. In addition, today we are sharing new preclinical data which suggest that Solid’s novel capsid may offer enhanced muscle tropism compared with AAV9, and has the potential to benefit patients with Duchenne as well as the broader gene therapy landscape for muscle-related disorders.”

SGT-001 Update
On March 14, 2022, Solid released data demonstrating that patients showed sustained benefit compared with natural history trajectories two years after treatment with SGT-001 across functional, pulmonary and patient reported outcome measures.

Manufacturing Update
As the company focuses on advancing SGT-001, it will be streamlining operations and making the strategic shift to a commercially scaled transient transfection-based manufacturing process. Following a robust manufacturing analysis, Solid believes that a new, outsourced process may provide improvements to manufacturability as well as additional organizational efficiencies.

Clinical Update
The company also announced that it has concluded enrollment in IGNITE DMD, its Phase 1/2 clinical trial for SGT-001, and will continue monitoring dosed patients for five years post-treatment. The company anticipates that future patients will be treated with SGT-001 manufactured using the new transient transfection-based process. Solid currently expects to continue dosing with SGT-001 in 2023.

SGT-003 Update
Today, Solid released new preclinical data suggesting that a novel, next generation capsid candidate may have meaningful advantages for the delivery of muscle-related gene therapies. New data from a non-human primate study using a reporter transgene in Solid’s novel capsid demonstrated increased muscle tropism, decreased liver biodistribution and improved efficiency compared with AAV9. These results are consistent with earlier in vitro and in vivo studies in both dystrophic (MDX) and wild type mouse models, which suggested improved muscle tropism with Solid’s novel capsid as well as improved expression of Solid’s microdystrophin compared with AAV9. Solid’s novel, muscle tropic capsid has been combined with the company’s differentiated microdystrophin for the SGT-003 program for Duchenne. The company remains on track for an early 2023 IND submission for SGT-003.

Strategic Prioritization, Corporate Update and Financial Position
The company also announced a reorganization of its corporate operations to prioritize the advancement of its key programs, SGT-001 and SGT-003. Solid anticipates that the use of transfection-based manufacturing processes for both SGT-001 and SGT-003 will allow the company to focus its operating structure and better leverage external manufacturing expertise. In addition, the company plans to narrow Research & Development activities to those related to SGT-001, SGT-003 and next generation capsids. In connection with these activities, the company will reduce its headcount by approximately 35 percent. The reorganization will result in a reduction in planned corporate expenditures which is anticipated to extend funding of operations through important clinical milestones and into Q2 2024.

Joel Schneider, Ph.D., Solid’s Chief Operating Officer, will also be leaving the company at the end of May to accept a role as the Chief Executive Officer for a privately held novel, viral-based gene therapy platform company.

“The strategic decision to streamline our manufacturing operations will allow us to consolidate our resources to support both SGT-001 and SGT-003 to important clinical milestones. I would like to extend my thanks and appreciation to the team members who were impacted by this reorganization. Each individual has made important contributions toward our mission of improving the lives of patients with Duchenne,” said Mr. Ganot.

Mr. Ganot added, “I would also like to thank Joel for his leadership and service to Solid over the last eight years, and for the instrumental role he played to advance the field of gene therapy for Duchenne towards scientific translation and clinical development, as well as the possibilities it brings to patients worldwide.”

Click here to read the full press release.