Plus Therapeutics adds SpectronRx for Reyobiq manufacturing

Plus Therapeutics has started manufacturing activities and technology transfer with SpectronRx to support late-stage clinical manufacturing of Reyobiq and rhenium-186.

The work is being conducted under a previously executed master services agreement. SpectronRx will serve as a second GMP manufacturing site alongside Radiomedix, while rhenium-186 isotope supply will continue through Telix Pharmaceuticals, according to Plus Therapeutics.

The agreement includes technology transfer for the Reyobiq manufacturing process, rhenium-186 isotope processing, analytical methods, technical expertise, and regulatory support. Plus Therapeutics said the work is intended to support future commercial-scale production.

SpectronRx’s Indiana facility will provide on-demand production of both rhenium-186 isotope and finished Reyobiq drug product at the same site. That setup is designed to simplify logistics and improve coordination across the radiopharmaceutical production process.

Reyobiq, also known as rhenium Re-186 obisbemeda, is a radiopharmaceutical candidate targeting central nervous system cancers. Plus Therapeutics said it is being evaluated for recurrent glioblastoma, leptomeningeal metastases, and pediatric brain cancer in the ReSPECT-GBM, ReSPECT-LM, and ReSPECT-PBC clinical trials.

“We are focused on advancing our REYOBIQ development, including progress towards our 2026 target milestone to complete manufacturing scale-up for REYOBIQ late-stage clinical supply needs,” said Marc H. Hedrick, MD, president and CEO of Plus Therapeutics.

The manufacturing update follows a January FDA Type B meeting on Reyobiq development for leptomeningeal metastases. Plus Therapeutics said at the time that the meeting covered potential pivotal study design and that the company planned to accelerate commercial manufacturing and scale-up activities.

Manufacturing matters in radiopharmaceutical development because isotope availability, production timing, release testing, and distribution can affect whether a therapy can be supplied consistently in multicenter trials. Adding a second GMP partner gives Plus Therapeutics additional production redundancy as the program moves toward later-stage clinical needs.

The company’s 2025 results also identified Reyobiq manufacturing scale-up as a 2026 priority, alongside clinical development activities in leptomeningeal metastases and pediatric brain cancer.

SpectronRx CEO John Zehner said radiopharmaceutical development depends on infrastructure that can “reliably scale alongside clinical and commercial demand.”