Bispecific conjugates break new ground
A pair of bispecific antibody-drug conjugates, SystImmune's (Baili's) izalontamab brengitecan and CSPC Pharmaceutical's anbenitamab repodatecan, are to be tested in broader settings than their already extensive phase 3 programmes. Listings on the clinicaltrials.gov registry in recent days have revealed new pivotal trials of the former in urothelial bladder cancer and of the latter in a breast cancer trial testing it head to head against Roche's Kadcyla. Still, these are both Chinese studies, and the focus surrounding iza-can, an EGFR x HER3 bispecific, remains on a high-profile deal with Bristol Myers Squibb worth $800m up front; Bristol's long-awaited global phase 1/2 solid tumour study began last month. Still, bladder cancer marks iza-can's seventh cancer type being tested in phase 3, signifying the push SystImmune is putting behind this bispecific ADC. Meanwhile, anbe-can, a biparatopic HER2 x HER2 targeting ADC until recently known as JSKN003, was already in phase 3 in breast cancer, but specifically in the HER2-low niche; taking on Kadcyla could broaden its potential. CSPC licensed mainland China rights to the project to Alphamab last September.
New pivotal trials of bispecific ADCs
| Project | Targets | Companies | New phase 3 | Other phase 3s of note |
|---|---|---|---|---|
| Izalontamab brengitecan | EGFR x HER3 | SystImmune (Baili)/ Bristol Myers Squibb | Post-PD-(L)1 + chemo urothelial bladder cancer, vs chemo | Numerous, including NSCLC, SCLC, nasopharyngeal, oesophageal & breast cancers |
| Anbenitamab repodatecan | HER2 x HER2 | CSPC/ Alphamab | Head to head vs Kadcyla in 2nd-line HER2+ve breast cancer | 2nd-line+ HER2-low breast cancer, started Dec 2023 2nd-line ovarian cancer, started Jan 2025 |
Source: OncologyPipeline.
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