Phase 3 Trial of Selpercatinib in Advanced RET-Mutant Medullary Thyroid Cancer.

BACKGROUND: Selpercatinib, a highly selective, potent RET inhibitor, has shown efficacy in advanced RET-mutant medullary thyroid cancer in a phase 1-2 trial, but its efficacy as compared with approved multikinase inhibitors is unclear. METHODS: We conducted a phase 3, randomized trial comparing selpercatinib as first-line therapy with the physician's choice of cabozantinib or vandetanib (control group). Eligible patients had progressive disease documented within 14 months before enrollment. The primary end point in the protocol-specified interim efficacy analysis was progression-free survival, assessed by blinded independent central review. Crossover to selpercatinib was permitted among patients in the control group after disease progression. Treatment failure-free survival, assessed by blinded independent central review, was a secondary, alpha-controlled end point that was to be tested only if progression-free survival was significant. Among the other secondary end points were overall response and safety. RESULTS: A total of 291 patients underwent randomization. At a median follow-up of 12 months, median progression-free survival as assessed by blinded independent central review was not reached in the selpercatinib group and was 16.8 months (95% confidence interval [CI], 12.2 to 25.1) in the control group (hazard ratio for disease progression or death, 0.28; 95% CI, 0.16 to 0.48; P<0.001). Progression-free survival at 12 months was 86.8% (95% CI, 79.8 to 91.6) in the selpercatinib group and 65.7% (95% CI, 51.9 to 76.4) in the control group. Median treatment failure-free survival as assessed by blinded independent central review was not reached in the selpercatinib group and was 13.9 months in the control group (hazard ratio for disease progression, discontinuation due to treatment-related adverse events, or death, 0.25; 95% CI, 0.15 to 0.42; P<0.001). Treatment failure-free survival at 12 months was 86.2% (95% CI, 79.1 to 91.0) in the selpercatinib group and 62.1% (95% CI, 48.9 to 72.8) in the control group. The overall response was 69.4% (95% CI, 62.4 to 75.8) in the selpercatinib group and 38.8% (95% CI, 29.1 to 49.2) in the control group. Adverse events led to a dose reduction in 38.9% of the patients in the selpercatinib group, as compared with 77.3% in the control group, and to treatment discontinuation in 4.7% and 26.8%, respectively. CONCLUSIONS: Selpercatinib treatment resulted in superior progression-free survival and treatment failure-free survival as compared with cabozantinib or vandetanib in patients with RET-mutant medullary thyroid cancer. (Funded by Loxo Oncology, a subsidiary of Eli Lilly; LIBRETTO-531 ClinicalTrials.gov number, NCT04211337.).

Cabozantinib for previously treated radioiodine-refractory differentiated thyroid cancer: Updated results from the phase 3 COSMIC-311 trial.

BACKGROUND: At an interim analysis (median follow-up, 6.2 months; n = 187), the phase 3 COSMIC-311 trial met the primary end point of progression-free survival (PFS): cabozantinib improved PFS versus a placebo (median, not reached vs. 1.9 months; p < .0001) in patients with previously treated radioiodine-refractory differentiated thyroid cancer (RAIR-DTC). The results from an exploratory analysis using an extended datacut are presented. METHODS: Patients 16 years old or older with RAIR-DTC who progressed on prior lenvatinib and/or sorafenib were randomized 2:1 to oral cabozantinib tablets (60 mg/day) or a placebo. Placebo patients could cross over to open-label cabozantinib upon radiographic disease progression. The objective response rate (ORR) in the first 100 randomized patients and the PFS in the intent-to-treat population, both according to Response Evaluation Criteria in Solid Tumors version 1.1 by blinded, independent review, were the primary end points. RESULTS: At the data cutoff (February 8, 2021), 258 patients had been randomized (cabozantinib, n = 170; placebo, n = 88); the median follow-up was 10.1 months. The median PFS was 11.0 months (96% confidence interval [CI], 7.4-13.8 months) for cabozantinib and 1.9 months (96% CI, 1.9-3.7 months) for the placebo (hazard ratio, 0.22; 96% CI, 0.15-0.32; p < .0001). The ORR was 11.0% (95% CI, 6.9%-16.9%) versus 0% (95% CI, 0.0%-4.1%) (p = .0003) with one complete response with cabozantinib. Forty placebo patients crossed over to open-label cabozantinib. Grade 3/4 treatment-emergent adverse events occurred in 62% and 28% of the cabozantinib- and placebo-treated patients, respectively; the most common were hypertension (12% vs. 2%), palmar-plantar erythrodysesthesia (10% vs. 0%), and fatigue (9% vs. 0%). There were no grade 5 treatment-related events. CONCLUSIONS: At extended follow-up, cabozantinib maintained superior efficacy over a placebo in patients with previously treated RAIR-DTC with no new safety signals.

Larotrectinib Treatment for Patients With TRK Fusion-Positive Salivary Gland Cancers.

BACKGROUND: Larotrectinib is a first-in-class, highly selective, and central nervous system-active tropomyosin receptor kinase (TRK) inhibitor approved for the treatment of adult and pediatric patients with TRK fusion cancer. We report the efficacy and safety of larotrectinib in patients with TRK fusion-positive salivary gland cancers. PATIENTS AND METHODS: Patients with TRK fusion-positive salivary gland cancer treated with larotrectinib were identified from two clinical trials (NCT02122913 and NCT02576431). Patients received larotrectinib 100 mg twice daily (BID) except for one patient who received 150 mg BID in the phase I trial. The primary endpoint was objective response rate (ORR) as assessed by the investigator using Response Evaluation Criteria in Solid Tumors version 1.1. RESULTS: At the data cut-off (July 20, 2020), 24 patients with TRK fusion-positive salivary gland cancer had been treated. The most common histologies were secretory carcinoma (54%), adenocarcinoma (25%), and mucoepidermoid carcinoma (13%). All 24 patients had an ETV6-NTRK3 gene fusion. The ORR was 92% (95% confidence interval, 73-99). Best overall response was complete response in three (13%) patients, partial response in 19 (79%), and progressive disease in two (8%). The rate of progression-free survival at 24 months was 78% (median follow-up 30.9 months). Most treatment-related adverse events (AEs) were grade 1-2, and no patients discontinued treatment due to AEs. CONCLUSION: Larotrectinib demonstrated robust and durable efficacy in patients with TRK fusion-positive salivary gland tumors of various histologies, and a favorable safety profile. These findings support NTRK gene fusion testing in patients with advanced salivary gland cancers. CLINICALTRIALS.GOV NUMBERS: NCT02122913 and NCT02576431.

Rationale and design of ON-TRK: a novel prospective non-interventional study in patients with TRK fusion cancer treated with larotrectinib.

BACKGROUND: Tropomyosin receptor kinase (TRK) fusion proteins resulting from neurotrophic tyrosine receptor kinase (NTRK) gene fusions are rare primary oncogenic drivers in a wide array of tumors. Larotrectinib is a first-in-class, highly selective, central nervous system-active TRK inhibitor approved by the US Food and Drug Administration (FDA), European Medicines Agency (EMA), and over 40 countries for the treatment of TRK fusion solid tumors in adult and pediatric patients. Due to the rarity of TRK fusion cancer, larotrectinib was granted accelerated approval based on a relatively small number of patients enrolled in three early phase trials. ON-TRK aims to evaluate the safety profile of larotrectinib in a broader population and over extended time periods. METHODS: ON-TRK is a prospective, non-interventional, open-label, multicenter, multi-cohort, post-approval study in adult and pediatric patients with locally advanced or metastatic TRK fusion cancer treated with larotrectinib that will describe the safety and effectiveness of larotrectinib in real-world practice conditions. Adult patients will be grouped by tumor type and followed for at least 2 years. Patients < 18 years old will be enrolled under a 'pediatric' cohort regardless of tumor type and will be followed for 5 years to evaluate the risk of potential long-term adverse effects of larotrectinib on their growth and development. The effectiveness of larotrectinib in the overall study population as well as in patient subgroups will also be evaluated. Procedures avoided in patients with infantile fibrosarcoma (e.g., amputation) and the number of patients who were able to undergo surgery with a curative intent (excluding amputation) because of the use of larotrectinib will be described. Larotrectinib treatment patterns in real-world practice, including dosing and duration of treatment, will be described. DISCUSSION: The FDA Accelerated Approval Program allows for earlier approval of and patient access to drugs that treat serious conditions and fill an unmet medical need. This study is designed to fulfill post-approval requirements set by the FDA as well as post-marketing requirements set forth by local regulatory bodies and is part of the risk management plan for the EMA. STUDY REGISTRATION: This study is registered at ClinicalTrials.gov ( NCT04142437 ). PROTOCOL VERSION: v2.5, 25 March 2021.

LIBRETTO-531: a phase III study of selpercatinib in multikinase inhibitor-naïve RET-mutant medullary thyroid cancer.

Selpercatinib is a first-in-class, highly selective and potent, central nervous system-active RET kinase inhibitor. In the phase I/II trial, selpercatinib demonstrated clinically meaningful antitumor activity with manageable toxicity in heavily pre-treated and treatment-naive patients with RET-mutant medullary thyroid cancer (MTC). LIBRETTO-531 (NCT04211337) is a multicenter, open-label, randomized, controlled, phase III trial comparing selpercatinib to cabozantinib or vandetanib in patients with advanced/metastatic RET-mutant MTC. The primary objective is to compare progression-free survival (per RECIST 1.1) by blinded independent central review of patients with progressive, advanced, multikinase inhibitor-naive, RET-mutant MTC treated with selpercatinib versus cabozantinib or vandetanib. Key secondary objectives are to compare other efficacy outcomes (per RECIST 1.1) and tolerability of selpercatinib versus cabozantinib or vandetanib.

Selpercatinib (also known by the brand name Retevmo^®/Retsevmo^®) is a new treatment available in multiple countries for people with advanced or metastatic RET-mutant medullary thyroid cancer (MTC). Thyroid cancer starts in your thyroid gland and may spread or metastasize to other parts of the body, including lungs, bones, and occasionally the brain, which means the cancer is likely to be advanced. Advanced thyroid cancer can be driven by a gene in your body, one of which is RET. This is a summary of the LIBRETTO-531 study which compares selpercatinib, which is a strong and selective inhibitor of RET, with two approved drugs, cabozantinib and vandetanib. Patients with advanced or metastatic RET-mutant MTC who have not already received treatment with kinase inhibitors are being enrolled. This trial will evaluate how long people during and after treatment live with the disease without it getting worse. Selpercatinib may affect both healthy cells and tumor cells, which can result in side effects, which will also be evaluated in this study. This study is active and currently recruiting new patients. Clinical Trial Registration: NCT04211337 (ClinicalTrials.gov).

Cabozantinib for radioiodine-refractory differentiated thyroid cancer (COSMIC-311): a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Patients with radioiodine-refractory differentiated thyroid cancer (DTC) previously treated with vascular endothelial growth factor receptor (VEGFR)-targeted therapy have aggressive disease and no available standard of care. The aim of this study was to evaluate the tyrosine kinase inhibitor cabozantinib in this patient population. METHODS: In this global, randomised, double-blind, placebo-controlled, phase 3 trial, patients aged 16 years and older with radioiodine-refractory DTC (papillary or follicular and their variants) and an Eastern Cooperative Oncology Group performance status of 0 or 1 were randomly assigned (2:1) to oral cabozantinib (60 mg once daily) or matching placebo, stratified by previous lenvatinib treatment and age. The randomisation scheme used stratified permuted blocks of block size six and an interactive voice-web response system; both patients and investigators were masked to study treatment. Patients must have received previous lenvatinib or sorafenib and progressed during or after treatment with up to two VEGFR tyrosine kinase inhibitors. Patients receiving placebo could cross over to open-label cabozantinib on disease progression confirmed by blinded independent radiology committee (BIRC). The primary endpoints were objective response rate (confirmed response per Response Evaluation Criteria in Solid Tumours [RECIST] version 1.1) in the first 100 randomly assigned patients (objective response rate intention-to-treat [OITT] population) and progression-free survival (time to earlier of disease progression per RECIST version 1.1 or death) in all patients (intention-to-treat [ITT] population), both assessed by BIRC. This report presents the primary objective response rate analysis and a concurrent preplanned interim progression-free survival analysis. The study is registered with ClinicalTrials.gov, NCT03690388, and is no longer enrolling patients. FINDINGS: Between Feb 27, 2019, and Aug 18, 2020, 227 patients were assessed for eligibility, of whom 187 were enrolled from 164 clinics in 25 countries and randomly assigned to cabozantinib (n=125) or placebo (n=62). At data cutoff (Aug 19, 2020) for the primary objective response rate and interim progression-free survival analyses, median follow-up was 6·2 months (IQR 3·4-9·2) for the ITT population and 8·9 months (7·1-10·5) for the OITT population. An objective response in the OITT population was achieved in ten (15%; 99% CI 5·8-29·3) of 67 patients in the cabozantinib group versus 0 (0%; 0-14·8) of 33 in the placebo (p=0·028) but did not meet the prespecified significance level (α=0·01). At interim analysis, the primary endpoint of progression-free survival was met in the ITT population; cabozantinib showed significant improvement in progression-free survival over placebo: median not reached (96% CI 5·7-not estimable [NE]) versus 1·9 months (1·8-3·6); hazard ratio 0·22 (96% CI 0·13-0·36; p<0·0001). Grade 3 or 4 adverse events occurred in 71 (57%) of 125 patients receiving cabozantinib and 16 (26%) of 62 receiving placebo, the most frequent of which were palmar-plantar erythrodysaesthesia (13 [10%] vs 0), hypertension (11 [9%] vs 2 [3%]), and fatigue (ten [8%] vs 0). Serious treatment-related adverse events occurred in 20 (16%) of 125 patients in the cabozantinib group and one (2%) of 62 in the placebo group. There were no treatment-related deaths. INTERPRETATION: Our results show that cabozantinib significantly prolongs progression-free survival and might provide a new treatment option for patients with radioiodine-refractory DTC who have no available standard of care. FUNDING: Exelixis.

Efficacy of Larotrectinib in TRK Fusion-Positive Cancers in Adults and Children.

BACKGROUND: Fusions involving one of three tropomyosin receptor kinases (TRK) occur in diverse cancers in children and adults. We evaluated the efficacy and safety of larotrectinib, a highly selective TRK inhibitor, in adults and children who had tumors with these fusions. METHODS: We enrolled patients with consecutively and prospectively identified TRK fusion-positive cancers, detected by molecular profiling as routinely performed at each site, into one of three protocols: a phase 1 study involving adults, a phase 1-2 study involving children, or a phase 2 study involving adolescents and adults. The primary end point for the combined analysis was the overall response rate according to independent review. Secondary end points included duration of response, progression-free survival, and safety. RESULTS: A total of 55 patients, ranging in age from 4 months to 76 years, were enrolled and treated. Patients had 17 unique TRK fusion-positive tumor types. The overall response rate was 75% (95% confidence interval [CI], 61 to 85) according to independent review and 80% (95% CI, 67 to 90) according to investigator assessment. At 1 year, 71% of the responses were ongoing and 55% of the patients remained progression-free. The median duration of response and progression-free survival had not been reached. At a median follow-up of 9.4 months, 86% of the patients with a response (38 of 44 patients) were continuing treatment or had undergone surgery that was intended to be curative. Adverse events were predominantly of grade 1, and no adverse event of grade 3 or 4 that was considered by the investigators to be related to larotrectinib occurred in more than 5% of patients. No patient discontinued larotrectinib owing to drug-related adverse events. CONCLUSIONS: Larotrectinib had marked and durable antitumor activity in patients with TRK fusion-positive cancer, regardless of the age of the patient or of the tumor type. (Funded by Loxo Oncology and others; ClinicalTrials.gov numbers, NCT02122913 , NCT02637687 , and NCT02576431 .).

Lenvatinib plus pembrolizumab in patients with advanced endometrial cancer: an interim analysis of a multicentre, open-label, single-arm, phase 2 trial.

BACKGROUND: Lenvatinib is a multikinase inhibitor of VEGFR1, VEGFR2, and VEGFR3, and other receptor tyrosine kinases. Pembrolizumab, an antibody targeting PD-1, has moderate efficacy in biomarker-unselected endometrial cancer. We aimed to assess the combination of lenvatinib plus pembrolizumab in patients with advanced endometrial carcinoma, after establishing the maximum tolerated dose in a phase 1b study. METHODS: In this open-label, single-arm, phase 2 study done at 11 centres in the USA, eligible patients were aged 18 years or older and had metastatic endometrial cancer (unselected for microsatellite instability or PD-L1), had an Eastern Cooperative Oncology Group performance status of 0 or 1, had received no more than two previous systemic therapies, had measurable disease according to the immune-related Response Evaluation Criteria In Solid Tumors (irRECIST), and had a life expectancy of 12 weeks or longer. Patients received 20 mg oral lenvatinib daily plus 200 mg intravenous pembrolizumab every 3 weeks. Treatment continued until disease progression, development of unacceptable toxic effects, or withdrawal of consent. The primary endpoint of this interim analysis was the proportion of patients with an objective response at week 24 as assessed by investigators according to irRECIST in the per-protocol population. This trial is registered with ClinicalTrials.gov, number NCT02501096. FINDINGS: Between Sept 10, 2015, and July 24, 2017, 54 patients were enrolled, 53 of whom were included in the analysis. At the cutoff date for anti-tumour activity data (Dec 15, 2017), median study follow-up was 13·3 months (IQR 6·7-20·1). 21 (39·6% [95% CI 26·5-54·0]) patients had an objective response at week 24. Serious treatment-related adverse events occurred in 16 (30%) patients, and one treatment-related death was reported (intracranial haemorrhage). The most frequently reported any-grade treatment-related adverse events were hypertension (31 [58%]), fatigue (29 [55%]), diarrhoea (27 [51%]), and hypothyroidism (25 [47%]). The most common grade 3 treatment-related adverse events were hypertension (18 [34%]) and diarrhoea (four [8%]). No grade 4 treatment-related adverse events were reported. Five (9%) patients discontinued study treatment because of treatment-related adverse events. INTERPRETATION: Lenvatinib plus pembrolizumab showed anti-tumour activity in patients with advanced recurrent endometrial cancer with a safety profile that was similar to those previously reported for lenvatinib and pembrolizumab monotherapies, apart from an increased frequency of hypothyroidism. Lenvatinib plus pembrolizumab could represent a new potential treatment option for this patient population, and is being investigated in a randomised phase 3 study. FUNDING: Eisai and Merck.

Safety and antitumor activity of the anti-PD-1 antibody pembrolizumab in patients with advanced, PD-L1-positive papillary or follicular thyroid cancer.

BACKGROUND: Treatment options for advanced thyroid cancer refractory to standard therapies are limited. The safety and efficacy of pembrolizumab were evaluated in patients with advanced differentiated thyroid cancer expressing programmed death ligand 1 (PD-L1). METHODS: Patients with advanced thyroid cancer were enrolled in the nonrandomized, phase Ib KEYNOTE-028 trial conducted to evaluate safety and antitumor activity of the anti-programmed death 1 (PD-1) antibody pembrolizumab in advanced solid tumors. Key eligibility criteria were advanced papillary or follicular thyroid cancer, failure of standard therapy, and PD-L1 expression in tumor or stroma cells (assessed by immunohistochemistry). Pembrolizumab 10 mg/kg was administered every 2 weeks up to 24 months or until confirmed progression or intolerable toxicity. The primary endpoint was objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors, version 1.1. RESULTS: Twenty-two patients were enrolled: median age was 61 years; 59% were women; and 68% had papillary carcinoma. Median follow-up was 31 months (range, 7-34 months). Treatment-related adverse events were observed in 18 (82%) patients; those occurring in ≥15% of patients were diarrhea (n = 7) and fatigue (n = 4). One grade ≥ 3 treatment-related adverse event occurred (colitis, grade 3); no treatment-related discontinuations or deaths occurred. Two patients had confirmed partial response, for an ORR of 9% (95% confidence interval [CI], 1-29%); response duration was 8 and 20 months. Median progression-free survival was 7 months (95% CI, 2-14 months); median overall survival was not reached (95% CI, 22 months to not reached). CONCLUSIONS: Results of this phase Ib proof-of-concept study suggest that pembrolizumab has a manageable safety profile and demonstrate evidence of antitumor activity in advanced differentiated thyroid cancer in a minority of patients treated. Further analyses are necessary to confirm these findings. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02054806 . Registered 4 February 2014.

Treatment-emergent hypertension and efficacy in the phase 3 Study of (E7080) lenvatinib in differentiated cancer of the thyroid (SELECT).

BACKGROUND: Hypertension (HTN) is an established class effect of vascular endothelial growth factor receptor (VEGFR) inhibition. In the phase 3 Study of (E7080) Lenvatinib in Differentiated Cancer of the Thyroid (SELECT) trial, HTN was the most frequent adverse event of lenvatinib, an inhibitor of VEGFR1, VEGFR2, VEGFR3, fibroblast growth factor receptor 1 (FGFR1), FGFR2, FGFR3, FGFR4, platelet-derived growth factor receptor α (PDGFRα), ret proto-oncogene (RET), and stem cell factor receptor (KIT). This exploratory analysis examined treatment-emergent hypertension (TE-HTN) and its relation with lenvatinib efficacy and safety in SELECT. METHODS: In the multicenter, double-blind SELECT trial, 392 patients with progressive radioiodine-refractory differentiated thyroid cancer (RR-DTC) were randomized 2:1 to lenvatinib (24 mg/d on a 28-day cycle) or placebo. Survival endpoints were assessed with Kaplan-Meier estimates and log-rank tests. The influence of TE-HTN on progression-free survival (PFS) and overall survival (OS) was analyzed with univariate and multivariate Cox proportional hazards models. RESULTS: Overall, 73% of lenvatinib-treated patients and 15% of placebo-treated patients experienced TE-HTN. The median PFS for lenvatinib-treated patients with (n = 190) and without TE-HTN (n = 71) was 18.8 and 12.9 months, respectively (hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.39-0.88; P = .0085). For lenvatinib-treated patients, the objective response rate was 69% with TE-HTN and 56% without TE-HTN (odds ratio, 1.72; 95% CI, 0.98-3.01). The median change in tumor size for patients with and without TE-HTN was -45% and -40%, respectively (P = .2). The median OS was not reached for patients with TE-HTN; for those without TE-HTN, it was 21.7 months (HR, 0.43; 95% CI, 0.27-0.69; P = .0003). CONCLUSIONS: Although HTN is a clinically significant adverse event that warrants monitoring and management, TE-HTN was significantly correlated with improved outcomes in patients with RR-DTC, indicating that HTN may be predictive for lenvatinib efficacy in this population. Cancer 2018;124:2365-72. © 2018 American Cancer Society.

Lenvatinib versus placebo in radioiodine-refractory thyroid cancer.

BACKGROUND: Lenvatinib, an oral inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, fibroblast growth factor receptors 1 through 4, platelet-derived growth factor receptor α, RET, and KIT, showed clinical activity in a phase 2 study involving patients with differentiated thyroid cancer that was refractory to radioiodine (iodine-131). METHODS: In our phase 3, randomized, double-blind, multicenter study involving patients with progressive thyroid cancer that was refractory to iodine-131, we randomly assigned 261 patients to receive lenvatinib (at a daily dose of 24 mg per day in 28-day cycles) and 131 patients to receive placebo. At the time of disease progression, patients in the placebo group could receive open-label lenvatinib. The primary end point was progression-free survival. Secondary end points included the response rate, overall survival, and safety. RESULTS: The median progression-free survival was 18.3 months in the lenvatinib group and 3.6 months in the placebo group (hazard ratio for progression or death, 0.21; 99% confidence interval, 0.14 to 0.31; P<0.001). A progression-free survival benefit associated with lenvatinib was observed in all prespecified subgroups. The response rate was 64.8% in the lenvatinib group (4 complete responses and 165 partial responses) and 1.5% in the placebo group (P<0.001). The median overall survival was not reached in either group. Treatment-related adverse effects of any grade, which occurred in more than 40% of patients in the lenvatinib group, were hypertension (in 67.8% of the patients), diarrhea (in 59.4%), fatigue or asthenia (in 59.0%), decreased appetite (in 50.2%), decreased weight (in 46.4%), and nausea (in 41.0%). Discontinuations of the study drug because of adverse effects occurred in 37 patients who received lenvatinib (14.2%) and 3 patients who received placebo (2.3%). In the lenvatinib group, 6 of 20 deaths that occurred during the treatment period were considered to be drug-related. CONCLUSIONS: Lenvatinib, as compared with placebo, was associated with significant improvements in progression-free survival and the response rate among patients with iodine-131-refractory thyroid cancer. Patients who received lenvatinib had more adverse effects. (Funded by Eisai; SELECT ClinicalTrials.gov number, NCT01321554.).

Vemurafenib in patients with BRAF(V600E)-positive metastatic or unresectable papillary thyroid cancer refractory to radioactive iodine: a non-randomised, multicentre, open-label, phase 2 trial.

BACKGROUND: About half of patients with papillary thyroid cancer have tumours with activating BRAF(V600E) mutations. Vemurafenib, an oncogenic BRAF kinase inhibitor approved for BRAF-positive melanoma, showed clinical benefit in three patients with BRAF(V600E)-positive papillary thyroid cancer in a phase 1 trial. We aimed to establish the activity of vemurafenib in patients with BRAF(V600E)-positive papillary thyroid cancer. METHODS: We did an open-label, non-randomised, phase 2 trial at ten academic centres and hospitals worldwide in patients aged 18 years or older with histologically confirmed recurrent or metastatic papillary thyroid cancer refractory to radioactive iodine and positive for the BRAF(V600E) mutation. Participants either had never received a multikinase inhibitor targeting VEGFR (cohort 1) or had been treated previously with a VEGFR multikinase inhibitor (cohort 2). Patients received vemurafenib 960 mg orally twice daily. The primary endpoint was investigator-assessed best overall response in cohort 1 (confirmed on two assessments 4 weeks or longer apart). Analyses were planned to have a minimum median follow-up of 15 months (data cutoff April 18, 2014) and were done in safety, intention-to-treat, and per-protocol populations. This trial is closed and is registered at ClinicalTrials.gov, number NCT01286753. FINDINGS: Between June 23, 2011, and Jan 15, 2013, 51 patients were enrolled to the study, 26 in cohort 1 and 25 in cohort 2. Median duration of follow-up was 18·8 months (IQR 14·2-26·0) in cohort 1 and 12·0 months (6·7-20·3) in cohort 2. Partial responses were recorded in ten of 26 patients in cohort 1 (best overall response 38·5%, 95% CI 20·2-59·4). Grade 3 or 4 adverse events were recorded in 17 (65%) of 26 patients in cohort 1 and 17 (68%) of 25 patients in cohort 2; the most common grade 3 and 4 adverse events were squamous cell carcinoma of the skin (seven [27%] in cohort 1, five [20%] in cohort 2), lymphopenia (two [8%] in each cohort), and increased γ-glutamyltransferase (one [4%] in cohort 1, three [12%] in cohort 2). Two individuals in cohort 2 died due to adverse events, one from dyspnoea and one from multiorgan failure, but neither was treatment related. Serious adverse events were reported for 16 (62%) of 26 patients in cohort 1 and 17 (68%) of 25 patients in cohort 2. INTERPRETATION: Vemurafenib showed antitumour activity in patients with progressive, BRAF(V600E)-positive papillary thyroid cancer refractory to radioactive iodine who had never been treated with a multikinase inhibitor. As such, this agent represents a potential new treatment option for these patients. FUNDING: F Hoffmann-La Roche.

Correlative analyses of RET and RAS mutations in a phase 3 trial of cabozantinib in patients with progressive, metastatic medullary thyroid cancer.

BACKGROUND: Cabozantinib significantly prolonged progression-free survival (PFS) versus a placebo in patients with progressive, metastatic medullary thyroid cancer (MTC; P < .001). An exploratory analysis of phase 3 trial data evaluated the influence of rearranged during transfection (RET) and RAS (HRAS, KRAS, and NRAS) mutations on cabozantinib clinical activity. METHODS: Patients (n = 330) were randomized to cabozantinib (140 mg/day) or a placebo. The primary endpoint was PFS. Additional outcome measures included PFS, objective response rates (ORRs), and adverse events in RET and RAS mutation subgroups. RESULTS: Among all study patients, 51.2% were RET mutation-positive (38.2% with RET M918T), 34.8% were RET mutation-unknown, and 13.9% were RET mutation-negative. Sixteen patients were RAS mutation-positive. Cabozantinib appeared to prolong PFS versus the placebo in the RET mutation-positive subgroup (hazard ratio [HR], 0.23; 95% confidence interval [CI], 0.14-0.38; P < .0001), the RET mutation-unknown subgroup (HR, 0.30; 95% CI, 0.16-0.57; P = .0001), and the RAS mutation-positive subgroup (HR, 0.15; 95% CI, 0.02-1.10; P = .0317). The RET M918T subgroup achieved the greatest observed PFS benefit from cabozantinib versus the placebo (HR, 0.15; 95% CI, 0.08-0.28; P < .0001). The ORRs for RET mutation-positive, RET mutation-negative, and RAS mutation-positive patients were 32%, 22%, and 31%, respectively. No PFS benefit was observed in patients lacking both RET and RAS mutations, although the ORR was 21%. The safety profile for all subgroups was similar to that for the overall cabozantinib arm. CONCLUSIONS: These data suggest that cabozantinib provides the greatest clinical benefit to patients with MTC who have RET M918T or RAS mutations. However, a prospective trial is needed to confirm the relation between genetic variation and the response to cabozantinib. Cancer 2016;122:3856-3864. © 2016 American Cancer Society.

Sorafenib in radioactive iodine-refractory, locally advanced or metastatic differentiated thyroid cancer: a randomised, double-blind, phase 3 trial.

BACKGROUND: Patients with radioactive iodine ((131)I)-refractory locally advanced or metastatic differentiated thyroid cancer have a poor prognosis because of the absence of effective treatment options. In this study, we assessed the efficacy and safety of orally administered sorafenib in the treatment of patients with this type of cancer. METHODS: In this multicentre, randomised, double-blind, placebo-controlled, phase 3 trial (DECISION), we investigated sorafenib (400 mg orally twice daily) in patients with radioactive iodine-refractory locally advanced or metastatic differentiated thyroid cancer that had progressed within the past 14 months. Adult patients (≥18 years of age) with this type of cancer were enrolled from 77 centres in 18 countries. To be eligible for inclusion, participants had to have at least one measurable lesion by CT or MRI according to Response Evaluation Criteria In Solid Tumors (RECIST); Eastern Cooperative Oncology Group performance status 0-2; adequate bone marrow, liver, and renal function; and serum thyroid-stimulating hormone concentration lower than 0·5 mIU/L. An interactive voice response system was used to randomly allocate participants in a 1:1 ratio to either sorafenib or matching placebo. Patients, investigators, and the study sponsor were masked to treatment assignment. The primary endpoint was progression-free survival, assessed every 8 weeks by central independent review. Analysis was by intention to treat. Patients in the placebo group could cross over to open-label sorafenib upon disease progression. Archival tumour tissue was examined for BRAF and RAS mutations, and serum thyroglobulin was measured at baseline and at each visit. This study is registered with ClinicalTrials.gov, number NCT00984282, and with the EU Clinical Trials Register, number EudraCT 2009-012007-25. FINDINGS: Patients were randomly allocated on a 1:1 basis to sorafenib or placebo. The intention-to-treat population comprised 417 patients (207 in the sorafenib group and 210 in the placebo group) and the safety population was 416 patients (207 in the sorafenib group and 209 in the placebo group). Median progression-free survival was significantly longer in the sorafenib group (10·8 months) than in the placebo group (5·8 months; hazard ratio [HR] 0·59, 95% CI 0·45-0·76; p<0·0001). Progression-free survival improved in all prespecified clinical and genetic biomarker subgroups, irrespective of mutation status. Adverse events occurred in 204 of 207 (98·6%) patients receiving sorafenib during the double-blind period and in 183 of 209 (87·6%) patients receiving placebo. Most adverse events were grade 1 or 2. The most frequent treatment-emergent adverse events in the sorafenib group were hand-foot skin reaction (76·3%), diarrhoea (68·6%), alopecia (67·1%), and rash or desquamation (50·2%). INTERPRETATION: Sorafenib significantly improved progression-free survival compared with placebo in patients with progressive radioactive iodine-refractory differentiated thyroid cancer. Adverse events were consistent with the known safety profile of sorafenib. These results suggest that sorafenib is a new treatment option for patients with progressive radioactive iodine-refractory differentiated thyroid cancer. FUNDING: Bayer HealthCare Pharmaceuticals and Onyx Pharmaceuticals (an Amgen subsidiary).

Real-world practice patterns and outcomes for RAI-refractory differentiated thyroid cancer.

Background: The optimal timing for initiating multi-kinase inhibitors (MKIs) in patients with radioactive iodine-refractory (RAI-R) differentiated thyroid cancer (DTC) remains unclear. Thus, we evaluated the real-world practice patterns and outcomes in asymptomatic patients with progressive RAI-R DTC (≥1 lesion ≥1 cm in diameter) in the USA (US population) and outside the USA (non-US population). Methods: In this prospective, non-interventional, open-label study, eligible patients were chosen by treating physicians to receive MKI therapy (cohort 1) or undergo active surveillance (cohort 2) at study entry. Cohort 2 patients were allowed to transition to MKI therapy later. The primary endpoint was time to symptomatic progression (TTSP) from study entry. Data were compared descriptively. When endpoints were inestimable, 36-month rates were calculated. Results: Of the 647 patients, 478 underwent active surveillance (cohort 2) and 169 received MKI treatment (cohort 1). Patients underwent surveillance at a higher rate in the US (92.6%) vs the non-US (66.9%) populations. Half of US and non-US patients who qualified for MKI treatment had initial American Thyroid Association (ATA) low-to-intermediate-risk disease. In cohort 2, the 36-month TTSP rates from study entry were 65.6% and 66.5% in the US and non-US populations, respectively. Cohort 2 patients treated later demonstrated 36-month TTSP rates of 30.8% and 55.8% in the US and non-US populations, respectively. Conclusions: Active surveillance is a viable option for asymptomatic patients with progressive RAI-R DTC. However, early intervention with MKI therapy may be more suitable for others. Further research is needed to identify patients who are optimal for active surveillance. Registration: NCT02303444.

Increased Progression-Free Survival with Cabozantinib Versus Placebo in Patients with Radioiodine-Refractory Differentiated Thyroid Cancer Irrespective of Prior Vascular Endothelial Growth Factor Receptor-Targeted Therapy and Tumor Histology: A Subgroup Analysis of the COSMIC-311 Study.

Background: Lenvatinib and sorafenib are standard of care first-line treatments for advanced, radioiodine-refractory (RAIR) differentiated thyroid cancer (DTC). However, most patients eventually become treatment-resistant and require additional therapies. The phase 3 COSMIC-311 study investigated cabozantinib in patients with RAIR DTC who progressed on lenvatinib, sorafenib, or both and showed that cabozantinib provided substantial clinical benefit. Presented in this study is an analysis of COSMIC-311 based on prior therapy and histology. Methods: Patients were randomized 2:1 (stratification: prior lenvatinib [yes/no]; age [≤65, >65 years]) to oral cabozantinib (60 mg tablet/day) or matched placebo. Eligible patients received 1-2 prior vascular endothelial growth factor receptor-targeting tyrosine kinase inhibitors for DTC (lenvatinib or sorafenib required), had a confirmed DTC diagnosis, and were refractory to or ineligible for radioiodine therapy. For this analysis, progression-free survival (PFS) and objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 by a blinded independent radiology committee were evaluated by prior therapy (lenvatinib only, sorafenib only, both) and histology (papillary, follicular, oncocytic, poorly differentiated). Results: Two hundred fifty-eight patients were randomized (170 cabozantinib/88 placebo) who previously received sorafenib only (n = 96), lenvatinib only (n = 102), or both (n = 60). The median follow-up was 10.1 months. The median PFS (months) with cabozantinib/placebo was 16.6/3.2 (sorafenib only: hazard ratio [HR] 0.13 [95% confidence interval, CI, 0.06-0.26]), 5.8/1.9 (lenvatinib only: HR 0.28 [95% CI 0.16-0.48]), and 7.6/1.9 (both: HR 0.27 [95% CI 0.13-0.54]). The ORR with cabozantinib/placebo was 21%/0% (sorafenib only), 4%/0% (lenvatinib only), and 8%/0% (both). Disease histology consisted of 150 papillary and 113 follicular, including 43 oncocytic and 36 poorly differentiated. The median PFS (months) with cabozantinib/placebo was 9.2/1.9 (papillary: HR 0.27 [95% CI 0.17-0.43]), 11.2/2.5 (follicular: HR 0.18 [95% CI 0.10-0.31]), 11.2/2.5 (oncocytic: HR 0.06 [95% CI 0.02-0.21]), and 7.4/1.8 (poorly differentiated: HR 0.18 [95% CI 0.08-0.43]). The ORR with cabozantinib/placebo was 15%/0% (papillary), 8%/0% (follicular), 11%/0% (oncocytic), and 9%/0% (poorly differentiated). Safety outcomes evaluated were consistent with those previously observed for the overall population. Conclusions: Results indicate that cabozantinib benefits patients with RAIR DTC, regardless of prior lenvatinib or sorafenib treatments or histology. Clinical Trial Registration Number: NCT03690388.

Vandetanib in locally advanced or metastatic differentiated thyroid cancer refractory to radioiodine therapy.

VERIFY study is a randomized, double-blind, multicenter phase III clinical trial aimed to determine the efficacy and safety of vandetanib in tyrosine kinase inhibitor-naive patients with locally advanced or metastatic differentiated thyroid cancer (DTC), refractory to radioiodine (RAI) therapy with documented progression (NCT01876784). Patients were randomized 1:1 to vandetanib or placebo. The primary endpoint was progression-free survival (PFS). Secondary endpoints included best objective response rate, overall survival (OS), safety, and tolerability. Patients continued to receive randomized treatment until disease progression or for as long as they were receiving clinical benefit unless criteria for treatment discontinuation were met. Following randomization, 117 patients received vandetanib and 118 patients received placebo. Median PFS was 10.0 months in the vandetanib group and 5.7 months in the placebo group (hazard ratio [HR] 0.75; 95% confidence interval [CI] 0.55-1.03; p = 0.080). OS was not significantly different between treatment arms. Common Terminology Criteria for Adverse Events [CTCAE] adverse events of grade ≥3 were reported in 55.6% of patients in the vandetanib arm and 25.4% in the placebo arm. Thirty-three deaths (28.2%; one related to study treatment) occurred in the vandetanib arm compared with 16 deaths (13.6%; two related to treatment) in the placebo arm. No statistically significant improvement was observed in PFS in treatment versus placebo in patients with locally advanced or metastatic, RAI-refractory DTC. Moreover, active treatment was associated with more adverse events and more deaths than placebo though the difference in OS was not statistically significant.

Evaluation of potential biomarkers for lenvatinib plus pembrolizumab among patients with advanced endometrial cancer: results from Study 111/KEYNOTE-146.

BACKGROUND: Lenvatinib plus pembrolizumab demonstrated clinically meaningful benefit in patients with previously treated advanced endometrial carcinoma in Study 111/KEYNOTE-146 (NCT02501096). In these exploratory analyses from this study, we evaluated the associations between clinical outcomes and gene expression signature scores and descriptively summarized response in biomarker subpopulations defined by tumor mutational burden (TMB) and DNA variants for individual genes of interest. METHODS: Patients with histologically confirmed metastatic endometrial carcinoma received oral lenvatinib 20 mg once daily plus intravenous pembrolizumab 200 mg every 3 weeks for 35 cycles. Archived formalin-fixed paraffin-embedded tissue was obtained from all patients. T-cell-inflamed gene expression profile (TcellinfGEP) and 11 other gene signatures were evaluated by RNA sequencing. TMB, hotspot mutations in PIK3CA (oncogene), and deleterious mutations in PTEN and TP53 (tumor suppressor genes) were evaluated by whole-exome sequencing (WES). RESULTS: 93 and 79 patients were included in the RNA-sequencing-evaluable and WES-evaluable populations, respectively. No statistically significant associations were observed between any of the RNA-sequencing signature scores and objective response rate or progression-free survival. Area under the receiver operating characteristic curve values for response ranged from 0.39 to 0.54; all 95% CIs included 0.50. Responses were seen regardless of TMB (≥175 or <175 mutations/exome) and mutation status. There were no correlations between TcellinfGEP and TMB, TcellinfGEP and microvessel density (MVD), or MVD and TMB. CONCLUSIONS: This analysis demonstrated efficacy for lenvatinib plus pembrolizumab regardless of biomarker status. Results from this study do not support clinical utility of the evaluated biomarkers. Further investigation of biomarkers for this regimen is warranted. TRIAL REGISTRATION NUMBER: NCT02501096.

Pralsetinib in Patients with Advanced/Metastatic Rearranged During Transfection (RET)-Altered Thyroid Cancer: Updated Efficacy and Safety Data from the ARROW Study.

Background: Rearranged during transfection (RET) alterations are targetable oncogenic drivers in thyroid cancer. Primary data from the open-label, phase 1/2 ARROW study demonstrated clinical activity and manageable safety with pralsetinib, a selective RET inhibitor, in patients with advanced/metastatic RET-altered thyroid cancer. We present an updated analysis with more patients and longer follow-up. Methods: Adult patients with advanced/metastatic RET-mutant medullary thyroid cancer (MTC) or RET fusion-positive thyroid cancer who initiated oral pralsetinib at 400 mg once daily were included. Primary endpoints were overall response rate (ORR) by blinded independent central review (per RECIST v1.1) and safety. Secondary endpoints included duration of response (DoR), progression-free survival (PFS), and overall survival. Responses were assessed in three cohorts of patients with baseline measurable disease: patients with RET-mutant MTC who had received prior cabozantinib and/or vandetanib (C/V), treatment-naïve patients with RET-mutant MTC, and patients with previously treated RET fusion-positive thyroid cancer. Patient-reported outcomes (PROs) were an exploratory endpoint. Results: As of October 18, 2021, the measurable disease population comprised of 61 patients with RET-mutant MTC and prior C/V, 62 treatment-naïve patients with RET-mutant MTC, and 22 patients with RET fusion-positive thyroid cancer who had received prior systemic therapy, including radioactive iodine. The ORR was 55.7% [confidence interval; 95% CI: 42.4-68.5] in patients with RET-mutant MTC and prior C/V, 77.4% [95% CI: 65.0-87.1] in treatment-naïve patients with RET-mutant MTC, and 90.9% [95% CI: 70.8-98.9] in patients with previously treated RET fusion-positive thyroid cancer. Median DoR and median PFS were both 25.8 months in patients with RET-mutant MTC and prior C/V, not reached in treatment-naïve patients with RET-mutant MTC, and 23.6 and 25.4 months, respectively, in patients with previously treated RET fusion-positive thyroid cancer. In the RET-altered thyroid cancer safety population (N = 175), 97.1% of patients reported a treatment-related adverse event (TRAE); these led to discontinuation in 5.7% and dose reduction in 52.6% of patients. There was one death (0.6%) due to a TRAE. PROs improved or remained stable after pralsetinib treatment. Conclusions: In this updated analysis of the ARROW study, pralsetinib continued to show deep and durable clinical activity and a manageable safety profile in patients with advanced/metastatic RET-altered thyroid cancer. Clinical Trial Registration: NCT03037385.

Population Pharmacokinetics and Exposure-Response Analysis for the Phase 3 COSMIC-311 Trial of Cabozantinib for Radioiodine-Refractory Differentiated Thyroid Cancer.

BACKGROUND AND OBJECTIVE: In the USA, cabozantinib was approved for the treatment of patients aged ≥ 12 years with radioiodine-refractory differentiated thyroid cancer (DTC) who progressed on prior vascular endothelial growth factor (VEGFR)-targeted therapy based on the Phase 3 COSMIC-311 trial, which evaluated cabozantinib 60 mg/day versus placebo. Approved dosing is 60 mg/day for adults and for pediatric patients aged ≥ 12 years with body surface area (BSA) ≥ 1.2 m2, and 40 mg/day for pediatric patients aged ≥ 12 years with BSA < 1.2 m2. This report describes a population pharmacokinetic (PopPK) and exposure-response analysis of COSMIC-311. METHODS: A PopPK model was developed using concentration-time data from COSMIC-311 and 6 other cabozantinib studies. The final (full) PopPK model was used to simulate the effect of sex, body weight, race, and patient population. For exposure-response analysis, derived datasets from COSMIC-311 were constructed for time-to-event analyses of progression-free survival (PFS) and safety endpoints. RESULTS: The PopPK analysis included 4746 cabozantinib PK samples from 1745 patients and healthy volunteers. Body weight had minimal impact on cabozantinib exposure but increasing body weight was associated with increased apparent volume of distribution. Based on model-based simulation, adolescents < 40 kg had higher maximum plasma concentration at steady state of cabozantinib 60 mg/day compared to adults. Allometric scaling simulation in adolescents < 40 kg demonstrated higher exposure with 60 mg/day relative to adults receiving the same dose, while exposure with 40 mg/day in adolescents < 40 kg was similar to 60 mg/day in adults. The exposure-response analysis included 115 patients. There was no clear relationship between PFS or dose modification and cabozantinib exposure. A statistically significant relationship was demonstrated for cabozantinib exposure and hypertension (Grade ≥ 3) and fatigue/asthenia (Grade ≥ 3). CONCLUSIONS: These results support the dosing strategy implemented in COSMIC-311 and the BSA-based label recommendations for adolescents. The cabozantinib dose should be reduced to manage adverse events as indicated.