Regeneron is buying something it cannot easily build: a radiopharmacy network, a chain of facilities that manufacture and ship radioactive drugs to hospitals before they decay. The Tarrytown, New York biotech announced a collaboration with Telix Pharmaceuticals on Monday, a deal structured to look like a licensing agreement but reads more like an acquisition of infrastructure. Telix gets $40 million upfront for the use of its manufacturing platform. The real money, if things go well, comes either through co-funding and profit-sharing or through opt-out milestone payments of up to $2.1 billion in aggregate for the initial four programs, plus royalties on sales.
Radiopharmaceuticals are drugs that carry a radioactive atom directly to tumors, guided by an antibody or small molecule that binds to cancer-specific proteins. The approach has been around for decades but the field had a breakthrough when Novartis's Pluvicto, which targets a protein called PSMA on prostate cancer cells, reached $605 million in the fourth quarter of 2025 alone, up 72% from the same period the prior year. For the full year, Pluvicto generated approximately $2 billion, up 43% year over year, according to Novartis financial results. Those numbers are why every major oncology company is now trying to get into the space.
Regeneron brings VelocImmune mice, a proprietary platform that generates fully-human antibodies, a technology that has underpinned much of its oncology work including the drug Libtayo, which posted $1.45 billion in 2025 sales. What Regeneron does not have is a way to manufacture and distribute radiolabeled drugs, which require a specialized supply chain because the radioactive isotopes decay within days.
Telix acquired that capability. The Melbourne, Australia-based company bought RLS Radiopharmacies in September 2024 for up to $250 million, gaining a network of radiopharmacies across the United States. It has also purchased the isotope production technology firm ARTMS for up to $82 million and a contract manufacturer called IsoTherapeutics for $13.6 million. The result is a vertically integrated supply chain that starts with isotope production and ends with a dispensed dose to a hospital or clinic. That is what Regeneron is buying access to.
The first program in the collaboration is TLX591, a radiolabeled antibody that targets the same PSMA protein as Pluvicto. TLX591 is in a Phase III trial called LITHE in metastatic castration-resistant prostate cancer. Early data from an earlier part of that study showed a safety profile consistent with this class of therapy, with Grade 4 low platelet counts occurring in 31% of patients and Grade 4 low white blood cell counts in 25%, rates that investigators said matched expectations for the mechanism.
William Blair analysts called the deal a validation of Telix's approach, noting that Regeneron's willingness to partner rather than build signals that Telix's infrastructure is genuinely scarce. The firms that can make and distribute radiopharmaceuticals at scale are currently few. Telix reported $804 million in revenue for fiscal 2025, up 56% year over year, and guided for $950 million to $970 million in 2026 revenue as its imaging agents Zircaix and Pixclara move toward potential approvals.
The deal structure gives Telix a choice at each program: co-fund development and share profits equally, or take the milestone and royalty path. The co-fund option is economically superior if the drug succeeds, because profit-sharing in a large market dwarfs flat milestone payments. The opt-out path is the insurance policy. Regeneron, meanwhile, pays a modest upfront fee to access a platform it would need years and hundreds of millions to replicate, and retains the ability to expand the collaboration to eight programs from four with additional payments.
Regeneron expects to record an acquired in-process research and development charge of approximately $102 million pre-tax in first quarter 2026 results related to this collaboration and other licensing agreements.
Whether $40 million is cheap or expensive for that access depends on what Telix's radiopharmacy network is actually worth. The RLS acquisition alone cost up to $250 million. If Telix's manufacturing edge is durable and the number of approved radiopharmaceutical programs grows as the field expects, Regeneron will have bought into the infrastructure at a fraction of its replacement cost.
