GT Medical Technologies Raises $100 Million Series E Led by Viking Global

GT Medical Technologies has closed an oversubscribed $100 million Series E equity financing, the Tempe, Arizona, company announced on June 9. New investor Viking Global Investors led the round, with participation from existing investors including MVM Partners, Gilde Healthcare, Evidity Health Capital, Medtech Venture Partners and FemHealth Ventures.

The company makes GammaTile, which it describes as an FDA-cleared bioresorbable radiotherapy implant placed at the time of brain tumor removal surgery to deliver radiation directly to the site where the tumor was removed.

"This financing is validation of GammaTile's potential to be a standard of care treatment for operable brain tumors and will accelerate our ability to bring this important therapy to even more patients," said Per Langoe, GT Medical Technologies' chief executive officer.

Where the money goes

GT Medical said the funds will be used to accelerate investments across commercial and operational initiatives following the release last month of final data from its ROADS randomized controlled trial. Proceeds will also support continued expansion of the company's recently initiated BRIDGES randomized controlled trial in patients with newly diagnosed glioblastomas.

The round is nearly twice the size of the company's previous raise. In July 2025, GT Medical said it had completed an oversubscribed $53 million Series D equity financing, made up of a $37 million first close led by Evidity Health Capital and an additional $16 million final close from new investors including FemHealth Ventures, Warren Point Capital and an undisclosed strategic investor.

"We are excited to lead this financing and to work with GT to unlock the potential of GammaTile therapy," said Jason Rostovsky, a principal at Viking Global Investors. The release describes Viking as a global investment firm managing $52 billion of capital across public and private investments.

The trial data behind the raise

ROADS is a randomized Phase 3 trial comparing surgery followed by post-operative stereotactic radiation with surgery plus GammaTile's cesium-131 tile-based radiation therapy in patients with newly diagnosed brain metastases. The results were presented at the 2026 American Society of Clinical Oncology conference on May 30, according to the company.

The company reported that the 12-month rate of recurrence in the tumor surgical bed was 1.3% with GammaTile compared with 15.4% with standard of care, and that 24-month overall survival was 61.7% versus 35.7%. GT Medical said GammaTile reduced the risk of tumor recurrence and death at 12 months by 93% and 41%, respectively. Those figures are company-reported from the conference presentation.

The company did not disclose its valuation, revenue or the size of individual investors' commitments in the Series E announcement.