Regeneron and Tessera Therapeutics Partner to Develop TSRA-196, an Investigational Gene Editing Therapy for Alpha-1 Antitrypsin Deficiency
Tuesday, December 02, 2025
Regeneron Pharmaceuticals and Tessera Therapeutics have entered a global partnership to develop and commercialise TSRA-196, an investigational in vivo Gene Writing therapy for alpha-1 antitrypsin deficiency (AATD).
AATD is a genetic condition caused by mutations in the SERPINA1 gene, which is responsible for producing alpha-1 antitrypsin, a protein that protects lung tissue. Severe AATD, often linked to the Z allele, causes the protein to misfold and build up in the liver, leading to inflammation and fibrosis. Low levels of circulating protein also increase the risk of lung damage, including COPD and emphysema.
Approximately 200,000 people in the U.S. and Europe have the PiZZ genotype, which reduces serum AAT to about 15% of normal levels. There are currently no FDA-approved treatments that target the genetic cause of the condition, and current therapies are limited to weekly intravenous augmentation for patients with lung involvement.
TSRA-196 aims to correct the genetic mutation that causes the disease and restore the production of functional alpha-1 antitrypsin protein through a potential one-time treatment.
Tessera plans to submit an Investigational New Drug application and several Clinical Trial Applications to the U.S. FDA by the end of the year.
The collaboration combines Regeneron’s experience in genetic medicines with Tessera’s Gene Writing technology and non-viral delivery platforms. Both companies will share the global development costs and any future profits equally. Tessera will receive US$150 million, including an upfront cash payment and equity investment, and may receive up to US$125 million in development milestone payments. Tessera will lead the first-in-human study, while Regeneron will take responsibility for later-stage global development and commercialisation.
The partnership follows promising preclinical data presented at a recent gene and cell therapy meeting. Findings showed durable and accurate editing of SERPINA1—the gene linked to AATD—in mice and non-human primates after a single dose. The data indicated strong liver-targeted editing, no germline or off-target changes, and favourable safety outcomes using Tessera’s lipid nanoparticle delivery system. These results support the transition of TSRA-196 into clinical development.
The agreement is subject to standard closing conditions, including regulatory clearance under the Hart-Scott-Rodino Antitrust Improvements Act in the United States.
Source: regeneron.com
