New radiopharma Actithera emerges with $75.5m in financing

A new player in radioligand therapies (RLTs), Norway and US-based Actithera, has arrived on the scene with $75.5 million in first-round financing and a lead asset for cancer in preclinical development.

The proceeds will be used to move the RLT – which targets the cancer antigen fibroblast activation protein (FAP) – into clinical testing in "multiple indications," said the company, although it has not given any details of the lead indications or a timeline for those studies.

FAP is found in particular on the "stroma" of a tumour, an ecosystem of connective tissue and various non-malignant cell types like blood and immune cells that is thought to be involved in the origin and spread of cancers. Its presence tends to be associated with worse clinical outcomes.

The protein has attracted interest both as a way to diagnose and image tumours and as a target for radiopharmaceuticals that can direct cell-killing radiotherapy to them, reducing the risk of off-target side effects.

Biopharma companies have been trying to develop drugs that target FAP for some time, including Roche, which has taken multiple candidates into the clinic, but also chalked up a string of failed programmes. That list includes fusion protein simlukafusp alfa, which reached phase 2 before being dropped.

On the radiopharma front, Actithera is entering a category that already has a number of players, notably Novartis, which has licensed diagnostic and therapeutic candidates from 3B Pharma and iTheranostics, as well as Noria Therapeutics, which is partnered with Lantheus on a FAP-targeting imaging agent, and Eli Lilly with PNT2004, an early clinical-stage therapeutic acquired when it bought Point Biopharma in 2023.

Other players, meanwhile, include Philogen, Jiangsu HengRui, and Chengdu New Radiomedicine, which all have candidates in early-stage clinical development.

Actithera's take on the RLT category is the development of small-molecule radioligands that can overcome current challenges in radiopharma development, including targeting delivery specifically to the site of the cancer, achieving long tumour residence times, and rapidly clearing the RLT from the body to reduce toxicity.

The company reckons its FAP candidate offers "best-in-class potential due to its optimal pharmacokinetic profile and tumour specificity."

The Oslo and Cambridge, Massachusetts-based company was founded by former EMD Serono executive Dr Andreas Goutopolous, a medicinal chemist by training who will also serve as its chief executive.

"We set out to bring structure-based and kinetics-driven thinking from small-molecule drug design into the world of radiopharmaceuticals," he said. "We engineer our radioconjugates for extended retention within tumours, making them ideally suited for longer-lived radionuclides, and ultimately delivering more convenient dosing schedules and enhanced efficacy and safety for patients."

The Series A was co-led by founding investor M Ventures and new lead investors Hadean Ventures, Sofinnova Partners, and 4BIO Capital, with a syndicate that also included Bioqube Ventures, Surveyor Capital, and others.