GammaTile funding follows phase 3 brain-metastasis data

A $100M Series E financing round will fund GT Medical Technologies’ commercial and operational expansion for GammaTile, its implantable radiotherapy system for operable brain tumors.

Viking Global Investors led the round. Existing investors MVM Partners, Gilde Healthcare, Evidity Health Capital, Medtech Venture Partners, and FemHealth Ventures also participated.

GammaTile is an FDA-cleared bioresorbable collagen implant embedded with cesium-131 radiation sources. FDA records state that it is indicated for patients with newly diagnosed malignant intracranial neoplasms and patients with recurrent intracranial neoplasms.

The device is placed in the resection cavity immediately after surgical excision of a brain neoplasm. FDA summary documents describe it as adjuvant radiation therapy intended to treat neoplastic cells remaining near the resection cavity.

GT Medical said the financing follows final data from ROADS, a randomized controlled phase 3 trial in patients with newly diagnosed brain metastases. The data were presented at the 2026 American Society of Clinical Oncology meeting.

ROADS compared resection plus post-operative stereotactic radiation with resection plus cesium-131 tile-based radiation therapy. The ASCO abstract lists 230 randomized patients across 32 U.S. centers.

GT Medical said GammaTile reduced the risk of tumor recurrence and death at 12 months by 93% and 41%, respectively, compared with standard of care. The company also reported a 12-month surgical-bed recurrence rate of 1.3% with GammaTile, compared with 15.4% for standard of care.

Surgical-bed recurrence-free survival was also improved, according to the company. Median time to an event was not reached in the GammaTile arm, compared with 10.9 months in the standard-of-care arm.

The company reported 24-month overall survival of 61.7% with GammaTile, compared with 35.7% for standard of care. GT Medical said those data came from the ROADS presentation at ASCO26.

Part of the new funding will support BRIDGES, a randomized controlled trial in patients with newly diagnosed glioblastoma. GT Medical announced first patient enrollment in that trial in January 2026.

ClinicalTrials.gov lists BRIDGES as a phase 3 prospective, randomized, superiority, open-label, multi-site study. The study compares standard of care with GammaTile placement during glioblastoma resection followed by external beam radiation therapy and temozolomide.