Pioglitazone Therapy of PAX8-PPARγ Fusion Protein Thyroid Carcinoma

CONTEXT

A subset of thyroid carcinomas expresses an oncogenic paired box 8 (PAX8) and peroxisome proliferator activated receptor γ (PPARγ) fusion protein (PPFP). The PPARγ/PPFP ligand pioglitazone is highly therapeutic in a transgenic mouse model of PPFP thyroid carcinoma, but whether pioglitazone is therapeutic in patients with PPFP thyroid carcinoma is unknown.

CASE DESCRIPTION

Tumor blocks from 40 patients with progressive thyroid cancer despite standard-of-care therapy were screened for PPFP, and the tumor from only one patient (2.5%) was positive. The patient had a 6.0-cm acetabular soft tissue metastasis from Hürthle cell carcinoma that caused severe pain on weight bearing and had a serum thyroglobulin level of 1974 ng/mL. After 24 weeks of therapy with pioglitazone, the metastatic lesion was 3.9 cm, the thyroglobulin level was 49.4 ng/mL, and the patient was pain-free. Thirteen months after discontinuation of pioglitazone, the metastatic lesion was 3.6 cm, the thyroglobulin level was 4.7 ng/mL, and the patient remained pain-free.

CONCLUSIONS

Pioglitazone may be therapeutic in patients with PPFP thyroid cancer. However, thyroid cancers that are progressive despite standard-of-care therapy appear to only rarely express PPFP.

Combination therapy with capecitabine and temozolomide in patients with low and high grade neuroendocrine tumors, with an exploratory analysis of O6-methylguanine DNA methyltransferase as a biomarker for response

Recent advances in the treatment of neuroendocrine tumors (NET), including the combination regimen of capecitabine and temozolomide (CAPTEM), have mostly focused on grade 1 and 2 pancreatic neuroendocrine tumors (pNET). We undertook a retrospective review of 38 patients with advanced NET treated with CAPTEM, including patients with non-pancreatic tumors as well as grade 2 and 3 tumors. O⁶-methylguanine DNA methyltransferase (MGMT) expression was assessed as a predictive biomarker. We found that CAPTEM demonstrated activity in patients with all grades and in pNET and non-pNET. Median progression free survival (mPFS) was 13.0 months (95% CI: 5.6-17.0) and median overall survival (mOS) 29.3 months (95% CI 17.7 - 45.3). Among evaluable patients, there were 11 (38%) partial responses, 15 (52%) stable disease, and 3 (10%) progressive disease for a disease control rate of 90%. A higher rate of partial responses occurred in patients whose tumors had low levels of MGMT expression (63%) compared to intermediate-high (17%) (p=0.19). Our results show that CAPTEM therapy is active in patients with NET including in previously treated patients and in those with poorly-differentiated histology. We observed a trend towards increased response rate, median PFS, and median OS in patients whose tumors had low MGMT protein expression.

Endocrine dysfunction following immune checkpoint inhibitor therapy

PURPOSE OF REVIEW

Immune checkpoint inhibitors (ICI) represent an important milestone in the modern era of antineoplastic therapy and have ushered optimism amongst oncologists and patients alike. These agents, however, are associated with significant potential toxicities, the importance of which cannot be overstated. The clinical presentation, diagnosis, and management strategies of immune-related endocrinopathies associated with ICI use are described in this case-based review.

RECENT FINDINGS

An increasing number of ICI have shown promise in the management of various malignancies in the recent years. These include cytotoxic T lymphocyte antigen-4 inhibitors, programmed cell death 1 (PD-1) antibodies, and PD-ligand 1 (PD-L1) antibodies. Several endocrinopathies, including hypophysitis, thyroid dysfunction, hyperglycemia, and primary adrenal insufficiency, have been associated with the use of these agents. Toxicities may range from mild transient laboratory abnormalities to potentially life-threatening ones, warranting immediate therapeutic intervention. Combination ICI therapies may be associated with a greater risk of endocrine dysfunction when compared with monotherapy. The clinical presentation and laboratory assessment of these patients often pose a diagnostic challenge as they may be confused by the symptoms related to their underlying malignancy or potential associated acute illnesses.

SUMMARY

ICI use is associated with serious endocrinopathies that may have a nonspecific initial presentation. A constant eye for these symptoms and a systematic approach to diagnosis are essential for prompt initiation of therapy and prevention of significant complications.

Cabozantinib As Salvage Therapy for Patients With Tyrosine Kinase Inhibitor-Refractory Differentiated Thyroid Cancer: Results of a Multicenter Phase II International Thyroid Oncology Group Trial

Purpose Sorafenib and lenvatinib are oral multikinase inhibitors targeting vascular endothelial growth factor receptor (VEGFR) and approved for radioiodine (RAI)-refractory differentiated thyroid cancer (DTC). However, there are no approved second- or third-line therapies. MET is implicated in resistance to VEGFR inhibitors. Cabozantinib is an oral multikinase inhibitor targeting MET in addition to VEGFR and is approved for medullary thyroid cancer. In a phase I study of cabozantinib, five of eight patients with DTC previously treated with a VEGFR-targeted therapy had an objective response to cabozantinib. Patients and Methods Patients with RAI-refractory disease with Response Evaluation Criteria in Solid Tumor (RECIST) measurable disease and evidence of progression on prior VEGFR-targeted therapy were enrolled in this single-arm phase II study. The cabozantinib starting dose was 60 mg/day orally but could be escalated to 80 mg if the patient did not experience a response. Patients underwent tumor assessment according to RECIST v1.1 every 8 weeks. In this study, if at least five of 25 response-evaluable patients had an objective response, cabozantinib would be considered a promising agent in this patient population. Results Twenty-five patients were enrolled. The median age was 64 years, and 64% of patients were men. Twenty-one patients had received only one prior VEGFR-targeted therapy (sorafenib, pazopanib, or cediranib), and four patients had received two such therapies. The most common treatment-related adverse events were fatigue, weight loss, diarrhea, palmar-plantar erythrodysesthesia, and hypertension. One drug-related death was noted. Of the 25 patients, 10 (40%) had a partial response, 13 (52%) had stable disease, and two (8%) had nonevaluable disease. The median progression-free survival and overall survival were 12.7 months and 34.7 months, respectively. Conclusion Cabozantinib demonstrated clinically significant, durable objective response activity in patients with RAI-refractory DTC who experienced disease progression while taking prior VEGFR-targeted therapy.

Transforming Growth Factor β1-Induced NADPH Oxidase-4 Expression and Fibrotic Response in Conjunctival Fibroblasts

Purpose

Fibrotic scarring after ocular surgeries and chemical burn injuries can impede clarity of the cornea and cause vision impairment. Transforming growth factor β (TGFβ) signaling pathway is known to mediate fibrotic scarring, and NADPH oxidase-derived reactive oxygen species has been shown to be an effector molecule that facilitates TGFβ1-mediated responses. The present study explores the expression profile and functional importance of NADPH oxidase (Nox) in conjunctival fibroblasts. In addition, the effect of curcumin on the TGFβ1-induced NADPH oxidase expression and collagen synthesis was also investigated.

Methods

The mRNA expression of Nox isoforms in rabbit conjunctival fibroblasts was measured by real-time PCR. The production of hydrogen peroxide (H2O2) and total collagen by these cells was measured by Amplex Red assay and Picro-Sirius red assay, respectively. Nox4 was knocked down by adenovirus-mediated siRNA targeting Nox4 (Adv-Nox4i).

Results

We describe for the first time that conjunctival fibroblasts express mRNA encoding for Nox2, Nox3, Nox4, and Nox5. TGFβ1 was found to induce Nox4 mRNA expression and total collagen release by these cells (P < 0.05; n = 4), and both responses are blocked by Smad3 inhibitor SIS3. Suppressing Nox4 gene transcription with Adv-Nox4i completely attenuated TGFβ1-stimulated H2O2 release and collagen production by conjunctival fibroblasts (P < 0.05; n = 4-6). Similarly, curcumin also inhibited TGFβ1-induced Smad3 phosphorylation, Nox4-derived H2O2 production, and total collagen synthesis by conjunctival fibroblasts (P < 0.05; n = 4-6).

Conclusions

The present study suggests that TGFβ1-mediated production of collagen by conjunctival fibroblasts involves Nox4-derived H2O2 pathway and this effect of Nox4 is abrogated by curcumin. This mechanism might be exploited to prevent fibrotic scarring after surgeries and chemical burn injuries in the eye.

Results of randomized phase II trial of dabrafenib versus dabrafenib plus trametinib in BRAF-mutated papillary thyroid carcinoma

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Background: BRAF mutations are present in ~44% of papillary thyroid carcinoma (PTC) and its role in development of PTC is well established. We hypothesized that dabrafenib (BRAF inhibitor) would have efficacy in BRAF mutated PTC and that combining it with trametinib (MEK inhibitor) would result in greater clinical efficacy than dabrafenib alone, through vertical inhibition of the RAF/MAP/ERK pathway and mitigation of potential mechanisms of resistance. Methods: Patients (pts) with BRAF mutated radioiodine refractory PTC who had evidence of disease progression within 13 months prior were randomized to Arm A (dabrafenib 150 mg PO BID) or Arm B (dabrafenib 150 mg PO BID + trametinib 2 mg PO qd). Cross-over to Arm B was allowed at time of progression. Responses were assessed by modified RECISTv1.1 every 2 months. Primary endpoint was objective response rate (ORR) (complete-, partial- and minor-response). With assumed true ORR of 15% vs 35%; and 90% power to identify the correct regimen as most promising, 26 pts were to be accrued in each Arm. Results: In this randomized phase 2 trial, 53 pts (median age 63 years, 38 females) were enrolled; 25% of pts had 1-3 prior therapy with multi-kinase inhibitors. Median follow up was 13 months. Preliminary efficacy results are outlined in Table. The treatment-related adverse events were similar to previously reported phase III clinical trial of these drugs in melanoma. Conclusions: Single agent dabrafenib, as well as combination of dabrafenib/trametinib are well tolerated therapies that result in similar high objective response rates with durable responses in pts with progressive BRAF-mutated PTC. BRAF-pathway targeted therapies provide novel treatment options. Clinical trial information: NCT01723202. [Table: see text]

Outcomes of metastatic adrenocortical carcinoma (ACC): A 16-year single institutional experience

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Background: ACC is a rare malignancy with limited data to guide management of metastatic disease. Prior research regarding survival has focused on pts with locoregional disease, but has not offered insight into the management and outcomes of pts with metastatic disease. Methods: We retrospectively reviewed patients (pts) with metastatic ACC who were treated with systemic therapy between January 2000 and October 2016 at The Ohio State University Comprehensive Cancer Center. Kaplan-Meier and Cox proportional hazards regression models were used for survival analysis. Results: A total of 18 pts received systemic therapy for distant metastatic disease. Median age at diagnosis was 51 (range 31 – 72). Median overall survival (OS) from time of diagnosis of ACC was 15.5 months (95% CI 4.8 – 28.2), and from time of systemic treatment (ST) was 7.1 months (95% CI 3.3 – 26). A germline variant of uncertain significance in MSH2 (c.138C > G) was identified in one patient. Baseline FDG-PET scans were obtained in 11/18 pts, and demonstrated avidity in all patients. Maximum SUV ranged from 4.1 to 47.6, with a median of 15. First line therapy was etoposide, doxorubicin, cisplatin, and mitotane (EDPM) in 13/18 pts and clinical trial with IMC-A12 (IGF-1 receptor antibody) in four pts. Median duration of first line therapy was 1.8 months (95% CI 0.9 – 2.8). Survival was not statistically different for patients receiving EDPM as first or second line therapy (median OS 23.3 vs 12.0 months, p = 0.96). Additional lines of therapy included EDPM, IMC-A12, AT-101, mifepristone, OSI-906 (IGF-1R inhibitor), and nivolumab. Median lines of therapy given were 2. The presence of bone metastases (p = 0.69) or lung metastases (p = 0.21) at the time of initiation of ST was not associated with OS from ST. Conclusions: In our experience, the prognosis of pts with metastatic ACC receiving systemic therapy is poor with most pts receiving ≤ 2 lines of therapy. Patients receiving first or second line EDPM seemed to have worse outcomes than noted in previously published trials, possibly due to our patients being sicker at baseline. Metastasis to the lung or bone at initiation of ST did not impact OS.

Effect of cabozantinib on bone turnover markers (BTM) and bone metastases (BM) in radioiodine refractory (RAIR)-differentiated thyroid cancer (DTC)

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Background: Cabozantinib is a small molecule multiple-receptor tyrosine kinase inhibitor that primarily targets MET and vascular endothelial growth factor receptor 2 (VEGFR2). We evaluated the effect of cabozantinib on BTM in RAIR DTC. We also assessed the response of BM to cabozantinib using 18F Sodium Fluoride (NaF) PET and radionuclide bone scans. Methods: This prospective analysis was performed as part of a multicenter International Thyroid Oncology Group phase II study of cabozantinibin patients with RAIR DTC who progressed on prior VEGFR-targeted therapy (NCT01811212). BTM [serum C-telopeptide (CTx), osteocalcin, N-telopeptide (NTx), procollagen type 1 (Pc1) and urinary NTx] and NaF PET or Tc-MDP scans were done at baseline and after 8 weeks of therapy. A paired t-test was used between baseline and week 8 BTM. Results: Primary study results were presented elsewhere (Shah, et al. 2015, International Thyroid Congress) showing a response rate of 36% with cabozantinib. Of 25 patients (pts) enrolled, 21 had BM, 10 of whom were on bone-modifying agents (BMA) prior to week 8. Only 2 pts had elevated BTM at baseline. In all pts who had paired BTM, there was a statistically significant decline in all BTM except NTx by week 8 (table). Pts not on BMA also had a significant decline in CTx (p 0.0003), urine NTx (p 0.0300), and Pc1 (p 0.0030) compared to baseline. 19 pts were evaluable for overall response and there was no correlation between BTM and response rate. 6/21 patients underwent paired NaF PET scans and 4/6 had minor reduction in lesion uptake at 8 weeks. Conclusions: Interestingly, most of our patients had normal baseline BTM despite BM. Cabozantinib was associated with a strikingly significant reduction in all BTM (even when BTM were within normal limits at baseline) except NTx by week 8. Minor decreases in bone lesion uptake was noted on NaF PET in 4/6 evaluable patients. Clinical trial information: NCT01811212. [Table: see text]

Incidence and timing of common adverse events in Lenvatinib-treated patients from the SELECT trial and their association with survival outcomes

PURPOSE

In the study of (E7080) lenvatinib in differentiated cancer of the thyroid, most patients experienced an adverse event. In this report, we examine common lenvatinib-emergent adverse events in this phase three, randomized, double-blind study.

METHODS

Adverse events were graded per Common Terminology Criteria for Adverse Events v4.0. 392 patients were enrolled (lenvatinib: 261, placebo: 131) and received lenvatinib 24 mg/day or placebo. The main outcome measures were: associations with progression-free survival and overall survival in exploratory univariate and multivariate analyses along with additional variables.

RESULTS

The most common any-grade adverse events (any grade; grade 3) in lenvatinib-treated patients included proteinuria (32%; 10%), diarrhea (67%; 9%), fatigue/asthenia/malaise (67%; 10%), rash (23%; 0.4%), and palmar-plantar erythrodysesthesia syndrome (33%; 3%). There were no grade 4 events for these adverse events. They generally occurred early (median time to first onset [weeks]: proteinuria [6.1], diarrhea [12.1], fatigue/asthenia/malaise [3.0], rash [7.3], and palmar-plantar erythrodysesthesia syndrome [5.9]), and were resolved primarily with dose modifications (median time to resolution [weeks]: proteinuria [8.8], diarrhea [18.1], fatigue/asthenia/malaise [16.3], rash [5.9], and palmar-plantar erythrodysesthesia syndrome [20.0]). Discontinuation due to these adverse events occurred in 2 (1%) patients with proteinuria and 4 (2%) with fatigue. Progression-free survival was not associated with any of the adverse events. Eastern Cooperative Oncology Group performance status (P = 0.001), follicular histology (P = 0.002), and diarrhea (P = 0.023) were associated with overall survival in multivariate analyses (median overall survival for patients with diarrhea: not reached; without: 17.1 months).

CONCLUSIONS

In the study of (E7080) lenvatinib in differentiated cancer of the thyroid, the most common adverse events typically occurred early and were primarily managed with dose modifications. Overall survival was significantly associated with diarrhea.

Abstract 3116: MGMT immunohistochemistry (IHC) as a biomarker for response to combination therapy with capecitabine and temozolomide (C/T) in patients (pts) with advanced neuroendocrine carcinomas (aNEC)

Introduction: Tumor O6-methylguanine-methyltransferase (MGMT) reverses temozolomide-induced DNA injury, and low MGMT tumor expression has been shown as a predictor of response to temozolomide in glioblastoma. C/T therapy induces partial responses in up to 70% of pts with grade 1-2 pancreatic NEC but the role of MGMT expression as a predictor is unclear. We evaluated MGMT expression by IHC as a prognostic and predictive biomarker for pts with aNEC of all grades and primary sites treated with C/T.

Methods: A retrospective review was carried out at Ohio State University of 29 pts with aNEC who received C/T therapy from 2009 to 2013 and who were evaluable for RECIST response. MGMT expression was assessed when available by IHC on pre-treatment tumor samples to test the hypothesis that low MGMT expression (&lt;10%) predicts response to C/T therapy vs high levels (≥10%).

Results: Of 29 pts, primary NEC site was pancreas in 18 pts, and non-pancreas in 11 pts. Objective response, progression-free survival (PFS) and overall survival (OS) data are outlined in the Table. Partial response (PR) rate was 50% in pts with pancreas primary vs 18% for non-pancreas primary. High PRs were observed in pts with grade 3 NEC (57%). Median PFS in the MGMT-low group was 16.6 months vs 9.5 months in the MGMT-high group (p = 0.19). Median OS in the MGMT low group was 42.9 months vs 18.1 months in the MGMT-high group (p = 0.16). There was a trend toward higher rate of PR (63%) in pts whose tumors had low levels of MGMT expression compared to those with high levels (17%) (p = 0.18).

Conclusion: We observed a trend towards increased PR, median PFS, and median OS in aNEC pts whose tumors had low MGMT protein expression by IHC. The small sample size likely limited the statistical significance of the data. Results of this trial serve as strong rationale for future prospective trials to clarify role of MGMT expression in choosing C/T therapy for pts with NEC. Objective response rate, progression free survival (PFS) and overall survival (OS)N%PR%SD%PDMedian PFSp-valueMedian OSp-valueAll patients2938521013.029.3Low MGMT by IHC (&lt;10%)126238016.60.1942.90.16High MGMT by IHC (≥10%)81767179.518.1Well-differentiated tumor grade (Ki-67 &lt;3%)74357020.00.34NR0.027Moderately differentiated tumor grade (Ki-67 3-20%)13316189.525.9Poorly-differentiated tumor grade (Ki-67 &gt;20%)75714298.413.1

Citation Format: Dwight Owen, Andrew J. Alexander, Lai Wei, Jessica Hemminger, Manisha H. Shah. MGMT immunohistochemistry (IHC) as a biomarker for response to combination therapy with capecitabine and temozolomide (C/T) in patients (pts) with advanced neuroendocrine carcinomas (aNEC). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3116.

Phase I study of IMGN901, a CD56-targeting antibody-drug conjugate, in patients with CD56-positive solid tumors

Background IMGN901 is a CD56-targeting antibody-drug conjugate designed for tumor-selective delivery of the cytotoxic maytansinoid DM1. This phase 1 study investigated the safety, tolerability, pharmacokinetics, and preliminary activity of IMGN901 in patients with CD56-expressing solid tumors. Methods Patients were enrolled in cohorts of escalating IMGN901 doses, administered intravenously, on 3 consecutive days every 21 days. A dose-expansion phase accrued patients with small cell lung cancer (SCLC), Merkel cell carcinoma (MCC), or ovarian cancer. Results Fifty-two patients were treated at doses escalating from 4 to 94 mg/m(2)/day. The maximum tolerated dose (MTD) was determined to be 75 mg/m(2). Dose-limiting toxicities included fatigue, neuropathy, headache or meningitis-like symptoms, chest pain, dyspnea, and myalgias. In the dose-expansion phase (n = 45), seven patients received 75 mg/m(2) and 38 received 60 mg/m(2) for up to 21 cycles. The recommended phase 2 dose (RP2D) was established at 60 mg/m(2) during dose expansion. Overall, treatment-emergent adverse events (TEAEs) were experienced by 96.9 % of all patients, the majority of which were Grade 1 or 2. The most commonly reported Grade 3 or 4 TEAEs were hyponatremia and dyspnea (each 8.2 %). Responses included 1 complete response (CR), 1 clinical CR, and 1 unconfirmed partial response (PR) in MCC; and 1 unconfirmed PR in SCLC. Stable disease was seen for 25 % of all evaluable patients who received doses ≥60 mg/m(2). Conclusions The RP2D for IMGN901 of 60 mg/m(2) administered for 3 consecutive days every 3 weeks was associated with an acceptable tolerability profile. Objective responses were observed in patients with advanced CD56+ cancers.

Comprehensive Genomic Profiling of Clinically Advanced Medullary Thyroid Carcinoma

OBJECTIVE

The aim of this study was to determine the genomic alterations of cancer-related genes in advanced medullary thyroid carcinoma during the course of clinical care.

METHODS

Hybrid-capture-based comprehensive genomic profiling was performed on 34 consecutive medullary thyroid carcinoma cases to identify all four classes of genomic alterations, and outcome for an index patient was collected.

RESULTS

RET was mutated in 88% (30/34) of cases, with RET M918T being responsible for 70% (21/30) of the RET alterations. The other RET alterations were RET E632_L633del, C634R, C620R, C618G/R/S, V804M, and RET amplification. Two of the four RET wild-type patients harbored mutations in KRAS or HRAS (1/34 each). The next most frequent genomic alterations were amplifications of CCND1, FGF3, and FGF19 and alterations in CDKN2A (3/34 each). One case with a RET M918T mutation developed acquired resistance to progressively dose-escalated vandetanib. When the mTOR inhibitor everolimus was added to continued vandetanib treatment, the patient achieved a second 25% reduction of tumor volume (RECIST 1.1) for 8 months.

CONCLUSIONS

Comprehensive genomic profiling identified the full breadth of RET alterations in metastatic medullary thyroid carcinoma and possible cooperating oncogenic driver alterations. This approach may refine the use of targeted therapy for these patients.

Evaluation of patients with disseminated or locoregionally advanced thyroid cancer: a primer for medical oncologists

Historically, patients with thyroid cancers are managed by endocrinologists, surgeons and radiation oncologists. Due to recent progress in this field with advances in treatment of thyroid cancer, medical oncologists are now commonly involved in care of patients with advanced thyroid cancers. In this manuscript, we describe general principles in management of patients with various types of thyroid cancers including differentiated, medullary and anaplastic thyroid cancers.

Elevated Alkaline Phosphatase Prior to Transarterial Chemoembolization for Neuroendocrine Tumors Predicts Worse Outcomes

INTRODUCTION

We hypothesized that an elevated preoperative alkaline phosphatase (AP) predicted worse outcomes for patients undergoing transarterial chemoembolization (TACE) for neuroendocrine tumor (NET) liver metastases.

METHODS

We reviewed all patients who underwent TACE for metastatic NET between 2009 and 2013. Survival was evaluated using preprocedure variables.

RESULTS

One hundred and nine patients underwent 210 TACE procedures. The average age was 57.7 years (range 20-78). Primary sites included pancreas (N = 20), other gastrointestinal (N = 52), lung (N = 9), and unknown (N = 28). The tumor was grade 1 in 68 (62 %), grade 2 in 21 (19 %), and grade 3 in 3 (3 %). Extrahepatic disease was present in 54 (50 %) and greater than 50 % hepatic tumor burden by imaging in 63 (58 %). Elevated bilirubin occurred in 8 (7 %), elevated AP in 22 (20 %), elevated ALT in 21 (19 %), and elevated AST in 41 (38 %). Univariate predictors included tumor grade (43 vs 27 vs 21 months, p = 0.015), hepatic tumor burden (59 vs 37 months, p = 0.009), and elevated AP (59 vs 23 months, p < 0.001). On multivariate analysis, only elevated AP (p = 0.001) predicted worse survival.

CONCLUSIONS

Elevated AP prior to TACE for metastatic NET portends a worse survival outcome, even more so than tumor grade or extent of hepatic disease.

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

PURPOSE

Positive results of phase I studies evaluating lenvatinib in solid tumors, including thyroid cancer, prompted a phase II trial in advanced medullary thyroid carcinoma (MTC).

EXPERIMENTAL DESIGN

Fifty-nine patients with unresectable progressive MTC per Response Evaluation Criteria In Solid Tumors (RECIST) v1.0 within the prior 12 months received lenvatinib (24-mg daily, 28-day cycles) until disease progression, unmanageable toxicity, withdrawal, or death. Prior anti-VEGFR therapy was permitted. The primary endpoint was objective response rate (ORR) by RECIST v1.0 and independent imaging review.

RESULTS

Lenvatinib ORR was 36% [95% confidence interval (CI), 24%-49%]; all partial responses. ORR was comparable between patients with (35%) or without (36%) prior anti-VEGFR therapy. Disease control rate (DCR) was 80% (95% CI, 67%-89%); 44% had stable disease. Among responders, median time to response (TTR) was 3.5 months (95% CI, 1.9-3.7). Median progression-free survival (PFS) was 9.0 months (95% CI, 7.0-not evaluable). Common toxicity criteria grade 3/4 treatment-emergent adverse events included diarrhea (14%), hypertension (7%), decreased appetite (7%), fatigue, dysphagia, and increased alanine aminotransferase levels (5% each). Ret proto-oncogene status did not correlate with outcomes. Low baseline levels of angiopoietin-2, hepatocyte growth factor, and IL8 were associated with tumor reduction and prolonged PFS. High baseline levels of VEGF, soluble VEGFR3, and platelet-derived growth factor BB, and low baseline levels of soluble Tie-2, were associated with tumor reduction.

CONCLUSIONS

Lenvatinib had a high ORR, high DCR, and a short TTR in patients with documented progressive MTC. Toxicities were managed with dose modifications and medications.

Neuroendocrine tumors, version 1.2015

Neuroendocrine tumors (NETs) comprise a broad family of tumors that may or may not be associated with symptoms attributable to hormonal hypersecretion. The NCCN Clinical Practice Guidelines in Oncology for Neuroendocrine Tumors discuss the diagnosis and management of both sporadic and hereditary NETs. This selection from the guidelines focuses on sporadic NETs of the pancreas, gastrointestinal tract, lung, and thymus.

A phase 2 trial of lenvatinib (E7080) in advanced, progressive, radioiodine-refractory, differentiated thyroid cancer: A clinical outcomes and biomarker assessment

BACKGROUND

Lenvatinib is an oral, multitargeted tyrosine kinase inhibitor of the vascular endothelial growth factor receptors 1 through 3 (VEGFR1-VEGFR3), fibroblast growth factor receptors 1 through 4 (FGFR1-FGFR4), platelet-derived growth factor receptor α (PDGFRα), ret proto-oncogene (RET), and v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) signaling networks implicated in tumor angiogenesis. Positive phase 1 results in solid tumors prompted a phase 2 trial in patients with advanced, radioiodine-refractory, differentiated thyroid cancer (RR-DTC).

METHODS

Fifty-eight patients with RR-DTC who had disease progression during the previous 12 months received lenvatinib 24 mg once daily in 28-day cycles until disease progression, unmanageable toxicity, withdrawal, or death. Previous VEGFR-targeted therapy was permitted. The primary endpoint was the objective response rate (ORR) based on independent imaging review. Secondary endpoints included progression-free survival (PFS) and safety. Serum levels of 51 circulating cytokines and angiogenic factors also were assessed.

RESULTS

After ≥14 months of follow-up, patients had an ORR of 50% (95% confidence interval [CI], 37%-63%) with only partial responses reported. The median time to response was 3.6 months, the median response duration was 12.7 months, and the median PFS was 12.6 months (95% CI, 9.9-16.1 months). The ORR for patients who had received previous VEGF therapy (n = 17) was 59% (95% CI, 33%-82%). Lower baseline levels of angiopoietin-2 were suggestive of tumor response and longer PFS. Grade 3 and 4 treatment-emergent adverse events, regardless of their relation to treatment, occurred in 72% of patients and most frequently included weight loss (12%), hypertension (10%), proteinuria (10%), and diarrhea (10%).

CONCLUSIONS

In patients with and without prior exposure to VEGF therapy, the encouraging response rates, median time to response, and PFS for lenvatinib have prompted further investigation in a phase 3 trial. Cancer 2015;121:2749-2756. © 2015 American Cancer Society.

The Raf Kinase Inhibitor Sorafenib Inhibits JAK-STAT Signal Transduction in Human Immune Cells

Sorafenib is an oral multikinase inhibitor that was originally developed as a Raf kinase inhibitor. We hypothesized that sorafenib would also have inhibitory effects on cytokine signaling pathways in immune cells. PBMCs from normal donors were treated with varying concentrations of sorafenib and stimulated with IFN-α or IL-2. Phosphorylation of STAT1 and STAT5 was measured by flow cytometry and confirmed by immunoblot analysis. Changes in IFN-α- and IL-2-stimulated gene expression were measured by quantitative PCR, and changes in cytokine production were evaluated by ELISA. Cryopreserved PBMCs were obtained from cancer patients before and after receiving 400 mg sorafenib twice daily. Patient PBMCs were thawed, stimulated with IL-2 or IFN-α, and evaluated for phosphorylation of STAT1 and STAT5. Pretreatment of PBMCs with 10 μM sorafenib decreased STAT1 and STAT5 phosphorylation after treatment with IFN-α or IL-2. This inhibitory effect was observed in PBMCs from healthy donors over a range of concentrations of sorafenib (5-20 μM), IL-2 (2-24 nM), and IFN-α (10(1)-10(6) U/ml). This effect was observed in immune cell subsets, including T cells, B cells, NK cells, regulatory T cells, and myeloid-derived suppressor cells. Pretreatment with sorafenib also inhibited PBMC expression of IFN-α- and IL-2-regulated genes and inhibited NK cell production of IFN-γ, RANTES, MIP1-α, and MIG in response to IFN-α stimulation. PBMCs from patients receiving sorafenib therapy showed decreased responsiveness to IL-2 and IFN-α treatment. Sorafenib is a Raf kinase inhibitor that could have off-target effects on cytokine-induced signal transduction in immune effector cells.

Differential effects of superoxide dismutase and superoxide dismutase/catalase mimetics on human breast cancer cells

Reactive oxygen species (ROS) such as superoxide and hydrogen peroxide (H2O2) have been implicated in development and progression of breast cancer. In the present study, we have evaluated the effects of the superoxide dismutase (SOD) mimetic MnTmPyP and the SOD/catalase mimetic EUK 134 on superoxide and H2O2 formation as well as proliferation, adhesion, and migration of MCF-7 and MDA-MB-231 cells. Superoxide and H2O2 production was examined using dihydroethidium and Amplex red assays, respectively. Cell viability and adhesion were measured using a tetrazolium-based MTT assay. Cell proliferation was determined using trypan blue assay. Cell cycle progression was analyzed using flow cytometry. Clonal expansion of a single cell was performed using a colony formation assay. Cell migration was measured using transwell migration assay. Dual luciferase assay was used to determine NF-κB reporter activity. EUK 134 effectively reduced both superoxide and H2O2, whereas MnTmPyP removed superoxide but enhanced H2O2 formation. EUK 134 effectively attenuated viability, proliferation, clonal expansion, adhesion, and migration of MCF-7 and MDA-MB-231 cells. In contrast, MnTmPyP only reduced clonal expansion of MCF-7 and MDA-MB-231 cells but had no effect on adhesion and cell cycle progression. Tumor necrosis factor-alpha-induced NF-κB activity was reduced by EUK 134, whereas MnTmPyP enhanced this activity. These data indicate that the SOD mimetic MnTmPyP and the SOD/catalase mimetic EUK 134 exert differential effects on breast cancer cell growth. Inhibition of H2O2 signaling using EUK 134-like compound might be a promising approach to breast cancer therapy.

Bone metastases and skeletal-related events from neuroendocrine tumors

Neuroendocrine tumors (NETs) metastasize to bone; however, a multi-institution evaluation of the natural history and complications of bone metastases across multiple NET subtypes has not, to our knowledge, previously been conducted. At two tertiary academic centers, we identified patients with bone metastases from databases of patients with a diagnosis of NET between 2004 and 2008. Detection of bone metastases, occurrence of skeletal-related events (SREs), and interventions were analyzed using summary statistics and categorical methods. Time-to-event data were assessed using Kaplan-Meier estimates and log-rank tests. Between 2004 and 2008, 82 out of 691 NET patients (12%) were reported to have bone metastases. Of the 82 patients with bone metastases, 55% were men and their median age was 49. Bone metastases occurred in 25% of pheochromocytomas and paragangliomas, 20% of high-grade neuroendocrine carcinomas, 9% of carcinoid tumors, and 8% of pancreatic NETs. At time of detection of bone metastases, 60% reported symptoms, including pain; 10% developed cord compression, 9% suffered a pathological fracture, and 4% developed hypercalcemia. Occurrence of SREs did not differ significantly with regard to tumor histology. Of patients with bone metastases, 67 (82%) received at least one form of bone-directed treatment, 50% received radiation, 45% received a bisphosphonate, 18% underwent surgery, 11% received (131)I-MIBG, 5% received denosumab, and 46% were treated with more than one treatment modality. Bone metastases occur in a substantial number of patients diagnosed with NETs. Patients are often symptomatic and many develop SREs. Given the recent therapeutic advances and increasing life expectancy of patients with NETs, development of guidelines for surveillance and clinical care of bone metastases from NETs is needed.