The US Food and Drug Administration (FDA) has granted approval for Daiichi Sankyo and AstraZeneca’s Enhertu (fam-trastuzumab deruxtecan-nxki) to treat unresectable or metastatic non-small cell lung cancer (NSCLC) in adults.

The treatment is indicated for such patients whose tumours have activating HER2 (ERBB2) mutations and previously received systemic therapy. 

Based on objective response rate (ORR) and duration of response (DoR), the indication received approval under an accelerated pathway.

The latest approval was based on the findings from the Phase II DESTINY-Lung02 clinical trial, which assessed the safety and efficacy of two doses of Enhertu in HER2 mutant metastatic NSCLC patients. 

According to the interim efficacy data from a pre-specified patient cohort, a 5.4 mg/kg dose of Enhertu was found to provide a confirmed ORR of 57.7%, as evaluated by blinded independent central review (BICR). 

In the trial, 1.9% and 55.8% of subjects had complete and partial responses, respectively, with a median duration of response of 8.7 months.

A specifically engineered HER2-directed antibody drug conjugate (ADC), Enhertu is being co-developed and co-marketed by Daiichi Sankyo along with AstraZeneca.

Enhertu is claimed to be the first HER2-directed therapy to receive approval for treating HER2 mutant metastatic NSCLC patients. 

Subsequent to US approval for the new indication, Daiichi Sankyo is entitled to receive a milestone payment of $125m from AstraZeneca.

Daiichi Sankyo president and CEO and Oncology Business global head Ken Keller said: “We are excited that the FDA has granted accelerated approval for Enhertu for patients with HER2 mutant metastatic non-small cell lung cancer. 

“Enhertu has now been approved in three different tumour types, underscoring its significant potential across several HER2 targetable tumours. 

“We are continuing to evaluate the efficacy and safety of Enhertu versus standard chemotherapy in our DESTINY clinical trials in lung cancer.”

The latest development comes after Enhertu received FDA approval for treating unresectable or metastatic HER2-low (IHC 1+ or IHC 2+/ISH-) breast cancer.