Same ROR1 antibody, different outcome

When University of California at San Francisco licensed to VelosBio rights to develop the anti-ROR1 antibody UC-961 as an ADC it also signed over the same molecule to Oncternal, allowing that biotech to develop it as a naked MAb and Car-T therapy. But the deals took starkly different paths: in 2020 VelosBio was bought for $2.8bn by Merck & Co, while Oncternal limped on before being sold on Tuesday to the unknown biotech Ho’ola Therapeutics. The value of the latest deal is just $3m up front, plus the hope of future milestones. The MAb in question is now known as zilovertamab, and Oncternal gave up developing it in its naked form in 2023, switching to the Car-T project ONCT-808, which uses zilovertamab's binding region. Development of ONCT-808 was marred by a patient death, and last September Oncternal ended all clinical activity and put itself up for sale, with $14.5m in the bank at that time. Its stock was delisted from Nasdaq in March. Ho'ola's plans for zilovertamab and ONCT-808 are unclear, but future milestones clearly relate to these assets' development. Meanwhile, Merck's ADC incarnation, zilovertamab vedotin, is in phase 3, though its own development hasn't been smooth either.

Applications of UCSF’s UC-961 (later known as cirmtuzumab, then zilovertamab)

Note: *sale not announced until 1 Jul 2025. Source: OncologyPipeline.