“Today, you could estimate that one family per day is being treated with and impacted by gene therapy. We want to see that increase to 10s, 100s, 1,000s per day, and reaching that goal comes from investing in research, clinical trials and manufacturing,” said Ken Mills, CEO of clinical stage US biotechnology company, Regenxbio.
Regenxbio, said its CEO, has played a pivotal role in the gene therapy industry since its founding in 2008, as a result of research from the lab of gene therapy pioneer, Jim Wilson, University of Pennsylvania.
The company's NAV technology platform consists of over 100 novel adeno-associated virus (AAV) vectors, one of which was used in the US Food and Drug Administration (FDA) approved gene therapy, ZOLGENSMA, for spinal muscular atrophy in children under two years old.
The developer has also licensed out its technology to a growing list of partners and licensees that includes Novartis, Eli Lily and Pfizer and has a robust in-house pipeline of candidates for retinal and rare diseases.
Regulatory roadblocks
Looking at the US gene therapy regulatory landscape, what are the current roadblocks?
“AAV-mediated gene therapies offer the possibility of a one-time administration that could address the underlying disease and change the way critical medicine is delivered to patients, but the regulatory landscape has not evolved as quickly as the innovations of AAV gene therapy.
“We’ve seen that the FDA is open to working with industry and gene therapy stakeholders to determine the appropriate path forward, to streamline clinical development and get medicines to patients faster. Leveraging accelerated approvals and surrogate endpoints in clinical trials, such as a biomarker, may play a large role,” Mills told BioPharma-Reporter.
The Pathway Development Consortium (PDC) launched in 2021 by Regenxbio and Solid Biosciences is working to advance opportunities to leverage the FDA’s accelerated approval pathway for gene therapy candidates.
“Our mission to bring together patients, industry, regulators, academia, payers and other stakeholders for meaningful scientific and policy discussion,” said the CEO.
Manufacturing capacity
There is a significant strain on manufacturing capabilities in the gene therapy sector – both capacity and reproducibility, but more importantly, talent, commented Mills.
“As the sector has grown rapidly and expanded broadly, we have seen these rate-limiting factors continue to persist. In addition, significant strain on supply chains is likely to continue into 2022 and will impact pharma and biotech. Consistent, reliable manufacturing is critical to gene therapy trial development, product approval, and commercialization, so it is crucial to overcome these capabilities challenges.”
Contract development and manufacturing organizations (CDMOs) are critical partners, said the executive, and he anticipates continued investment in manufacturing capabilities through in-house facilities and CDMOs next year.
“And as the field continues to advance, we will start to see more and more efficiencies that companies like Regenxbio can capitalize upon to allow for rapid manufacturing and formulation development.”
Investments
Regenxbio has invested in the establishment of a “robust” suspension cell culture-based manufacturing process and new manufacturing facility at its headquarters in Rockville, Maryland.
“We have also invested to ensure the hiring of the right people to make this possible. Five to 10 years ago, you did not see a lot of process development teams, and now they are crucial to drive the scalability of capabilities across clinical and commercial strategy.”
Through the expansion of its expert manufacturing team and facility build out, he said the company’s researchers and process development team have been able to work side by side to mitigate potential issues early in the development process.
The goal is always to get therapies approved and to patients as quickly as possible, and a reliable, scalable chemistry, manufacturing and controls (CMC) process is crucial in accomplishing this, said Mills.
“Our philosophy initially was to develop the best process platform that could be utilized across multiple programs with a highly similar process that could be easily transferred to a CDMO. We also have a platform downstream process developed that works across our programs, giving consistent downstream yields that are appropriate for the current phase of development.
“We have developed proprietary formulations that are indication-specific. The formulations are stable at the intended storage conditions over several years and we have ongoing monitoring of product quality during that period to ensure consistent performance.”
A look back…
In terms of the highlights for the biotech this year, Mills said it was a fast paced, high-achieving 12 months for the company.
“In September, we announced a partnership with AbbVie to develop and commercialize RGX-314, our gene therapy for the treatment of wet AMD, diabetic retinopathy, and other chronic retinal diseases. Under the terms of the agreement, AbbVie will provide Regenxbio a US$370m upfront payment with the potential for the company to receive up to US$1.38bn in additional development, regulatory and commercial milestones.
“We are currently running a pivotal program of RGX-314 for the treatment of wet AMD, and we expect to file a BLA in 2024. We are also conducting additional trials evaluating RGX-314 delivered directly to the suprachoroidal space of the eye for the treatment of wet AMD and diabetic retinopathy. In 2021, we reported initial data from both of those trials.”
Regenxbio also announced, early in 2021, a new pipeline candidate for treating Duchenne muscular dystrophy (Duchenne) - RGX-202. That is designed, said Mills, to deliver an optimized microdystrophin transgene with a unique C-terminal domain and a muscle specific promoter to support targeted therapy for improved resistance to muscle damage associated with Duchenne.
“We received Orphan Drug Designation from the FDA in November and shared that we expect to submit an Investigational New Drug (IND) application to the FDA for RGX-202 by the end of 2021.
“Commercial-scale cGMP material has already been produced at 1,000 liter capacity using our suspension cell culture manufacturing process, and the company's internal cGMP facility is expected to allow for production up to 2,000 liters for the clinical development of RGX-202.”
