Aptamer Group launches targeted radiopharmaceutical program

Aptamer Group plc, the developer of next‑generation synthetic binders for the life sciences industry, today announced the launch of a new targeted radiopharmaceutical program in collaboration with Radiopharmium Ltd, a UK-based specialist consultancy in radiopharmaceutical development.

A high growth market with unmet need

The targeted radiopharmaceuticals market is valued at approximately US$7.5 billion in 2025 and represents one of oncology’s fastest-growing sectors. Radiopharmaceuticals deliver a radioactive payload directly to diseased tissue, but a persistent challenge is the degradation of the targeting molecule once it carries a radioactive payload, shortening shelf life, increasing waste, and complicating distribution. The industry standard is to add protective additives such as ascorbic acid to mitigate this degradation.

Optimer^® platform: A potentially differentiated stability profile

Aptamer has previously developed fully integrated radioligand conjugates incorporating proprietary chemistry, linkers, and chelation systems, and evaluated their stability under clinically relevant conditions using Ga-68 (Gallium-68) and Lu-177 (Lutetium-177), radioactive isotopes widely used in cancer imaging and targeted therapy.

In comparative testing at 24 hours, Lu-177 Optimer^®-based radioligands demonstrated only 8 % degradation in the absence of protective additives, compared with 34–83 % degradation seen with leading peptide comparators under the same conditions. The company believes these results may support extended shelf life, reduced waste, and simplified logistics, offering a potentially differentiated profile relative to existing approaches.

Program development and milestones

Three strategic therapeutic targets, representing high-value clinical conditions, have been identified for Optimer^® radioconjugate development. The program will progress through in vitro validation before advancing to in vivo studies assessing targeting and therapeutic performance.

Key program highlights:

• Three therapeutic targets selected across high-value clinical indications
• Optimer^® radioconjugates to be validated in vitro before progressing to in vivo models
• Combined with the existing partnered program with a top 3 global pharmaceutical company, the pipeline is expected to comprise four radiotherapy assets
• In vivo data targeted for delivery by end of 2026

Expert leadership

The program will be led by Dr Louis Allott, CEO of Radiopharmium Ltd and a member of Aptamer’s Scientific Advisory Board. Dr Allott is a recognized expert in radiopharmaceutical development, with experience spanning laboratory discovery through to clinical translation. He will take a fractional role as Director of Radioligand Development for Aptamer, overseeing radiochemical conjugation and biological evaluation in established preclinical models.

Dr Arron Tolley, Chief Executive Officer of Aptamer Group, commented:

“We are excited to launch this program in a high‑growth field where the limitations of existing targeting technologies create a compelling opportunity for our Optimer^® platform.

A key challenge in radiopharmaceuticals is maintaining the stability of the targeting molecule once it is carrying a radioactive payload. Our data indicates that Optimer^®-based radioligands may offer improved stability compared to existing approaches, which could translate into practical advantages in manufacturing, distribution, and clinical use, subject to further validation.

With Louis leading this program and access to world-class preclinical models through Radiopharmium, we are well-positioned to advance multiple assets towards in vivo validation and further demonstrate the potential of our platform in this rapidly growing therapeutic field.”

I am delighted to be working with Aptamer, a recognised leader in the field of aptamer technology with a strong track record of success. The combination of Aptamer’s innovative Optimer^® platform and Radiopharmium’s expertise in radiopharmaceutical development makes this collaboration well‑positioned to demonstrate the potential of aptamer‑based targeting in next‑generation radiopharmaceuticals.”

Dr Louis Allott, Chief Executive Officer, Radiopharmium Ltd