Radiopharm Theranostics Receives Positive Recommendation from Data Safety and Monitoring Committee to Advance to Cohort 4 in 177Lu-RAD202 Phase 1 HEAT Clinical Trial

Rhea-AI Summary

Radiopharm Theranostics (ASX: RAD, Nasdaq: RADX) reported that the independent Data Safety and Monitoring Committee has issued a positive recommendation to advance its Phase 1 ‘HEAT’ trial of radiotherapeutic candidate 177Lu-RAD202 (RAD202) in HER2-positive advanced solid tumors to Cohort 4 at a 180mCi dose level.

According to the company, the DSMC’s review supports the safety profile observed so far and enables continued evaluation at higher doses at clinical centers across Australia. RAD202 is a proprietary single-domain monoclonal antibody targeting HER2; in a previous diagnostic study in ten HER2-positive breast cancer patients it showed clinical proof-of-concept with positive safety and biodistribution.

Positive

• DSMC backs dose escalation to 180mCi Cohort 4 in Phase 1 HEAT
• Favorable safety profile cited by DSMC to support trial continuation
• Prior proof-of-concept in ten HER2-positive breast cancer patients with positive safety and biodistribution
• Active clinical pipeline including one Phase 2 and five Phase 1 trials in solid tumors

Negative

• None.

Argus Aug 20 session 6 alerts

-8.40% close to close 6.3x rel. volume Open Argus

Details

Market move: RADX -8.40% in the Aug 20 session. Phase 1 cohort advancement

-5.5% Trough in 1 hr 29 min

$18.76M Market Cap

On Aug 20, the day this news came out, RADX closed 8.40% below the previous close. Argus tracked a trough of -5.5% from its starting point during tracking. Our momentum scanner recorded 6 alerts for this stock that day. Relative volume reached 6.3x the daily average during tracking.

Data tracked by StockTitan Argus for the Aug 20 session.

Key Figures

Next dose level: 180mCi Trial phase: Phase 1 Prior dose level: 130mCi +2 more

Next dose level

180mCi

Phase 1 HEAT trial, Cohort 4

Trial phase

Phase 1

HEAT clinical trial

Prior dose level

130mCi

Previous HEAT dose level announced April 8, 2026

Diagnostic study patients

10 patients

Previous HER2-positive breast cancer diagnostic study

Announcement date

August 20, 2026

Company announcement

Previous Clinical trial Reports

5 past events · Latest: Aug 17

Same Type 5 events

1. Aug 17

   FDA trial planning

   24h Move

   +4.3%

   FDA meeting scheduled to align on RAD101 pivotal Phase 3 design

2. Apr 20

   Phase 1 clinical data

   24h Move

   +4.6%

   Initial HEAT findings showed tumor uptake and no dose-limiting toxicities

3. Apr 08

   Phase 1 cohort advancement

   24h Move

   +3.0%

   DSMC recommended advancing RAD202 to 130mCi Cohort 3

4. Mar 27

   Phase 1 trial initiation

   24h Move

   +0.0%

   First patient was dosed in the RAD402 Phase 1 prostate cancer study

5. Mar 24

   Phase 2 clinical data

   24h Move

   -10.8%

   RAD101 achieved its primary endpoint in 90% of evaluable patients

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Key Terms

data safety and monitoring committee, biodistribution, single-domain monoclonal antibody, radiotherapeutic

4 terms

data safety and monitoring committee medical

"received a positive recommendation from the Data Safety and Monitoring Committee (DSMC)"

An independent panel of experts that regularly reviews patient safety data and trial results during a clinical study to protect participants and ensure the study is producing reliable information. Like impartial referees who can pause, modify, or stop a trial if safety concerns or clear benefits appear, their findings can alter a drug or device’s development timeline, regulatory prospects, and investor risk, so their assessments matter for company value and timelines.

biodistribution medical

"demonstrated clinical proof-of-concept and had positive safety and biodistribution"

Biodistribution is the map of where a drug, vaccine, or diagnostic agent travels and accumulates inside the body after administration. Investors care because where a product ends up affects how well it works, what side effects it may cause, and whether regulators will approve it—similar to tracking dye in a plumbing system to find leaks or blockages; unexpected destinations can raise safety, cost, and market-adoption risks.

single-domain monoclonal antibody medical

"RAD202 is a proprietary single-domain monoclonal antibody (sdAb)"

A single-domain monoclonal antibody is a small, lab-made protein that binds to one specific part of a single target molecule, like a tiny key made to fit one lock. Because it is smaller and simpler than traditional antibodies, it can reach tight spaces on a target and be cheaper to produce, so its specificity, manufacturability, and clinical effects are key factors investors watch when assessing therapeutic potential and commercial value.

radiotherapeutic medical

"advance its clinical-stage radiotherapeutic asset, 177Lu-RAD202"

A radiotherapeutic is a medical treatment that uses high-energy radiation — such as focused X-rays, gamma rays or radioactive particles — to kill or damage diseased cells, most often cancer. Investors care because these products require specialized manufacturing, clinical testing and regulatory approval, carry unique safety and distribution challenges, and can command significant market value if proven effective, much like a precision tool that needs careful handling and certification before wide use.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Advancing RAD202 Phase 1 trial to next dose level of 180mCi in patients with HER2+ advanced solid tumors

Previous diagnostic study of RAD202 in ten HER2-positive breast cancer patients demonstrated clinical proof-of-concept with positive safety and biodistribution

SYDNEY, Aug. 20, 2026 (GLOBE NEWSWIRE) -- Radiopharm Theranostics (ASX: RAD, Nasdaq: RADX, “Radiopharm” or the “Company”), a clinical-stage biopharmaceutical company focused on developing innovative oncology radiopharmaceuticals for areas of high unmet medical need, today announced that it has received a positive recommendation from the Data Safety and Monitoring Committee (DSMC) to advance its clinical-stage radiotherapeutic asset, 177Lu-RAD202 (RAD202), to the next dose level of 180mCi in the Phase 1 ‘HEAT’ clinical trial in patients with Human Epidermal Growth Factor Receptor 2 (HER2)-positive advanced solid tumors¹. The DSMC is a multidisciplinary committee that conducts detailed reviews of study data, discusses potential safety events and provides recommendations regarding trial continuation.

“Advancing RAD202 into Cohort 4 marks a significant step forward in the development of one of our most promising therapeutic candidates,” said Riccardo Canevari, CEO and Managing Director of Radiopharm Theranostics. “The DSMC’s recommendation supports the favorable safety profile observed to date and allows us to continue evaluating higher dose levels in patients with HER2-positive advanced solid tumors. As we execute on our clinical development strategy, we remain focused on unlocking the full potential of RAD202 and generating meaningful data that could support a differentiated radiotherapeutic option for HER2-positive patients in need of new treatment alternatives.”

The Phase 1 ‘HEAT’ study is currently being conducted at clinical centers across Australia. The announcement of the previous dose level in this study of 130mCi was released on 8 April 2026.

About 177Lu-RAD202:

RAD202 is a proprietary single-domain monoclonal antibody (sdAb) that targets the Human Epidermal Growth Factor Receptor 2 (HER2)-positive expression in advanced solid tumors. HER2 is overexpressed in breast cancer and several other solid tumors and represents a validated target in oncology. In a previous diagnostic study of ten HER2-positive breast cancer patients, RAD202 demonstrated clinical proof-of-concept and had positive safety and biodistribution.

About Radiopharm Theranostics

Radiopharm Theranostics is a clinical stage radiotherapeutics company developing a world-class platform of innovative radiopharmaceutical products for diagnostic and therapeutic applications in areas of high unmet medical need. Radiopharm is listed on ASX (RAD) and on NASDAQ (RADX). The company has a pipeline of distinct and highly differentiated platform technologies spanning peptides, small molecules and monoclonal antibodies for use in cancer. The clinical program includes one Phase 2 and five Phase 1 trials in a variety of solid tumor cancers including lung, breast, prostate and brain. Learn more at radiopharmtheranostics.com.

Authorized on behalf of the Radiopharm Theranostics Board of Directors by Executive Chairman Paul Hopper.

For more information:

Investors:
Riccardo Canevari
CEO & Managing Director
P: +1 862 309 0293
E: rc@radiopharmtheranostics.com

Anne Marie Fields
Precision AQ (formerly Stern IR)
E: annemarie.fields@precisionaq.com

Media:
Matt Wright
NWR Communications
P: +61 451 896 420
E: matt@nwrcommunications.com.au

Follow Radiopharm Theranostics:
Website – https://radiopharmtheranostics.com/
X – https://x.com/TeamRadiopharm  
LinkedIn – https://www.linkedin.com/company/radiopharm-theranostics/
InvestorHub – https://investorhub.radiopharmtheranostics.com/

¹ clinicaltrials.gov/study/NCT06824155

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What did the DSMC recommend for Radiopharm Theranostics’ RAD202 HEAT trial in August 2026 (NASDAQ: RADX)?

The DSMC recommended advancing 177Lu-RAD202 to Cohort 4 at a 180mCi dose level. According to Radiopharm Theranostics, this follows a detailed safety review and supports continued dose escalation in the Phase 1 HEAT trial for HER2-positive advanced solid tumor patients in Australia.

What is 177Lu-RAD202 being tested for in Radiopharm Theranostics’ Phase 1 HEAT trial (RADX)?

177Lu-RAD202 is being tested in HER2-positive advanced solid tumors in the Phase 1 HEAT trial. According to Radiopharm Theranostics, the study evaluates a HER2-targeting radiotherapeutic in patients with advanced disease, with dose levels now progressing to 180mCi at Australian clinical centers.

What prior clinical evidence supports Radiopharm Theranostics’ RAD202 program (NASDAQ: RADX)?

RAD202 previously showed clinical proof-of-concept in a diagnostic study of ten HER2-positive breast cancer patients. According to Radiopharm Theranostics, that study demonstrated positive safety and biodistribution, supporting further development of RAD202 as a therapeutic radiopharmaceutical for HER2-positive advanced solid tumors.

Where is Radiopharm Theranostics’ Phase 1 HEAT trial of RAD202 being conducted?

The Phase 1 HEAT trial for 177Lu-RAD202 is being conducted at clinical centers across Australia. According to Radiopharm Theranostics, the study is enrolling patients with HER2-positive advanced solid tumors, with dose escalation recently recommended to advance to a 180mCi Cohort 4 level.

What type of molecule is Radiopharm Theranostics’ 177Lu-RAD202 in the HEAT trial (RADX)?

177Lu-RAD202 is a proprietary single-domain monoclonal antibody (sdAb) targeting HER2-positive expression in advanced solid tumors. According to Radiopharm Theranostics, HER2 is overexpressed in breast and several other cancers, making it a validated oncology target for both diagnostic and therapeutic radiopharmaceutical applications.

How does the RAD202 HEAT trial fit into Radiopharm Theranostics’ broader pipeline (ASX: RAD, NASDAQ: RADX)?

RAD202 HEAT is one of several active trials in Radiopharm Theranostics’ oncology pipeline. According to the company, its clinical program includes one Phase 2 and five Phase 1 trials using peptides, small molecules and antibodies across solid tumors such as lung, breast, prostate and brain cancers.