Phase 2bData readout

OST-HER2

Pediatric lung metastatic osteosarcoma

OSTXOS Therapies

Expected catalystSeptember 15, 2026Company guidance: Sep 15, 2026

Catalyst overview

Event details

Drug or asset: OST-HER2
Development stage: Phase 2b
Event type: Data readout
Indication: Pediatric lung metastatic osteosarcoma

Research summary

What is being tracked?

This catalyst tracks a Phase 2b data readout for OST-HER2 in Pediatric lung metastatic osteosarcoma. The expected timing is based on the latest available company guidance and may change.

Development notes

05/18/26:- FDA/MHRA meetings and ASCO 2026 2.5-year OS precede BLA/MAA filings; H2 2026 Ph3, 3-year OS, decisions. 06/02/26:- 2.5-year OS 75%. FDA/MHRA mtgs Early Jun 2026; 3-year OS Early Q4 2026; Ph3 Late Q3 2026. 06/08/26:- FDA and MHRA aligned on Ph3 design. Ph3 starts Late Q3 2026; potential Q4 2026 decisions. 06/30/26:- Type B FDA meeting requested. Ph2b 3-year OS data readout expected Early Fall 2026. 08/13/26:- Interim 3-year OS data expected Early September 2026. FDA Type C meeting Mid-September 2026; BLA targeted Year-End 2026. 08/17/26:- 2.5-year OS data showed 75% versus 47%. Metastatic Osteosarcoma Program interim 3-year OS data is expected Early September 2026; FDA Type C meeting will occur Mid-September 2026; BLA submission is expected H2 2026.

Verification

Primary source

Confirm timing and program details against the company announcement or filing.

Open source

What is being tracked?

This catalyst tracks a Phase 2b data readout for OST-HER2 in Pediatric lung metastatic osteosarcoma. The expected timing is based on the latest available company guidance and may change.