Clinical efficacy of targeted biologic agents as second-line therapy of advanced thyroid cancer
Taofeek K Owonikoko1, Rajasree P Chowdry, Zhengjia Chen
1Department of Hematology and Medical Oncology, School of Medicine.
Unlabelled:
Targeted biologic agents showed clinically meaningful efficacy as front-line therapy for advanced radioiodine-refractory and medullary thyroid cancer. The clinical benefit of these agents beyond the front line has yet to be established.
Methods:
We assessed the clinical benefit of targeted agents in patients with advanced differentiated and medullary thyroid cancer treated at a single academic cancer center. We determined efficacy and compared front-line and second-line benefit using biochemical and anatomic response, time to treatment failure, and progression-free survival (PFS). Statistical differences were assessed by t test and chi-square test. Survival curves were generated by the Kaplan-Meier method. Differences in survival were assessed using the log-rank test, and a p value <.05 was considered significant.
Results:
We identified 39 patients with advanced differentiated and medullary thyroid cancer treated with targeted biologic agents. Median age was 56.3 years. Overall, 25 men and 14 women participated. Histology showed 23% medullary and 77% differentiated cancer. Nineteen patients progressed on front-line therapy and subsequently received second-line therapy. Targeted agents conferred clinically meaningful benefit in the second-line setting in terms of biochemical response (13.3%), clinical benefit (83.3%), median time to treatment failure (4.0 months; 95% confidence interval: 2.6-8.2), and median PFS (4.6 months; 95% confidence interval: 3.2-8.2). Second-line benefit (median PFS) was more modest in comparison to the front-line setting in both genders (women: 3 months vs. 12.2 months; men: 6 months vs. 19.7 months), in differentiated cancers (4.1 months vs. 15.7 months), and with vascular targeting agents (4.4 months vs. 20.1 months).
Conclusion:
Patients with advanced thyroid cancer derived meaningful clinical benefit from additional therapy with a biologic agent following disease progression on front-line targeted therapy.
Insights
Targeted biologic agents offer clinical benefit in advanced thyroid cancer, even after initial treatment failure. Second-line therapy with these agents shows meaningful efficacy, though less than front-line treatment.
Area of Science:
- Oncology
- Thyroid Cancer Research
- Targeted Therapy
Background:
- Targeted biologic agents demonstrate efficacy in front-line therapy for advanced radioiodine-refractory and medullary thyroid cancer.
- The clinical benefit of these agents beyond the front-line setting remains to be fully established.
Purpose of the Study:
- To assess the clinical benefit of targeted biologic agents in patients with advanced differentiated and medullary thyroid cancer.
- To compare the efficacy of front-line versus second-line targeted therapy.
Main Methods:
- Retrospective analysis of 39 patients with advanced differentiated and medullary thyroid cancer treated at a single academic center.
- Efficacy assessment included biochemical and anatomic response, time to treatment failure, and progression-free survival (PFS).
- Statistical comparisons utilized t-tests, chi-square tests, and log-rank tests for survival analysis.
Main Results:
- Targeted agents provided clinically meaningful benefit in the second-line setting, with a median PFS of 4.6 months.
- Second-line therapy showed a median time to treatment failure of 4.0 months and a clinical benefit rate of 83.3%.
- Second-line benefit was more modest compared to front-line therapy across different patient subgroups.
Conclusions:
- Patients with advanced thyroid cancer can derive meaningful clinical benefit from biologic agents as additional therapy after disease progression on front-line targeted treatment.
- Second-line targeted therapy represents a viable option for patients with advanced thyroid cancer who have progressed on initial treatment.
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