Study details
The DESTINY-Lung01 trial included 42 patients with HER2-mutated NSCLC who received T-DXd at a dose of 6.4 mg/kg every 3 weeks. The patients’ median age was 63 years, and about 64% were female. Eastern Cooperative Oncology Group performance status was 0 in about one-quarter of the patients, and 1 in the remainder.
Patients had received up to six prior lines of treatment, including platinum-based chemotherapy in about 91%, a PD-1 or PD-L1 inhibitor in 55%, and docetaxel in 19%.
The confirmed ORR by independent central review was 61.9% (26/42). That included a single complete response (2.4%) and 25 partial responses (59.5%).
The duration of response was not reached (95% CI, 5.3 months to not estimable), and the median PFS was 14.0 months (95% CI, 6.4-14.0 months).
All patients experienced a treatment-related adverse event. Treatment-related events of grade 3 or greater were seen in 22 patients (52%). These mainly included decreased neutrophil count, anemia, nausea, vomiting, and fatigue.
There were five cases of interstitial lung disease, all of which were grade 2. In four cases, T-DXd was withdrawn. In one case, the drug was interrupted. All patients were treated with steroids.
“Two [patients] recovered, one recovered with sequelae, one was recovering, and one had not recovered by data cutoff,” Dr. Smit said.
DESTINY-Lung01 also includes a cohort of patients with HER2-expressing NSCLC not reported at the meeting. Enrollment in the HER2-mutated cohort that was reported has been expanded with another 50 patients to “better characterize the risk-benefit ratio,” Dr. Smit said.
The DESTINY-Lung01 study is sponsored by Daiichi Sankyo Inc. Dr. Smit reported relationships with Daiichi Sankyo and many other companies. Dr. Dy reported disclosures related to Amgen, AstraZeneca/Medimmune, GlaxoSmithKline, Takeda, and Tesaro.
SOURCE: Smit EF et al. ASCO 2020, Abstract 9504.