Radiopharm Theranostics To Meet FDA On Phase 3 Design For RAD101; Phase 2b Shows 93% MRI Concordance
Radiopharm Theranostics (RADX) said it will hold an End-of-Phase 2 meeting with the FDA on Oct. 1, 2026 to align on pivotal Phase 3 trial design for RAD101 in suspected recurrent brain metastases after radiotherapy. The company cited Phase 2b results showing 93% MRI concordance and selective tumor uptake. RAD101 has Fast Track status and Siemens will manufacture and distribute it for a planned Phase 3 starting Q4 2026.
How this was made

The 30-second read
Why it matters
The scheduled FDA meeting and the stated intent to finalize a registrational strategy by end-2026 are actionable for biotech traders tracking regulatory de-risking and Phase 3 readiness.
Market read
Traders get a concrete regulatory timeline (Oct 1 FDA meeting) plus supportive Phase 2b efficacy signal (93% MRI concordance) and operational support (Siemens partnership) for a Q4 2026 Phase 3 start.
What to watch
The article does not provide Phase 2b sample size, lesion-level breakdown, or how MRI concordance translates to regulatory-grade diagnostic performance, which could temper enthusiasm.
Background
Radiopharm is developing RAD101, a Fluorine-18-labeled imaging agent for distinguishing recurrent brain metastases from treatment effects, and has Fast Track designation.
Ticker impact
Radiopharm Theranostics scheduled an End-of-Phase 2 FDA meeting for RAD101 Phase 3 design, with Phase 2b showing 93% MRI concordance.
Shares may remain bid into the Oct 1, 2026 FDA meeting as traders price higher probability of a clear registrational pathway.
The article discloses a specific FDA meeting date and concrete Phase 2b performance (93% concordance), plus Fast Track status and a Siemens manufacturing/distribution partnership supporting a planned multicenter Phase 3 starting Q4 2026.
Market effects
Adds incremental momentum to the radiopharmaceutical imaging/oncology pipeline narrative, particularly for F-18 small-molecule agents targeting brain metastases.
Primarily US regulatory-driven, with potential spillover to US-listed biotech sentiment around imaging diagnostics.
Siemens Healthineers manufacturing and distribution involvement links the program to broader global radiopharmacy supply chains.
Counterpoint
FDA End-of-Phase 2 alignment does not guarantee Phase 3 success; endpoint, enrollment, or statistical requirements could still change materially after the meeting.
Key entities
- companyRadiopharm Theranostics Ltd.
Clinical-stage radiopharmaceutical developer advancing RAD101 toward a pivotal Phase 3 trial.
- productRAD101
F-18-labeled small-molecule imaging agent targeting fatty acid synthase (FASN) for recurrent brain metastases diagnosis.
- regulatorU.S. FDA
Will meet with the company on Oct 1, 2026 to align Phase 3 trial design.
- partnerSiemens Healthineers
Manufactures and distributes Fluorine-18-labeled RAD101 via its U.S. radiopharmacy network for a planned multicenter Phase 3.


