# Aptamer expands pipeline with targeted radiopharmaceutical initiative

- Link: https://www.directorstalkinterviews.com/aptamer-expands-pipeline-with-targeted-radiopharmaceutical-initiative/4121245158
- Published: 2026-03-18T07:26:21+00:00
- Author: Amilia Stone

**Aptamer Group plc** (LON:APTA), the developer of next‑generation synthetic binders
for the life sciences industry, has announced the launch of a new programme to develop
targeted radiopharmaceuticals, in collaboration with Radiopharmium Ltd, a UK-based
consultancy providing specialist expertise, contacts and access to facilities in
radiopharmaceutical development, from early research to manufacturing.

**Building a proprietary radiopharmaceutical pipeline**

In parallel to the project with a top 3 pharma partner developing radioligand delivery
vehicles (RNS dated 8 October 2025), Aptamer has identified three strategic therapeutic
targets, representing high‑value clinical conditions, for which Optimer® radioconjugates
will be developed. The targeted radiopharmaceuticals market is valued at approximately
US$7.5 billion in 2025 and is a high‑growth high priority sector, with current targeting
technologies presenting well-recognised limitations.

Radiopharmaceuticals deliver a radioactive payload directly to diseased tissue, 
but the payload can degrade the delivery molecule over time, shortening shelf life,
increasing waste, and complicating distribution. The industry standard is to add
protective additives, such as ascorbic acid. Based on recent studies, Aptamer believes
that the properties of its Optimer® platform, including enhanced tissue penetration,
reduced immunogenicity, and ease of chemical optimisation, position it well to address
these limitations and potentially provide differentiated therapeutic candidates.

**Demonstrating differentiated radioligand stability**

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

In comparative testing at 24 hours, Lu-177 Optimer®-based radioligands were stable
in the presence of ascorbic acid, a known antioxidant, showing only 8% degradation
in its absence. This compares with 34-83% degradation of leading peptide comparators
under the same conditions, in the absence of ascorbic acid.

The observed improvement in intrinsic stability, both with and without protective
additives, may support extended shelf life, reduced waste, and simplified handling
and logistics. This offers a potentially differentiated profile for Optimer®-radioligands
relative to existing approaches and may support ongoing and future collaborations
in radioligand imaging and therapy. 

**Programme development and milestones**

Optimers will be developed to targets initially and validated through _in vitro_
laboratory-based experiments. They will then be optimised and prepared for radiopharmaceutical
incorporation before further _in vitro_ and _in vivo_ studies to assess targeting
and therapeutic performance.

Combined with the Company’s existing partnered radiotherapy development programme
with a top‑3 global pharmaceutical company, this new initiative is expected to expand
Aptamer’s radiotherapy pipeline to four assets, with _in vivo_ data targeted for
delivery by the end of 2026.

**World‑class expertise and preclinical access**

The programme will be overseen by Dr Louis Allott, a member of Aptamer’s Scientific
Advisory Board and a recognised expert in the development and production of radiopharmaceuticals,
with direct experience spanning laboratory discovery through to clinical translation.

Through his consultancy, Radiopharmium Ltd, Dr Allott will take a fractional role
as Director of Radioligand Development for Aptamer, overseeing the radiochemical
conjugation of Optimer® binders and their biological evaluation in established preclinical
models. This work will involve the design, synthesis, and evaluation of radiolabelled
Optimer®‑based ligands in validated animal models to assess safety, targeting performance,
and therapeutic potential prior to clinical trials.

> **Dr Arron Tolley, Chief Executive Officer of Aptamer Group, commented:**
> “We are excited to launch this programme 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 programme 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.”

> **Dr Louis Allott, Chief Executive Officer of Radiopharmium Ltd, commented:**
> “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.”

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