Actithera’s radiopharma assets irreversibly bind to their targets, allowing for longer retention of the drug inside tumors.
Massachusetts startup Actithera closed an oversubscribed series A financing Wednesday, beefing up its capital by $75.5 million to advance next-generation radiopharmaceuticals.
The money will help support the development of the company’s lead asset, a radioligand therapy that targets the fibroblast activation protein (FAP), for which it plans to initiate clinical studies in “multiple indications,” as per Wednesday’s release. Actithera did not reveal its priority indications nor did it specify a timeline for the asset’s early-stage development.
The series A round was co-led by M Ventures, Actithera’s founding investor, alongside new lead investors Sofinnova Partners, 4BIO Capital and Hadean Ventures. Other participating investors include second founding investor Arkin Bio Ventures II as well as Surveyor Capital and Bioqube Ventures.
Aside from advancing its lead FAP-targeting asset, Actithera will also use its series A proceeds to further develop its discovery engine, which allows the startup to produce radiotherapies that can form covalent and irreversible bonds with its targets to maximize treatment specificity. Actithera’s assets are also isotope-agnostic, meaning they can be designed to carry alpha- or beta-emitting payloads.
The use of covalent chemistry also leads to the “extended retention” of Actithera’s radioconjugates inside tumors, CEO and founder Andreas Goutopoulos said in a prepared statement on Wednesday. Ultimately, Actithera expects its covalent technology to provide patients with “more convenient dosing schedules and enhanced efficacy and safety,” Goutopoulos added.
With its series A round closed, Actithera enters the burgeoning radiopharma space, currently dominated by a handful of Big Pharma players. Leading the pack is Novartis, which owns two commercial radiotherapies: Lutathera, for gastroenteropancreatic neuroendocrine tumors, and Pluvicto, approved for metastatic castration-resistant prostate cancer. Last year, both drugs together earned more than $2.1 billion.
In building out their radiopharma pipelines, many of these industry powerhouses have turned to smaller players, licensing their assets or acquiring them outright. Eli Lilly is a prime example, signing a flurry of deals to beef up its radiopharma presence. In October 2023, for instance, the pharma bought Point Biopharma for $1.4 billion, following this up a few months later with a collaboration with Aktis Oncology worth a potential $1.1 billion and an up-to $1.14 billion deal with Radionetics Oncology.
AstraZeneca and Bristol Myers Squibb have also signed high-ticket acquisitions in the radiopharma space, with the former’s $2.4 billion buyout of Fusion Pharmaceuticals in March 2024 and the latter’s $4.1 billion takeover of RayzeBio in December 2023.
