Radiopharm Theranostics Presents Initial Findings from Phase 1 Trial of 177Lu-RAD202 in HER2+ Solid Tumors

New data shows promising tumor uptake and favorable safety profile in first-in-human study of novel radiopharmaceutical therapy

Apr. 20, 2026 at 11:42am

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A glowing, neon-outlined HER2 receptor molecule against a dark background, conceptually representing the targeted approach of a new radiopharmaceutical therapy.A novel radiopharmaceutical therapy targets HER2-positive cancer cells with precision and energy.San Diego Today

Radiopharm Theranostics, a clinical-stage biopharmaceutical company, announced that new data from the ongoing Phase 0/1 HEAT trial evaluating 177Lu-RAD202, a first-in-class HER2-targeted radiopharmaceutical therapy, will be presented at the American Association for Cancer Research (AACR) Annual Meeting 2026. The initial findings from the lowest dose cohort of three patients with advanced HER2-positive breast and urothelial cancers showed meaningful tumor uptake of 177Lu-RAD202 and a favorable safety profile, supporting continued dose escalation which was recently approved by the Data Safety and Monitoring Committee.

Why it matters

The development of 177Lu-RAD202 represents an important advancement in HER2-targeted radiopharmaceutical therapies, which have the potential to provide a new treatment option for patients with HER2-positive advanced solid tumors who have limited effective treatment options. The initial positive results from the HEAT trial demonstrate the therapeutic potential of this novel approach and pave the way for further evaluation at higher, more therapeutic dose levels.

The details

In the first-in-human HEAT trial, 177Lu-RAD202 demonstrated encouraging tumor uptake and a favorable safety profile in the lowest dose cohort of three patients with advanced HER2-positive breast and urothelial cancers. No dose-limiting toxicities or treatment discontinuations due to adverse events were observed, and the observed dosimetry supported continued dose escalation. The Data Safety and Monitoring Committee recently approved advancing 177Lu-RAD202 to the next highest dose of 130 mCi.

  • The AACR poster presentation will take place on April 20, 2026 at 9:00 AM PT.
  • On April 8, 2026, Radiopharm Theranostics announced the positive recommendation from the Data Safety and Monitoring Committee to advance 177Lu-RAD202 to the third cohort at a dose level of 130mCi in the Phase 1 HEAT clinical trial.

The players

Radiopharm Theranostics

A clinical-stage biopharmaceutical company focused on developing innovative oncology radiopharmaceuticals for areas of high unmet medical need.

Dr. Dimitris Voliotis

Chief Medical Officer of Radiopharm Theranostics and the presenter of the AACR poster.

177Lu-RAD202

A first-in-class HER2-targeted radiopharmaceutical therapy being evaluated in the HEAT trial.

HEAT trial

A first-in-human, open-label, multicenter integrated Phase 0/1 study evaluating 177Lu-RAD202 in patients with HER2-positive locally-advanced or metastatic solid tumors.

Data Safety and Monitoring Committee (DSMC)

A multidisciplinary committee that conducts detailed reviews of study data, discusses potential safety events, and provides recommendations regarding trial continuation.

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What they’re saying

“These first-in-human results represent an important early milestone for our HER2-targeted radiopharmaceutical program. In a heavily pre-treated patient population with significant unmet need, 177Lu-RAD202 demonstrated encouraging tumor uptake and a favorable safety profile at the lowest dose level. Importantly, the observed dosimetry supports continued dose escalation, which was recently approved by the Data Safety and Monitoring Committee (DSMC) to advance to the third cohort at 130 mCi dosing. We look forward to further evaluating the therapeutic potential of this novel approach and expect to see signs of antitumor activity at higher, more therapeutic dose levels.”

— Dr. Dimitris Voliotis, Chief Medical Officer of Radiopharm Theranostics

What’s next

The Data Safety and Monitoring Committee has approved advancing 177Lu-RAD202 to the third cohort at a dose level of 130mCi in the Phase 1 HEAT clinical trial.

The takeaway

The initial positive results from the HEAT trial of 177Lu-RAD202, a novel HER2-targeted radiopharmaceutical therapy, demonstrate its potential to provide a new treatment option for patients with HER2-positive advanced solid tumors who have limited effective treatment options. The continued advancement of this therapy through the clinical trial process is an important step forward in addressing this significant unmet medical need.