TetraKit's EIC Accelerator Cancer Tracer Starts First Human Imaging

Radioactive cancer drugs are hard to make. A radioligand needs a molecule that finds the tumour and a radioactive atom that destroys it, and every pairing usually needs its own chemistry, often under time pressure because the isotope decays. TetraKit Technologies, a Copenhagen company founded in 2021, builds on a fast "click" reaction between a tetrazine and its partner molecule, so that the same kit can attach different radioactive atoms to different targeting molecules.

The EIC Accelerator selected TetraKit at its October 2024 cut-off for blended finance, and CORDIS records a grant of €2,458,700.30 for a project running from July 2025 to June 2027. Its goal is to take the lead drug, 131I-DualFAPi, toward clinical development in metastatic triple-negative breast cancer. A year in, according to its first periodic report, the animal toxicology is done and first-in-human imaging of the diagnostic twin of the drug has been initiated in Germany. The therapy itself has no clinical trial application yet.

A click reaction for radioactive drugs

TetraKit describes its tetrazine ligation and linker technology as ultrafast, which matters when the isotope decays while the drug is being made. The platform attaches radiohalogens such as fluorine-18, iodine-123, iodine-131 and the alpha emitter astatine-211, or radiometals, to targeting molecules "in a plug-and-play fashion", according to the project summary. The Hub lists four founders: Andreas Jensen as CEO, Matthias Herth as CSO, Umberto Battisti as head of R&D and Vladimir Shalgunov as director radiochemist.

The same chemistry allows matched pairs: one version of a molecule with an imaging isotope to find the tumours, and another with a therapeutic isotope to treat them, an approach known as theranostics. TetraKit's lead pair targets fibroblast activation protein, FAP: 123I-DualFAPi for imaging and 131I-DualFAPi for therapy.

A promising but small mouse study

In May 2026 the team published its preclinical comparison in the Journal of Nuclear Medicine. In mice with glioblastoma xenografts, 131I-DualFAPi-5 showed higher tumour uptake at four hours than a lutetium-177 FAP dimer, similar or better tumour-to-organ ratios, rapid renal excretion and no sign that iodine was being stripped off in the body. Three of six mice treated with the TetraKit compound reached near-complete remission around day 30, against one of six with the comparator. A higher dose of 60 MBq was stopped after 13 days because of toxicity. The radiolabelling gave a yield of 64% and a purity of at least 97%.

The authors themselves note that six mice per group are few and that larger studies are needed. The study also used a brain tumour model, while the EIC project targets breast cancer.

The first EIC year

The first periodic report, for July 2025 to June 2026, lists the main preclinical steps as done. The extended single-dose toxicology under good laboratory practice found nothing that would block clinical use, and the 131I-DualFAPi formulation was finalised with 24-hour stability at the injectable dose. The company transferred the 123I-DualFAPi imaging agent to University Hospital Magdeburg, prepared a first-in-human package under the German named-patient route and initiated first-in-human imaging. GMP precursor production is described as well advanced, and work on the investigator's brochure, the drug dossier and scientific advice with the European Medicines Agency has started.

What the report does not contain is just as telling. It gives no number of patients imaged and no imaging or dosimetry data, and no clinical trial application for the therapy has been submitted. The report puts overall implementation at about 45%.

1. GLP toxicologyDeliveredExtended single-dose study completed, no blocking findings (deliverable D1.1).
2. First-in-human imaging with 123I-DualFAPiStartedInitiated at University Hospital Magdeburg; no patient numbers or images published.
3. GMP manufacturingAdvancedFormulation fixed; GMP precursor production well advanced.
4. Phase 1/2 trial of 131I-DualFAPiNot startedNo clinical trial application submitted by June 2026.

Funded by loans and grants

Before the EIC, TetraKit was financed by Copenhagen's BioInnovation Institute: a €500,000 convertible loan from its Venture Lab and a further €1.3 million from its Venture House programme, for €1.8 million in total, announced in March 2023. No priced investment round has been announced, and whether the EIC Fund has invested the equity part of the blended award is not public. The company's Danish accounts were not available for this article, so its losses and cash position are not known here.

The CORDIS objective is explicit about the plan: complete a Phase 1/2 programme and then sign a strategic partnership for later development and commercialisation. That partnership depends on clinical data the project has not yet produced.

Europe's stake

The EIC grant pays for the expensive step from the lab to the first patients for a platform developed in Copenhagen, with its first human imaging at a German university hospital and scientific advice from the European Medicines Agency. If the platform works across isotopes and targets as claimed, its value lies in being reusable: one chemistry for many radiopharmaceuticals rather than a new process for each.