A median progression-free survival of 22.1 months emerged from the final phase 2 PECATI clinical trial evaluating lenvatinib plus pembrolizumab for advanced thymic tumors.
Researchers tracked 43 patients with metastatic B3-thymoma or thymic carcinoma who experienced disease progression after at least one platinum-based chemotherapy regimen. The multicenter, single-arm study administered oral lenvatinib at 20 mg daily alongside intravenous pembrolizumab at 200 mg every three weeks. Findings appeared in the Journal of Thoracic Oncology, the official journal of the International Association for the Study of Lung Cancer.
Patient cohorts included 84% with thymic carcinoma and 16% with B3-thymoma. Nearly two-thirds of participants presented with stage IVB disease, while over half had at least three metastatic sites.
Approximately 44% of the cohort received two or more prior lines of treatment for advanced disease.
The combination therapy yielded a median overall survival of 40.2 months, with 53% of patients remaining alive at three years. Investigators recorded an objective response rate of 25.6%, which included one complete response, and a disease control rate of 93%.
“The results suggest that the combination may represent a potential treatment option for selected patients whose disease has progressed following platinum-based chemotherapy, although careful monitoring for treatment-related toxicities remains essential,” said Dr. Jordi Remon from the Department of Cancer Medicine at Gustave Roussy in Villejuif, France.
Proactive management of adverse events remains necessary due to significant treatment-related toxicity observed during the trial. Grade 3 or higher treatment-related adverse events affected 44.2% of patients.
Investigators said that 27.9% of participants discontinued at least one study drug because of toxicity. Immune-related adverse events occurred in 39.5% of patients, including serious cases of colitis, pneumonitis, myocarditis, encephalitis, and liver toxicity.
Two deaths occurred during the study period, though investigators determined neither was related to the treatment.
“The study’s relatively small sample size and single-arm design means the results cannot establish that the combination is superior to other treatments,” Remon said.
The trial design cannot determine the individual contribution of each drug to the observed outcomes. Investigators emphasized that further prospective studies are required to clarify these mechanisms and optimize patient selection.
“Further prospective studies will be needed to determine the optimal treatment sequence, identify patients most likely to benefit and establish whether these combinations can improve outcomes while maintaining acceptable safety,” Remon said.
Rare thoracic cancers develop in the thymus, an organ located in the chest behind the breastbone. B3-thymoma and thymic carcinoma represent the most aggressive forms of these rare malignancies.
Participants received oral lenvatinib at 20 mg daily paired with intravenous pembrolizumab at 200 mg every three weeks. Treatment continued until disease progression, unacceptable toxicity, or completion of a maximum of 35 treatment cycles.
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