Phase II trial of thalidomide for therapy of radioiodine-unresponsive and rapidly progressive thyroid carcinomas

Background: There are no known effective therapies for distantly metastatic, rapidly progressive thyroid carcinomas unresponsive to radioiodine. Objective: Since thyroid carcinomas are hypervascular and thalidomide is antiangiogenic, we assessed thalidomide's tumoristatic effects and toxicity in a phase II trial. Design: Thirty-six patients with follicular, papillary, insular, or medullary thyroid carcinomas and distant, radioiodine-unresponsive metastases (volumes increasing ≥30% per year before entry) were accrued between July 2001 and December 2002. Daily thalidomide started at 200 mg, increasing over 6 weeks to 800 mg or maximum tolerated dose. Toxicities and responses were assessed at 8-week intervals with tumor volume assessments. Main outcomes: Twenty-eight of 36 patients were evaluable, 5 with partial responses (PR: 18%; 95% confidence interval [95% CI]: 6-37%) and 9 patients with stable disease (SD: 32%; 95% CI: 12-42%) for overall 50% response (95% CI: 31-69%). Median PR duration was 4 months (range: 2-6 months), and SD duration was 6 months (range: 2-14 months). Median survival was 23.5 months for responders (PR + SD) and 11 months for nonresponders. Most frequent toxicity was fatigue (69% grade 1-2, 8% grade 3-4). Four patients had grade 3-4 infections (without neutropenia), one had pericardial effusion, and one had pulmonary embolus. Conclusions: Thalidomide confers therapeutic benefit in subsets of thyroid cancer patients with rapidly progressive, distantly metastatic disease.