Neoadjuvant treatment of primary inoperable or local recurrent thymoma with octreotide LAR to improve tumor resectability.
7105 Background: The therapeutic outcome for unresectable, locally advanced, malignant thymoma is poor. Most important factor for long-term survival in thymoma patients is complete resection (R0) of the tumor. The study was performed to evaluate the efficacy of octreotide LAR plus prednisone in patients with primary inoperable or local recurrent thymoma to reduce tumor size. Methods: This was an open label, single-arm study in patients with inoperable or local recurrent thymoma. Patients were considered unlikely to achieve R0 resection at enrollment. Octreotide LAR was administered once every 2 weeks in combination with prednisone. Two stages were planned according to Fleming’s one sample multiple testing procedure for phase II clinical trials. The objective of the study was to show that octreotide LAR is effective in this patient population with respect to tumor shrinkage. Response was defined as decrease in tumor volume of at least 20% at month 3 as compared to baseline. Results: 17 thymoma patients at Masaoka stage III were recruited. Octreotide LAR showed a response in 15 of 17 patients (88.24%) at week 12. Two patients had discontinued the study before week 12 due to unsatisfactory therapeutic effect or adverse events. At Week 12, 5 patients (29.41%) operable for radical resection. 10 patients (58.82%) were not operable for radical resection. 16 of 17 patients (94.12%) experienced adverse events (AEs). The most frequent AEs were gastrointestinal disorders (70.59%), infections and infestations (64.71%), and blood/lymphatic system disorders (41.18%). Conclusions: Octreotide LAR was shown to be effective in patients with inoperable thymoma with respect to tumor shrinkage.Octreotide LAR was generally well tolerated. The reported AEs are in accordance with the known safety profile.