Maria E. Cabanillas

Treatment with Tyrosine Kinase Inhibitors for Patients with Differentiated Thyroid Cancer: the M. D. Anderson Experience

OBJECTIVES Until recently, treatment options for patients with progressive, radioactive iodine-resistant differentiated thyroid cancer (DTC) have been limited. In our clinical practice, we have begun to use sorafenib and sunitinib for patients with progressive DTC who are not able or willing to participate in clinical trials. In this paper, we describe the University of Texas M. D. Anderson Cancer Centers experience with the off-label use of these tyrosine kinase inhibitors for DTC. METHODS Adult patients were included if they had a diagnosis of radioactive iodine-refractory DTC, were treated with single agent sorafenib or sunitinib, and had both baseline and at least one follow-up scan for restaging purposes. All imaging data were collected, as well as the TSH-suppressed thyroglobulin (Tg) levels corresponding to each scan date. The primary endpoints were radiographic response and progression-free survival (PFS). Secondary objectives were tissue-specific radiographic responses and correlation of Tg with overall response. RESULTS We identified 33 patients from our clinical database. Fifteen patients (nine women, six men) met inclusion criteria, with a median age of 61 yr (range, 38-83 yr). Eight patients had papillary and seven had follicular thyroid carcinoma. Sorafenib was used in 13 and sunitinib in two, including one patient who failed prior sorafenib therapy. All patients had evidence of progressive disease (PD) before start of therapy, with a median PFS of only 4 months. Best response in target lesions was: partial response (PR) in three (20%), stable disease (SD) in nine (60%), and PD in three (20%). Clinical benefit (PR+SD) was 80%. The sunitinib patient previously refractory to sorafenib had a 38% reduction in tumor size. The most noticeable organ-specific response was observed in lung (median change, -22%) compared to lymph nodes (median change, 0%). Pleural disease and nonirradiated bone metastases demonstrated PD. All histological subtypes had similar responses. The median PFS was 19 months. The median overall survival has not yet been reached, but at 2 yr of follow-up, overall survival is 67%. Log Tg correlated with radiographic response (P = 0.0005). CONCLUSIONS Sorafenib and sunitinib appear to be effective in patients with widely metastatic, progressive DTC, with most patients achieving SD or PR, despite having PD at baseline. The most noticeable responses occurred in the lungs in contrast with minimal changes in nodal metastases and PD in pleural and nonirradiated bone metastases, suggesting a tissue-specific response to therapy. Log Tg significantly correlated with response to treatment and therefore may have value as a surrogate marker of response.

Clinical responses to vemurafenib in patients with metastatic papillary thyroid cancer harboring BRAFV600E mutation

BACKGROUND Clinical benefit from cytotoxic chemotherapy for metastatic papillary thyroid carcinoma (PTC) is disappointing, and effective therapeutic approaches for these patients are urgently needed. Because kinase-activating mutations in the BRAF proto-oncogene commonly occur in advanced PTC, and inhibition of BRAF(V600E) has shown promising clinical activity in melanoma, BRAF inhibitor therapy may be an effective strategy to treat metastatic PTC. METHODS The dose escalation portion of a first-in-human, phase I study of vemurafenib, a selective RAF inhibitor, included three patients with metastatic PTC harboring the BRAF(V600E) mutation. Vemurafenib was initially dosed at 240-360 mg twice a day, later escalated to 720 mg twice a day. Response evaluation was performed every 8 weeks per Response Evaluation Criteria in Solid Tumors (RECIST). RESULTS Among the three patients, one had a confirmed partial response with reduction of pulmonary target lesions by 31%, and the duration of response was 7.6 months before the disease progressed in the lungs and the bones. The time to progression was 11.7 months. The other two patients had stable disease, and the time to progression was 13.2 and 11.4 months, respectively. CONCLUSIONS Vemurafenib appears to have a promising clinical activity in patients with metastatic PTC, and our data suggest that the BRAF(V600E) mutant kinase is a relevant target for therapy in this patient population. Further investigation of inhibitors of mutated BRAF kinase in patients with PTC in a phase II study is warranted.

Differentiated Thyroid Cancer: Management of Patients with Radioiodine Nonresponsive Disease

Differentiated thyroid carcinoma (papillary and follicular) has a favorable prognosis with an 85% 10-year survival. The patients that recur often require surgery and further radioactive iodine to render them disease-free. Five percent of thyroid cancer patients, however, will eventually succumb to their disease. Metastatic thyroid cancer is treated with radioactive iodine if the metastases are radioiodine avid. Cytotoxic chemotherapies for advanced or metastatic noniodine avid thyroid cancers show no prolonged responses and in general have fallen out of favor. Novel targeted therapies have recently been discovered that have given rise to clinical trials for thyroid cancer. Newer aberrations in molecular pathways and oncogenic mutations in thyroid cancer together with the role of angiogenesis in tumor growth have been central to these discoveries. This paper will focus on the management and treatment of metastatic differentiated thyroid cancers that do not take up radioactive iodine.

Treatment with Sunitinib for Patients with Progressive Metastatic Pheochromocytomas and Sympathetic Paragangliomas

CONTEXT Patients with progressive metastatic pheochromocytomas (PHEOs) or sympathetic paragangliomas (SPGLs) face a dismal prognosis. Current systemic therapies are limited. OBJECTIVES The primary end point was progression-free survival determined by RECIST 1.1 criteria or positron emission tomography with [(18)F]fluorodeoxyglucose/computed tomography ([(18)F]FDG-PET/CT), in the absence of measurable soft tissue targets. Secondary endpoints were tumor response according to RECIST criteria version 1.1 or FDG uptake, blood pressure control, and safety. DESIGN We conducted a retrospective review of medical records of patients with metastatic PHEO/SPGL treated with sunitinib from December 2007 through December 2011. An intention-to-treat analysis was performed. PATIENTS AND SETTING Seventeen patients with progressive metastatic PHEO/SPGLs treated at the Institut Gustave-Roussy and MD Anderson Cancer Center. INTERVENTIONS Patients treated with sunitinib. RESULTS According to RECIST 1.1, eight patients experienced clinical benefit; three experienced partial response, and five had stable disease, including four with predominant skeletal metastases that showed a 30% or greater reduction in glucose uptake on [(18)F]FDG-PET/CT. Of 14 patients who had hypertension, six became normotensive and two discontinued antihypertensives. One patient treated with sunitinib and rapamycin experienced a durable benefit beyond 36 months. The median overall survival from the time sunitinib was initiated was 26.7 months with a progression-free survival of 4.1 months (95% confidence interval = 1.4-11.0). Most patients who experienced a clinical benefit were carriers of SDHB mutations. CONCLUSION Sunitinib is associated with tumor size reduction, decreased [(18)F]FDG-PET/CT uptake, disease stabilization, and hypertension improvement in some patients with progressive metastatic PHEO/PGL. Prospective multi-institutional clinical trials are needed to determine the true benefits of sunitinib.

Use of the Tyrosine Kinase Inhibitor Sunitinib in a Patient with von Hippel-Lindau Disease : Targeting Angiogenic Factors in Pheochromocytoma and Other von Hippel-Lindau Disease-Related Tumors

CONTEXT von Hippel-Lindau disease is characterized by highly vascularized tumors of multiple organs. EVIDENCE ACQUISITION We present a patient with von Hippel-Lindau disease with multiple renal and pancreatic tumors and a malignant pheochromocytoma infiltrative of the sacrum and associated with lymph nodule metastases. The pheochromocytoma expressed high protein level of vascular endothelial growth factor and platelet-derived growth factor-beta receptor. The patient presented with a poor performance status, severe pelvic pain, weight loss, and manifestations of catecholamine excess. EVIDENCE SYNTHESIS Treatment against malignant pheochromocytoma with surgery, chemotherapy, or participation in clinical trials was not feasible because of the patients poor performance status, the presence of multiple tumors, and the extension of the pheochromocytoma into the bones. Patient was treated with sunitinib, a potent tyrosine kinase inhibitor of vascular endothelial growth factor, platelet-derived growth factor, RET, c-KIT, and FLT-3 receptors. Six months of treatment with sunitinib was associated with normalization of the patients performance status and blood pressure, absence of symptoms of catecholamine excess, weight gain, disappearance of pain, shrinkage of each of the tumors (50% in the largest renal tumor, 38% in the largest islet cell tumor, 21% in the pelvic malignant pheochromocytoma), and reduction of plasma normetanephrines and chromogranin A. CONCLUSION This study provides evidence that targeting tyrosine kinase receptors such as the vascular endothelial growth factor pathway and the platelet-derived growth factor-beta receptor may have value in the treatment of VHL-related tumors including pheochromocytoma.

Inhibition of the Ras/Raf/MEK/ERK and RET Kinase Pathways with the Combination of the Multikinase Inhibitor Sorafenib and the Farnesyltransferase Inhibitor Tipifarnib in Medullary and Differentiated Thyroid Malignancies

PURPOSE Ras/Raf/MAPK kinase/ERK and rearranged in transformation (RET) kinase pathways are important in thyroid cancer. We tested sorafenib, a B-Raf, RET, and vascular endothelial growth factor receptor kinase inhibitor, combined with tipifarnib, a farnesyltransferase inhibitor that inactivates Ras and other farnesylated proteins. PATIENTS AND METHODS We treated 35 patients with differentiated thyroid cancer (DTC) and medullary thyroid cancer (MTC) in a phase I trial. Sorafenib and tipifarnib were given for 21 d with 7 d rest in each 28-d cycle. RESULTS We enrolled 22 patients with metastatic DTC (16 papillary, five follicular, and one poorly differentiated) and 13 patients with MTC, of whom 15 with DTC and 10 with MTC reached first restaging. When tissue was available, eight of 15 DTC patients (53%) had B-Raf mutations; eight of 13 MTC (61.5%) patients had RET mutations. MTC partial response rate was 38% (five of 13) (duration = 9+, 12, 13, 16+, and 34+ months), stable disease of at least 6 months was 31% (four of 13). The DTC partial response rate was 4.5% (one of 22), and stable disease of at least 6 months was 36% (eight of 22). Median progression-free survival for all 35 patients was 18 months (95% confidence interval, 14.6 to not reached months). Median overall survival has not been reached, with a median follow-up of 24 months with 80% overall survival. Grade 1-2 toxicities were mainly rash, fatigue, and diarrhea. The most common grade 3-4 toxicities were rash, rise in amylase/lipase, and fatigue. CONCLUSIONS Inhibiting the Ras/Raf/MAPK kinase/ERK and RET kinase pathways with sorafenib and tipifarnib is well tolerated and active against thyroid cancer.

A Phase II Trial of the Multitargeted Tyrosine Kinase Inhibitor Lenvatinib (E7080) in Advanced Medullary Thyroid Cancer

Purpose: Positive results of phase I studies evaluating lenvatinib in solid tumors, including thyroid cancer, prompted a phase II trial in advanced medullary thyroid carcinoma (MTC). Experimental Design: Fifty-nine patients with unresectable progressive MTC per Response Evaluation Criteria In Solid Tumors (RECIST) v1.0 within the prior 12 months received lenvatinib (24-mg daily, 28-day cycles) until disease progression, unmanageable toxicity, withdrawal, or death. Prior anti-VEGFR therapy was permitted. The primary endpoint was objective response rate (ORR) by RECIST v1.0 and independent imaging review. Results: Lenvatinib ORR was 36% [95% confidence interval (CI), 24%–49%]; all partial responses. ORR was comparable between patients with (35%) or without (36%) prior anti-VEGFR therapy. Disease control rate (DCR) was 80% (95% CI, 67%–89%); 44% had stable disease. Among responders, median time to response (TTR) was 3.5 months (95% CI, 1.9–3.7). Median progression-free survival (PFS) was 9.0 months (95% CI, 7.0–not evaluable). Common toxicity criteria grade 3/4 treatment-emergent adverse events included diarrhea (14%), hypertension (7%), decreased appetite (7%), fatigue, dysphagia, and increased alanine aminotransferase levels (5% each). Ret proto-oncogene status did not correlate with outcomes. Low baseline levels of angiopoietin-2, hepatocyte growth factor, and IL8 were associated with tumor reduction and prolonged PFS. High baseline levels of VEGF, soluble VEGFR3, and platelet-derived growth factor BB, and low baseline levels of soluble Tie-2, were associated with tumor reduction. Conclusions: Lenvatinib had a high ORR, high DCR, and a short TTR in patients with documented progressive MTC. Toxicities were managed with dose modifications and medications. Clin Cancer Res; 22(1); 44–53. ©2015 AACR.

BRAF inhibitor dabrafenib in patients with metastatic BRAF-mutant thyroid cancer

BACKGROUND Mutations of v-raf murine sarcoma viral oncogene homolog B (BRAF) are commonly identified in papillary and anaplastic thyroid carcinoma and are associated with worse prognosis compared with the wild type. BRAF inhibition in papillary thyroid carcinoma cell lines and xenografts inhibits proliferation and decreases downstream phosphorylation. Our objectives were to analyze safety and efficacy of the selective BRAF inhibitor dabrafenib in patients with metastatic BRAF-mutant thyroid carcinoma. METHODS We present the subset of patients with BRAF-mutant thyroid carcinoma enrolled in a larger phase 1 study, the main results of which are reported elsewhere. RESULTS Fourteen patients with BRAF(V600E)-mutant thyroid carcinoma were enrolled, of whom 13 (93%) had received prior radioactive iodine. The median duration on treatment was 8.4 months, and seven (50%) patients received treatment for ≥10 months. The most common treatment-related adverse events were skin papillomas (n=8, 57%), hyperkeratosis (n=5, 36%), and alopecia (n=4, 29%), all of which were grade 1. Treatment-related adverse events grade ≥3 included grade 4 elevated lipase and grade 3 elevated amylase, fatigue, febrile neutropenia, and cutaneous squamous cell carcinoma (n=1 for each). Four (29%) partial responses were observed, and nine (64%) patients achieved at least 10% decrease. Only one responder progressed while on the study drug after a response duration of 9.3 months. The other three responders had not progressed, with response duration of 4.6+, 10.4+, and 21.4+ months. With seven (50%) patients showing no progression at the time of study completion, the median progression-free survival was 11.3 months. CONCLUSIONS Dabrafenib was well tolerated and resulted in durable responses in BRAF-mutant differentiated thyroid carcinoma patients.

Efficacy and Tolerability of Vemurafenib in Patients with BRAFV600E -Positive Papillary Thyroid Cancer: M.D. Anderson Cancer Center Off Label Experience

CONTEXT Vemurafenib, a selective BRAF inhibitor, appears to have promising clinical activity in patients with papillary thyroid cancer (PTC) harboring the BRAF(V600E) mutation. OBJECTIVE To determine the efficacy and safety of vemurafenib when used outside of a clinical trial. DESIGN A retrospective review at MD Anderson Cancer Center. METHODS The best responses were evaluated using RECIST v1.1. A single radiologist reviewed all images. Adverse events (AEs) were evaluated using CTCAE v.4.0. RESULTS We identified 17 patients with advanced PTC harboring the BRAF(V600E) mutation who were treated with vemurafenib outside of a clinical trial. Median age at diagnosis was 63 years, and 53% were male. At vemurafenib start, 3 (18%) patients had disease confined to the neck, and 14 (72%) had distant metastases. Tyrosine kinase inhibitors had been previously administered to 4 (24%) patients. Two (12%) patients discontinued vemurafenib because of AEs before restaging. Best response: partial response (PR) in 7/15 (47%) and stable disease (SD) in 8/15(53%) patients. The rate of durable response (PR plus SD ≥ 6 months) was 67%. Median time to treatment failure was 13 months. There was no association between change in thyroglobulin and tumor size. Drug discontinuation, drug interruptions, and dose reductions were needed in 5 (29%), 13 (76%), and 10 (59%) patients, respectively. Most common AEs were fatigue (71%), weight loss (71%), anorexia (65%), arthralgias (59%), hair loss (59%), rash (59%), hand-foot syndrome (53%), calluses (47%), diarrhea (47%), fever (41%), dry mouth (35%), nausea (35%), and verrucous keratosis (35%). Grade ≥ 3 AEs were present in 8 (47%) patients. CONCLUSIONS Vemurafenib is a potentially effective and well-tolerated treatment strategy in patients with advanced PTC harboring the BRAF(V600E) mutation. Our results are similar to those reported in a phase II clinical trial and support the potential role of vemurafenib in this patient population.

The Noninvestigational Use of Tyrosine Kinase Inhibitors in Thyroid Cancer: Establishing a Standard for Patient Safety and Monitoring

CONTEXT The increasing use of tyrosine kinase inhibitor therapy outside of the context of the clinical trial for treatment of advanced thyroid cancer has highlighted the need for a systematic approach to the clinical application of these agents in order to improve patient safety and monitoring promote consistency among providers, and ensure compliance with both institutional and industry standards. EVIDENCE We reviewed professional thyroid cancer guidelines, the National Comprehensive Cancer Network task force reports, American Society of Clinical Oncology safety standards, review articles, and clinical trials published within the past 10 yr and also included relevant older studies. CONCLUSIONS Review of available published data and the collective experience prescribing tyrosine kinase inhibitors at The University of Texas MD Anderson Cancer Center have highlighted the need for a systematic, comprehensive, and uniform approach to managing these patients. This paper discusses the approach adopted by the Department of Endocrine Neoplasia at the MD Anderson Cancer Center and illustrates practice patterns, experience, and our standardized approach related to prescribing commercially available tyrosine kinase inhibitors outside of the context of a clinical trial for patients with advanced thyroid cancer.