Combination of anlotinib and irinotecan as second-line therapy in extensive-stage small-cell lung cancer relapsed within six months: a single-arm phase Ⅱ study

Purpose

There is still no satisfactory treatment strategy for patients with extensive-stage small-cell lung cancer (ES-SCLC) relapsed within 6 months after first-line treatment.

Patients and Methods

Subjects received 12 mg oral anlotinib on days 1–14 and irinotecan (65 mg/m²) on day 1 and 8 every 3 weeks (up to 4 cycles), followed by anlotinib maintainance therapy with anlotinib alone. The primary endpoint was objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), disease control rate (DCR), overall survival (OS) and safety.

Results

Thirty-seven patients were evaluable for efficacy and safety profile. ORR was 62.2 % (23/37) and DCR was 91.9 % (34/37). Median PFS and OS for all the patients were 4.5 and 7.2 months. PFS and OS of patients with a 3 < chemothrerapy-free survival (CTFI) ≤ 6 months were better than those of patients with a CTFI ≤ 3 months (PFS 6.5 vs 3.9 months, P = 0.0073; OS 18.5 vs 5.9 months, P < 0.001). Patients who previously received chemotherapy alone or chemotherapy combined with immunotherapy as first-line treatment had similar median PFS and OS (mPFS 4.4 vs 4.9 months, P = 0.38; mOS 7.2 vs 8.3 months, P = 0.79). Only three patients (8.5 %) suffered from Grade 3 adverse effects, which were thrombocytopenia, leukopenia, and anemia.

Conclusion

The combination of anlotinib and irinotecan as second-line treatment for ES-SCLC patients who relapsed within 6 months demonstrated promising efficacy and had manageable toxicities. Patients with 3 < CTFI ≤ 6 months had longer PFS and OS than those with CTFI ≤ 3 months. Previous immunotherapy did not affect the efficacy of subsequent anlotinib and irinotecan. It may become a novel therapeutic strategy for this population. The trial was registered with www.clinicaltrials.gov (No. NCT04757779).