Cellectar Biosciences Signs Strategic Supply Agreement With Ionetix for Actinium-225 and Astatine-211 to Advance Targeted Alpha Therapy Development

Cellectar Biosciences, Inc, a late-stage clinical biopharmaceutical company focused on developing cancer therapies, announced that it has entered into a multi-year supply agreement with Ionetix Corporation. Ionetix is a recognized leader in cyclotron technology and a full-service manufacturer of radioisotopes. The agreement covers the supply of two key alpha-emitting radioisotopes, Actinium-225 (Ac-225) and Astatine-211 (At-211), which are essential for advancing targeted alpha therapy programs.

Under the terms of the agreement, Ionetix will supply Cellectar with a dependable, clinical- and commercial-scale source of cGMP-grade Ac-225 and At-211. This supply is intended to support Cellectar’s ongoing and future drug development activities, from clinical trials through potential commercial launches of its targeted alpha therapy candidates.

The Company stated that securing a consistent and scalable source of high-quality alpha-emitting isotopes is a critical step as it expands its radiotherapeutic pipeline beyond its current beta and Auger emitter programs. This includes advancing CLR-225 into clinical development as a potential treatment option for difficult-to-treat solid tumors, such as pancreatic cancer. The collaboration is expected to provide long-term isotope availability to support these efforts.

Cellectar’s proprietary phospholipid ether platform is designed to deliver a wide range of radioactive isotopes directly to tumor cells across multiple cancer types. This approach allows the Company to select the most suitable isotope for a specific tumor. When used with this platform, Ac-225 and At-211 are well suited for targeted alpha therapies because they emit highly localized, high-energy radiation that can destroy cancer cells while minimizing damage to surrounding healthy tissue.

Ionetix expressed its support for Cellectar’s development strategy and noted that it is expanding its production capabilities to meet growing demand. The company is in the process of installing a second cyclotron at its Michigan facility, which will allow for dedicated, commercial-scale production of Ac-225 and At-211. This expanded infrastructure is expected to support the continued development of next-generation targeted alpha therapies and ensure a reliable isotope supply as programs move toward later-stage development and potential commercialization.