Efficacy

Lenvima (Lenvatinib) Efficacy in Thyroid Cancer

Lenvima, known generically as lenvatinib, is an oral medication that is approved for the treatment of certain types of thyroid cancer. Specifically, it is indicated for the treatment of locally recurrent or metastatic, progressive, radioactive iodine-refractory differentiated thyroid cancer (DTC). The efficacy of Lenvima in this context was demonstrated in a phase III clinical trial known as SELECT. In this study, Lenvima significantly increased progression-free survival (PFS) when compared to placebo. Patients treated with Lenvima had a median PFS of 18.3 months, compared to 3.6 months in those receiving placebo, marking a substantial improvement in delaying disease progression.

In addition to its use in DTC, Lenvima has also shown efficacy in treating advanced medullary thyroid cancer (MTC) and anaplastic thyroid cancer (ATC), which are less common and more aggressive forms of thyroid cancer. While the medication is not specifically approved for these types of thyroid cancer, its antiangiogenic and antineoplastic properties have led to clinical interest in its off-label use for these conditions, with some evidence suggesting potential benefits.

Retsevmo (Selpercatinib) Efficacy in Thyroid Cancer

Retsevmo, with the generic name selpercatinib, is a newer targeted therapy approved for the treatment of thyroid cancers with specific genetic alterations. It is indicated for patients with metastatic RET (rearranged during transfection) fusion-positive thyroid cancer who require systemic therapy following prior treatment and those with advanced or metastatic RET-mutant medullary thyroid cancer (MTC) who require systemic therapy. The efficacy of Retsevmo was evaluated in the LIBRETTO-001 trial, which showed a high response rate in patients with RET-mutant MTC and RET fusion-positive thyroid cancers. The overall response rate (ORR) in patients with RET-mutant MTC was approximately 69%, with a median duration of response not reached at the time of data cut-off, indicating a significant and durable response in this patient population.

Furthermore, in patients with RET fusion-positive thyroid cancer, Retsevmo demonstrated an ORR of 79%, with many patients experiencing a significant shrinkage of their tumors. These results underscore the importance of genetic testing in thyroid cancer to identify patients who may benefit from targeted therapies like Retsevmo. The precision with which Retsevmo targets RET-driven cancers represents a paradigm shift in the management of these thyroid cancers, offering a promising treatment option for patients with these specific genetic alterations.