Regeneron Pharmaceuticals Inc. (NASDAQ: REGN) and Telix Pharmaceuticals Limited (NASDAQ: TLX) announced a collaboration to develop and commercialize radiopharmaceutical therapies for cancer treatment.

Under the agreement, Telix will receive $40 million upfront for four initial therapeutic programs. The companies will share costs and profits equally on a 50/50 basis, with Telix retaining co-promotion rights for certain products. Regeneron has the option to expand the collaboration to include four additional programs with additional upfront payments.

Should Telix choose not to participate in the co-funding model for any program, it would instead receive up to $535 million in development and commercial milestone payments plus low double-digit royalties on net sales for that program. The total potential milestone payments across all programs could reach $2.1 billion.

The collaboration combines Regeneron's antibody discovery platforms and oncology experience with Telix's radiopharmaceutical development and manufacturing capabilities. The partnership will focus on multiple solid tumor targets from Regeneron's antibody portfolio, generated using its VelocImmune technology.

The companies also plan to jointly develop radio-diagnostics for patient selection and treatment response assessment. Telix will lead commercialization of diagnostic assets while Regeneron will receive a percentage of profits.

"Targeted radiopharmaceuticals represent a rapidly emerging frontier in oncology and an exciting opportunity to bring new treatment options to patients in need," said John Lin, Senior Vice President of Oncology & Antibody Technology Research at Regeneron.

The collaboration allows Regeneron to explore combining radiopharmaceuticals with its existing immunotherapy platform, particularly in areas such as lung cancer where its PD-1 inhibitor serves as a standard of care treatment.