Patients diagnosed with recurrent or progressive extensive-stage small cell lung cancer (ES-SCLC) may benefit from treatment with ifinatamab deruxtecan (I-DXd), a B7-H3–directed antibody-drug conjugate, according to data presented at the International Association for the Study of Lung Cancer (IASLC) 2025 World Conference on Lung Cancer (WCLC; Abstract OA06.03).
Recent data from the phase II IDeate-Lung01 trial in 137 patients who had received at least one prior line of platinum-based chemotherapy showed a confirmed objective response rate of 48.2% and a disease control rate of 87.6% in those who received the agent, according to results presented by Myung-Ju Ahn, MD, of Samsung Medical Center, Seoul, Republic of Korea.
Patients with ES-SCLC face a poor prognosis and have limited treatment options. B7-H3 is overexpressed in all subtypes of SCLC, and its overexpression has been associated with worse clinical outcomes, making it an attractive target for novel therapies. This analysis of IDeate-Lung01 included patients treated with I-DXd at 12 mg/kg intravenously every 3 weeks during the dose-optimization and dose-extension parts of the study.
At the March 3, 2025, data cutoff, 137 patients had received I-DXd after one (23.4%), two (54.7%), or three (21.9%) prior lines of systemic therapy. After a median duration of follow-up of 12.8 months, the median duration of response was 5.3 months, and the median time to response was 1.4 months. Median progression-free survival was 4.9 months, and median overall survival was 10.3 months. Clinical benefit was observed regardless of platinum sensitivity or the number of prior treatments; for example, among the second-line subgroup (n = 32), the objective response rate was 56.3%, and progression-free and overall survival times were numerically longer than those in the overall population.
Treatment-related adverse events (TRAEs) of any grade occurred in 89.8% of patients, with 36.5% of patients experiencing a TRAE of grade 3 or higher, and 4.4% of patients experiencing grade 5 TRAEs. Adjudicated treatment-related interstitial lung disease or pneumonitis occurred in 17 patients; 6 of these cases were grade ≥ 3. Safety findings were consistent with prior reports, with no new safety signals observed.
“These results demonstrate the remarkable efficacy of ifinatamab deruxtecan in patients with ES-SCLC, a population who have a substantial unmet need,” said Dr. Ahn. “The manageable safety profile and high response rates support further investigation of I-DXd in SCLC.”
Disclosure: For full disclosures of the study authors, visit cattendee.abstractsonline.com.
