The treatment landscape in thyroid cancer: a focus on cabozantinib

Decoding kinase-adverse event associations for small molecule kinase inhibitors

Small molecule kinase inhibitors (SMKIs) are being approved at a fast pace under expedited programs for anticancer treatment. In this study, we construct a multi-domain dataset from a total of 4638 patients in the registrational trials of 16 FDA-approved SMKIs and employ a machine-learning model to examine the relationships between kinase targets and adverse events (AEs). Internal and external (datasets from two independent SMKIs) validations have been conducted to verify the usefulness of the established model. We systematically evaluate the potential associations between 442 kinases with 2145 AEs and made publicly accessible an interactive web application “Identification of Kinase-Specific Signal” (https://gongj.shinyapps.io/ml4ki). The developed model (1) provides a platform for experimentalists to identify and verify undiscovered KI-AE pairs, (2) serves as a precision-medicine tool to mitigate individual patient safety risks by forecasting clinical safety signals and (3) can function as a modern drug development tool to screen and compare SMKI target therapies from the safety perspective.

Small molecule kinase inhibitors (SMKIs) are being approved at a fast pace under expedited programs for anticancer treatment. Here, the authors employ a machine-learning model to examine the relationships between kinase targets and adverse events in the trials of 16 FDA-approved SMKIs.

Medullary thyroid carcinoma: recent advances in identification, treatment, and prognosis

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor that represents <5% of all thyroid malignancies and is generally more aggressive than differentiated thyroid cancer. The aim of this study is to provide an update, through review of clinical studies of patients with MTC published between January 1, 2016, and June 1, 2021, on recent advances in the diagnosis and treatment of MTC. This review focuses on updates in biochemical testing, imaging, hereditary disease, surgical management, adjuvant therapies, and prognosis. Recent advances reviewed herein have sought to diagnose MTC at earlier stages of disease, predict when patients with a hereditary syndrome may develop MTC, use functional imaging to assess for distant metastases, perform optimal initial surgery with appropriate lymphadenectomy, employ targeted systemic therapies for patients with progressive metastatic disease, and better predict patient-specific outcomes.

Novel Therapeutics in Radioactive Iodine-Resistant Thyroid Cancer

Iodine-resistant cancers account for the vast majority of thyroid related mortality and, until recently, there were limited therapeutic options. However, over the last decade our understanding of the molecular foundation of thyroid function and carcinogenesis has driven the development of many novel therapeutics. These include FDA approved tyrosine kinase inhibitors and small molecular inhibitors of VEGFR, BRAF, MEK, NTRK and RET, which collectively have significantly changed the prognostic outlook for this patient population. Some therapeutics can re-sensitize de-differentiated cancers to iodine, allowing for radioactive iodine treatment and improved disease control. Remarkably, there is now an FDA approved treatment for BRAF-mutated patients with anaplastic thyroid cancer, previously considered invariably and rapidly fatal. The treatment landscape for iodine-resistant thyroid cancer is changing rapidly with many new targets, therapeutics, clinical trials, and approved treatments. We provide an up-to-date review of novel therapeutic options in the treatment of iodine-resistant thyroid cancer.

Neoadjuvant selpercatinib for advanced medullary thyroid cancer

Background

Targeted kinase inhibitors have been increasingly utilized in the treatment of advanced medullary thyroid cancer (MTC) over the last decade. Recently, highly potent next generation selective RET inhibitors have been clinically validated, and selpercatinib was recently Food and Drug Administration (FDA)‐approved for advanced MTC. The advent of highly selective, potent RET inhibitors is broadening the treatment options for patients with RET‐mutated cancers.

Methods

We report the first published case of neoadjuvant selpercatinib followed by surgery for a patient with initially unresectable, widely metastatic, RET‐mutated MTC who was treated on a single patient protocol.

Results

After greater than 50% RECIST response, the patient underwent complete surgical resection followed by selpercatinib resumption. He remains locoregionally disease‐free 21 months after starting therapy with stable metastatic disease (after initial partial response); and calcitonin/CEA continue to decline.

Conclusion

This novel treatment strategy for locoregionally advanced RET‐mutated MTC warrants further study in clinical trials.

Therapeutic options for advanced thyroid cancer

Thyroid cancer can be largely classified as well-differentiated, poorly differentiated, medullary and anaplastic. Differentiated thyroid cancer (DTC) includes follicular and papillary subtypes, with the incidence of papillary thyroid cancer (PTC) on the rise. The mainstay of treatment for DTC includes a combination of surgery, radioactive iodine (RAI) and levothyroxine suppression. DTC portends a favorable prognosis, even in the presence of distant metastases, with a 50% rate of 5-year survival largely due to tumor cell's sensitivity to RAI therapy influencing disease outcome. In radioactive iodine refractory differentiated thyroid cancer (RAI-refractory DTC) there is a lower survival rate prompting the use of other therapeutic options available. RAI refractoriness is more common in older patients (age >40), large metastases and lesions that are fluorodeoxyglucose (FDG) avid on position emission tomography (PET). Over the past decade, Identification of genetic mutations in the signaling pathway involved in thyroid tumorigenesis has led to the approval of tyrosine kinase inhibitors (TKIs); Sorafenib and Lenvatinib in RAI-refractory DTC. Similarly, metastatic medullary thyroid cancer (MTC) implies an unfavorable 10-year survival rate of only 20% as the principal treatment options focuses on loco regional control via surgical and/or non-surgical options. The approval of TKIs such as Cabozantinib and Vandetanib has introduced an encouraging, novel, systemic therapeutic option for metastatic MTC. Lastly, anaplastic thyroid cancer (ATC) carries the worst prognosis with high recurrence rates. Treatment includes surgery, chemotherapy and external beam radiation. The FDA recently approved Dabrafenib plus trametinib for BRAF V600E mutated ATC. Considering the modality of chemotherapy and the expanding field of targeted therapies, the role of the oncologist and interaction with endocrinologist in the management of thyroid cancer needs further clarification aiming at collaborative management plans more than ever. This review summarizes the key phase III trials that led to the approval of TKIs in the treatment of DTC and metastatic MTC. Additionally, the review aims to clarify the patient selection criteria for initiation of TKIs and examine the implications, considerations and adverse effects prior to utilizing targeted therapy. Clinical trials are ongoing with promising results and may contribute to the addition of several targeted molecules and immune check point inhibitors to the therapeutic armamentarium for RAI-refractory DTC, medullary and anaplastic thyroid cancer.

BPI-9016M, a c-Met inhibitor, suppresses tumor cell growth, migration and invasion of lung adenocarcinoma via miR203-DKK1

Activation of c-Met plays a critical role in tumorigenesis, migration and invasion in lung cancer. Here, we explored the therapeutic efficacy of a novel small-molecule c-Met inhibitor (BPI-9016M) in lung adenocarcinoma and investigated the underlying molecular mechanisms. Method: BPI-9016M, a c-Met tyrosine kinase receptor inhibitor, was used to treat patient-derived xenografts (PDX) from lung adenocarcinoma in NOD/SCID mice. Immunohistochemistry and Western blot analysis were used to determine the expression of c-Met and its downstream signaling molecules. CCK8, wound healing, and trans-well assays were used to analyze cell proliferation, spreading, migration and invasion. RNA sequencing and quantitative real-time PCR (qPCR) was used to screen and validate the expression of downstream genes in lung adenocarcinoma cells treated with BPI-9016M. Luciferase reporter assay was used to detect the interaction between miRNA and the targeted gene. Results: BPI-9016M significantly suppressed growth in three out of four lung adenocarcinoma PDX models, particularly in the tumors with high expression of c-Met. In lung adenocarcinoma cell lines, BPI-9016M treatment resulted in increased miR203, which reduced migration and invasion and also repressed Dickkopf-related protein 1 (DKK1) expression. Forced overexpression of DKK1 or down-regulation of miR203 reversed the inhibitory effect of BPI-9016M on migration and invasion. C-Met was verified to positively and negatively associate with DKK1 and miR203, respectively. High expression of c-Met/DKK1 or low expression of miR203 related to poor outcome of lung adenocarcinoma patients. Furthermore, we observed significantly enhanced tumor cell growth inhibition upon combining BPI-9016M treatment with miR203 mimics or DKK1 siRNA. Conclusion: Our data indicated that BPI-9016M is an effective agent against lung adenocarcinoma, particularly in tumors with c-Met activation, and likely functions through upregulation of miR203 leading to reduced DKK1 expression.

Lenvatinib as a novel treatment for anaplastic thyroid cancer: A retrospective study

Anaplastic thyroid cancer (ATC) is associated with an extremely poor prognosis and is resistant to the majority of chemotherapies. In 2015, lenvatinib was approved for treating ATC in Japan. The present study aimed to evaluate the overall survival (OS) of patients with ATC treated with lenvatinib. A total of 23 patients with a definitive histological diagnosis of ATC who were treated at Kanagawa Cancer Center (Yokohama, Kanagawa. Japan) were enrolled. Surgical treatment was possible in 10 patients (including one debulking surgery), and lenvatinib treatment was postoperatively started. The remaining 13 patients were not eligible for debulking surgery; thus, lenvatinib was promptly approved as a life-saving treatment. The therapeutic effect was determined according to the Response Evaluation Criteria In Solid Tumors criteria (ver.1.1). The patients exhibited a lenvatinib response rate of 17.4% and a disease control rate of 43.5%. However, lenvatinib was associated with a 100% incidence of treatment-related adverse events (AEs), with hypertension being the most common AE (91.3%). Additionally, dose interruptions and reductions were required due to the development of tumor fistulas or other tumor-related AEs, and 9 (39.1%) patients discontinued treatment due to grade 3 or higher AEs. The median OS time was 166 days. Overall, the present study demonstrated the effectiveness of lenvatinib against ATC, which is often chemotherapy-resistant. Successful treatment of fistulas developing due to tumor necrosis at the site of the primary lesion is crucial for improving the patient outcome. The response to lenvatinib in patients with ATC varies on a case-by-case basis and requires further investigation in future studies.

Practical management of adverse events associated with cabozantinib treatment in patients with renal-cell carcinoma

Cabozantinib is an oral tyrosine-kinase inhibitor whose targets include VEGFR, MET, and AXL. Cabozantinib is approved for the treatment of patients with advanced clear-cell renal-cell carcinoma (RCC) who have received prior antiangiogenic therapy. In the pivotal Phase III trial of second-line RCC, cabozantinib was associated with a significant improvement in overall survival, progression-free survival, and antitumor response compared with everolimus. Adverse events (AEs) were common for patients receiving cabozantinib, but were effectively managed with supportive care and dose modifications, as discontinuations of cabozantinib due to an AE were infrequent. This article reviews the management of the more common AEs associated with cabozantinib based on findings from the pivotal study, clinical practice guidelines, and the authors' real-world clinical experience, with support from published literature. We focus on hypertension, palmar-plantar erythrodysesthesia, diarrhea, nausea, vomiting, decreased appetite, fatigue, and stomatitis. Effective management of these AEs involves a multimodal strategy that includes patient education, prophylactic and supportive care, and dose modifications. Effective AE management can allow patients to maintain antitumor activity with cabozantinib while mitigating the impact on quality of life.

The molecular basis for RET tyrosine-kinase inhibitors in thyroid cancer

RET receptor tyrosine kinase acts as a mutated oncogenic driver in several human malignancies and it is over-expressed in other cancers. Small molecule compounds with RET tyrosine kinase inhibitory activity are being investigated for the targeted treatment of these malignancies. Multi-targeted compounds with RET inhibitory concentration in the nanomolar range have entered clinical practice. This review summarizes mechanisms of RET oncogenic activity and properties of new compounds that, at the preclinical stage, have demonstrated promising anti-RET activity.

Lenvatinib for Anaplastic Thyroid Cancer

BACKGROUND

Lenvatinib has been approved by regulatory agencies in Japan, the United States, and the European Union for treatment of radioiodine-refractory differentiated thyroid cancer (RR-DTC). Thyroid cancer, however, is a clinically diverse disease that includes anaplastic thyroid cancer (ATC), the subtype associated with the highest lethality. Effective therapy for ATC is an unmet need.

PATIENTS AND METHODS

This phase 2, single-arm, open-label study in patients with thyroid cancer, including ATC, RR-DTC, and medullary thyroid cancer was conducted from 3 September 2012 to 9 July 2015. Patients received lenvatinib 24 mg daily until disease progression or development of unacceptable toxicity. The primary endpoint was safety, and the secondary endpoint was efficacy, as assessed by progression-free survival (PFS), overall survival (OS), and objective response rate.

RESULTS

At data cutoff, 17 patients with ATC were enrolled. All experienced ≥1 treatment-emergent adverse event (TEAE). The most frequent TEAEs were decreased appetite (82%), hypertension (82%), fatigue (59%), nausea (59%), and proteinuria (59%). Of note, only one patient required lenvatinib withdrawal because of a TEAE, and this TEAE was considered unrelated to lenvatinib. The median PFS was 7.4 months [95% confidence interval (CI): 1.7-12.9], the median OS was 10.6 months (95% CI: 3.8-19.8), and the objective response rate was 24%.

CONCLUSION

In this study, lenvatinib demonstrated manageable toxicities with dose adjustments and clinical activity in patients with ATC. This clinical activity of lenvatinib warrants further investigation in ATC.

CLINICALTRIALSGOV

NCT01728623.

MiR-182 promotes cancer invasion by linking RET oncogene activated NF-κB to loss of the HES1/Notch1 regulatory circuit

Background

Dominant-activating mutations in the RET proto-oncogene, a receptor tyrosine kinase, are responsible for the development of medullary thyroid carcinoma (MTC) and causative for multiple endocrine neoplasia (MEN) type 2A and 2B. These tumors are highly aggressive with a high propensity for early metastasis and chemoresistance. This attribute makes this neoplasia an excellent model for probing mechanisms underlying cancer progression.

Methods

The expression level of miR-182 was measured in MTC tumor specimens and in TT cells by real-time RT-PCR. TT cells and modified NThy-ori 3.1 that stably express RETM918T were used to investigate RET-dependent regulation of miR-182. Identification and validation of miR-182 targets and pathways was accomplished with luciferase assays, qRT-PCR, Western blotting and immunofluorescence. In vitro, overexpression and knockdown experiments were carried out to examine the impact of miR-182 and HES1 on invasion and migration.

Results

We found that miR-182 expression is significantly upregulated in MTC patient samples and tumor-derived cell lines harboring mutated RET. Inhibition of RET oncogenic signaling through a dominant-negative RET∆TK mutant in TT cells reduces miR-182, whereas overexpression of RETM918T in NThy-ori 3.1 cells increases miR-182 levels. We further show that overexpression of this miRNA in NThy.miR-182 cells promotes the invasive and migratory properties without affecting cell proliferation. MiR-182 is upregulated after RET induced NF-κB translocation into the nucleus via binding of NF-κB to the miR-182 promoter. Database analysis revealed that HES1, a repressor of the Notch pathway, is a target of miR-182, whose upregulation correlates with loss of HES1 transcription in MTC tissue samples and mutant RET cell lines. Moreover, we demonstrated that the 3′UTR of the HES1 mRNA bearing the targeting sequence for miR-182 clearly reduced luciferase reporter activity in cells expressing miR-182. Decreased expression of HES1 promotes migration by upregulating Notch1 inhibitor Deltex1 and consequent repression of Notch1.

Conclusion

We demonstrate a novel mechanism for MTC aggressiveness in which mutated RET/NF-κB-driven expression of miR-182 impedes HES1 activation in a negative feedback loop. This observation might open new possibilities to treat RET oncogene associated metastatic cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-016-0563-x) contains supplementary material, which is available to authorized users.

Role of CDKN2C Copy Number in Sporadic Medullary Thyroid Carcinoma

BACKGROUND

The cyclin-dependent-kinase inhibitors (CDKN)/retinoblastoma (RB1) pathway has been implicated as having a role in medullary thyroid carcinoma (MTC) tumorigenesis. CDKN2C loss has been associated with RET-mediated MTC in humans but with minimal phenotypic correlation provided. The objective of this study was to evaluate the association between tumor RET mutation status, CDKN2C loss, and aggressiveness of MTC in a cohort of patients with sporadic disease.

METHODS

Tumors from patients with sporadic MTC treated at a single institution were evaluated for somatic RET^M918T mutation and CDKN2C copy number loss. These variables were compared to patient demographics, pathology detail, clinical course, and disease-specific and overall survival.

RESULTS

Sixty-two MTC cases with an initial surgery date ranging from 1983 to 2009 met the inclusion criteria, of whom 36 (58%) were male. The median age at initial surgery was 53 years (range 22-81 years). The median tumor size was 30 mm (range 6-145 mm) with 29 (57%) possessing extrathyroidal extension. Nodal and/or distant metastasis at presentation was found in 47/60 (78%) and 12/61 (20%) patients, respectively. Median follow-up time was 10.5 years (range 1.1-27.8 years) for the censored observations. The presence of CDKN2C loss was associated with worse M stage and overall AJCC stage. Median overall survival of patients with versus without CDKN2C loss was 4.14 [confidence interval (CI) 1.93-NA] versus 18.27 [CI 17.24-NA] years (p < 0.0001). Median overall survival of patients with a combined somatic RET^M918T mutation and CDKN2C loss versus no somatic RET^M918T mutation and CDKN2C loss versus somatic RET^M918T mutation and CDKN2C 2N versus no somatic RET^M918T mutation and CDKN2C 2N was 2.38 [CI 1.67-NA] years versus 10.81 [CI 2.46-NA] versus 17.24 [CI 9.82-NA] versus not reached [CI 13.46-NA] years (p < 0.0001).

CONCLUSIONS

The detection of somatic CDKN2C loss is associated with the presence of distant metastasis at presentation as well decreased overall survival, a relationship enhanced by concomitant RET^M918T mutation. Further defining the genes involved in the progression of metastatic MTC will be an important step toward identifying pathways of disease progression and new therapeutic targets.

Efficacy and safety of vascular endothelial growth factor receptor tyrosine kinase inhibitors in the treatment of advanced thyroid cancer: a meta-analysis of randomized controlled trials

Background

We performed a systematic review and meta-analysis to determine the efficacy and safety of the US Food and Drug Administration approved vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs) in the treatment of advanced thyroid cancer.

Patients and methods

We included prospective randomized controlled trials that compared VEGFR-TKIs with placebo for advanced thyroid cancer. The endpoints included safety (fatal adverse events [FAEs], treatment discontinuation, and any severe [grade 3 or 4] adverse events [AEs]) and efficacy (objective response rate, progression-free survival, and overall survival). The pooled relative risk (RR) or hazard ratio (HR) was calculated by using either random-effects or fixed-effects models according to the heterogeneity of included studies.

Results

A total of 1,614 advanced thyroid cancer patients from five randomized controlled trials were identified for analysis. Compared with placebo alone, VEGFR-TKIs significantly increased the risk of treatment discontinuation (RR: 3.80, 95% confidence interval [CI]: 2.56–5.65, P<0.001) and any severe AEs (RR: 2.63, 95% CI: 1.72–4.03, P<0.001), but not of FAEs (RR: 1.24, 95% CI: 0.65–2.39, P=0.52). The use of VEGFR-TKIs in advanced thyroid cancer was associated with a significant improvement in objective response rate (RR: 8.73, 95% CI: 1.72–44.4, P=0.009) and progression-free survival (HR: 0.41, 95% CI: 0.27–0.61, P<0.001), with a tendency to improve overall survival (HR: 0.83, 95% CI: 0.68–1.01, P=0.06).

Conclusion

The use of small-molecule VEGFR-TKIs in advanced thyroid cancer did significantly increase the risk of treatment discontinuation and any severe AEs, but not of FAEs, compared with placebo alone. It is important for physicians to weigh the risk of toxicities as well as the potential survival benefits associated with VEGFR-TKI treatment in advanced thyroid cancer patients.