Andelyn Biosciences, a cell and gene therapy contract development and manufacturing organization, has entered into a collaboration with Tern Therapeutics to perform late-stage process performance qualification (PPQ) manufacturing of TTX-381, an investigational gene therapy targeting vision loss in children with CLN2 Batten disease. The partnership was announced on September 3, 2025, marking a significant milestone in advancing treatment for this ultra-rare pediatric neurodegenerative disorder.
Addressing an Urgent Medical Need
CLN2 Batten disease results from a deficiency in the TPP1 protein, with an estimated incidence of 0.5 per 100,000 live births. The disease follows a devastating trajectory, with symptoms typically appearing between ages two and four, beginning with seizures and developmental decline. Progressive vision loss follows soon after and can lead to complete blindness as early as age seven, underscoring the urgency for therapeutic development.
Currently, no treatments are available for the ocular manifestations of CLN2 disease, leaving affected children and families without effective options to preserve vision or maintain quality of life and independence.
Innovative Gene Therapy Approach
TTX-381 represents a novel therapeutic approach as a one-time, subretinal AAV gene therapy. The treatment is engineered to deliver a functional copy of the TPP1 gene directly to retinal cells, restoring enzyme activity with the goal of slowing or preventing vision loss. This targeted approach has the potential to profoundly improve patient quality of life and independence by preserving crucial visual function.
The therapy's design addresses the root cause of vision loss in CLN2 disease by replacing the deficient TPP1 protein through direct gene delivery to the affected retinal tissue.
Manufacturing Partnership and Expertise
The collaboration centers on Andelyn's specialized expertise in AAV vector manufacturing and its demonstrated track record in PPQ batch production. With more than 20 years of experience, Andelyn has produced cGMP material for more than 450 clinical batches and 75 global clinical trials, positioning the company as a key partner for advancing gene therapies toward commercial readiness.
"Partnering with Tern Therapeutics on this transformative program underscores Andelyn's commitment to enabling breakthrough therapies for rare and devastating diseases," said Matt Niloff, chief commercial officer at Andelyn. "Our deep experience in AAV process development and manufacturing, coupled with regulatory alignment and proven execution of PPQ batches, positions us to help bring this therapy to patients as efficiently and safely as possible."
Strategic Significance for Rare Disease Development
The late-stage PPQ manufacturing milestone represents a crucial validation step for the cell and gene therapy sector, demonstrating that production processes are consistent, reproducible, and capable of meeting regulatory requirements for potential commercial launch. Late-stage process validation remains one of the most challenging phases of gene therapy development, requiring both technical rigor and alignment with regulatory expectations.
Alex Bailey, chief executive officer at Tern, emphasized the importance of this manufacturing partnership: "We're excited to partner with Andelyn and leverage their long history with AAV technologies, strong late-stage manufacturing capability, and a shared dedication to rare disease patients. Together, we aim to deliver a therapy that has the potential to change the lives of children and families facing CLN2 Batten disease, providing hope where today there are no effective treatment options."
Industry Impact and Future Implications
This partnership highlights the critical role of specialized manufacturers in advancing therapies for rare diseases and demonstrates how external expertise in complex biologics manufacturing can accelerate the path from preclinical development to potential commercial approval. The collaboration also illustrates the maturing infrastructure supporting gene therapy commercialization, with increasing emphasis on process validation, scalability, and regulatory alignment.
For the pharmaceutical development community, the TTX-381 program represents both the promise of gene therapy for rare diseases and the importance of strategic manufacturing partnerships in delivering next-generation therapies to patients with urgent medical needs.
