{"entity":{"id":"actithera","kind":"company","name":"Actithera","aka":[],"tldr":"Actithera designs small radioactive drugs that stick to a protein found around many solid tumours (FAP) and stay there longer, so more of the radiation reaches the cancer. Its first medicine was being prepared for human trials in 2026.","summary":"Actithera is a radiopharmaceutical biotech headquartered in Oslo, Norway and Cambridge, Massachusetts. It was founded in 2021 by Andreas Goutopoulos with seed investors M Ventures and Arkin Bio Ventures II, and came into public view with a USD 75.5 million Series A in July 2025, co-led by M Ventures, Hadean Ventures, Sofinnova Partners and 4BIO Capital, with Bioqube Ventures, Innovestor, Investinor, Surveyor Capital and Arkin Bio Ventures II participating. Its discovery platform applies medicinal chemistry to small-molecule radioligands, including covalent-targeting chemistry licensed from the Weizmann Institute, to lengthen tumour residence time while keeping systemic clearance rapid; the company describes its approach as isotope-agnostic and suited to longer-lived radionuclides. The lead development candidate is directed at fibroblast activation protein (FAP), and the company's site says it has an asset in IND-enabling studies.","asOf":"2026-10-29","links":[{"label":"Official website","url":"https://actithera.com/"},{"label":"Series A press release (PDF)","url":"https://actithera.com/wp-content/uploads/2025/07/250709-Actithera-Series-A-PR-Final.pdf"},{"label":"BioPharma Dive: Actithera Series A","url":"https://www.biopharmadive.com/news/actithera-radiopharmaceutical-cancer-series-a/752493/"},{"label":"News and press","url":"https://actithera.com/recent-news-press/"}],"tags":[],"related":[],"cancers":[],"sections":["radiopharma"],"technologies":["radioligand-therapy"],"targets":["fap"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Included because the July 2025 Series A was its first announced financing; the founding year (2021) and investors are from the company's own Series A press release of 9 July 2025. The isotope for the FAP candidate is not disclosed. Steven Kelly is named as CEO on the current website; the Series A release named Goutopoulos as founder and CEO."],"hq":"Cambridge, MA","country":"US","companyType":"radiopharma","website":"https://actithera.com/","founded":2021,"stage":"startup","investors":["sofinnova-partners"],"funding":[{"round":"Series A","year":2025,"amountUsd":75500000,"source":"https://actithera.com/wp-content/uploads/2025/07/250709-Actithera-Series-A-PR-Final.pdf"}]},"route":"/companies/actithera/","neighbours":{"section":[{"id":"radiopharma","kind":"section","name":"Radiopharmaceuticals & Theranostics","route":"/fronts/radiopharma/"}],"technology":[{"id":"radioligand-therapy","kind":"technology","name":"Radioligand therapy (beta emitters)","route":"/technologies/radioligand-therapy/"}],"target":[{"id":"fap","kind":"target","name":"FAP","route":"/targets/fap/"}],"company":[{"id":"sofinnova-partners","kind":"company","name":"Sofinnova Partners","route":"/companies/sofinnova-partners/"}]}}