Shah, Manisha H.

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.

224 Background: In the phase 3 RADIANT-3 trial, everolimus (EVE) demonstrated significantly improved median progression-free survival (PFS) versus placebo (PBO) (11.0 vs 4.6 months; HR=0.35, p < 0.0001) in patients (pts) with pancreatic neuroendocrine tumors (pNET) (Yao et al, NEJM, 2011). Here we present a planned exploratory analysis by prior chemotherapy (chemo) use. Methods: Pts with progressive low- or intermediate-grade pNET were prospectively stratified by prior chemo use and randomized (1:1) to EVE 10 mg/d (n = 207) or PBO (n = 203) plus best supportive care. Results: Of the 410 pts, 206 (50%) had received prior chemo and 204 (50%) were chemo naive. Baseline characteristics (age, sex, race, tumor type, histologic grade) and baseline tumor biomarker levels were similar for pts with/without prior chemo. More chemo-naive pts were newly diagnosed (time since initial diagnosis ≤ 6 mo: 50 [25%] vs. 7 [3%] pts with prior chemo). A lower proportion of chemo-naive pts received prior somatostatin therapy (45% vs. 54% prior chemo). EVE significantly prolonged median PFS regardless of prior chemo use (with prior chemo: 11.0 vs. 3.2 months; HR = 0.35, 95% CI 0.25-0.49, p < 0.001; chemo naive: 11.4 vs. 5.4 months; HR = 0.42, 95% CI 0.29-0.60; p < 0.001). Stable disease was the best overall response in 73% of EVE-treated pts irrespective of prior chemo use. The benefit from EVE irrespective of prior chemo was further demonstrated by disease stabilization or minor tumor shrinkage and in the lower incidence of progressive disease in waterfall plots. Safety of EVE was consistent regardless of prior chemo use. The most common drug-related adverse events (chemo vs chemo naive) included rash (53% vs. 52%), stomatitis (52% vs. 56%), diarrhea (41% vs. 52%), and fatigue (37% vs. 51%). Conclusions: This planned subgroup analysis demonstrated the beneficial effects of EVE in pts with pNET regardless of prior chemo use. These findings support the possible first-line use of EVE for pts with pNET.

260 Background: Recent placebo-controlled phase III trials of the mTOR inhibitor everolimus and the VEGF/ PDGF receptor inhibitor sunitinib in PNET noted improved progression-free survival (PFS). However, objective response rates (RR) with these agents are <10%. Preclinical studies suggest enhanced anti-tumor effects with combined mTOR and VEGF targeted therapy. Methods: We conducted a phase II trial of the mTOR inhibitor TEM (25 mg IV q week) and the VEGF-A monoclonal antibody BEV (10 mg/kg IV q 2 weeks) in patients (pts) with well or moderately differentiated PNET and progressive disease by RECIST within 7 months of study entry. Co-primary endpoints were RR and 6-month PFS. Planned enrollment is 50 patients, with interim analysis after the first 25 evaluable pts. Pts had no prior mTOR or VEGF targeted agents, ECOG PS 0-1, and adequate hematologic and organ function. Continued octreotide was allowed, but not required. Prior interferon, embolization, and ≤ 2 chemotherapy regimens were allowed. Results: Confirmed PR was documented in 11 of the first 25 (44%) evaluable patients. 20 of 25 (80%) patients were progression-free at 6 months. Both endpoints exceeded pre-defined criteria to continue enrollment. For 35 evaluable patients, the most common grade 3-4 adverse events attributed to therapy were leukopenia (12%), hypertension (12%), hyperglycemia (12%), mucositis (9%), and fatigue (9%). Conclusions: The combination of TEM/BEV has substantial activity in a multi-center phase II trial with RR of 44%, well in excess of single targeted agents in PNET. 6-month PFS was a notable 80% in a population of patients with RECIST criteria progression within 7 months of study entry. Accrual is ongoing. Supported by NCI N01 Contracts: 662205, 62203, 62208, 62209, 62206, 62204, 62207, 62201.

Purpose There are few effective therapies for pancreatic neuroendocrine tumors (PNETs). Recent placebo-controlled phase III trials of the mammalian target of rapamycin (mTOR) inhibitor everolimus and the vascular endothelial growth factor (VEGF)/platelet-derived growth factor receptor inhibitor sunitinib have noted improved progression-free survival (PFS). Preclinical studies have suggested enhanced antitumor effects with combined mTOR and VEGF pathway–targeted therapy. We conducted a clinical trial to evaluate combination therapy against these targets in PNETs. Patients and Methods We conducted a two-stage single-arm phase II trial of the mTOR inhibitor temsirolimus 25 mg intravenously (IV) once per week and the VEGF-A monoclonal antibody bevacizumab 10 mg/kg IV once every 2 weeks in patients with well or moderately differentiated PNETs and progressive disease by RECIST within 7 months of study entry. Coprimary end points were tumor response rate and 6-month PFS. Results A total of 58 patients were enrolled, and 56 patients were eligible for response assessment. Confirmed response rate (RR) was 41% (23 of 56 patients). PFS at 6 months was 79% (44 of 56). Median PFS was 13.2 months (95% CI, 11.2 to 16.6). Median overall survival was 34 months (95% CI, 27.1 to not reached). For evaluable patients, the most common grade 3 to 4 adverse events attributed to therapy were hypertension (21%), fatigue (16%), lymphopenia (14%), and hyperglycemia (14%). Conclusion The combination of temsirolimus and bevacizumab had substantial activity and reasonable tolerability in a multicenter phase II trial, with RR of 41%, well in excess of single targeted agents in patients with progressive PNETs. Six-month PFS was a notable 79% in a population of patients with disease progression by RECIST criteria within 7 months of study entry. On the basis of this trial, continued evaluation of combination mTOR and VEGF pathway inhibitors is warranted.

Abstract Background: Stage IVC (metastatic) anaplastic thyroid cancer (ATC) has a median overall survival (OS) of only 1.9 months. Single agent paclitaxel has modest activity in ATC. In pre-clinical studies, CS-7017 inhibited ATC proliferation through a novel mechanism–activation of PPAR-γ, followed by sequential upregulation of RhoB, then p21. Moreover, CS-7017 augmented the proapoptotic effects of paclitaxel. Based on these results, a multicenter study was conducted to determine if CS-7017+paclitaxel might prove safe and effective in advanced ATC. Design: A Phase 1 study was conducted to determine the Phase 2 dose. In Phase 1, patients received CS-7017 orally BID for one week (run-in phase), followed by a 3 h iv infusion of paclitaxel (175 mg/m2) every 3 weeks in combination with BID CS-7017. CS-7017 doses were escalated (0.15, 0.3, or 0.5 mg). Tissue biopsies were obtained at baseline and at one and three weeks for immunohistochemistry of PPAR-γ responsive proteins; serum CS-7017 PK studies were also performed. Results: Nineteen patients were enrolled, but 4 were not dosed (3 due to progression, 1 ineligible). Seven participated in CS-7017 dose levels 1a/1b (0.15 mg BID), six in dose level 2 (0.3 mg BID), and two in dose level 3 (run-in phase only–0.5 mg BID). Demographics: Of the 15 treated patients, 10 (67%) were women. Median age was 59 years (range: 43-82) Efficacy: Of 15 patients receiving drug, one had a confirmed partial response (PR) lasting from Day 69 to Day 175, and eight had stable disease (SD) as their best response. Median Time to Progression in 7 patients at Dose Level 1 was 49 days, but 70 days in Dose Level 2 (43% prolongation); corresponding median survival was 99 (0.15 mg BID) vs. 140 days (0.3 mg BID, 42% increase). Median peak CS-7017 blood level was 8.6 ng/mL (range: 5.1 to 13.7) for Level 1 and 22.0 ng/mL (17.0 to 31.5) for Dose Level 2. Adverse Events: Ten patients had AEs ≥ Grade 3, with two (anemia and localized edema) related to CS-7017. Thirteen events of fluid retention/edema were reported in 8 patients, with only 2 events of CTCAE grade ≥ 3. Eight patients had ≥ one SAE, with one (anemia) due to CS-7017. One SAE (anaphylactic reaction) was related to paclitaxel. No dose limiting toxicity was observed. Immunohistochemistry: Biopsies were available on 7 patients. PPAR-γ, RXR-α, RhoB were present in all; Angiopoietin-like 4 was induced by CS-7017. Conclusions: Combination therapy with CS-7017 and paclitaxel was tolerated and has biologic activity in patients with metastatic anaplastic thyroid carcinoma, with initial exploratory data suggesting a dose-dependent improvement in time to progression and survival in response to escalating CS-7017 dosage. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1278. doi:10.1158/1538-7445.AM2011-1278

Purpose No established treatment exists for pancreatic neuroendocrine tumor (NET) progression after failure of chemotherapy. Everolimus (RAD001), an oral inhibitor of mammalian target of rapamycin, in combination with octreotide has demonstrated encouraging antitumor activity in patients with NETs. Patients and Methods This open-label, phase II study assessed the clinical activity of everolimus in patients with metastatic pancreatic NETs who experienced progression on or after chemotherapy. Patients were stratified by prior octreotide therapy (stratum 1: everolimus 10 mg/d, n = 115; stratum 2: everolimus 10 mg/d plus octreotide long-acting release [LAR], n = 45). Tumor assessments (using Response Evaluation Criteria in Solid Tumors) were performed every 3 months. Chromogranin A (CgA) and neuron-specific enolase (NSE) were assessed monthly if elevated at baseline. Trough concentrations of everolimus and octreotide were assessed. Results By central radiology review, in stratum 1, there were 11 partial responses (9.6%), 78 patients (67.8%) with stable disease (SD), and 16 patients (13.9%) with progressive disease; median progression-free survival (PFS) was 9.7 months. In stratum 2, there were two partial responses (4.4%), 36 patients (80%) with SD, and no patients with progressive disease; median PFS was 16.7 months. Patients with an early CgA or NSE response had a longer PFS compared with patients without an early response. Coadministration of octreotide LAR and everolimus did not impact exposure to either drug. Most adverse events were mild to moderate and were consistent with those previously seen with everolimus. Conclusion Daily everolimus, with or without concomitant octreotide LAR, demonstrates antitumor activity as measured by objective response rate and PFS and is well tolerated in patients with advanced pancreatic NETs after failure of prior systemic chemotherapy.