Regeneron Pharmaceuticals has entered the radiopharmaceuticals field through a multi-programme collaboration with Telix Pharmaceuticals, marking a strategic expansion of its oncology pipeline into targeted radiation-based therapies.

The agreement brings together Regeneron’s antibody discovery and oncology development capabilities with Telix’s radiopharmaceutical expertise and manufacturing infrastructure. The companies will jointly develop and commercialise next-generation radiopharmaceutical therapies across multiple solid tumour targets, with four initial programmes planned under the collaboration and potential expansion to additional programmes.

Radiopharmaceuticals are an emerging class of cancer therapies that combine targeting molecules, such as antibodies or peptides, with radioactive isotopes designed to deliver radiation directly to tumour cells while limiting exposure to surrounding healthy tissue. The field has gained momentum as developers seek more precise treatment approaches in difficult-to-treat cancers.

Under the terms of the agreement, Regeneron and Telix will share costs and global commercialisation responsibilities on a 50/50 basis, with both companies participating in potential profits. Telix will receive an upfront payment of $40 million for access to its radiopharmaceutical manufacturing platform supporting the initial programmes, with additional payments linked to programme expansion.

The structure also includes milestone payments that could total up to $2.1 billion, depending on development and commercial progress, alongside low double-digit royalties in certain scenarios. Telix retains optionality to co-fund commercialisation or opt out in favour of milestone-based returns.

The collaboration includes the development of companion radiodiagnostic tools designed to support patient selection and monitor treatment response, reflecting the growing role of theranostic approaches in precision oncology.

John Lin, senior vice president of oncology and antibody technology research at Regeneron, said radiopharmaceuticals represent an expanding frontier in cancer treatment and an opportunity to extend the company’s biologics platform into new modalities.

He said the company plans to explore both monotherapy use and combination approaches with its existing immunotherapy portfolio, including in tumour types with high unmet need such as lung cancer.

Israel Lowy, senior vice president and oncology clinical development unit head at Regeneron, said the collaboration complements the company’s antibody engineering expertise and strengthens its ability to evaluate novel treatment modalities alongside established immunotherapy approaches.

Christian Behrenbruch, managing director and group chief executive of Telix Pharmaceuticals, said the partnership reflects the convergence of biologics and radiopharmaceutical development and supports the advancement of next-generation precision oncology programmes.

Radiopharmaceutical therapy has become an increasingly active area of investment across the oncology sector, as companies explore targeted alpha and beta-emitting isotopes combined with biologic delivery systems. The field has traditionally been constrained by manufacturing complexity and isotope supply limitations, but growing infrastructure investment is helping to expand clinical development activity.

The collaboration positions both companies to advance multiple programmes simultaneously across discovery, development and commercialisation stages, reflecting increasing industry interest in platform-based oncology partnerships rather than single-asset transactions.