Intrigue in radioligands, or drugs made of radioactive atoms attached to homing proteins, has been growing in the past few years, particularly for treating metastatic prostate cancer. Novartis and Endocyte have led that charge with Pluvicto, which is aimed at PSMA, an antigen overexpressed in prostate cancer cells.
Other biotechs have also emerged, including one literally named PSMA Therapeutics, hoping to go after that same target with a targeted radiation drug.
Not Aktis Oncology.
Aktis, while still a radioligand biotech, wants to take the success Endocyte and Novartis had in PSMA-positive prostate cancer to a myriad of other indications, though it won’t say what they are. Aktis CEO Matthew Roden did offer that the biotech has two lead programs, and “we are not going after PSMA.”
“Rather we took that finding and said we need to find a way to translate that into other commonly occurring tumor types,” Roden told
Endpoints News
.
So Aktis is building out a platform of mini-proteins that could direct radiation in the form of decaying atoms to an array of tumors. And now, the biotech has an additional $84 million to develop that portfolio and build out its radioisotope supply.
Aktis was born from MPM Capital in 2020 and launched from stealth a year later with $72 million, which included backing from Novartis and Bristol Myers Squibb. Now, the biotech has added a third Big Pharma backer in Merck’s venture arm.
Novartis bet $6B on the idea — now Versant, venBio have $45M to birth a platform play for radiopharmaceuticals
Aside from developing its homing protein platform, Aktis has also been tackling a key issue in the targeted radiation field — radioisotope supply. Radioisotopes, these large (relatively speaking), decaying atoms, are the crux of the approach: The particles they emit are lethal to cells. But Actinium-225, the radioisotope Aktis and others are using, hadn’t had much purpose before targeted radiotherapy came along.
So prior to 2020, when a key paper on an Actinium-225 radiotherapy was published, no one really was capable of making Actinium-225 at scale, Roden said.
The supply issue is further complicated by the very nature of radioisotopes — they decay.
“You can’t really build up an inventory of a drug that has a decaying isotope in it, so you have to make fresh ones every week,” Roden noted.
On Tuesday, Aktis
announced
three Actinium-225 supply contracts which use different methods to make the radioisotope. Roden said they will give Aktis access to the isotope through its preclinical, clinical and even commercial stages.
“That’s necessary, but not sufficient to have the end-to-end supply chain, and we have lots of work ongoing to continue to build out that network of supply that’s needed to deliver what we intend to be mainstream anti-cancer agents,” Roden said.
The radioligand space has grown substantially in the past few years. Novartis has been the frontrunner here,
with two approved drugs in Pluvicto
and Lutathera, which is indicated for certain digestive tract cancers.
Versant and venBio unveiled RayzeBio
in 2020. And last year,
Bayer bought PSMA Therapeutics
and its fellow Weill Cornell spinout Noria to buoy its own radiation therapy pipeline. Also last year, German biotech
ITM raised $109 million
as its radioligand for digestive tract cancers is going through a Phase III study. Just yesterday, the Australian biotech
AdvanCell disclosed an $18 million AUD round
led by Morningside.
Other new investors in Aktis included Cowen Healthcare Investments, MRL Ventures Fund, ArrowMark Partners, Mirae Asset Venture Investment, Timefolio Capital, and Pappas Capital. Aktis’ existing investors — MPM Capital, Vida Ventures, EcoR1 Capital, Octagon Capital, TCG Crossover, Bristol Myers Squibb, and Novartis — also pitched in.