Andrew P. Beelen

Effect of Tarenflurbil on Cognitive Decline and Activities of Daily Living in Patients With Mild Alzheimer Disease: A Randomized Controlled Trial

CONTEXT Amyloid-beta peptide (Abeta(42)) has been implicated in the pathogenesis of Alzheimer disease (AD). Tarenflurbil, a selective Abeta(42)-lowering agent, demonstrated encouraging results on cognitive and functional outcomes among mildly affected patients in an earlier phase 2 trial. OBJECTIVE To determine the efficacy, safety, and tolerability of tarenflurbil. DESIGN, SETTING, AND PATIENTS A multicenter, randomized, double-blind, placebo-controlled trial enrolling patients with mild AD was conducted at 133 trial sites in the United States between February 21, 2005, and April 30, 2008. Concomitant treatment with cholinesterase inhibitors or memantine was permitted. INTERVENTION Tarenflurbil, 800 mg, or placebo, administered twice a day. MAIN OUTCOME MEASURES Co-primary efficacy end points were the change from baseline to month 18 in total score on the subscale of the Alzheimer Disease Assessment Scale-Cognitive Subscale (ADAS-Cog, 80-point version) and Alzheimer Disease Cooperative Studies-activities of daily living (ADCS-ADL) scale. Additional prespecified slope analyses explored the possibility of disease modification. RESULTS Of the 1684 participants randomized, 1649 were included in the analysis, and 1046 completed the trial. Tarenflurbil had no beneficial effect on the co-primary outcomes (difference in change from baseline to month 18 vs placebo, based on least squares means: 0.1 for ADAS-Cog; 95% CI, -0.9 to 1.1; P = .86 and -0.5 for ADCS-ADL; 95% CI, -1.9 to 0.9; P = .48) using an intent-to-treat analysis. No significant differences occurred in the secondary outcomes. The ADAS-Cog score decreased by 7.1 points over 18 months. The tarenflurbil group had a small increase in frequency of dizziness, anemia, and infections. CONCLUSION Tarenflurbil did not slow cognitive decline or the loss of activities of daily living in patients with mild AD. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00105547.

Effects of Food on the Relative Bioavailability of Lapatinib in Cancer Patients

PURPOSE This study was conducted to characterize the effect of food on the relative bioavailability of lapatinib. PATIENTS AND METHODS A single 1,500-mg, oral dose of lapatinib was administered to 27 patients with advanced solid tumors on each of three occasions that were 1 week apart, in random order: after an overnight fast, with a low-fat breakfast, and with a high-fat breakfast. RESULTS The low-fat breakfast produced mean increases in lapatinib area under the concentration-time curve (AUC) of 167% (2.67-fold) and maximum concentration (C(max)) of 142% (2.42-fold). The high-fat breakfast produced mean increases in lapatinib AUC of 325% (4.25-fold) and C(max) of 203% (3.03-fold) compared with the fasted state. Increased bioavailability in the fed state did not significantly decrease relative variability. Therefore, absolute variability in systemic exposure was increased. CONCLUSION These large increases in lapatinib bioavailability and absolute variability support the recommendation for dosing in the fasted state to achieve consistent therapeutic exposure. Prescribers and patients should consider the potential consequences of toxicity or diminished efficacy that might result from dosing without regard to variations in diet.

Modulation of Cell Cycle Progression in Human Tumors: A Pharmacokinetic and Tumor Molecular Pharmacodynamic Study of Cisplatin Plus the Chk1 Inhibitor UCN-01 (NSC 638850)

Background: UCN-01, a Chk1 inhibitor, abrogates S and G2 arrest and enhances cancer cell killing by DNA-damaging drugs in preclinical models. UCN-01 avidly binds α1-acid glycoprotein in plasma; whether sufficient drug concentrations are achieved in human tumors is unknown. A phase I trial tested the hypothesis that UCN-01 abrogates cisplatin-induced cell cycle arrest (in tumors) at tolerable doses. Methods: Patients with advanced cancer received i.v. cisplatin, followed 22 hours later by UCN-01 (3-day continuous i.v. infusion of a 28-day cycle). Platinum was measured by atomic absorption, UCN-01 by high-performance liquid chromatography, and cell cycle progression in tumor biopsies by geminin immunostaining (biomarker for S/G2 phases of cell cycle). Results: The first two patients treated with cisplatin (20 mg/m2 plus UCN-01 45 mg/m2/d) experienced dose-limiting toxicities (subarachnoid hemorrhage, hyperglycemia, hypoxia, cardiac ischemia, and atrial fibrillation). Following 25% UCN-01 dose reduction, no toxicities greater than grade 2 were seen. Median plasma UCN-01 half-life (T1/2) was 405 hours. Salivary UCN-01 concentrations showed a rapid initial decline (median T1/2α, 29.9 hours), followed by a terminal decay parallel to that in plasma. UCN-01 pharmacokinetics, and the timing of clinical toxicities, suggests that UCN-01 is bioavailable despite α1-acid glycoprotein binding. Marked suppression of cells in S/G2 in tumor biopsies was seen by geminin immunohistochemistry, suggesting that UCN-01 is bioavailable at concentrations sufficient to inhibit Chk1. Conclusions: Cisplatin (30 mg/m2), followed 22 hours later by UCN-01 (34 mg/m2/d for 3 days), is well tolerated clinically and yields UCN-01 concentrations sufficient to affect cell cycle progression in tumors.

Ethylene glycol toxicity associated with ischemia, perforation, and colonic oxalate crystal deposition.

Severe ethylene glycol toxicity can cause profound morbidity and is almost universally fatal if untreated. Central nervous system depression with intoxication, pulmonary edema, and acute oliguric renal failure with crystalluria are among the most commonly encountered complications of ingestion. The previously reported gastrointestinal side effects of ethylene glycol toxicity are mostly nonspecific, including nausea, abdominal pain, and cramping. In addition, hepatic damage due to calcium oxalate deposition has been reported. We describe a patient who developed acute colonic ischemia following ethylene glycol intoxication. Three months after the ingestion, the patient presented with severe abdominal pain secondary to a colonic stricture and perforation, necessitating emergent colectomy. Histology of the resected colon revealed polarizable polyhedral crystals suggestive of oxalate deposition. The pathophysiology underlying ethylene glycol intoxication, treatment strategies, and gastrointestinal toxicity are discussed.

A phase I, dose-escalation study of cyclical weekly oral temozolomide and weekly PEG-interferon alpha-2b in patients with refractory or advanced solid tumours

Abstract Background: Temozolomide (TMZ) is an oral alkylating agent used in the treatment of central nervous system neoplasms and metastatic melanoma. Preclinical and clinical data suggested that combining TMZ with interferon alpha-2b (IFN-alpha-2b) may result in increased anti-tumour efficacy. Methods: This was a phase I, dose-escalation study to define the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) of cyclical oral TMZ (days 1–7 and 15–21) in combination with pegylated IFN-alpha-2b (PEG-IFN-alpha-2b) in patients with advanced solid tumours. Results: We treated 19 patients (10 female and nine male), median age 58 years (range: 41–79 years). Ten patients tolerated TMZ at 100 mg/m2 on days 1–7 and 15–21 plus PEG-IFN-alpha-2b at 1·5 mcg/kg/week on 28-day cycles which was the MTD of the combination. The pharmacokinetic parameters of PEG-IFN-alpha-2b were not altered by TMZ, at the MTD. Conclusion: The MTD of cyclical oral TMZ was 100 mg/m2 on days 1-7 and 15-21 when combined with weekly subcutaneous PEG-IFNα-2b at 1.5 mcg/kg/week on 28 days cycles. The PK of PEG-IFN-alpha-2b appeared consistent with those when it is used as monotherapy.

Abstract A96: Phase 1 study of HSP90 inhibitor MPC-3100 in subjects with refractory or recurrent cancer.

Background: MPC-3100 is an orally-bioavailable, fully-synthetic inhibitor of the molecular chaperone HSP90. HSP90 is important for post-translational protein folding, stabilization, and function of so-called client proteins, many of which are necessary for growth and survival of cancer cells. In preclinical studies, MPC-3100 has demonstrated client protein modulation and antitumor activity against a broad range of tumor types. Methods: In this first-in-human, open label, dose escalating, 3+3 design with accelerated titration, multiple-dose study, the safety and tolerability of single agent MPC-3100 were assessed in subjects with recurrent or refractory cancer. Secondary objectives were to characterize the pharmacokinetic parameters (PK) of MPC-3100, assess antitumor activity, and evaluate pharmacodynamic (PD) biomarkers. Subjects received oral MPC-3100 once daily for 21 days followed by 7 days off at doses of 50, 100, 165, 245, or 340 mg/m2 (Cohorts 1–5, respectively) or for 28 days continuously at total daily doses of 480 mg or 640 mg administered as 240 mg or 320 mg Q12H (Cohorts 6 and 7, respectively) per 28-day cycle. Clinical examinations, blood draws for PK and PD, and tumor assessments were performed at pre-specified times during the study. Results: MPC-3100 was administered to 26 subjects [13 M, 13 F; median age 63.5 yr, range 45–85 yr; ECOG performance status 0 (n=13), 1 (n=11) and 2 (n=2) at screening; most-represented primary cancer types colon (n=6), prostate (6), and breast (3); median of 4 (range 0 to 16) prior chemotherapies]. The total number of cycles of MPC-3100 administered to all subjects was 44 (median 1, range Conclusions: MPC-3100 appears to be safe and tolerable when administered orally at doses below 600 mg per day to subjects with recurrent or refractory cancer. Side-effects were generally manageable or reversible upon discontinuation of MPC-3100. Biomarker modulation indicates appropriate HSP90 inhibition. Nearly half of the subjects attained stable disease. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A96.

Comparison of MPC-6827 activity in xenograft models with different dosing schedules.

e13080 Background: MPC-6827 is a small molecule microtubule disrupting agent that is being evaluated in phase II studies for the treatment of glioblastoma multiforme. It crosses the blood-brain barrier and achieves brain to plasma concentration ratios of up to 30 in animal models. MPC-6827 is active in multiple xenograft models when dosed on a weekly schedule. Here we explore its activity when dosed on a daily schedule or continuously for 24 hours. METHODS B16 mouse melanoma or OVCAR3 human ovarian cancer cells were implanted subcutaneously into athymic mice (nu/nu) for xenograft studies. MPC-6827 was dosed intravenously (IV) at its maximal tolerated dose of 7.5 mg/kg once or daily at 1 mg/kg for five days for the B16 study. For the OVCAR-3 study, MPC-6827 was dosed at 5 mg/kg once IV or at 2.5-, 5- or 10 mg/kg/day intraperitoneally (IP) with an Alzet mini-pump for one day. RESULTS In the B16 model, MPC-6827 dosed at 7.5 mg/kg resulted in 72% tumor growth inhibition (TGI) on Day 7 relative to vehicle (p=0.01), whereas 1 mg/kg daily dosing for five days resulted in only 22% TGI (p=0.68). In the OVCAR-3 model, MPC-6827 delivered IP at 2.5 mg/kg over a period of 24 h resulted in no inhibition of xenograft growth relative to vehicle on Day 17. In contrast, the single 5 mg/kg IV dose resulted in 50% regression. The median time to tumor volume >1,500 mm3 was 31 days for the vehicle group, 28.5 days for the 2.5 mg/kg/day IP group and >39 days (p=0.04) for the 5 mg/kg IV group. Plasma concentration of MPC-6827 was 35 ng/mL at 24 h when delivered IP at 2.5 mg/kg/day, whereas Cmax was 1291- and 105 ng/mL with a 5- and 1 mg/kg IV dose, respectively. The AUC for the 5- and 1 mg/kg doses were 657- and 79 hr*ng/mL, respectively. CONCLUSIONS MPC-6827 shows significant activity in animal models when dosed intermittently at 5 mg/kg or higher. Anti-xenograft activity is not observed when the single dose is divided into proportionately smaller daily doses or when the compound is dosed continuously for 24 hours. Thus the optimal dosing regimen for MPC-6827 in xenograft models is intermittent high doses, which result in transiently elevated plasma concentrations of the compound.

Abstract 2617: MPC-3100, a synthetic Hsp90 inhibitor, induces biomarker changes in vitro and in vivo

Introduction: MPC-3100 is a fully synthetic, orally bioavailable, Hsp90 inhibitor in clinical development. It is broadly active in xenograft models with anti-tumor activity ranging from tumor regression to tumor growth inhibition in many cancer types including colon, gastric, ovarian, prostate, breast, lung and myeloid leukemia. Here we evaluate the effect of MPC-3100 on stability of client proteins in cells and xenograft tumors. We also determine the effect on Hsp70 protein levels, a biomarker of Hsp90 inhibition, in peripheral blood mononuclear cells (PBMCs) from cancer patients receiving MPC-3100. Methods: Her2, Akt, Cdk4, c-Raf and Hsp70 client protein levels were monitored in cell culture with protein immunoblots. Formalin-fixed, paraffin-embedded sections of xenograft tumors from mice dosed orally with MPC-3100 were analyzed by immunohistochemistry (IHC) to monitor changes in Her2, Akt and Hsp70 protein levels. To monitor changes in Hsp70 in cancer patients treated with MPC-3100, PBMCs were collected prior to drug administration, 8 and 24 hours post-dose on Day 1 and 24 hours post-dose on Days 7 and 21 of the first treatment cycle. Hsp70 protein levels were determined by ELISA. Results: Exposure of HCT-116, NCI-N87 and DU-145 cells to MPC-3100 in vitro resulted in a time-dependent reduction in client protein levels with maximal reduction by 24 hours. The IC 50 values for client protein reduction ranged from 0.1 μM to 0.5 μM, comparable to the cellular cytotoxicity values of MPC-3100 at 72 hours for the various cell lines. IHC revealed reduction in Her2 and Akt protein in N87 xenografts in mice given a single oral dose of 200 mg/kg MPC-3100 relative to tumors from animals dosed with vehicle. Healthy volunteer PBMCs exposed to 1 μM MPC-3100 for 24 hours ex vivo revealed a reduction in Akt, c-Raf and Cdk4 protein levels ranging from 50% to 90%. PBMCs from cancer patients receiving MPC-3100 showed an increase of 28 to 589 ng of Hsp70 protein per mg total protein over baseline by Day 8. The increase in Hsp70 expression was seen as early as 8 hours after the first dose and sustained through at least Day 22. Conclusions: The changes in client proteins and biomarkers observed in cells and tumor xenografts exposed to MPC-3100 confirm that the cellular cytotoxic activity and anti-tumor activity in xenografts are a result of Hsp90 inhibition. The consistent increase in Hsp70 expression in PBMCs from cancer patients receiving MPC-3100 indicates that Hsp90 function is inhibited in patients at doses that have been well tolerated in the clinic. 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 2617. doi:10.1158/1538-7445.AM2011-2617

Ethylene glycol toxicity associated with ischemia, perforation, and colonic oxalate crystal deposition

Severe ethylene glycol toxicity can cause profound morbidity and is almost universally fatal if untreated. Central nervous system depression with intoxication, pulmonary edema, and acute oliguric renal failure with crystalluria are among the most commonly encountered complications of ingestion. The previously reported gastrointestinal side effects of ethylene glycol toxicity are mostly nonspecific, including nausea, abdominal pain, and cramping. In addition, hepatic damage due to calcium oxalate deposition has been reported. We describe a patient who developed acute colonic ischemia following ethylene glycol intoxication. Three months after the ingestion, the patient presented with severe abdominal pain secondary to a colonic stricture and perforation, necessitating emergent colectomy. Histology of the resected colon revealed polarizable polyhedral crystals suggestive of oxalate deposition. The pathophysiology underlying ethylene glycol intoxication, treatment strategies, and gastrointestinal toxicity are discussed.