Zymeworks wakes up to the Enhertu threat

Zymeworks has finally admitted defeat against the juggernaut that is AstraZeneca and Daiichi’s HER2-targeting ADC Enhertu. In yesterday's fourth-quarter results release Zymeworks said it was deprioritising zanidatamab zovodotin, a HER2 x HER2 bispecific ADC, a follow-on to its naked HER2 x HER2 MAb zanidatamab. Zymeworks blamed the “evolving clinical landscape” and said it would keep looking for partners for zanidatamab zovodotin. But BeiGene walked away from a collaboration in Asia last September, and it’s hard to see Zymeworks drumming up much interest. The door for zanidatamab zovodotin has been closing for some time, but as recently as November's Jefferies London healthcare meeting the company still thought there was a path forward, admittedly not in breast cancer but in NSCLC. Zymeworks said this was worth pursuing given the relatively modest outlay, but it has clearly now decided to save the cash. Other clinical-stage HER2 x HER2 bispecific ADC developers, according to OncologyPipeline, include China’s Alphamab Oncology and Xuanzhu Biopharmaceutical. However, the monospecific HER2-targeting ADC pipeline is a different story: OncologyPipeline lists 35 clinical-stage projects in 632 trials.