Phase Ib study of atezolizumab combined with cobimetinib in patients with solid tumors.

BACKGROUND: Preclinical evidence suggests that MEK inhibition promotes accumulation and survival of intratumoral tumor-specific T cells and can synergize with immune checkpoint inhibition. We investigated the safety and clinical activity of combining a MEK inhibitor, cobimetinib, and a programmed cell death 1 ligand 1 (PD-L1) inhibitor, atezolizumab, in patients with solid tumors. PATIENTS AND METHODS: This phase I/Ib study treated PD-L1/PD-1-naive patients with solid tumors in a dose-escalation stage and then in multiple, indication-specific dose-expansion cohorts. In most patients, cobimetinib was dosed once daily orally for 21 days on, 7 days off. Atezolizumab was dosed at 800 mg intravenously every 2 weeks. The primary objectives were safety and tolerability. Secondary end points included objective response rate, progression-free survival, and overall survival. RESULTS: Between 27 December 2013 and 9 May 2016, 152 patients were enrolled. As of 4 September 2017, 150 patients received ≥1 dose of atezolizumab, including 14 in the dose-escalation cohorts and 136 in the dose-expansion cohorts. Patients had metastatic colorectal cancer (mCRC; n = 84), melanoma (n = 22), non-small-cell lung cancer (NSCLC; n = 28), and other solid tumors (n = 16). The most common all-grade treatment-related adverse events (AEs) were diarrhea (67%), rash (48%), and fatigue (40%), similar to those with single-agent cobimetinib and atezolizumab. One (<1%) treatment-related grade 5 AE occurred (sepsis). Forty-five (30%) and 23 patients (15%) had AEs that led to discontinuation of cobimetinib and atezolizumab, respectively. Confirmed responses were observed in 7 of 84 patients (8%) with mCRC (6 responders were microsatellite low/stable, 1 was microsatellite instable), 9 of 22 patients (41%) with melanoma, and 5 of 28 patients (18%) with NSCLC. Clinical activity was independent of KRAS/BRAF status across diseases. CONCLUSIONS: Atezolizumab plus cobimetinib had manageable safety and clinical activity irrespective of KRAS/BRAF status. Although potential synergistic activity was seen in mCRC, this was not confirmed in a subsequent phase III study. CLINICALTRIALS.GOV IDENTIFIER: NCT01988896 (the investigators in the NCT01988896 study are listed in the supplementary Appendix, available at Annals of Oncology online).

A phase Ib study of selumetinib (AZD6244, ARRY-142886) in combination with sorafenib in advanced hepatocellular carcinoma (HCC).

BACKGROUND: Treatment with sorafenib, although associated with inhibition of tumour growth and angiogenesis in in vivo studies, leads to up-regulation of pERK. The addition of MEK inhibition could potentially abrogate this effect and potentiate anti-tumour activity. This phase I study investigated the maximum tolerated dose (MTD), safety, tolerability, pharmacokinetics (PK) and biomarker correlates of selumetinib combined with sorafenib in patients with advanced hepatocellular carcinoma (HCC). METHODS: Patients with Child-Pugh (CP) score ≤7 were treated with 400 mg twice daily of sorafenib with escalating doses of selumetinib in a 3 + 3 study design. The dose-limiting toxicity (DLT) evaluation period was 28 days. PK of selumetinib was determined. Angiogenic effect was evaluated with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). RESULTS: Twenty-seven patients of Asian ethnicity were enrolled. The MTD was selumetinib 75 mg daily with sorafenib 400 mg twice daily. DLT included grade 3 transaminitis, diarrhoea and fatigue. Most common treatment-related adverse events at MTD (all grades) were diarrhoea (85%), rash (59%), hypertension (44%), fatigue (30%), anorexia (22%) and hand-foot syndrome (22%). Four patients (15%) had PR and 13 (48%) had SD. PR or SD was observed for ≥6 months in seven patients. The median overall survival was 14.4 months. Selumetinib exposures in combination with sorafenib were comparable to other monotherapy studies. A reduction in permeability-surface area product noted in DCE-MRI with treatment correlated with worse survival outcomes. CONCLUSION: The MTD of selumetinib was 75 mg daily when combined with sorafenib 400 mg twice a day in CP ≤7 HCC. Acceptable adverse events and encouraging anti-tumour activity warrant further evaluation. DCE-MRI findings deserve prospective evaluation. CLINICALTRIALSGOV IDENTIFIER: NCT01029418.

Phase I and biomarker study of OPB-51602, a novel signal transducer and activator of transcription (STAT) 3 inhibitor, in patients with refractory solid malignancies.

BACKGROUND: The aim of this study was to determine the maximum-tolerated dose (MTD), safety, pharmacokinetics, and pharmacodynamics of OPB-51602, an oral, direct signal transduction activator of transcription 3 (STAT3) inhibitor, in patients with refractory solid tumors. PATIENTS AND METHODS: Three cohorts were studied: cohort A, a sequential dose escalation of OPB-51602 administered intermittently (days 1-14 every 21 days); cohort B, an expansion cohort evaluating the dose lower than the MTD; cohort C, evaluating continuous daily dosing. RESULTS: Fifty-one patients were studied at 2, 4, and 5 mg per day dosing. The MTD was 5 mg; first-cycle dose-limiting toxicities (DLTs) were grade 3 hyponatremia in one patient, and grade 3 dehydration in another. Intermittent dosing of both 2 and 4 mg doses were tolerable, and the recommended phase II dose was 4 mg. Cohort B investigated 4 mg intermittently, whereas cohort C investigated 4 mg continuously. Common toxicities included fatigue, nausea/vomiting, diarrhea, anorexia, and early-onset peripheral neuropathy. Drug-induced pneumonitis occurred in two patients in cohort C. Continuous dosing was associated with a higher incidence of peripheral neuropathy and a lower mean relative dose intensity, compared with intermittent dosing. Steady-state pharmacokinetics was characterized by high oral clearance, mean elimination half-life ranging from 44 to 61 h, and a large terminal-phase volume of distribution. An active metabolite, OPB-51822, accumulated to a greater extent than OPB-51602. Flow cytometry of peripheral blood mononuclear cells demonstrated pSTAT3 (Tyr(705)) inhibition following exposure. Two patients achieved partial responses at 5 mg intermittently and 4 mg continuously; both had epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) with prior EGFR tyrosine kinase inhibitor exposure. CONCLUSION: OPB-51602 demonstrates promising antitumor activity, particularly in NSCLC. Its long half-life and poorer tolerability of continuous dosing, compared with intermittent dosing, suggest that less frequent dosing should be explored. CLINICALTRIALSGOV IDENTIFIER: NCT01184807.

Multicenter phase II study of the AKT inhibitor MK-2206 in recurrent or metastatic nasopharyngeal carcinoma from patients in the mayo phase II consortium and the cancer therapeutics research group (MC1079).

BACKGROUND: This study investigated the activity of MK-2206, an AKT inhibitor, in metastatic or recurrent nasopharyngeal carcinoma (NPC). METHOD: Oral MK-2206 at a dose of 200 mg was administered on days 1, 8, 15 and 22 of a 28-day cycle until progression. Plasma EBV DNA clearance during the first month of treatment was measured, and archived tumors were analyzed for the expression of AKT and PIK3CA mutation and PIK3CA amplification. The dual primary endpoint was objective response rate and 6-month progression-free survival (PFS) rate. RESULTS: 21 patients were enrolled and one patient achieved a partial response (5 %) and 11 had stable disease (52 %), with a median PFS of 3.5 months (95 % confidence interval, CI: 0.9-7.3). The 6-month PFS rate was 43 % (95 % CI: 22-66 %) and the median OS was 10 months (95 % CI: 5.9 months-not reached). Seven patients (33 %) experienced grade 3 toxicities which could be related to MK-2206. Macular-papular rash was the most common (n = 6), followed by hyperglycemia (n = 2) and fatigue (n = 1). In the 12 tumor samples analyzed, PIK3CA amplification was detected in one patient's primary NPC, who had SD lasting over 12 months. Patients with decreasing EBV DNA values over time were more likely to be alive and progression-free for at least 6 months than those without a decrease (p = 0.001). CONCLUSION: The study was terminated due to the limited activity observed in this heavily pre-treated group of patients. Further studies are needed to elucidate the optimal way of selecting patients for AKT inhibitors.

Body fat composition impacts the hematologic toxicities and pharmacokinetics of doxorubicin in Asian breast cancer patients.

Body surface area (BSA)-based dosing leads to wide inter-individual variations in drug pharmacokinetics and pharmacodynamics, whereas body composition has been shown to be a more robust determinant of efficacy and toxicity of certain chemotherapeutic agents. We correlated various parameters of body composition with doxorubicin pharmacokinetics and hematologic toxicities in Asian patients with locally advanced or metastatic breast cancer. Our analysis included 84 patients from two studies who received pre- or post-operative single-agent doxorubicin; pharmacokinetic parameters were available for 44 patients. Body composition parameters were derived from CT cross-sectional images and population pharmacokinetic analysis was conducted using mixed-effects modeling. Higher intra-abdominal fat volume and fat ratio (intra-abdominal:total abdominal fat volume) correlated with greater incidence of grade 4 leukopenia on cycle 1 day 15 (mean intra-abdominal fat volume: 97.4 ± 46.5 cm(3) vs 63.4 ± 30.9 cm(3), p = 0.014; mean fat ratio: 0.43 ± 0.11 vs 0.33 ± 0.09, p = 0.012, grade 4 vs grade 0-3 leukopenia). On subset analysis, this relationship was maintained even in underweight patients. Concordantly, there were positive correlations between doxorubicin AUC and intra-abdominal fat volume as well as total abdominal fat volume (r (2) = 0.324 and 0.262, respectively, all p < 0.001). BSA and muscle volume did not predict for doxorubicin pharmacokinetics or toxicities. High-intra-abdominal fat volume but not BSA predicted for greater doxorubicin exposure and hematologic toxicities, suggesting that body composition is superior to BSA in determining doxorubicin pharmacokinetics and pharmacodynamics. Body composition has an emerging role in chemotherapy dose determination.

Biophysical cues enhance myogenesis of human adipose derived stem/stromal cells.

Adipose-derived stem/stromal cell (ASC)-based tissue engineered muscle grafts could provide an effective alternative therapy to autografts - which are limited by their availability - for the regeneration of damaged muscle. However, the current myogenic potential of ASCs is limited by their low differentiation efficiency into myoblasts. The aim of this study was to enhance the myogenic response of human ASCs to biochemical cues by providing biophysical stimuli (11% cyclic uniaxial strain, 0.5 Hz, 1h/day) to mimic the cues present in the native muscle microenvironment. ASCs elongated and fused upon induction with myogenic induction medium alone. Yet, their myogenic characteristics were significantly enhanced with the addition of biophysical stimulation; the nuclei per cell increased approximately 4.5-fold by day 21 in dynamic compared to static conditions (23.3 ± 7.3 vs. 5.2 ± 1.6, respectively), they aligned at almost 45° to the direction of strain, and exhibited significantly higher expression of myogenic proteins (desmin, myoD and myosin heavy chain). These results demonstrate that mimicking the biophysical cues inherent to the native muscle microenvironment in monolayer ASC cultures significantly improves their differentiation along the myogenic lineage.

Translational aspects of genetic factors in the prediction of drug response variability: a case study of warfarin pharmacogenomics in a multi-ethnic cohort from Asia.

Genetic markers displaying highly significant statistical associations with complex phenotypes may not necessarily possess sufficient clinical validity to be useful. Understanding the contribution of these markers beyond readily available clinical biomarkers is particularly important in pharmacogenetics. We demonstrate the utility of genetic testing using the example of warfarin in a multi-ethnic setting comprising of three Asian populations that are broadly representative of the genetic diversity for half of the population in the world, especially as distinct interethnic differences in warfarin dose requirements have been previously established. We confirmed the roles of three well-established loci (CYP2C9, VKORC1 and CYP4F2) in explaining warfarin dosage variation in the three Asian populations. In addition, we assessed the relationship between ethnicity and the genotypes of these loci, observing strong correlations at VKORC1 and CYP4F2. Subsequently, we established the additional utility of these genetic factors in predicting warfarin dose beyond ethnicity and clinical biomarkers through performing a series of systematic cross-validation analyses of the relative predictive accuracies of various fixed-dose regimen, clinical and genetic models. Through a pharmacogenetics model for warfarin, we show the importance of genetic testing beyond readily available clinical biomarkers in predicting dose requirements, confirming the role of genetic profiling in personalized medicine.

Phase I and pharmacodynamic study of an orally administered novel inhibitor of histone deacetylases, SB939, in patients with refractory solid malignancies.

BACKGROUND: The objective of this study was to assess the safety, maximum tolerated dose (MTD), pharmacokinetics, pharmacodynamics, and preliminary efficacy of SB939, a novel histone deacetylase (HDAC) inhibitor, in patients with advanced solid malignancies. PATIENTS AND METHODS: Dose-escalating cohorts of three to six patients received SB939 orally thrice weekly for 3 weeks in a 4-week cycle. Acetylated histone H3 (acH3) was measured in peripheral blood mononuclear cells (PBMCs). RESULTS: Thirty patients treated at one of five doses (10-80 mg/day) received 79 cycles of SB939 (range, 1-12 cycles). Dose-limiting toxic effects were fatigue, hypokalemia, troponin T elevation, and QTc prolongation. Peak plasma concentration (C(max)) and area under the concentration-time curve extrapolated to infinity increased dose proportionally. The MTD of SB939 was 80 mg/day. The mean elimination half-life and oral clearance of SB939 were 7.2 ± 0.6 h and 53.0 ± 8.5 l/h, respectively, with no substantial accumulation on day 15. An increase in acH3 was observed at hour 3 and correlated with dose and C(max). Stable disease was seen in several tumor types treated at ≥40 mg. HDAC inhibition was consistently observed at 60 mg, the recommended dose. CONCLUSIONS: SB939 can be safely administered at the recommended dose and reaches plasma levels that strongly inhibit HDAC in PBMCs. These data support further efficacy studies of SB939.

Serial changes in the expression of breast cancer-related proteins in response to neoadjuvant chemotherapy.

BACKGROUND: Tumour expression of cyclooxygenase-2 (COX-2), epidermal growth factor receptor (EGFR), erythroblastic leukaemia viral oncogene homologue-2 (ErbB2), Ki-67 and p53 in breast cancer are associated with poorer outcomes. We investigated in vivo changes of these proteins with neoadjuvant chemotherapy. PATIENTS AND METHODS: Four core biopsies were taken from 100 breast cancer patients at baseline, during and upon completion of neoadjuvant chemotherapy. Immunohistochemical expression of these proteins were evaluated and correlated with clinicopathological features, clinical response and progression-free survival (PFS). RESULTS: There was a statistically significant change from positivity to negativity in COX-2 expression with chemotherapy (P = 0.002), predominantly in clinical responders (P = 0.002). COX-2-positive tumours that remained positive had shorter PFS than those that turned negative. Estrogen receptor (ER)+ and COX-2+ tumours at baseline that remained COX-2+ fared worse than those that became COX-2 negative (PFS 27 versus 52 months, P = 0.002). No significant changes in IHC expression were observed for ER, progesterone receptor, ErbB2, EGFR, p53 or Ki67. CONCLUSIONS: Chemotherapy induced change in COX-2 expression from positivity to negativity predominantly among clinical responders and is associated with longer PFS. Interaction between COX-2 and ER was observed, suggesting that some hormone receptor-positive patients may benefit from combining COX-2 inhibition with hormonal therapy.

Ovariectomy and genes encoding core circadian regulatory proteins in murine bone.

SUMMARY: This study investigated the influence of ovarian hormone deficiency on core circadian regulatory protein (CCRP) in the context of bone loss. Our data suggest that ovarian hormone deficiency disrupts diurnal rhythmicity and CCRP expression in bone. Further studies should determine if chronobiology provides a novel therapeutic target for osteoporosis intervention. INTRODUCTION: CCRP synchronize metabolic activities and display an oscillatory expression profile in murine bone. In vitro studies using bone marrow mesenchymal stromal/stem cells have demonstrated that the CCRP is present and can be regulated within osteoblast progenitors. In vivo studies have shown that the CCRP regulates bone mass via leptin/neuroendocrine pathways. The current study used an ovariectomized murine model to test the hypothesis that ovarian hormone deficiency is associated with either an attenuation and/or temporal phase shift of the CCRP oscillatory expression in bone and that these changes are correlated with the onset of osteoporosis. METHODS: Sham-operated controls and ovariectomized female C57BL/6 mice were euthanized at 4-h intervals 2 weeks post-operatively. RESULTS: Ovariectomy attenuated the oscillatory expression of CCRP mRNAs in the femur and vertebra relative to the controls and reduced the wheel-running activity profile. CONCLUSION: Ovarian hormone deficiency modulates the expression profile of the CCRP with potential impact on bone marrow mesenchymal stem cell lineage commitment.

Pharmacokinetics and pharmacodynamics of docetaxel with or without ketoconazole modulation in chemonaive breast cancer patients.

BACKGROUND: We previously found 70 mg flat-dose docetaxel coadministered with ketoconazole to modulate CYP3A4 to be the maximum tolerated dose that resulted in comparable docetaxel area under the plasma concentration-time curve (AUC) as 75-100 mg/m² docetaxel. PATIENTS AND METHODS: We compared cycle 1 docetaxel pharmacokinetics and pharmacodynamics between ketoconazole-modulated (70 mg flat-dose docetaxel, n = 31) and conventional-dosed docetaxel (75 mg/m², n = 51) in chemonaive breast cancer patients in two sequential phase II studies. RESULTS: Ketoconazole-modulated docetaxel resulted in reduced docetaxel clearance (22.05 ± 8.29 versus 36.52 ± 13.39 l/h, P < 0.001), similar docetaxel AUC (3.93 ± 2.77 versus 3.77 ± 2.70 mg/l·h, P = 0.794) and tumor efficacy (cycle 1 responder 52% versus 55%) and less day 8 neutrophil suppression (1.24 ± 1.02 × 109/l versus 0.47 ± 0.56 × 109/l, P < 0.001), grade 4 neutropenia (32.3% versus 72.0%, P < 0.001) and febrile neutropenia (3.2 versus 23.5%, P = 0.015), compared with conventional-dosed docetaxel. Chinese had the lowest docetaxel clearance, highest AUC and most myelosuppression, followed by Malays and Indians, in response to ketoconazole-modulated docetaxel, while no significant interethnic differences were observed with conventional-dosed docetaxel. CONCLUSIONS: Ketoconazole-modulated docetaxel achieved similar docetaxel AUC and tumor efficacy but reduced neutrophil suppression and febrile neutropenia at ∼40% reduced dose, representing a feasible alternative to conventional-dosed docetaxel. Interethnic differences in CYP3A4 inhibition by ketoconazole exist and are important when evaluating the impact of concomitant medications.

Expression profile of mRNAs encoding core circadian regulatory proteins in human subcutaneous adipose tissue: correlation with age and body mass index.

OBJECTIVE: Circadian mechanisms underlie the physiology of mammals as an adaptation to the earth's rotation on its axis. Highly conserved core circadian regulatory proteins (CCRPs) maintain an oscillatory expression profile in the central and peripheral tissues. The CCRP include both a positive and negative arm, as well as downstream transcriptional regulators. Recent studies in murine models have determined that the mRNAs encoding the CCRP are present in multiple adipose tissue depots and exhibit a robust oscillatory expression profile. This study set out to examine the expression of CCRP mRNAs in human subcutaneous adipose tissues. DESIGN: Retrospective analysis of total RNA isolated from subcutaneous adipose tissue. SUBJECTS: A total of 150 healthy female and male lean (body mass index (BMI) <25), overweight (BMI between 25 and 29.99) or obese (BMI >30) subjects of varied ethnic backgrounds undergoing elective liposuction or surgical procedures. RESULTS: The expression of the CCRP mRNAs displayed a significant correlation between each other and mRNAs representative of adipogenic biomarkers. Hierarchical cluster analyses of mRNAs isolated from the cohort of female Caucasian subjects (n=116) identified three major clusters based on expression of downstream CCRP mRNAs. The mRNAs encoding D site of albumin promoter-binding protein (DBP), E4 promoter-binding protein 4 (E4BP4), PPARgamma coactivator-1beta (PGC-1beta) and Rev-erbalpha were negatively correlated with BMI in a lean cluster (n=66), positively correlated with BMI in a younger overweight/obese cluster (n=19), and not significantly correlated with BMI in an older, overweight/obese cluster (n=31). CONCLUSIONS: These data confirm and extend findings that link the CCRP and circadian mechanisms to the risk of obesity.

Influence of UGT1A9 intronic I399C>T polymorphism on SN-38 glucuronidation in Asian cancer patients.

Genetic polymorphisms in hepatically expressed UGT1A1 and UGT1A9 contribute to the interindividual variability i-n irinotecan disposition and toxicity. We screened UGT1A1 (UGT1A1*60, g.-3140G>A, UGT1A1*28 and UGT1A1*6) and UGT1A9 (g.-118(T)(9>10) and I399C>T) genes for polymorphic variants in the promoter and coding regions, and the genotypic effect of UGT1A9 I399C>T polymorphism on irinotecan disposition in Asian cancer patients was investigated. Blood samples were collected from 45 patients after administration of irinotecan as a 90 min intravenous infusion of 375 mg/m(2) once in every 3 weeks. Genotypic-phenotypic correlates showed that cancer patients heterozygous or homozygous for the I399C>T allele had approximately 2-fold lower systemic exposure to SN-38 (P<0.05) and a trend towards a higher relative extent of glucuronidation (REG) of SN-38 (P>0.05). UGT1A1-1A9 diplotype analysis showed that patients harbouring the H1/H2 (TG6GT(10)T/GG6GT(9)C) diplotype had 2.4-fold lower systemic exposure to SN-38 glucuronide (SN-38G) compared with patients harbouring the H1/H5 (TG6GT(10)T/GG6GT(10)C) diplotype (P=0.025). In conclusion, this in vivo study supports the in vitro findings of Girard et al. and suggests that the UGT1A9 I399C>T variant may be an important glucuronidating allele affecting the pharmacokinetics of SN-38 and SN-38G in Asian cancer patients receiving irinotecan chemotherapy.

PXR, CAR and HNF4alpha genotypes and their association with pharmacokinetics and pharmacodynamics of docetaxel and doxorubicin in Asian patients.

Previously studied candidate genes have failed to account for inter-individual variability of docetaxel and doxorubicin disposition and effects. We genotyped the transcriptional regulators of CYP3A and ABCB1 in 101 breast cancer patients from 3 Asian ethnic groups, that is, Chinese, Malays and Indians, in correlation with the pharmacokinetics and pharmacodynamics of docetaxel and doxorubicin. While there was no ethnic difference in docetaxel and doxorubicin pharmacokinetics, ethnic difference in docetaxel- (ANOVA, P=0.001) and doxorubicin-induced (ANOVA, P=0.003) leukocyte suppression was observed, with Chinese and Indians experiencing greater degree of docetaxel-induced myelosuppression than Malays (Bonferroni, P=0.002, P=0.042), and Chinese experiencing greater degree of doxorubicin-induced myelosuppression than Malays and Indians (post hoc Bonferroni, P=0.024 and 0.025). Genotyping revealed both PXR and CAR to be well conserved; only a PXR 5'-untranslated region polymorphism (-24381A>C) and a silent CAR variant (Pro180Pro) were found at allele frequencies of 26 and 53%, respectively. Two non-synonymous variants were identified in HNF4alpha (Met49Val and Thr130Ile) at allele frequencies of 55 and 1%, respectively, with the Met49Val variant associated with slower neutrophil recovery in docetaxel-treated patients (ANOVA, P=0.046). Interactions were observed between HNF4alpha Met49Val and CAR Pro180Pro, with patients who were wild type for both variants experiencing least docetaxel-induced neutropenia (ANOVA, P=0.030). No other significant genotypic associations with pharmacokinetics or pharmacodynamics of either drug were found. The PXR-24381A>C variants were significantly more common in Indians compared to Chinese or Malays (32/18/21%, P=0.035) Inter-individual and inter-ethnic variations of docetaxel and doxorubicin pharmacokinetics or pharmacodynamics exist, but genotypic variability of the transcriptional regulators PAR, CAR and HNF4alpha cannot account for this variability.

Mitochondrial uncoupling reveals a novel therapeutic opportunity for p53-defective cancers.

There are considerable challenges in directly targeting the mutant p53 protein, given the large heterogeneity of p53 mutations in the clinic. An alternative approach is to exploit the altered fitness of cells imposed by loss-of-wild-type p53. Here we identify niclosamide through a HTS screen for compounds selectively killing p53-deficient cells. Niclosamide impairs the growth of p53-deficient cells and of p53 mutant patient-derived ovarian xenografts. Metabolome profiling reveals that niclosamide induces mitochondrial uncoupling, which renders mutant p53 cells susceptible to mitochondrial-dependent apoptosis through preferential accumulation of arachidonic acid (AA), and represents a first-in-class inhibitor of p53 mutant tumors. Wild-type p53 evades the cytotoxicity by promoting the transcriptional induction of two key lipid oxygenation genes, ALOX5 and ALOX12B, which catalyzes the dioxygenation and breakdown of AA. Therefore, we propose a new paradigm for targeting cancers defective in the p53 pathway, by exploiting their vulnerability to niclosamide-induced mitochondrial uncoupling.

Irofulven as first line therapy in recurrent or metastatic gastric cancer: a phase II multicenter study by the Cancer Therapeutics Research Group (CTRG).

BACKGROUND: The purpose of this study was to evaluate the tolerability and efficacy of irofulven, a DNA interacting acylfulvene analog, as first line therapy for patients with recurrent or metastatic gastric cancer. PATIENTS AND METHODS: Twenty-three patients with recurrent or metastatic gastric cancer received irofulven at a dose of 0.45 mg/kg administered intravenously over 30-min infusion (up to a maximum of 50 mg), on days 1 and 8, every 3 weeks. RESULTS: The median number of cycles delivered per patient was 2 (range 1-6). Two patients (9%) had >or= 1-week delay in administration of subsequent cycle of chemotherapy. For the day 8 chemotherapy, dose reductions were required in seven patients (30%); dose omitting occurred in five patients (22%). Grade 3/4 anemia and neutropenia occurred in 22 and 17% of patients, respectively. There was no grade 4 thrombocytopenia and no neutropenic fever was observed. Of the 20 evaluable patients, there were no responses observed, 3 patients had stable disease after 2 cycles of treatment which was not confirmed by a further assessment. Median overall survival was 6.05 months (95% CI 4.55-9.39). CONCLUSIONS: Irofulven was tolerated at the dose of 0.45 mg/kg on days 1 and 8, every 3 weeks but showed no evidence of antitumor activity in patients with advanced gastric cancer.

Phase I study of ZD9331 on short daily intravenous bolus infusion for 5 days every 3 weeks with fixed dosing recommendations.

PURPOSE: To conduct a phase I study of ZD9331, a potent, nonpolyglutamatable thymidylate synthase inhibitor using a short daily infusion for 5 consecutive days every 21 days. PATIENTS AND METHODS: Patients with refractory cancer or cancer for which no standard therapy was available were treated in escalating doses using an accelerated titration design. Plasma and urine samples were collected at timed intervals in the first cycle for pharmacokinetic analysis. RESULTS: Seventy-four patients were enrolled at 12 dose levels from a starting dose of 0.4 mg/m(2)/d to 16 mg/m(2)/d and 25 mg/d fixed dosing, of which 67 were assessable for toxicity. Maximum-tolerated dose was reached at 16 mg/m(2)/d. Myelosuppression was dose-limiting, consisting of thrombocytopenia associated with neutropenic fever. Body-surface area did not correlate with drug clearance; therefore, fixed daily dosing of 25 mg/d was studied and found to be tolerable, with two of 12 dose-limiting events. Dose-limiting nonhematologic toxicity consisted of grade 3 erythematous maculopapular rash observed in one patient at 12 mg/m(2)/d and one patient at 25 mg/d. Pharmacokinetic analysis showed nonlinearity, with clearance increasing with dose. The mean clearance and terminal half-life of the drug were 6.6 +/- 2.0 mL/min and 71.3 +/- 27.0 hours, respectively. Area-under-the concentration-time curve was a better predictor of toxicity than dose, using multiple linear regression analyses. Minor response (40% shrinkage of tumor) was observed in one patient with colorectal cancer treated at 12 mg/m(2)/d. CONCLUSION: The recommended dose for ZD9331 on this schedule is 25 mg/d. Neutropenia, thrombocytopenia, and rash were dose-limiting, and efficacy studies in colorectal cancer are indicated.

Paraneoplastic progressive supranuclear palsy syndrome in a patient with B-cell lymphoma.

An important component in the diagnosis of atypical parkinsonian disorders is the exclusion of secondary causes. Paraneoplastic causes of parkinsonism are extremely rare. We describe a case which presented initially as probable progressive supranuclear palsy (PSP) but on follow-up displayed a rapidly progressive course, unexplained fever, peripheral neuropathy and an abnormal CSF. We highlight the difficulties faced in formulating a diagnosis for this unusual case prior to the discovery of an occult B-cell lymphoma, and discuss its relevance in the exclusion criteria for PSP. A paraneoplastic cause should be considered if disease progression is unusually rapid.

Development of a schedule-dependent population pharmacodynamic model for rhizoxin without quantitation of plasma concentrations.

In previous phase I reports of short bolus infusion of rhizoxin, problems in assay sensitivity prevented the description of pharmacokinetic-pharmacodynamic relationships, and a pharmacologically guided approach to dose escalation was deemed not feasible. In this report, we describe a mathematical model, which explains the schedule-dependent interpatient pharmacodynamic variability of rhizoxin administered on a continuous infusion schedule. Using patient demographic and toxicity data from 45 patients treated in a phase I dose and duration escalation study of rhizoxin, we sought to model the nadir neutrophil count. We hypothesized that a surrogate derived variable based on dose and duration would reflect a pharmacokinetic parameter that would be a significant covariate. Multiple linear regression analysis was carried out to determine the other significant covariates. Dose/m2 x Log(DUR/ALB) was significantly correlated with the LogANCnadir (Log10 neutrophil nadir; r = 0.56, P < 0.001). Other significant covariates included baseline performance status (PS), baseline serum bilirubin (BIL), and Log10 baseline neutrophil count (LogANCbaseline). Model bias and precision were assessed using the mean prediction error (MPE) and the root mean square error (RMSE) of the ANCnadir, respectively. We constructed 1-4 covariate models. The variability of ANCnadir was modeled with good precision and accuracy with a 4-covariate model (MPE and RMSE 0.113 +/- 0.182 x 10(3) cells/microl and 1.22 x 10(3) cells/microl, respectively). This model should be validated and improved on with further clinical data. We believe that such pharmacodynamic modeling should be explored further to determine its performance and clinical relevance compared with modeling using pharmacokinetic parameters.