Ironfist Therapeutics Announces Preclinical Proof of Concept for Novel Nanomedicine Radiopharmaceutical, Tamrada™

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REDWOOD CITY, Calif.--(BUSINESS WIRE)--Oct 3, 2025--

Ironfist Therapeutics ("Ironfist"), a preclinical-stage company developing a nanomedicine radiopharmaceutical (Tamrada) that selectively targets tumor associated macrophages without a targeting ligand, will be presenting positive preclinical proof of concept results in anti-PD-1 resistant triple negative breast (TNB) cancer models using 177 Lu-Tamrada at the 38 th Annual Congress of the European Association of Nuclear Medicine (EANM).

TNB cancer is aggressive and unresponsive to anti-PD-1 antibody therapy in humans and preclinical models. Previous studies in the TNB cancer (4T1) mouse model presented at the Society for Nuclear Medicine and Molecular Imaging (SNMMI 2025) indicated a maximum 64 Cu-Tamrada uptake of 41% ID/g in tumors. In this follow-up study, xenograft and orthotopic TNB cancer models were treated with the 177 Lu-Tamrada at different radiation doses and regimens with and without anti-PD-1 antibody.

Key findings include:

• Tamrada was tuned to optimize selectivity for TAMs and retention of 177 Lu to maximize in vivo delivery to tumors
• 177 Lu-Tamrada was retained in TAMs for over 10 days from a single administration (SPECT/CT)
• 177 Lu-Tamrada alone caused tumor inhibition in both xenograft and orthotopic 4T1 mouse models
• 30 MBq 177 Lu-Tamarada alone as a single or fractionated equivalent total dose (2x or 3x/week) caused significant (p < 0.05) tumor growth inhibition in orthotopic 4T1 tumor bearing mice compared to vehicle and anti-PD-1 treated mice.
• At equivalent total radiation doses, fractionated doses were better tolerated and caused greater tumor accumulation than single doses.

"These preclinical results coupled with our other 7 studies in a range of tumor types clearly demonstrate the therapeutic potential of targeting TAMs," said Jeffrey L Cleland, PhD, Chief Executive Officer of Ironfist Therapeutics. “With this theragnostic approach, 64 Cu/ 177 Lu-Tamrada has the potential to precisely treat a wide range of tumors, kill tumor cells through bystander effects, and unlock the immune system. We look forward to sharing our compelling efficacy results in a PSMA negative mouse model at a subsequent meeting in 2026.”

Unlike other radiopharmaceutical approaches, Tamrada is tumor agnostic because it is directly targeting TAMs. TAMs protect the tumor from the immune system, stimulate angiogenesis, and generate metastases. The hydroxyl dendrimer core of Tamrada was tuned specifically for selective uptake by TAMs without off target uptake in other macrophages. Once taken up by TAMs, Tamrada is not metabolized and is retained within the cells for up to one month providing a persistent source of radiation in the tumor with systemic clearance within 2-3 days.

Presentation Details:

Selective Killing of Tumor Associated Macrophages with a [ 177 Lu]Lu-Nanomedicine Unlocks Checkpoint Inhibition

About Tamrada

Tumors often enlist tumor-associated macrophages (TAMs) as protectors, shielding them from the immune system. Tamrada changes the story — reprogramming or removing these suppressive cells so the immune system can see the tumor clearly and strike with full force. Tamrada is designed from the novel nanomedicine technology of hydroxyl dendrimers invented at Johns Hopkins University. The nanomedicine component of Tamrada is comparable in size to an antibody fragment, does not leave the vasculature except in tumors, and has renal and biliary clearance without metabolism. 64 Cu/ 177 Lu-Tamrada enables precision dosing of cancer patients using a theragnostic approach. 177 Lu-Tamrada provides an additional benefit of a bystander effect by killing adjacent tumor cells. The nanomedicine in Tamrada is amendable to modifications to create a pipeline of radiopharmaceuticals with different radioisotopes.

About Ironfist Therapeutics

Ironfist Therapeutics is advancing a new class of nanomedicine radiopharmaceuticals that selectively target tumor associated macrophages. Our precision medicine approach to treat any tumor with TAMs has the potential to change the paradigm in cancer treatment by unlocking the immune system. Ironfist Therapeutics was founded by Jeff Cleland, Jay Zaveri, Arjun Sethi, Kannan Rangaramanujam, and Sujatha Kannan. For more information visit: www.ironfisttx.com

View source version on businesswire.com:https://www.businesswire.com/news/home/20251003915815/en/

CONTACT: Jeffrey L. Cleland, PhD

[email protected]

KEYWORD: CALIFORNIA UNITED STATES NORTH AMERICA

INDUSTRY KEYWORD: BIOTECHNOLOGY HEALTH RADIOLOGY PHARMACEUTICAL ONCOLOGY

SOURCE: Ironfist Therapeutics

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PUB: 10/03/2025 08:00 AM/DISC: 10/03/2025 08:01 AM

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