Pharmaceutical companies Merck and Daiichi Sankyo have withdrawn their regulatory application for patritumab deruxtecan, an antibody-drug conjugate designed to target the HER3 protein, after it failed to significantly improve overall survival in patients with locally advanced or metastatic non-small cell lung cancer. The move comes after a topline readout of the Phase III HERTHENA-Lung02 trial showed no significant improvement in overall survival.
The companies had previously submitted patritumab deruxtecan for approval, citing its potential to improve progression-free survival, but the FDA did not approve it due to issues with the ADC’s efficacy and safety package. However, Merck and Daiichi Sankyo maintained that the withdrawal is unrelated to the prior rejection.
Patritumab deruxtecan was designed to target HER3, a protein highly expressed in many types of solid tumors. The ADC carries an exatecan derivative payload that triggers cancer cell death when released inside a tumor. Despite this mechanism, the Phase III trial showed no significant improvement in overall survival, which may impact its potential as a treatment for NSCLC.
This news follows similar developments with another Daiichi Sankyo-partnered ADC, datopotamab deruxtecan, which was withdrawn due to unfavorable FDA review of its Phase III lung cancer trial. The companies are now resubmitting an application targeting a subpopulation of NSCLC patients with EGFR mutations, which received priority review from the FDA.
Source: https://www.biospace.com/drug-development/merck-daiichi-sankyo-pull-nsclc-filing-for-adc-citing-underwhelming-survival-findings