Merck and Daiichi Sankyo’s ADC Pact Hits Regulatory Setback in FDA Rejection

1. FDA Rejection: The FDA rejected Merck and Daiichi Sankyo's investigational antibody-drug conjugate patritumab deruxtecan due to issues with a third-party manufacturing facility.
2. Patritumab Deruxtecan: The ADC targets the HER3 protein and is designed for the treatment of locally advanced or metastatic non-small cell lung cancer bearing certain genetic mutations.
3. Deal Details: Merck paid $4 billion upfront and pledged $18 billion in subsequent payments to jointly develop and commercialize patritumab deruxtecan with Daiichi Sankyo.
4. HERTHENA-Lung01 Study: The pivotal Phase II study showed an objective response rate of 29.8% and documented one fatal case of interstitial lung disease.
5. Future Plans: The partners will work closely with the FDA and the third-party manufacturer to address the feedback and bring the drug to market as quickly as possible.