Efficacy and safety results of depatuxizumab mafodotin (ABT-414) in patients with advanced solid tumors likely to overexpress epidermal growth factor receptor.

BACKGROUND: Epidermal growth factor receptor (EGFR) alterations are associated with multiple cancers. Current EGFR-directed therapies have led to increased efficacy but are associated with specific side effects. The antibody-drug conjugate depatuxizumab mafodotin (depatux-m) targets EGFR with a monoclonal antibody linked to a cytotoxin, and is highly tumor-specific. METHODS: This phase 1/2 study evaluated the safety, pharmacokinetics, and efficacy of depatux-m in patients who had advanced solid tumors with known wild-type EGFR overexpression, amplification, or mutated EGFR variant III. A 3 + 3 dose escalation was used, and 2 dosing schedules were evaluated. Depatux-m also was manufactured under an alternate process to reduce the drug load and improve the safety profile, and it was tested at the maximum tolerated dose (MTD). In another cohort, prolonged infusion time of depatux-m was evaluated; and a cohort with confirmed EGFR amplification also was evaluated at the MTD. RESULTS: Fifty-six patients were treated. The MTD and the recommended phase 2 dose for depatux-m was 3.0 mg/kg. Common adverse events (AEs) were blurred vision (48%) and fatigue (41%). A majority of patients (66%) experienced 1 or more ocular AEs. Grade 3 or 4 AEs were observed in 43% of patients. One patient with EGFR-amplified, triple-negative breast cancer had a partial response. Stable disease was observed in 23% of patients. Pharmacokinetics revealed that depatux-m exposures were approximately dose-proportional. CONCLUSIONS: Depatux-m resulted in infrequent nonocular AEs but increased ocular AEs. Patient follow-up confirmed that ocular AEs were reversible. Lowering the drug-antibody ratio did not decrease the number of ocular AEs. A partial response in 1 patient with EGFR-amplified disease provides the opportunity to study depatux-m in diseases with a high incidence of EGFR amplification. Cancer 2018;124:2174-83. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Veliparib in combination with whole-brain radiation therapy for patients with brain metastases from non-small cell lung cancer: results of a randomized, global, placebo-controlled study.

Veliparib is a potent, orally bioavailable, poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitor that crosses the blood-brain barrier and has been shown to potentiate the effects of radiation in preclinical and early clinical studies. This phase 2, randomized, global study evaluated the efficacy and safety of veliparib in combination with whole-brain radiation therapy (WBRT) in patients with brain metastases from non-small cell lung cancer (NSCLC). Three-hundred and seven patients with brain metastases from NSCLC were randomized 1:1:1 to WBRT (30 Gy in 10 fractions) plus 50 mg veliparib twice daily (BID; n = 103), 200 mg veliparib BID (n = 102), or placebo BID (n = 102). Treatment began within 28 days of diagnosis. Tumor response and safety were assessed; the primary endpoint was overall survival (OS). Patients who received ≥1 dose of treatment were included in the safety analysis. All randomized patients were included in the efficacy endpoint analyses. Patient characteristics were well balanced between treatment arms. Median OS was 185 days for patients treated with WBRT plus placebo and 209 days for WBRT plus veliparib (50 or 200 mg). No statistically significant differences in OS, intracranial response rate, and time to clinical or radiographic progression between any of the treatment arms were noted. No differences were observed in adverse events (all grades) across treatment arms; nausea, fatigue, alopecia, and headache were the most commonly reported. No new safety signals were identified for veliparib. A significant unmet need for therapies that improve the outcomes of patients with brain metastases from NSCLC remains.

A Phase II Trial of a Histone Deacetylase Inhibitor Panobinostat in Patients With Low-Grade Neuroendocrine Tumors.

LESSONS LEARNED: Pancreatic neuroendocrine tumors versus carcinoid tumors should be examined separately in clinical trials.Progression-free survival is more clinically relevant as the primary endpoint (rather than response rate) in phase II trials for low-grade neuroendocrine tumors. BACKGROUND: The most common subtypes of neuroendocrine tumors (NETs) are pancreatic islet cell tumors and carcinoids, which represent only 2% of all gastrointestinal malignancies. Histone deacetylase (HDAC) inhibitors have already been shown to suppress tumor growth and induce apoptosis in various malignancies. In NET cells, HDAC inhibitors have resulted in increased Notch1 expression and subsequent inhibition of growth. We present here a phase II study of the novel HDAC inhibitor panobinostat in patients with low-grade NET. METHODS: Adult patients with histologically confirmed, metastatic, low-grade NETs and an Eastern Cooperative Oncology Group (ECOG) performance status of ≤2 were treated with oral panobinostat 20 mg once daily three times per week. Treatment was continued until patients experienced unacceptable toxicities or disease progression. The study was stopped at planned interim analysis based on a Simon two-stage design. RESULTS: Fifteen patients were accrued, and 13 were evaluable for response. No responses were seen, but the stable disease rate was 100%. The median progression-free survival (PFS) was 9.9 months, and the median overall survival was 47.3 months. Fatigue (27%), thrombocytopenia (20%), diarrhea (13%), and nausea (13%) were the most common related grade 3 toxicities. There was one grade 4 thrombocytopenia (7%). These results did not meet the prespecified criteria to open the study to full accrual. CONCLUSION: The HDAC inhibitor panobinostat has a high stable disease rate and reasonable PFS in low-grade NET, but has a low response rate.

A phase 1 study of ABT-806 in subjects with advanced solid tumors.

PURPOSE: ABT-806, a humanized recombinant monoclonal antibody, binds a unique epidermal growth factor receptor (EGFR) epitope exposed in the EGFRde2-7 (EGFRvIII) deletion mutant and other EGFR proteins in the activated state. This phase I study evaluated the safety, pharmacokinetics, and recommended phase two dose (RP2D) of ABT-806 in patients with solid tumors that commonly overexpress activated EGFR or EGFRvlll. METHODS: Patients with advanced solid tumors, including glioblastoma, were eligible. Following a dose escalation phase, expanded safety cohorts of patients with solid tumors or EGFR-amplified glioblastoma were enrolled. Adverse events (AEs) were graded by National Cancer Institute Common Terminology Criteria for Adverse Events v4.0; tumor response was assessed by Response Evaluation Criteria in Solid Tumors v1.1. EGFR protein expression was quantified by immunohistochemistry. RESULTS: 49 patients were treated. Frequent AEs (≥10 %) possibly/probably related to ABT-806 were fatigue (18 %), nausea (16 %), dermatitis acneiform (12 %), and vomiting (10 %). Only one dose-limiting toxicity (grade three morbilliform rash) occurred. The RP2D was the pre-specified highest dose (24 mg/kg). Systemic exposures were dose proportional between 2 and 24 mg/kg. Median time to progression was 55 days (95 % confidence interval, 53-57) in all patients and 43 days (22-57) for glioblastoma patients. No objective responses occurred; however, two patients had prolonged stable disease. An EGFR-amplified penile cancer patient has stable disease lasting over 2.5 years. CONCLUSIONS: ABT-806 has unique pharmacokinetic and safety profiles. Toxicities were infrequent and typically low grade at the RP2D. Linear ABT-806 pharmacokinetics suggest lack of significant binding to wild-type EGFR in normal tissues.

A multicenter phase 1 study of γ -secretase inhibitor RO4929097 in combination with capecitabine in refractory solid tumors.

BACKGROUND: RO4929097 is an oral inhibitor of γ -secretase that results in Notch signaling inhibition. Prior work has demonstrated that Notch signaling inhibition enhances chemotherapy sensitivity of cancer cells. This phase I study was conducted to determine maximum tolerated dose (MTD), toxicities and efficacy of RO4929097 and capecitabine in advanced solid tumors. METHODS: Patients with refractory solid tumors received capecitabine at a fixed dose of 1,000 mg/m(2) twice daily with escalating doses of RO4929097 on a 21-day cycle in a 3 + 3 design. Capecitabine was administered for 14 days and the RO49029097 once daily, 3 days per week, both for a 21 day cycle. RESULTS: Thirty patients were treated on six dose levels (20 to 150 mg). The maximally tolerated dose was not reached. One dose limiting toxicity was observed at each level 3 through 6 (hypophosphatemia, fatigue, and nausea/vomiting). Three confirmed partial responses were observed: two patients with fluoropyrimide-refractory colon cancer and one patient with cervical cancer. Autoinduction of RO4929097 was demonstrated with increasing dose levels and duration. CONCLUSIONS: The recommended phase 2 dose is capecitabine 1,000 mg/m(2) orally twice daily on days 1 through 14 with RO4929097 20 mg orally once daily on days 1-3, 8-10 and 15-17 with a 21 day cycle. Clinical benefit was observed in cervical and colon cancer. Autoinduction of RO4929097 was seen both with increasing cycle number and increasing dose. Plasma concentrations of RO4929097 were above those needed for Notch inhibition.

Veliparib in combination with whole brain radiation therapy in patients with brain metastases: results of a phase 1 study.

Veliparib, a potent, oral PARP inhibitor, potentiates the antitumor activity of radiation therapy and crosses the blood-brain barrier. This was a phase 1 dose-escalation study evaluating the safety, and secondarily the antitumor activity of veliparib in combination with whole brain radiation therapy (WBRT) in patients with brain metastases, in order to power future trials. Patients with brain metastases from primary solid tumors were treated with WBRT (30.0 or 37.5 Gy in 10 or 15 fractions) and veliparib (escalating doses of 10-300 mg, orally BID). Safety and tumor response were assessed. Observed survival was compared to predicted survival based on a published nomogram. Eighty-one patients (median age 58 years) were treated. The most common primary tumor types were non-small cell lung (NSCLC; n = 34) and breast cancer (n = 25). The most common AEs deemed possibly related to veliparib (AEs, ≥15 %) were fatigue (30 %), nausea (22 %), and decreased appetite (15 %). Fatigue (5 %), hypokalemia and hyponatremia (3 % each) were the only Grade 3/4 AEs deemed possibly related to veliparib observed in ≥2 patients. Although this was an uncontrolled study, preliminary efficacy results were better than predicted: the median survival time (MST, 95 % CI) for the NSCLC subgroup was 10.0 mo (3.9-13.5) and for the breast cancer subgroup was 7.7 mo (2.8-15.0) compared to a nomogram-model-predicted MST of 3.5 mo (3.3-3.8) and 4.9 mo (4.2-5.5). The addition of veliparib to WBRT did not identify new toxicities when compared to WBRT alone. Based on encouraging safety and preliminary efficacy results, a randomized, controlled phase 2b study is ongoing.

A phase I clinical trial of navitoclax, a targeted high-affinity Bcl-2 family inhibitor, in combination with gemcitabine in patients with solid tumors.

PURPOSE: To investigate the safety, optimal dosing, pharmacokinetics and clinical activity of a regimen of navitoclax (ABT-263) combined with gemcitabine in patients with solid tumors. EXPERIMENTAL DESIGN: Patients with solid tumors for which gemcitabine was deemed an appropriate therapy were enrolled into one of two different dosing schedules (21-day dosing schedule: navitoclax administered orally on days 1-3 and 8-10,; and gemcitabine 1,000 mg/m(2) on days 1 and 8; 28-day dosing schedule: navitoclax administrated orally on days 1-3, 8-10, and 15-17; and gemcitabine 1,000 mg/m(2) on days 1, 8 and 15). Navitoclax doses were escalated from 150 to 425 mg. An expanded safety cohort was conducted for the 21-day dosing schedule at the maximum tolerated dose (MTD) of navitoclax. RESULTS: Forty-six patients were enrolled at three U.S. centers. The most common adverse events included: hematologic abnormalities (thrombocytopenia, neutropenia, and anemia), liver enzyme elevations (ALT and AST), and gastrointestinal disturbances (diarrhea, nausea, and vomiting). Dose-limiting toxicities (DLTs) observed in cycle 1 were grade 4 thrombocytopenia (2 patients), grade 4 neutropenia (1 patient), and grade 3 AST elevation (2 patients). The MTD of navitoclax was 325 mg co-administered with gemcitabine 1,000 mg/m(2) for the 21-day schedule. No clinically significant pharmacokinetic drug-drug interactions were observed. There were no objective responses. Stable disease, reported at the end of cycle 2, was the best response in 54 % of evaluable patients (n = 39). CONCLUSIONS: The combination of navitoclax 325 mg with gemcitabine 1,000 mg/m(2) was generally well tolerated and exhibited a favorable safety profile in patients with advanced solid tumors.

A phase I study of sorafenib, oxaliplatin and 2 days of high dose capecitabine in advanced pancreatic and biliary tract cancer: a Wisconsin oncology network study.

Chemotherapy has yielded minimal clinical benefit in pancreatic and biliary tract cancer. A high-dose, short course capecitabine schedule with oxaliplatin, has shown some efficacy with a lower incidence of palmar-plantar erythrodysesthesia. Achieving high exposures of the targeted agent sorafenib may be possible with this shorter schedule of capecitabine by avoiding dermatologic toxicity. All patients had pancreatic or biliary tract cancer. Patients in both cohorts received oxaliplatin 85 mg/m2 followed by capecitabine 2,250 mg/m2 PO every 8 h x 6 doses starting on days 1 and 15 of a 28 day cycle, or 2DOC (2 Day Oxaliplatin/Capecitabine). Cohort 1 used sorafenib 200 mg BID, and cohort 2 used sorafenib 400 mg BID. Sixteen patients were enrolled. Across all cycles the most common grade 1 or 2 adverse events were fatigue (10 pts), diarrhea (10 pts), nausea (9 pts), vomiting (8 pts), sensory neuropathy (8 pts), thrombocytopenia (7 pts), neutropenia (5 pts), and hand-foot syndrome (5 pts). Grade 3 toxicites included neutropenia, mucositis, fatigue, vomiting and diarrhea. Cohort 1 represented the MTD. Two partial responses were seen, one each in pancreatic and biliary tract cancers. The recommended phase II dose of sorafenib in combination with 2DOC is 200 mg BID. There were infrequent grade 3 toxicities, most evident with sorafenib at 400 mg BID.

A phase I study of vorinostat in combination with bortezomib in patients with advanced malignancies.

BACKGROUND: A phase I study to assess the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacokinetics (PK) and antitumor activity of vorinostat in combination with bortezomib in patients with advanced solid tumors. METHODS: Patients received vorinostat orally once daily on days 1-14 and bortezomib intravenously on days 1, 4, 8 and 11 of a 21-day cycle. Starting dose (level 1) was vorinostat (400 mg) and bortezomib (0.7 mg/m(2)). Bortezomib dosing was increased using a standard phase I dose-escalation schema. PKs were evaluated during cycle 1. RESULTS: Twenty-three patients received 57 cycles of treatment on four dose levels ranging from bortezomib 0.7 mg/m(2) to 1.5 mg/m(2). The MTD was established at vorinostat 400 mg daily and bortezomib 1.3 mg/m(2). DLTs consisted of grade 3 fatigue in three patients (1 mg/m(2),1.3 mg/m(2) and 1.5 mg/m(2)) and grade 3 hyponatremia in one patient (1.5 mg/m(2)). The most common grade 1/2 toxicities included nausea (60.9%), fatigue (34.8%), diaphoresis (34.8%), anorexia (30.4%) and constipation (26.1%). Objective partial responses were observed in one patient with NSCLC and in one patient with treatment-refractory soft tissue sarcoma. Bortezomib did not affect the PKs of vorinostat; however, the Cmax and AUC of the acid metabolite were significantly increased on day 2 compared with day 1. CONCLUSIONS: This combination was generally well-tolerated at doses that achieved clinical benefit. The MTD was established at vorinostat 400 mg daily × 14 days and bortezomib 1.3 mg/m(2) on days 1, 4, 8 and 11 of a 21-day cycle.

Phase 2 study of bevacizumab plus erlotinib in patients with advanced hepatocellular cancer.

BACKGROUND: Epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) are rational targets for therapy in hepatocellular cancer (HCC). METHODS: Patients with histologically proven HCC and not amenable to curative or liver directed therapy were included in this 2-stage phase 2 trial. Eligibility included an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1 and Child's Pugh score of A or B, and 1 prior systemic therapy. Patients received erlotinib 150 mg daily and bevacizumab 10 mg/kg on days 1 and 15 every 28 days. Objective tumor response was the primary end point. RESULTS: Twenty-seven patients with advanced HCC (median age, 60 years) were enrolled in this multi-institutional study. The proportion of patients with Child's A classification was 74%. One patient had a confirmed partial response and 11 (48%) achieved stable disease. Median time to disease progression was 3.0 months (95% confidence interval [CI], 1.8-7.1). Median survival time was 9.5 months (95% CI, 7.1-17.1). Grade 3 toxicities included rash, hypertension, fatigue, and diarrhea. CONCLUSIONS: In this trial, erlotinib combined with bevacizumab had minimal activity in patients with advanced HCC based on objective response and progression-free survival. The role of targeting EGFR and VEGF in HCC needs further evaluation in molecularly selected patients.

A phase I trial of MK-0731, a kinesin spindle protein (KSP) inhibitor, in patients with solid tumors.

PURPOSE: The kinesin spindle protein (KSP) is essential for separation of spindle poles during mitosis. Its inhibition results in mitotic arrest. This phase I trial examined safety, tolerability, dose-limiting toxicity (DLT), maximum tolerated dose (MTD), pharmacokinetic parameters, and anti-tumor activity of MK-0731, a potent inhibitor of KSP. EXPERIMENTAL DESIGN: In part 1, patients with advanced solid tumors received MK-0731 intravenously over 24 h every 21 days starting at 6 mg/m(2), escalating until MTD was reached. In part 2, patients with taxane-resistant tumors received the MTD. Plasma samples were collected to analyze the pharmacokinetics of MK-0731. Tumor response was evaluated using Response Evaluation Criteria in Solid Tumors (RECIST) v1.0. RESULTS: In part 1, 21 patients (median age 63 years) were treated with MK-0731 at doses ranging from 6 to 48 mg/m(2)/24 h for median four cycles. The dose-limiting toxicity was neutropenia and the MTD was 17 mg/m(2)/24 h. At the MTD, AUC (±SD) was 10.5 (±7.3) µM × hour, clearance (±SD) was 153 mL/min (±84), and t(1/2) was 5.9 h. In part 2, 22 patients received the MTD and there were no DLTs. Although there were no objective tumor responses, four patients (with cervical, non-small cell lung, and ovarian cancers) had prolonged stable disease. CONCLUSIONS: MK-0731 at the MTD of 17 mg/m(2)/day every 21 days in patients with solid tumors had few grade 3 and 4 toxicities with the major DLTs at higher doses being myelosuppression. Anti-tumor efficacy was suggested by the length of stable disease in selected patients with taxane-resistant tumors.

An international, multicenter phase II trial of bortezomib in patients with hepatocellular carcinoma.

BACKGROUND AND RATIONALE: Bortezomib (PS-341, VELCADE®) is a selective inhibitor of the 26S proteasome, an integral component of the ubiquitin-proteasome pathway. This phase II study evaluated the activity and tolerability of bortezomib in unresectable hepatocellular carcinoma (HCC) patients. METHODS: The primary endpoint was confirmed tumor response rate (RR) with secondary endpoints including duration of response, time to disease progression, survival and toxicity. Treatment consisted of bortezomib, 1.3 mg/m2 IV bolus on days 1, 4, 8, and 11 of each 21-day treatment cycle. Eligibility included: no prior systemic chemotherapy, ECOG PS 0-2, Child-Pugh A or B, preserved hematologic, hepatic and neurologic function; prior liver-directed therapy was permitted. RESULTS: Thirty-five patients enrolled and received a median of 2 cycles of treatment (range 1-12). Overall, 24 and 4 patients had a maximum severity of grade 3 and 4 adverse events (AEs), respectively. No treatment related deaths occurred. Only thrombocytopenia (11%) was seen in greater than 10% of patients. One patient achieved a partial response, lasting 13 weeks during treatment and progressed 11.6 months later; two patients received treatment for greater than 6 months. Median time-to-progression was 1.6 months and median survival was 6.0 months. CONCLUSIONS: This international, multicenter trial evaluated bortezomib as monotherapy in unresectable HCC patients. And, despite the lack of significant activity, this report serves as a baseline clinical experience for the development of future dual biologic approaches including bortezomib.

A pilot phase II study of valproic acid for treatment of low-grade neuroendocrine carcinoma.

INTRODUCTION: Notch1 has been shown to be a tumor suppressor in neuroendocrine tumors (NETs). Previous in vitro studies in NET cell lines have also suggested that valproic acid (VPA), a histone deacetylase inhibitor, can induce Notch1 and that Notch1 activation correlates with a decrease in tumor markers for NETs. Thus, this study aimed to evaluate the role of VPA in treating NETs and to determine whether VPA induced the Notch signaling pathway signaling in vivo. PATIENTS AND METHODS: Eight patients with low-grade NETs (carcinoid and pancreatic) were treated with 500 mg of oral VPA twice a day with dosing adjusted to maintain a goal VPA level between 50 and 100 µg/mL. All patients were followed for 12 months or until disease progression. RESULTS: Notch1 signaling was absent in all tumors prior to treatment and was upregulated with VPA. One patient had an unconfirmed partial response and was noted to have a 40-fold increase in Notch1 mRNA levels. Four patients had stable disease as best response. Tumor markers improved in 5 out of 7 patients. Overall, treatment with VPA was well tolerated. CONCLUSION: . VPA activates Notch1 signaling in vivo and may have a role in treating low-grade NETs.

A preclinical and clinical study of lithium in low-grade neuroendocrine tumors.

BACKGROUND: Low-grade neuroendocrine tumors (NETs) respond poorly to chemotherapy; effective, less toxic therapies are needed. Glycogen synthase kinase (GSK)-3ß has been shown to regulate growth and hormone production in NETs. Use of lithium chloride in murine models suppressed carcinoid cell growth, reduced GSK-3ß levels, and reduced expression of chromogranin A. This study assessed the efficacy of lithium chloride in patients with NETs. DESIGN: Eligible patients had low-grade NETs. A single-arm, open-label phase II design was used. Lithium was dosed at 300 mg orally three times daily, titrated to serum levels of 0.8-1.0 mmol/L. The primary endpoint was objective tumor response by the Response Evaluation Criteria in Solid Tumors. Secondary endpoints included overall survival, progression-free survival, GSK-3ß phosphorylation, and toxicity. RESULTS: Fifteen patients were enrolled between October 3, 2007 and July 17, 2008, six men and nine women. The median age was 58 years. Patient diagnoses were carcinoid tumor for eight patients, islet cell tumor for five patients, and two unknown primary sites. Eastern Cooperative Oncology Group performance status scores were 0 or 1. Two patients came off study because of side effects. The median progression-free survival interval was 4.50 months. There were no radiographic responses. Because of an early stopping rule requiring at least one objective response in the first 13 evaluable patients, the study was closed to further accrual. Patients had pre- and post-therapy biopsies. CONCLUSIONS: Lithium chloride was ineffective at obtaining radiographic responses in our 13 patients who were treated as part of this study. Based on the pre- and post-treatment tumor biopsies, lithium did not potently inhibit GSK-3ß at serum levels used to treat bipolar disorders.

A multicenter, phase II study of bortezomib (PS-341) in patients with unresectable or metastatic gastric and gastroesophageal junction adenocarcinoma.

PURPOSE: The transcription factor nuclear factor-kB (NFkB) is implicated in gastric cancer carcinogenesis and survival, and its inhibition by proteosome inhibition is associated with preclinical gastric cancer anti-tumor activity. We examined the single agent efficacy of bortezomib, a selective proteasome inhibitor, in gastric adenocarcinoma. EXPERIMENTAL DESIGN: We performed a phase II trial of bortezomib in patients with advanced gastric adenocarcinoma. Bortezomib 1.3 mg/m(2) was administered on days 1, 4, 8, and 11 every 21 days. The primary endpoint was objective response rate(RR); the null hypothesis was RR <1% versus the alternative ≥15%. One response in the first stage(15 patients) was required before proceeding with an additional 18 patients. If at least 2 or more responses out of 33 were observed, further study with bortezomib was warranted. Correlative studies evaluated pre-treatment tumor expression of NFkB, IkB, p53, p21, and cyclin D1. RESULTS: We enrolled 16 patients (15 evaluable for response) from four institutions. No patients demonstrated an objective response(95% CI, 0-22%); one patient achieved stable disease. Fourteen out of 16 patients experienced ≥ grade 2 toxicity. The most common toxicity was fatigue in six patients (n = 4 grade 2, n = 2 grade 3). Seven patients experienced neuropathy (n = 5 grade 1, and 1 each grade 2 and 3). Seven (60%) had high cytoplasmic staining for NFkB. CONCLUSIONS: Single agent bortezomib is inactive in metastatic gastric adenocarcinoma and should not be pursued. Future study of proteasome inhibition in gastric adenocarcinoma should be considered in combination with targeted inhibition of other non-overlapping oncogenic pathways as a potential rational approach.

A Phase 1 and Biodistribution Study of ABT-806i, an 111In-Radiolabeled Conjugate of the Tumor-Specific Anti-EGFR Antibody ABT-806.

ABT-806 is a tumor-specific antibody targeting the epidermal growth factor receptor (EGFR). This study assessed safety, biodistribution, and pharmacokinetics of 111In-radiolabeled ABT-806 (ABT-806i) and effects of repeated doses of ABT-806 on receptor occupancy. Methods: Eligible patients had advanced tumors likely to express EGFR/EGFRvIII; adequate performance status and organ function; and measurable disease by RECIST 1.1. In cohort 1, 6 patients received a bolus administration of ABT-806i and underwent SPECT followed by whole-body planar scans. In cohort 2, 12 patients were imaged similarly as in 1 initially; thereafter, they received 3 doses of unlabeled ABT-806, before another dose of ABT-806i with associated SPECT and whole-body planar scans. At the end of both cohorts, patients who had stable or responding disease were able to enroll into an extension study (M12-326) in which they received unlabeled ABT-806 every 2 wk until disease progression, withdrawal of consent, or intolerable toxicity. Results: No toxicity related to ABT-806i infusion was observed. ABT-806i showed minimal uptake in normal tissues and cleared gradually from blood with a half-life of 6.0 ± 1.5 d. The mean effective dose of ABT-806i was 0.137 mSv/MBq for males and 0.183 mSv/MBq for females. ABT-806i tumor uptake varied and did not correlate with archived tumor EGFR expression. No change in ABT-806i uptake was observed after interval ABT-806 treatment, indicating stable EGFR expression in tumor. The patient with highest tumor uptake of ABT-806i had advanced head and neck cancer and experienced a partial response. Conclusion: ABT-806i allows for real-time imaging of EGFR conformational expression in tumors, has an acceptable radiation dosimetry, and provides important additional information about antigen expression compared with standard approaches using archival tissue. Its role to assist in patient selection for EGFR-based therapeutics and investigate treatment resistance should be further investigated.

ZM336372 induces apoptosis associated with phosphorylation of GSK-3beta in pancreatic adenocarcinoma cell lines.

INTRODUCTION: ZM336372 is small molecule tyrosine kinase modulator. It has been shown to inhibit glycogen synthase kinase-3beta (GSK-3beta) through phosphorylation of GSK-3beta at Ser 9. GSK-3beta has previously been shown to mediate cell survival in pancreatic cancer cells. Here we determine the effects of ZM336372 on GSK-3beta phosphorylation, apoptosis, and growth in pancreatic adenocarcinoma cell lines. METHODS: Panc-1 and MiaPaCa-2 cells were treated with ZM336372 or lithium chloride (LiCl) and compared with solvent control. The effects on proliferation for each cell line were determined using the MTT assay. Western blot analysis was performed to examine the effects of treatment on the phosphorylation of GSK-3beta. In addition, western blot was utilized to examine the cleavage of poly (ADP-ribose) polymerase (PARP), a marker of apoptosis. RESULTS: A dose-dependent increase in phosphorylation of GSK-3beta was observed after treatment with both ZM336372 and LiCl. Growth inhibition due to treatment with ZM336372 and LiCl also occurred in a dose-dependent fashion. An increase in cleaved PARP was demonstrated after treatment with both agents, as was seen previously with GSK-3beta inhibition in pancreatic adenocarcinoma cells. CONCLUSION: This is the first description of growth inhibition and apoptosis in pancreatic cancer cells related to GSK-3beta inhibition through treatment with ZM336372.

Phase I trial of 2-methoxyestradiol NanoCrystal dispersion in advanced solid malignancies.

PURPOSE: 2-methoxyestradiol (2ME2; Panzem) is an endogenous, estradiol-17beta metabolite that at pharmacologic doses exerts antimitotic and antiangiogenic activities. Studies with a 2ME2 capsule formulation showed limited oral bioavailability. We report the results of a phase I study using a NanoCrystal Dispersion formulation of 2ME2 (2ME2 NCD). EXPERIMENTAL DESIGN: Patients with refractory solid tumors received 2ME2 NCD orally. Patients received drug either every 6 hours (part A) or every 8 hours (part B). Doses were escalated in successive cohorts until the maximum tolerated dose (MTD) was identified. The primary objective was identifying the MTD. Secondary objectives were to evaluate the plasma pharmacokinetics of 2ME2 and efficacy. RESULTS: In part A, 16 patients received a median of 4 cycles of 2ME2 NCD. Dose-limiting toxicities (DLT) included fatigue (2), hypophosphatemia (2), increased alanine aminotransferase (1), and muscle weakness (1). Trough levels at steady-state reached the minimum effective concentration in all cohorts. The MTD was determined to be 1,000 mg orally every 6 hours. In part B, 10 patients received a median of 1 cycle. DLTs included elevated gamma-glutamyltransferase (1), hyponatremia (1), fatigue (1), and anorexia (1). An MTD could not be defined for part B because 4 of 10 patients had DLTs at the initial dose level and dose reduction was not pursued. Thirteen patients had stable disease (A, 11; B, 2); there were no confirmed responses. CONCLUSION: For 2ME2 NCD, the MTD and recommended phase II regimen is 1,000 mg orally every 6 hours. Treatment was generally well-tolerated.

Volociximab, a chimeric monoclonal antibody that specifically binds alpha5beta1 integrin: a phase I, pharmacokinetic, and biological correlative study.

PURPOSE: This study aimed to assess the safety and feasibility of administering volociximab, a chimeric monoclonal antibody that specifically binds to alpha(5)beta(1) integrin, and to determine the pharmacokinetics, pharmacodynamics, and preliminary evidence of antitumor activity. EXPERIMENTAL DESIGN: Patients with advanced solid malignancies were treated with escalating doses of volociximab i.v. administered over 60 minutes. Blood samples were assayed to determine plasma pharmacokinetic parameters, detect human antichimeric antibody formation, and determine the saturation of alpha5beta1 sites on peripheral blood monocytes. RESULTS: Twenty-one patients received 223 infusions of volociximab at doses ranging from 0.5 to 15 mg/kg i.v. on days 1, 15, 22, 29, and 36; and weekly thereafter. Treatment was well tolerated, and dose-limiting toxicity was not identified over the range examined. Mild (grade 1 or 2), reversible fatigue was the principal toxicity of volociximab at the highest dose levels of 10 and 15 mg/kg. Nausea, fever, anorexia, headache, vomiting, and myalgias were mild and infrequent, and there was no hematologic toxicity. Volociximab had biexponential distribution; clearance was inversely related to increasing dose, and the half-life at 15 mg/kg was estimated as being 30 days. Three patients tested positive for anti-volociximab antibodies. Saturation of monocyte alpha5beta1 integrin sites was dose-dependent up to 15 mg/kg. There was one minor response (renal, 7 months) and one durable stable disease (melanoma, 14 months). CONCLUSIONS: Volociximab can be safely administered at 15 mg/kg i.v. per week. The absence of severe toxicities and preliminary activity at the highest dose level warrants further disease-directed studies.

Beyond taxanes: a review of novel agents that target mitotic tubulin and microtubules, kinases, and kinesins.

Until recently, development of chemotherapeutic agents that target mitosis has centered on inhibiting the mitotic spindle through interactions with microtubules. The taxanes, while significantly advancing the treatment of many types of cancer, suffer from problems of hematopoeitic and neurologic toxicities, development of resistance, and an inconvenient formulation. Novel microtubule inhibitors currently in clinical trial and in clinical use have the main advantage of overcoming resistance. Still, they have side effects related to the inhibition of microtubules in normal host cells. Novel antimitotics, which target the mitotic spindle through interactions with nonmicrotubule mitotic mediators like mitotic kinases and kinesins, have been identified and are now in clinical trial. They offer the prospect of surmounting more of the problems inherent with taxanes and the hope of improving upon their broad antitumor efficacy. This review will concentrate on novel agents in later clinical development that target both the spindle microtubule and nonmicrotubule constituents of mitosis.