Joo Ern Ang

Phase II, Open-Label, Randomized, Multicenter Study Comparing the Efficacy and Safety of Olaparib, a Poly (ADP-Ribose) Polymerase Inhibitor, and Pegylated Liposomal Doxorubicin in Patients With BRCA1 or BRCA2 Mutations and Recurrent Ovarian Cancer

PURPOSE Olaparib (AZD2281), an orally active poly (ADP-ribose) polymerase inhibitor that induces synthetic lethality in BRCA1- or BRCA2-deficient cells, has shown promising clinical efficacy in nonrandomized phase II trials in patients with ovarian cancer with BRCA1 or BRCA2 deficiency. We assessed the comparative efficacy and safety of olaparib and pegylated liposomal doxorubicin (PLD) in this patient population. PATIENTS AND METHODS In this multicenter, open-label, randomized, phase II study, patients with ovarian cancer that recurred within 12 months of prior platinum therapy and with confirmed germline BRCA1 or BRCA2 mutations were enrolled. Patients were assigned in a 1:1:1 ratio to olaparib 200 mg twice per day or 400 mg twice per day continuously or PLD 50 mg/m(2) intravenously every 28 days. The primary efficacy end point was Response Evaluation Criteria in Solid Tumors (RECIST) -assessed progression-free survival (PFS). Secondary end points included objective response rate (ORR) and safety. RESULTS Ninety-seven patients were randomly assigned. Median PFS was 6.5 months (95% CI, 5.5 to 10.1 months), 8.8 months (95% CI, 5.4 to 9.2 months), and 7.1 months (95% CI, 3.7 to 10.7 months) for the olaparib 200 mg, olaparib 400 mg, and PLD groups, respectively. There was no statistically significant difference in PFS (hazard ratio, 0.88; 95% CI, 0.51 to 1.56; P = .66) for combined olaparib doses versus PLD. RECIST-assessed ORRs were 25%, 31%, and 18% for olaparib 200 mg, olaparib 400 mg, and PLD, respectively; differences were not statistically significant. Tolerability of both treatments was as expected based on previous trials. CONCLUSION The efficacy of olaparib was consistent with previous studies. However, the efficacy of PLD was greater than expected. Olaparib 400 mg twice per day is a suitable dose to explore in further studies in this patient population.

Circulating tumour cell (CTC) counts as intermediate end points in castration-resistant prostate cancer (CRPC): a single-centre experience

BACKGROUND The purpose of this study was to evaluate the association of circulating tumour cell (CTC) counts, before and after commencing treatment, with overall survival (OS) in patients with castration-resistant prostate cancer (CRPC). EXPERIMENTAL DESIGN A 7.5 ml of blood was collected before and after treatment in 119 patients with CRPC. CTCs were enumerated using the CellSearchSystem. RESULTS Higher CTC counts associated with baseline characteristics portending aggressive disease. Multivariate analyses indicated that a CTC >or=5 was an independent prognostic factor at all time points evaluated. Patients with baseline CTC >or=5 had shorter OS than those with <5 [median OS 19.5 versus >30 months, hazard ratio (HR) 3.25, P=0.012]; patients with CTC >50 had a poorer OS than those with CTCs 5-50 (median OS 6.3 versus 21.1 months, HR 4.1, P<0.001). Patients whose CTC counts reduced from >or=5 at baseline to <5 following treatment had a better OS compared with those who did not. CTC counts showed a similar, but earlier and independent, ability to time to disease progression to predict OS. CONCLUSION CTC counts predict OS and provide independent prognostic information to time to disease progression; CTC dynamics following therapy need to be evaluated as an intermediate end point of outcome in randomised phase III trials.

Effect of sleep deprivation on the human metabolome

Significance Sleep restriction and circadian clock disruption are associated with metabolic disorders including obesity and diabetes; this association can be studied by using the powerful tool of metabolomics. By using liquid chromatography/MS metabolomics, we have characterized plasma metabolites that were significantly affected by acute sleep deprivation (mainly lipids and acylcarnitines), all increasing during sleep deprivation. Observed increased levels of serotonin, tryptophan, and taurine may explain the antidepressive effect of sleep deprivation and deserve further study. Clear daily rhythms were observed in most metabolites, with 24 h wakefulness mainly reducing the amplitude of these rhythms. Our results further the understanding of sleep/wake regulation and the associated metabolic processes, and will be vital when using metabolic profiling to identify robust biomarkers for disease states and drug efficacy. Sleep restriction and circadian clock disruption are associated with metabolic disorders such as obesity, insulin resistance, and diabetes. The metabolic pathways involved in human sleep, however, have yet to be investigated with the use of a metabolomics approach. Here we have used untargeted and targeted liquid chromatography (LC)/MS metabolomics to examine the effect of acute sleep deprivation on plasma metabolite rhythms. Twelve healthy young male subjects remained in controlled laboratory conditions with respect to environmental light, sleep, meals, and posture during a 24-h wake/sleep cycle, followed by 24 h of wakefulness. Two-hourly plasma samples collected over the 48 h period were analyzed by LC/MS. Principal component analysis revealed a clear time of day variation with a significant cosine fit during the wake/sleep cycle and during 24 h of wakefulness in untargeted and targeted analysis. Of 171 metabolites quantified, daily rhythms were observed in the majority (n = 109), with 78 of these maintaining their rhythmicity during 24 h of wakefulness, most with reduced amplitude (n = 66). During sleep deprivation, 27 metabolites (tryptophan, serotonin, taurine, 8 acylcarnitines, 13 glycerophospholipids, and 3 sphingolipids) exhibited significantly increased levels compared with during sleep. The increased levels of serotonin, tryptophan, and taurine may explain the antidepressive effect of acute sleep deprivation and deserve further study. This report, to our knowledge the first of metabolic profiling during sleep and sleep deprivation and characterization of 24 h rhythms under these conditions, offers a novel view of human sleep/wake regulation.

Prospective Validation of a Prognostic Score to Improve Patient Selection for Oncology Phase I Trials

PURPOSE With the aim of improving patient selection for phase I trials, we previously performed a retrospective analysis of 212 phase I oncology patients where we were able to develop a prognostic score predicting overall survival (OS). This prospective study was performed to test the validity of the prognostic score. PATIENTS AND METHODS On the basis of our retrospective multivariate analysis, three factors were associated with poor survival (albumin < 35 g/L, lactate dehydrogenase [LDH] > upper limit of normal [ULN], and > two sites of metastases). We integrated these into a prognostic score ranging from 0 to 3 and analyzed this score in a prospectively selected cohort of 78 patients enrolled onto phase I trials. RESULTS All patients had progressive disease before study entry. The median age was 56 years (range, 18 to 79 years). After a median follow-up time of 27.3 weeks, patients with a prognostic score of 0 to 1 (n = 43) had superior OS (33.0 weeks; 95% CI, 24 to 42 weeks) compared with patients with a score of 2 to 3 (n = 35; 15.7 weeks; 95% CI, 11 to 21 weeks). Our multivariate analysis confirmed that our prognostic score was an independent marker for OS, with a hazard ratio of 1.4 (95% CI, 1.02 to 1.9; P = .036). CONCLUSION This is the first prospective analysis confirming that a prognostic score based on objective markers, including albumin less than 35 g/L, LDH more than ULN, and more than two sites of metastasis, is a helpful tool in the process of patient selection for phase I trial entry.

First-in-Human Phase I Study of Pictilisib (GDC-0941), a Potent Pan–Class I Phosphatidylinositol-3-Kinase (PI3K) Inhibitor, in Patients with Advanced Solid Tumors

Purpose: This first-in-human dose-escalation trial evaluated the safety, tolerability, maximal-tolerated dose (MTD), dose-limiting toxicities (DLT), pharmacokinetics, pharmacodynamics, and preliminary clinical activity of pictilisib (GDC-0941), an oral, potent, and selective inhibitor of the class I phosphatidylinositol-3-kinases (PI3K). Patients and Methods: Sixty patients with solid tumors received pictilisib at 14 dose levels from 15 to 450 mg once-daily, initially on days 1 to 21 every 28 days and later, using continuous dosing for selected dose levels. Pharmacodynamic studies incorporated 18F-FDG-PET, and assessment of phosphorylated AKT and S6 ribosomal protein in platelet-rich plasma (PRP) and tumor tissue. Results: Pictilisib was well tolerated. The most common toxicities were grade 1–2 nausea, rash, and fatigue, whereas the DLT was grade 3 maculopapular rash (450 mg, 2 of 3 patients; 330 mg, 1 of 7 patients). The pharmacokinetic profile was dose-proportional and supported once-daily dosing. Levels of phosphorylated serine-473 AKT were suppressed >90% in PRP at 3 hours after dose at the MTD and in tumor at pictilisib doses associated with AUC >20 h·μmol/L. Significant increase in plasma insulin and glucose levels, and >25% decrease in 18F-FDG uptake by PET in 7 of 32 evaluable patients confirmed target modulation. A patient with V600E BRAF–mutant melanoma and another with platinum-refractory epithelial ovarian cancer exhibiting PTEN loss and PIK3CA amplification demonstrated partial response by RECIST and GCIG-CA125 criteria, respectively. Conclusion: Pictilisib was safely administered with a dose-proportional pharmacokinetic profile, on-target pharmacodynamic activity at dose levels ≥100 mg and signs of antitumor activity. The recommended phase II dose was continuous dosing at 330 mg once-daily. Clin Cancer Res; 21(1); 77–86. ©2014 AACR.

CYP17 blockade by abiraterone: further evidence for frequent continued hormone-dependence in castration-resistant prostate cancer.

The limited prognosis of patients with castration-resistant prostate cancer (CRPC) on existing hormonal manipulation therapies calls out for the urgent need for new management strategies. The novel, orally available, small-molecule compound, abiraterone acetate, is undergoing evaluation in early clinical trials and emerging data have shown that the selective, irreversible and continuous inhibition of CYP17 is safe with durable responses in CRPC. Importantly, these efficacy data along with strong preclinical evidence indicate that a significant proportion of CRPC remains dependant on ligand-activated androgen receptor (AR) signalling. Coupled with the use of innovative biological molecular techniques, including the characterisation of circulating tumour cells and ETS gene fusion analyses, we have gained insights into the molecular basis of CRPC. We envision that a better understanding of the mechanisms underlying resistance to abiraterone acetate, as well as the development of validated predictive and intermediate endpoint biomarkers to aid both patient selection and monitor response to treatment, will improve the outcome of CRPC patients.

Efficacy of Chemotherapy in BRCA1/2 Mutation Carrier Ovarian Cancer in the Setting of PARP Inhibitor Resistance: A Multi-Institutional Study

Purpose: Preclinical data suggest that exposure to PARP inhibitors (PARPi) may compromise benefit to subsequent chemotherapy, particularly platinum-based regimens, in patients with BRCA1/2 mutation carrier ovarian cancer (PBMCOC), possibly through the acquisition of secondary BRCA1/2 mutations. The efficacy of chemotherapy in the PARPi-resistant setting was therefore investigated. Experimental Design: We conducted a retrospective review of PBMCOC who received chemotherapy following disease progression on olaparib, administered at ≥200 mg twice daily for one month or more. Tumor samples were obtained in the post-olaparib setting where feasible and analyzed by massively parallel sequencing. Results: Data were collected from 89 patients who received a median of 3 (range 1–11) lines of pre-olaparib chemotherapy. The overall objective response rate (ORR) to post-olaparib chemotherapy was 36% (24 of 67 patients) by Response Evaluation Criteria in Solid Tumors (RECIST) and 45% (35 of 78) by RECIST and/or Gynecologic Cancer InterGroup (GCIG) CA125 criteria with median progression-free survival (PFS) and overall survival (OS) of 17 weeks [95% confidence interval (CI), 13–21] and 34 weeks (95% CI, 26–42), respectively. For patients receiving platinum-based chemotherapy, ORRs were 40% (19 of 48) and 49% (26/53), respectively, with a median PFS of 22 weeks (95% CI, 15–29) and OS of 45 weeks (95% CI, 15–75). An increased platinum-to-platinum interval was associated with an increased OS and likelihood of response following post-olaparib platinum. No evidence of secondary BRCA1/2 mutation was detected in tumor samples of six PARPi-resistant patients [estimated frequency of such mutations adjusted for sample size: 0.125 (95%-CI: 0–0.375)]. Conclusions: Heavily pretreated PBMCOC who are PARPi-resistant retain the potential to respond to subsequent chemotherapy, including platinum-based agents. These data support the further development of PARPi in PBMCOC. Clin Cancer Res; 19(19); 5485–93. ©2013 AACR.

Identification of human plasma metabolites exhibiting time-of-day variation using an untargeted liquid chromatography-mass spectrometry metabolomic approach.

Although daily rhythms regulate multiple aspects of human physiology, rhythmic control of the metabolome remains poorly understood. The primary objective of this proof-of-concept study was identification of metabolites in human plasma that exhibit significant 24-h variation. This was assessed via an untargeted metabolomic approach using liquid chromatography–mass spectrometry (LC-MS). Eight lean, healthy, and unmedicated men, mean age 53.6 (SD ± 6.0) yrs, maintained a fixed sleep/wake schedule and dietary regime for 1 wk at home prior to an adaptation night and followed by a 25-h experimental session in the laboratory where the light/dark cycle, sleep/wake, posture, and calorific intake were strictly controlled. Plasma samples from each individual at selected time points were prepared using liquid-phase extraction followed by reverse-phase LC coupled to quadrupole time-of-flight MS analysis in positive ionization mode. Time-of-day variation in the metabolites was screened for using orthogonal partial least square discrimination between selected time points of 10:00 vs. 22:00 h, 16:00 vs. 04:00 h, and 07:00 (d 1) vs. 16:00 h, as well as repeated-measures analysis of variance with time as an independent variable. Subsequently, cosinor analysis was performed on all the sampled time points across the 24-h day to assess for significant daily variation. In this study, analytical variability, assessed using known internal standards, was low with coefficients of variation <10%. A total of 1069 metabolite features were detected and 203 (19%) showed significant time-of-day variation. Of these, 34 metabolites were identified using a combination of accurate mass, tandem MS, and online database searches. These metabolites include corticosteroids, bilirubin, amino acids, acylcarnitines, and phospholipids; of note, the magnitude of the 24-h variation of these identified metabolites was large, with the mean ratio of oscillation range over MESOR (24-h time series mean) of 65% (95% confidence interval [CI]: 49–81%). Importantly, several of these human plasma metabolites, including specific acylcarnitines and phospholipids, were hitherto not known to be 24-h variant. These findings represent an important baseline and will be useful in guiding the design and interpretation of future metabolite-based studies. (Author correspondence: Jooern.Ang@icr.ac.uk or Florence.Raynaud@icr.ac.uk)

Patient Selection for Oncology Phase I Trials: A Multi-Institutional Study of Prognostic Factors

PURPOSE The appropriate selection of patients for early clinical trials presents a major challenge. Previous analyses focusing on this problem were limited by small size and by interpractice heterogeneity. This study aims to define prognostic factors to guide risk-benefit assessments by using a large patient database from multiple phase I trials. PATIENTS AND METHODS Data were collected from 2,182 eligible patients treated in phase I trials between 2005 and 2007 in 14 European institutions. We derived and validated independent prognostic factors for 90-day mortality by using multivariate logistic regression analysis. RESULTS The 90-day mortality was 16.5% with a drug-related death rate of 0.4%. Trial discontinuation within 3 weeks occurred in 14% of patients primarily because of disease progression. Eight different prognostic variables for 90-day mortality were validated: performance status (PS), albumin, lactate dehydrogenase, alkaline phosphatase, number of metastatic sites, clinical tumor growth rate, lymphocytes, and WBC. Two different models of prognostic scores for 90-day mortality were generated by using these factors, including or excluding PS; both achieved specificities of more than 85% and sensitivities of approximately 50% when using a score cutoff of 5 or higher. These models were not superior to the previously published Royal Marsden Hospital score in their ability to predict 90-day mortality. CONCLUSION Patient selection using any of these prognostic scores will reduce non-drug-related 90-day mortality among patients enrolled in phase I trials by 50%. However, this can be achieved only by an overall reduction in recruitment to phase I studies of 20%, more than half of whom would in fact have survived beyond 90 days.

Advanced Solid Tumors Treated with Cediranib: Comparison of Dynamic Contrast-enhanced MR Imaging and CT as Markers of Vascular Activity

PURPOSE To assess baseline reproducibility and compare performance of dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging versus DCE computed tomographic (CT) measures of early vascular response in the same patients treated with cediranib (30 or 45 mg daily). MATERIALS AND METHODS After institutional review board approval, written informed consent was obtained from 29 patients with advanced solid tumors who had lesions 3 cm or larger and in whom simultaneous imaging of an adjacent artery was possible. Two baseline DCE MR acquisitions and two baseline DCE CT acquisitions 7 days or fewer apart (within 14 days of starting treatment) and two posttreatment acquisitions with each modality at day 7 and 28 (±3 days) were obtained. Nonmodeled and modeled parameters were derived (measured arterial input function [AIF] for CT, population-based AIF for MR imaging; temporal sampling rate of 0.5 second for CT, 3-6 seconds for MR imaging). Baseline variability was assessed by using intra- and intersubject analysis of variance and Bland-Altman analysis; a paired t test assessed change from baseline to after treatment. RESULTS The most reproducible parameters were DCE MR imaging enhancement fraction (baseline intrapatient coefficient of variation [CV]=8.6%), volume transfer constant (CV=13.9%), and integrated area under the contrast agent uptake curve at 60 seconds (CV=15.5%) and DCE CT positive enhancement integral (CV=16.0%). Blood plasma volume was highly variable and the only parameter with CV greater than 30%. Average reductions (percentage change) from baseline were consistently observed for all DCE MR imaging and DCE CT parameters at day 7 and 28 for both starting-dose groups (45 and 30 mg), except for DCE CT mean transit time. Percentage change from baseline for parameters reflecting blood flow and permeability were comparable, and reductions from baseline at day 7 were maintained at day 28. CONCLUSION DCE MR imaging and DCE CT can depict vascular response to antiangiogenic agents with response evident at day 7. Improved reproducibility with MR imaging favors its use in trials with small patient numbers.