Efficacy and Limitations of Lenvatinib Therapy for Radioiodine-Refractory Differentiated Thyroid Cancer: Real-World Experiences

Improving the response to lenvatinib in partial responders using a Constrained-Disorder-Principle-based second-generation artificial intelligence-therapeutic regimen: a proof-of-concept open-labeled clinical trial

Introduction

The main obstacle in treating cancer patients is drug resistance. Lenvatinib treatment poses challenges due to loss of response and the common dose-limiting adverse events (AEs). The Constrained-disorder-principle (CDP)-based second-generation artificial intelligence (AI) systems introduce variability into treatment regimens and offer a potential strategy for enhancing treatment efficacy. This proof-of-concept clinical trial aimed to assess the impact of a personalized algorithm-controlled therapeutic regimen on lenvatinib effectiveness and tolerability.

Methods

A 14-week open-label, non-randomized trial was conducted with five cancer patients receiving lenvatinib-an AI-assisted application tailored to a personalized therapeutic regimen for each patient, which the treating physician approved. The study assessed changes in tumor response through FDG-PET-CT and tumor markers and quality of life via the EORTC QLQ-THY34 questionnaire, AEs, and laboratory evaluations. The app monitored treatment adherence.

Results

At 14 weeks of follow-up, the disease control rate (including the following outcomes: complete response, partial response, stable disease) was 80%. The FDG-PET-CT scan-based RECIST v1.1 and PERCIST criteria showed partial response in 40% of patients and stable disease in an additional 40% of patients. One patient experienced a progressing disease. Of the participants with thyroid cancer, 75% showed a reduction in thyroglobulin levels, and 60% of all the participants showed a decrease in neutrophil-to-lymphocyte ratio during treatment. Improvement in the median social support score among patients utilizing the system supports an ancillary benefit of the intervention. No grade 4 AEs or functional deteriorations were recorded.

Summary

The results of this proof-of-concept open-labeled clinical trial suggest that the CDP-based second-generation AI system-generated personalized therapeutic recommendations may improve the response to lenvatinib with manageable AEs. Prospective controlled studies are needed to determine the efficacy of this approach.

Ten years' real-life experience on the use of multikinase inhibitors in patients with advanced differentiated thyroid cancer

PURPOSE

To evaluate objective response rates (ORR), progression-free survival (PFS), and overall survival (OS) associated with tyrosine kinase inhibitors (TKIs) in patients with radioiodine refractory differentiated thyroid cancer (RR-DTC). Additionally, to compare: (i) ORR and PFS among patients treated with lenvatinib and sorafenib; (ii) ORR and PFS among patients receiving lenvatinib as first-line vs. second-line and; (iii) adverse effects (AEs) observed in patients treated with these medications.

METHODS

Retrospective analysis of RR-DTC adult patients treated with TKIs at the Division of Endocrinology, Hospital de Clinicas, University of Buenos Aires (March 2011-November 2023).

RESULTS

Among 43 patients included in the study, 32 received sorafenib (30 as first-line and 2 as second-line), while 29 received lenvatinib (12 as first-line and 17 as second-line). The median PFS and OS for the entire cohort were 32.7 and 39.0 months, respectively. Lenvatinib demonstrated a significantly higher ORR compared to sorafenib (37.9% vs. 9.4%, p = 0.008). However, both drugs exhibited similar median PFS (23.2 vs. 16.0 months, p = 0.419). No significant difference was observed in ORR and PFS between patients receiving first-line vs. second-line lenvatinib. Sorafenib-treated patients experienced higher rates of hand-foot skin syndrome (69% vs. 41%, p = 0.032) and alopecia (25% vs. 3%, p = 0.018), whereas lenvatinib-treated patients had higher rates of proteinuria (31% vs. 0%, p < 0.001) and grade 3 hypertension (31% vs. 9%, p = 0.034).

CONCLUSION

TKIs demonstrated efficacy and tolerability comparable to real-world data in RR-DTC. PFS was not statistically different between sorafenib and lenvatinib. Our study will help guide physicians in making informed decisions regarding treatment sequencing with TKIs in these patients.

The importance of early-stage blood pressure control in thyroid cancer patients treated with lenvatinib from the perspective of dose intensity

PURPOSE

Lenvatinib (LEN) is a multikinase inhibitor that strongly inhibits tyrosine kinase receptors, especially VEGFR-2, which can cause hypertension, as well as strong tumor shrinkage. Though control of any side effects (SEs) is important for maintaining dose intensity (DI), hypertension is particularly important, because blood pressure (BP) can change quickly and respond to LEN administration and withdrawal, and it can be controlled with antihypertensive medications. Focusing on the early phase of treatment, the effect of BP 8 weeks after LEN initiation (BP8w) on DI at 8 weeks (DI8w) was investigated.

METHODS

The subjects were 85 thyroid cancer patients who started LEN at 24 mg/day and continued for ≥8 weeks. The BP at the start of LEN (BPbase), BP8w grade, and DI8w were examined.

RESULTS

Median (range) systolic BP changed significantly from BPbase of 117 (84-167) mmHg to BP8w of 134 (103-168) mmHg (p<0.001). Antihypertensive treatment at baseline, systolic BPbase, and male sex were related to higher DI8w on multivariate analysis. The median DI8w of the 23 patients who required dose modification due to hypertension was 20.2 mg/day (n=6) in grade 1, 15.8 mg/day (n=13) in grade 2, and 14.5 mg/day (n=4) in grade 3, showing a trend toward lower DI8w as the grade level increased.

CONCLUSION

LEN can increase BP by 20 mmHg at 8 weeks even with intensive antihypertensive management. Baseline antihypertensive treatment and BPbase can affect DI8w. A higher DI8w may be achieved by aiming for a low 8-week BP with more intensive antihypertensive therapy after LEN initiation.

Successful dose escalation of lenvatinib for thyroid cancer after disease progression

PURPOSE

Lenvatinib is started at a standard dose, continuing with dose reduction and interruption, balancing between efficacy and adverse events (AEs). Because few drugs are available for thyroid cancer, efforts for continuing treatment with one agent, such as "dose escalation (DE)", are made. The dose is increased, aiming to regain the anti-tumor effect after dose reduction. The effects of lenvatinib DE in differentiated thyroid carcinoma (DTC) patients are reported.

PATIENTS AND METHODS

The efficacy of lenvatinib DE in DTC patients using the serum thyroglobulin (Tg) level and management of AEs was investigated.

RESULTS

A total of 70 DE episodes in 33 patients were investigated. The median increased dose was 2.0 (1.0-14.0) mg, increased from 8.6 (2-16) mg to 10.1 (6-24) mg. The serum Tg level decreased in 53 DE episodes. Though the serum Tg level in 17 DE episodes was not decreased, the Tg rate of increase was decreased in 7 of these DE episodes using the Tg-doubling rate. Overall, clinical benefit was seen in 60 (86%) DE episodes. AEs that could not be controlled after DEs were seen in only 16% of cases. No intolerable AEs were observed in patients who received more drug holidays at the time of DEs compared to two times before the DEs.

CONCLUSION

DE may become one of the standard treatment strategies after disease progression if AEs are well managed. Drug holidays may be a key for successfully controlling AEs with DE. DE can be useful for controlling progressive disease with increasing Tg levels.

Mitochondrial Respiration Inhibition Suppresses Papillary Thyroid Carcinoma Via PI3K/Akt/FoxO1/Cyclin D1 Pathway

Background

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy, but little is known regarding PTC metabolic phenotypes and the effects of mitochondrial activity on PTC progression. The great potential of mitochondria-targeting therapy in cancer treatment promoted us to use tool compounds from a family of Mito-Fu derivatives to investigate how the regulation of mitochondrial respiration affected tumor progression characteristics and molecular changes in PTC.

Methods

Mito-Fu L20, a representative of 12 synthetic derivatives, was chosen for mitochondrial inhibition experiments. Sample sections from PTC patients were collected and processed to explore potential molecular alterations in tumor lymph node metastasis (LNM). In vitro analyses were performed using human PTC cell lines (K1 and TPC-1), with the human normal thyroid follicular cell line (Nthy) as a control. K1 cells were injected into nude mice to generate an animal model. The mice were injected with normal saline or Mito-Fu L20 at 20 or 50 mg/kg every other day; their body weights and tumor volumes were also measured over time. To elucidate the resulting metabolic phenotype, we measured oxygen consumption rate (OCR) and extracellular acidification rate (ECAR), cellular adenosine triphosphate (ATP) levels and reactive oxygen species (ROS) production, and mitochondrial membrane potential. Wound healing and Transwell assays, cell cycle assays, real-time fluorescence quantitative PCR, Western blotting, and immunohistochemical staining were performed to explore glycolysis-dominant metabolism in PTC.

Results

Cyclin D1 and mitochondrial complex IV were detected in tumor samples from PTC patients with LNM. Mito-Fu L20 showed dose-independent and reversible modulation of mitochondrial respiration in PTC. In addition to mitochondrial dysfunction and early apoptosis, G1/S phase arrest. Notably, reversible mitochondrial inhibition yielded durable suppression of tumor proliferation, migration, and invasion via the PI3K/Akt/FoxO1/Cyclin D1 pathway. In vivo experiments demonstrated that Mito-Fu L20 has a good safety profile and specific restorative effect on mitochondrial activity in the liver. In addition, Mito-Fu L20 showed antitumor effects, alleviated tumor angiogenesis, and improved thyroid function.

Conclusion

Reversible inhibition of ATP production and durable suppression of PTC growth indicates that the downregulation of mitochondrial function has a negative impact on tumor progression and LNM via the PI3K/Akt/FoxO1/Cyclin D1 pathway. The results provide new insights into the antitumor potential and clinical translation of mitochondrial inhibitors.

Daily Management of Patients on Multikinase Inhibitors’ Treatment

In a minority of differentiated thyroid cancer (TC) cases and in a large percentage of poorly differentiated TCs (PDTCs) and anaplastic TCs (ATCs), the prognosis is poor due to the lack of response to conventional treatments. In the last two decades, multikinase inhibitor (MKI) compounds have been developed and demonstrated to be very effective in these aggressive cases. Besides the great efficacy, several adverse events (AEs) have been reported in virtually all patients treated with MKIs, largely overlapping between different compounds and including hypertension, diarrhea, anorexia, decreased weight, fatigue, and proteinuria. Most grade 3–4 adverse reactions occur during the first 6 months of treatment and require dosage reduction and/or drug discontinuation. Due to severity of the AEs related to the treatment with MKIs, a multidisciplinary team is definitely required for the daily management of these patients, for the evaluation of the disease status, and the psychophysical condition. Moreover, it is crucial that the patients could have a facilitated access to reach either specialist doctors or nurses who must have been trained to follow them for their individual clinical complications. The follow-up visits should take place at monthly intervals until the sixth month and then every 1–2 months until the completion of the first year of treatment. The flow chart followed at our tertiary center is reported in the present review as a real-life-based example for the follow-up of patients with advanced TC on MKI treatment.

Emerging drugs for the treatment of radioactive iodine refractory papillary thyroid cancer

INTRODUCTION

The most frequent radioactive (RAI) refractory thyroid cancers are papillary thyroid carcinoma, followed by poorly differentiated thyroid carcinoma. They are rare and lethal. In recent years, significant therapeutic progress has been achieved.

AREAS COVERED

This paper offers insights on refractoriness to RAI treatment and the optimization of treatment initiation and treatment choice. Clinical trials performed with anti-angiogenic kinase inhibitors and with targeted inhibitors in patients with BRAF, RAS mutation or RET, TRK or ALK fusion are discussed.

EXPERT OPINION

These treatments provide high response rates. Anti-angiogenic kinase inhibitors improve median progression-free-survival; however, their benefit in terms of overall survival has been shown in only few subsets of patients. Treatment sequencing is challenging; in the absence of targetable abnormality, lenvatinib should be used as first line treatment. Options for second line treatment include lenvatinib (if not given at first line), cabozantinib or the addition of an anti-checkpoint antibody. In patients with a targetable abnormality, specific inhibitors, might be used as first line treatment and lenvatinib as second line or vice-versa. Further studies are needed, based on documented genomic and immunologic characteristics of the tumor to assess the potential role of combination and redifferentiation therapy.

Lenvatinib Therapy for Advanced Thyroid Cancer: Real-life Data on Safety, Efficacy and Some Rare Side Effects

Context

The SELECT trial led to the approval of lenvatinib for the treatment of advanced radioiodine-refractory differentiated thyroid carcinomas (DTCs) but also revealed an important adverse event (AE) profile which may limit its use in clinical practice.

Objective

We aim to describe the efficacy and toxicity profiles of lenvatinib in real life.

Methods

We included all patients who received lenvatinib for an advanced DTC at our institution, enrolling 27 patients. We reviewed retrospectively electronic medical records to assess efficacy and AEs.

Results

Among the 24 patients with evaluation of tumor response during treatment, overall response rate (ORR) was 37.0% (95% CI, 19.4%-57.6%), and disease control rate was 85.2% (95% CI, 66.3%-95.8%). The median progression-free survival (PFS) was 12 months (95% CI, 7.5-16.5]. The most prevalent AEs were hypertension (77.8%), fatigue (55.6%), and weight loss (51.9%). At least one grade ≥ 3 AE was experienced by 25/27 patients (92.6%), mostly hypertension (59.3%). Lenvatinib was discontinued due to AEs in 13/27 patients (48.1%). Interestingly, 1 patient experienced a grade 4 posterior reversible encephalopathy syndrome, and another developed a Takotsubo cardiomyopathy.

Conclusion

The safety profile of lenvatinib in our cohort was similar to that reported in the literature, with a predominance of hypertension. Rigorous blood pressure control is therefore essential to avoid discontinuing therapy. We also report 2 severe and rarely described AEs that physicians should watch for. As for efficacy, although less than in the SELECT trial, ORR and PFS were similar to other real-life studies.

Real-world insights into the efficacy and safety of tyrosine kinase inhibitors against thyroid cancers

Based on clinical trials demonstrating favorable short-term efficacy and tolerable toxicity, several tyrosine kinase inhibitors have been approved for treating locally recurrent or metastatic, progressive radioiodine-refractory differentiated thyroid cancer, BRAF^V600E-mutant anaplastic thyroid cancer, and advanced or progressive medullary thyroid cancer. Longer term efficacy and safety of these treatments have been investigated in multiple real-world studies, demonstrating indispensable complementary value. Hereby, we summarize data from a total of 27 real-world studies with a focus on long-term survival data and rare but life-threatening adverse effects. An overall picture of current real-world study was drawn, and integrated experience of multiple centers would be helpful to clinical practice and further research.

Long-term management of recurrent papillary thyroid carcinoma treated with lenvatinib for over 5 years: a case report

BACKGROUND

Few reports exist of the long-term management of recurrent and progressive papillary thyroid carcinoma (PTC) with a tyrosine kinase inhibitor for over 5 years.

CASE PRESENTATION

A 57-year-old woman was referred to a psychiatric hospital for the treatment of schizophrenia. The patient had been diagnosed with a PTC at the age of 40 and subsequently underwent a left thyroid lobectomy. At 47, completion total thyroidectomy and lymph node dissection were performed and the patient assessed as radioactive iodine refractory postoperatively. External radiation therapy was performed for Rouviere lymph nodes. At 57, neck and mediastinal lymph nodes, and lung metastases had progressed, and the trachea became narrowed by para-tracheal lymph node compression. After 2 weeks of sorafenib therapy on an outpatient basis, the patient was discovered unconsciousness at home and transferred to hospital by ambulance; sorafenib therapy was stopped. The patient was diagnosed with reversible posterior leukoencephalopathy syndrome by brain magnetic resonance imaging. External radiation therapy to the site of the tracheal stenosis in the neck and mediastinum was performed. The patient's mental symptoms worsened, and she was referred to a psychiatric hospital, Kachi Memorial Hospital, in July 2015. In September, the patient's mental state stabilized and in November, after computed tomography revealed rapid disease progression, lenvatinib was commenced at a daily dose of 24 mg. Measurable solid recurrence sites were neck lymph nodes in the pre-laryngeal subcutaneous space, right lobe of the lung, and left adrenal. After 3 months, the tumors shrank in a partial response (PR). Because of several adverse events, occasional dose reductions or discontinuations of lenvatinib were sometimes necessary. Since re-starting lenvatinib, treatment with this for 51 consecutive months was achieved while maintaining a PR. Although a new bone metastasis was noted after 57 months of lenvatinib, treatment was continued for another 9 months. The patient subsequently passed away in June 2021.

CONCLUSIONS

The long-term treatment of recurrent PTC with lenvatinib was feasible, with manageable adverse events, for more than 5 years.

New approaches for patients with advanced radioiodine-refractory thyroid cancer

The cumulative evidence over the past decades has shown that the incidence of differentiated thyroid carcinoma (DTC) has exponentially increased. Approximately 10% of patients with DTC exhibit recurrent or metastatic disease, and about two-thirds of the latter will be defined as refractory to radioactive iodine (RAIR) treatment. Since this condition implies 10-year survival rates less than 10% after detection, using available treatments, such as systemic and targeted therapies, have become increasingly relevant. The initiation of these treatments aims to reach stabilization, tumor volume reduction, and/or symptom improvement and it should be decided by highly specialized endocrinologists/oncologists on the basis of patient's features. Considering that despite enlarged progression-free survival was proven, multikinase inhibitors remain non-curative, their benefits last for a limited time and the side effects potentially cause harm and quality of life reduction. In this context, molecular testing of cancer cells provides a promising spectrum of targeted therapies that offer increased compatibility with individual patient needs by improving efficacy, progression free survival, overall survival and adverse events profile. This review article aims to provide a summary of the current therapeutic strategies in advanced RAIR-DTC, including approved target therapies as well as those for off-label use, RAI resensitization agents, and immunotherapy.

Nephrotoxicity in advanced thyroid cancer treated with tyrosine kinase inhibitors: An update

Over the past decade, the prognosis of advanced thyroid cancer (TC) patients has dramatically improved thanks to the introduction of tyrosine kinase inhibitors (TKIs). Despite their effectiveness, these drugs are burdened with several side effects that can negatively affect quality of life and compromise therapy continuation. Among renal adverse events (RAEs), proteinuria is the most frequently reported in clinical trials and real-life experiences, especially during treatment with lenvatinib or cabozantinib. This peculiar toxicity is commonly associated with targeted therapies with anti-angiogenic activity, even if the mechanisms underlying its onset and progression are not entirely clear. RAEs should be early recognized and properly managed to avoid renal function worsening and life-threatening consequences. Aiming at providing a comprehensive summary that can help clinicians to identify and manage TKIs-related RAEs in TC patients, we reviewed the current evidence about this topic, from pathogenesis and potential risk factors to diagnosis and treatment.

Kinase-Inhibitors in Iodine-Refractory Differentiated Thyroid Cancer-Focus on Occurrence, Mechanisms, and Management of Treatment-Related Hypertension

Differentiated thyroid cancer (DTC) usually has a good prognosis when treated conventionally with thyroidectomy, radioactive iodine (RAI) and thyroid-stimulating hormone suppression, but some tumors develop a resistance to RAI therapy, requiring alternative treatments. Sorafenib, lenvatinib and cabozantinib are multikinase inhibitors (MKIs) approved for the treatment of RAI-refractory DTC. The drugs have been shown to improve progression-free survival (PFS) and overall survival (OS) via the inhibition of different receptor tyrosine kinases (RTKs) that are involved in tumorigenesis and angiogenesis. Both sorafenib and lenvatinib have been approved irrespective of the line of therapy for the treatment of RAI-refractory DTC, whereas cabozantinib has only been approved as a second-line treatment. Adverse effects (AEs) such as hypertension are often seen with MKI treatment, but are generally well manageable. In this review, current clinical studies will be discussed, and the toxicity and safety of sorafenib, lenvatinib and cabozantinib treatment will be evaluated, with a focus on AE hypertension and its treatment options. In short, treatment-emergent hypertension (TE-HTN) occurs with all three drugs, but is usually well manageable and leads only to a few dose modifications or even discontinuations. This is emphasized by the fact that lenvatinib is widely considered the first-line drug of choice, despite its higher rate of TE-HTN.

Prognostic factors in patients with advanced differentiated thyroid cancer treated with multikinase inhibitors - a single Brazilian center experience

OBJECTIVE

The aim of this study was to describe the real-world experience multikinase inhibitors (MKI) in the treatment advanced differentiated thyroid carcinoma (DTC) refractory to radioactive iodine (RAIR) therapy.

METHODS

We reviewed the records of all patients with MKI-treated DTC from 2010 to 2018. Progression free survival (PFS), response rates (RR) and adverse events (AE) profiles were assessed. Clinical parameters were compared between groups with different outcomes (disease progression and death) to identify possible prognostic factors and benefit from treatment.

RESULTS

Forty-four patients received MKI for progressive RAIR DTC. Median PFS was 24 months (10.2-37.7) and median overall survival (OS) was 31 months. Best overall response was complete response in one patient (4.5%), partial response in nine (20.4%), stable disease in twenty-two (50%), and progressive disease (PD) in twelve (27.3%). Seventy-two point 7 percent patients had clinical benefit and AE were mild in most cases (82.7%). Progressive patients were more likely to have FDG positive target lesion than those who did not progress (p = 0.033) and higher maximum SUV on target lesions (p = 0.042). Presence of lung-only metastasis and lower thyroglobulin (Tg) during treatment was associated with stable disease (p = 0.015 and 0,049, respectively). Patients with shorter survival had larger primary tumor size (p = 0.015) and higher maximum SUV on target lesions (p = 0.023).

CONCLUSION

Our findings demonstrate safety and effectiveness of MKI in patients with advanced RAIR DTC. We were able to identify as possible prognostic markers of better outcomes: absence of FDG uptake on target lesions, lower maximum SUV on PET-CT, presence of lung-only metastasis and lower Tg during treatment.

Lenvatinib: an investigational agent for the treatment of differentiated thyroid cancer

INTRODUCTION

Differentiated thyroid cancer (DTC; >90% of all TCs) derives from follicular cells. Surgery is the main therapeutic strategy, and radioiodine (RAI) is administered after thyroidectomy. When DTC progresses, it does not respond to RAI and thyroid-stimulating hormone (TSH)-suppressive thyroid hormone treatment, and other therapies (i.e. surgery, external beam radiation therapy and chemotherapy) do not lead to a better survival. Thanks to the understanding of the molecular pathways involved in TC progression, important advances have been done. Lenvatinib is a multitargeted tyrosine kinase inhibitor of VEGFR1-3, FGFR1-4, PDGFRα, RET, and KIT signaling networks implicated in tumor angiogenesis, approved in locally recurrent or metastatic, progressive, RAI-refractory DTC. Unmet needs regarding the patient clinical therapy responsiveness in aggressive RAI-refractory DTC still remain.

AREAS COVERED

We provide an overview from the literature of in vitro, in vivo and real-life studies regarding lenvatinib as an investigational agent for the treatment of aggressive TC.

EXPERT OPINION

According to the SELECT trial, the treatment should be initiated with a dosage of 24 mg/day, subsequently decreasing it in relation to the side effects. The decision making process in patients with aggressive RAI-refractory DTC should be personalized and the potential toxicity should be properly managed.

Impact of lenvatinib on renal function: long-term analysis of differentiated thyroid cancer patients

Background

Because lenvatinib is well known to induce proteinuria by blocking the vascular endothelial growth factor (VEGF) pathway, renal function is a concern with long-term administration of lenvatinib. The long-term effects of lenvatinib on renal function in patients with advanced differentiated thyroid carcinoma (DTC) were analyzed.

Method

This study involved 40 DTC patients who continued lenvatinib therapy for ≥6 months. Estimated glomerular filtration rate (eGFR) was calculated as an indicator of renal function. The temporal course of eGFR, effects of baseline eGFR on eGFR changes, and factors affecting renal impairment were investigated.

Results

The overall cohort showed sustainable decreases in eGFR, with decreased values of 11.4, 18.3, and 21.0 mL/min/1.73 m² at 24, 36, and 48 months after starting treatment, respectively. No differences in eGFR decrease every 6 months were seen for three groups classified by baseline eGFR ≥90 mL/min/1.73 m² (n = 6), < 90 but ≥60 mL/min/1.73 m² (n = 26), or < 60 but ≥45 mL/min/1.73 m² (n = 8). Grade 3 proteinuria was associated with declines in eGFR (p = 0.0283). Long observation period was also associated with decreases in eGFR (p = 0.0115), indicating that eGFR may decrease in a time-dependent manner.

Conclusion

Lenvatinib can induce declines in eGFR, particularly with treatment duration > 2 years, regardless of baseline eGFR. Proteinuria is a risk factor for declines in eGFR. Patients who start lenvatinib with better renal function show a renal reserve capacity, prolonging clinical outcomes. Decision-making protocols must balance the benefits of lenvatinib continuation with acceptable risks of harm.

Multikinase inhibitors for the treatment of radioiodine refractory thyroid cancer: what have we learned from the 'real-world' experience?

PURPOSE OF REVIEW

Several molecularly targeted drugs for treating radioiodine resistant differentiated thyroid carcinomas (RAIR-DTC) have been identified. Among these, sorafenib and lenvatinib have been approved for clinical use in many countries. The present review will analyze efficacy and safety 'real-world' data (RWD) emerging after their commercialization.

RECENT FINDINGS

RWDs confirmed sorafenib and lenvatinib efficacy in terms of progression-free survival and, perhaps, overall survival improvement in patients with RAIR-DTC. Lenvatinib performance in RWDs appeared somehow lower than in randomized clinical trials (RCT), probably because the decision to start treatment in 'real life' was made when patients were in worse clinical conditions than in RCTs. Concerning safety, RWD studies corroborated RCT evidence of elevated overall and serious adverse event incidence. Notably, adverse events were manageable in most cases with appropriate treatment or dose reduction/interruption, so that the need for definitive withdrawal was limited. The suitability of multikinase inhibitors (MKI) as salvage therapy in RAIR-DTCs was also confirmed by RWD experience, at least for lenvatinib in the second-line setting.

SUMMARY

RWD analysis has corroborated RCT results in terms of MKI efficacy for both first-line and salvage treatment in patients with RAIR-DTC. The safety profiles emerging from RWDs seem to justify the caution recommended by most scientific guidelines.

Long-term management of lenvatinib-treated thyroid cancer patients: a real-life experience at a single institution

PURPOSE

The efficacy of lenvatinib for advanced and progressive radioactive iodine refractory differentiated thyroid cancer is well established. Herein, we retrospectively evaluated the long-term safety and efficacy of lenvatinib in 23 patients treated at a single Institution.

METHODS

Clinical data of all patients treated for a differentiated thyroid cancer with lenvatinib from April 2015 to September 2020 were retrospectively analyzed.

RESULTS

A total of 23 patients were included. In all, 21 patients received lenvatinib as first-line systemic therapy. Median age at initiation of lenvatinib treatment was 68 (44-90) years. Median duration of the study from initiation of lenvatinib to study end was 23 (2-65) months. The indication for lenvatinib treatment was documented progression of distant metastases in 20 patients and of locally advanced disease in the other 3 and median duration of lenvatinib therapy was 15 (2-64) months. Best treatment responses were: partial response in 6 patients, stable disease in 14, progressive disease in 1, and not evaluable in 2. Median progression-free survival was 25 months (95% CI: 12-40) and median overall survival was 46 months (95% CI: 28-65). Three patients had to discontinue lenvatinib treatment due to serious adverse events and no drug-related death was observed. Ten patients continued lenvatinib for more than 24 months and the only newly registered adverse event after this period of time was one case of G2 proteinuria. Six patients continued lenvatinib treatment beyond documented tumor progression due to oligoprogression or slowly progressive disease (median time 18.5 months, 8-42 months). A total of 14 patients were alive at the end of the study: 11 showed partial response/stable disease on lenvatinib, including 3 who had a stable disease after local ablative therapy for oligoprogressive metastases; 3 had to change treatment, including 2 for lenvatinib-related serious adverse events and 1 for progressive disease.

CONCLUSIONS

Long-term lenvatinib treatment is safe and some patients may experience persistent long-term control of the disease. Late treatment-related AEs rarely occurred. Oligoprogressive and slowly progressive disease can be managed without treatment withdrawal as long as there are some clinical benefits.

Long-Term Results of a Phase II Trial of Apatinib for Progressive Radioiodine Refractory Differentiated Thyroid Cancer

CONTEXT

Radioiodine refractory differentiated thyroid cancer (RAIR-DTC) has been a global challenge due to its poor prognosis and limited treatment options.

OBJECTIVE

We report here the long-term results of the phase II clinical trial of apatinib, an anti-angiogenic tyrosine kinase inhibitor, for RAIR-DTC.

METHODS

This was an open-label, exploratory phase II clinical trial among progressive RAIR-DTC patients. Apatinib treatment was given once daily until disease progression, unmanageable toxicity, withdrawal, or death. The primary end points were objective response rate (ORR) and disease control rate (DCR). Progression-free survival (PFS), overall survival (OS), duration of response, long-term safety, and the association between patients with different tumor genotype (BRAFV600E and TERT promotor mutation) and their PFS rates were also assessed.

RESULTS

The ORR was 80%, and the DCR was 95%. The overall median PFS was 18.4 months (95% CI, 9.2-36.8 months) and the median OS was 51.6 months (95% CI, 29.2-not reached [NR]). Patients with BRAFV600E mutation (10 of 18 evaluated) had a longer median PFS compared with patients with BRAF wild-type (NR vs 9.2 months; P = 0.002). The most common adverse events included palmar-plantar erythrodysesthesia syndrome (19/20), proteinuria (18/20), and hypertension (16/20).

CONCLUSION

In this long-term evaluation, apatinib displayed sustainable efficacy and tolerable safety profile, warranting it as a promising treatment option for progressive RAIR-DTC.

Sorafenib and Lenvatinib Treatment for Metastasis/Recurrence of Radioactive Iodine-refractory Differentiated Thyroid Carcinoma

BACKGROUND/AIM

Radioactive iodine-refractory differentiated thyroid carcinoma (RR-DTC) has been treated with multi-kinase inhibitors (MKIs), e.g., sorafenib (SOR) and lenvatinib (LEN). We analyzed the outcomes of RR-DTC patients who underwent SOR or LEN treatment at Kuma Hospital.

PATIENTS AND METHODS

We enrolled 21 and 18 patients treated with SOR and LEN, respectively.

RESULTS

The incidence of partial response in the LEN group was significantly higher than that in the SOR group. Serum thyroglobulin significantly decreased from the beginning of treatment to 1 month later in the LEN group (not in the SOR group). The neutrophil-lymphocyte ratio (NLR) was significantly decreased at 1 month later in both groups. An NLR ≥3 at the start of MKI treatment had a prognostic impact.

CONCLUSION

For RR-DTC, LEN could be more effective than SOR, at least in the short term. The first-line drug should be selected based on other factors (e.g., adverse events, patient background).

Clinical pharmacology and drug-drug interactions of lenvatinib in thyroid cancer

Lenvatinib is a non-selective tyrosine kinase inhibitor (TKI) with high in vitro potency against vascular endothelial growth factor receptors. Although this drug is used to treat several cancer types, it is the most effective TKI used in patients with thyroid cancer. Lenvatinib is well tolerated and the most common adverse drug reactions can be adequately managed by dose adjustment. Particularly, blood pressure and cardiac function monitoring, as well as antihypertensive treatment optimization, may be required in patients treated with lenvatinib. Dose reduction should be taken into account in patients with body weight <60 kg or severe hepatic failure. No significant change in lenvatinib pharmacokinetics has been observed with other patient-related factors and very few data are available on lenvatinib pharmacogenetics. Lenvatinib can be administered orally regardless of food and no clinically relevant drug-drug interactions have been reported.

Clinical Indications for Treatment with Multi-Kinase Inhibitors in Patients with Radioiodine-Refractory Differentiated Thyroid Cancer

Differentiated thyroid cancer is usually a slow-growing disease, even if the patients develop distant metastasis. For recurrent or metastatic disease, radioactive iodine therapy is a standard treatment. However, the disease gradually progresses in some of the patients and can ultimately develop into life-threatening conditions. For patients with progressive radioactive iodine-refractory differentiated thyroid cancer (RR-DTC), multi-kinase inhibitors (MKIs) including sorafenib and lenvatinib prolonged progression-free survival compared with placebo in pivotal randomized phase 3 trials, although the benefit in overall survival has not been clearly confirmed, possibly because the patients who received placebo were permitted to cross-over to lenvatinib upon disease progression. Moreover, the adverse events related to MKIs were not negligible. Therefore, the optimal timing of MKI initiation has long been controversial, and physicians should consider various patient and disease factors. Herein, we comprehensively review the clinical factors that can be helpful in determining the initiation of MKIs for patients with RR-DTC.

Lenvatinib as first-line treatment for advanced thyroid cancer: long progression-free survival

PURPOSE

Lenvatinib (LEN) has been approved for the treatment of patients with progressive radioiodine-refractory differentiated thyroid cancer (RAI-R DTC). Real-life studies reported a lower progression-free survival (PFS) than the registration study, likely due to the more advanced stage of tumors, the more frequent pretreatment with other TKIs, the limited follow-up, and the worse clinical condition of the patients included.

METHODS

We evaluated the clinical data of our cohort of 13 consecutive patients, all receiving LEN as a first-line TKI treatment, and followed-up in a single tertiary Center.

RESULTS

All patients had an ECOG of 0-1 and regional or distant metastases were documented in 61.5% and 77% of patients, respectively. Median PFS was 22 months (95% CI 14-35) with partial response in 69% and stable disease in 31% of patients. All patients experienced at least one adverse event (AE), the most frequent being fatigue, anorexia, diarrhea, and hypertension. The daily dose was reduced in 70% of patients and only one patient (7.7%) discontinued the drug for AEs.

CONCLUSION

In this series of RAI-R DTC patients, with the unique features to have an ECOG 0 or 1 and to be naive for TKI treatments, PFS was the longest among all real-life published so far, with the highest rate of patients with partial response and one of the lowest drug discontinuation rate for AEs. The correct timing of treatment start, the tailoring of the dose, and a proper management of the AEs may have a significant impact on the treatment response to LEN.

Questions and Controversies in the Clinical Application of Tyrosine Kinase Inhibitors to Treat Patients with Radioiodine-Refractory Differentiated Thyroid Carcinoma: Expert Perspectives

Notwithstanding regulatory approval of lenvatinib and sorafenib to treat radioiodine-refractory differentiated thyroid carcinoma (RAI-R DTC), important questions and controversies persist regarding this use of these tyrosine kinase inhibitors (TKIs). RAI-R DTC experts from German tertiary referral centers convened to identify and explore such issues; this paper summarizes their discussions. One challenge is determining when to start TKI therapy. Decision-making should be shared between patients and multidisciplinary caregivers, and should consider tumor size/burden, growth rate, and site(s), the key drivers of RAI-R DTC morbidity and mortality, along with current and projected tumor-related symptomatology, co-morbidities, and performance status. Another question involves choice of first-line TKIs. Currently, lenvatinib is generally preferred, due to greater increase in progression-free survival versus placebo treatment and higher response rate in its pivotal trial versus that of sorafenib; additionally, in those studies, lenvatinib but not sorafenib showed overall survival benefit in subgroup analysis. Whether recommended maximum or lower TKI starting doses better balance anti-tumor effects versus tolerability is also unresolved. Exploratory analyses of lenvatinib pivotal study data suggest dose-response effects, possibly favoring higher dosing; however, results are awaited of a prospective comparison of lenvatinib starting regimens. Some controversy surrounds determination of net therapeutic benefit, the key criterion for continuing TKI therapy: if tolerability is acceptable, overall disease control may justify further treatment despite limited but manageable progression. Future research should assess potential guideposts for starting TKIs; fine-tune dosing strategies and further characterize antitumor efficacy; and evaluate interventions to prevent and/or treat TKI toxicity, particularly palmar-plantar erythrodysesthesia and fatigue.

Safety and Quality-of-Life Data from an Italian Expanded Access Program of Lenvatinib for Treatment of Thyroid Cancer

Background: Lenvatinib, a multikinase inhibitor, is for progressive radioiodine-refractory-differentiated thyroid cancer (RR-DTC) patients. However, there are a lot of drug-related adverse events (AEs) that can affect the quality of life (QoL) of patients. The aims of this study were (a) to evaluate, and compared with other series, the safety of lenvatinib used in RR-DTC patients enrolled in an Italian expanded access program (EAP), and (b) to evaluate their QoL during treatment with lenvatinib. Methods: To evaluate the safety, we recorded and graded all AEs during the 6 months of lenvatinib treatment in 39 RR-DTC patients. We compared the safety profile of lenvatinib observed in our patients with that reported in the study of (E7080) levatinib in differentiated cancer of the thyroid (SELECT) and tumeurs thyroidiennes refractaires (TUTHYREF) network studies. Moreover, we evaluated the QoL in our series by using the European Organization for Research and Treatment (EORTC) Quality of Life Questionnaire-Core 30 and the pain visual analogue scale (VAS). Results: The most frequent AEs among our 39 RR-DTC patients were hypertension (80.5%), fatigue (58.3%), diarrhea (36.1%), stomatitis (33.3%), hand/foot syndrome (33.3%), and weight loss (30.5%). The most prevalent grade 3/4 AE was hypertension (25%). When compared with previous studies (i.e., SELECT and TUTHYREF), a significantly lower percentage of our patients experienced diarrhea, nausea, proteinuria, and weight loss. No statistically significant differences in the QoL of our patients evaluated before, during, and at the end of follow-up (6 months after starting the therapy) were found. However, a slight improvement of the general health and emotional and cognitive status associated with a slightly worsening of physical role and social functioning was observed during these 6 months. Pain, dyspnea, insomnia, and constipation moved toward better values, while fatigue, nausea and vomiting, appetite loss, and diarrhea worsened. By comparing the pain VAS, an overall reduction of the level of pain was found. Conclusions: The safety profile of the drug was similar to that already reported with some differences in the prevalence and severity of the AEs. Regarding the QoL, the EAP showed a trend of improvement of the global health status and a reduction of symptoms correlated to the disease. The clinical impact of fatigue, anorexia/weight loss and stomatitis, mainly due to the drug itself, continues to represent the major issue in the management of these patients.

Personalized treatment for differentiated thyroid cancer: current data and new perspectives

More conservative and personalized treatment options have been developed in recent years to face the rising diagnosis of low-risk differentiated thyroid carcinoma (DTC). The present review describes the change towards a more risk-adapted management either in the treatment or in the follow-up of DTC. Particular attention is given to the innovations introduced by the latest guidelines for low-risk tumors, starting from the most appropriate extension of surgery up to the postoperative management. The emerging role of active surveillance for low-risk microcarcinoma is discussed, as well as the development of percutaneous strategies in the setting of malignant thyroid disease. The recent use of approved new systemic target therapies for advanced radioiodine refractory thyroid cancer is reported, together with the description of new compounds in trial. Finally, we provide some considerations to improve the risk evaluation in a presurgical setting, especially related to the rising role of genetics, to enable better risk-based cancer management and personalized treatment choices.

Real-World Data for Lenvatinib in Radioiodine-Refractory Differentiated Thyroid Cancer (RELEVANT): A Retrospective Multicentric Analysis of Clinical Practice in Austria

BACKGROUND

Lenvatinib has proven efficacy in progressive, radioiodine- (RAI-) refractory thyroid cancer (TC). Dose reductions are commonly performed due to decreased tolerability and adverse effects. This retrospective multicenter study analyzed overall survival (OS) and progression-free survival (PFS) and tolerability in the Austrian patient population treated with lenvatinib.

METHODS

Clinical data of 43 patients (25 males and 18 females) with a median age of 70 years (range: 39-91 years) and RAI-refractory TC with metastases to the lymph nodes (74%), lungs (86%), bone (35%), liver (16%), and brain (12%) were analyzed. The mean duration of treatment with lenvatinib was 26.6 ± 15.4 months with dosage reductions required in 39 patients (91%).

RESULTS

PFS after 24 months was 71% (95% CI: 56-87), and overall survival (OS) was 74% (95% CI: 60-88), respectively. OS was significantly shorter (p=0.048) in patients with a daily maintenance dosage ≤ 10 mg (63%) (95% CI: 39-86) as compared to patients on ≥ 14 mg lenvatinib (82%) (95% CI: 66-98) daily. Dose reduction was noted in 39 patients (91%). Grade ≥3 toxicities (hypertension, diarrhea, weight loss, and palmar-plantar erythrodysesthesia syndrome) were most common leading to discontinuation of lenvatinib in 7 patients (16%).

CONCLUSION

Lenvatinib showed sustained clinical efficacy in patients with metastatic RAI-refractory TC even with reduced maintenance dosages over years. The effects were comparable to the registration trial, although patients had a higher median age and, more commonly, dose reductions.