Regeneron entered a global collaboration with Tessera Therapeutics to co-develop TSRA-196, a near-clinic in vivo gene-writing candidate for alpha-1 antitrypsin deficiency (AATD). The deal includes an upfront investment of roughly $150 million and gives Regeneron rights to advance a one‑and‑done genetic medicine into clinical testing. Tessera’s platform aims to write therapeutic sequences into the genome in situ, a distinct approach from nuclease-based editing. Company statements and industry reporting note the pact expands big‑biotech exposure to next‑generation gene‑writing modalities and accelerates TSRA‑196 toward human studies. Both firms framed the agreement as strategic: Regeneron strengthens its genetic‑medicine pipeline while Tessera secures development and commercialization muscle.