Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
5 result(s) for "Gresty, Christopher"
Sort by:
Patient-reported outcomes with olaparib plus abiraterone versus placebo plus abiraterone for metastatic castration-resistant prostate cancer: a randomised, double-blind, phase 2 trial
Results of this double-blind, phase 2 trial showed patients with metastatic castration-resistant prostate cancer given olaparib plus abiraterone versus placebo plus abiraterone had significantly improved progression-free survival. Here, we present an exploratory analysis of pain and health-related quality of life (HRQOL). This double-blind, randomised, placebo-controlled, phase 2 trial was conducted across 41 urological oncology sites in 11 countries in Europe and North America. Eligible patients were aged 18 years or older, had metastatic castration-resistant prostate cancer, and had previously received docetaxel and up to one additional line of previous chemotherapy. Metastatic castration-resistant prostate cancer was defined as increasing prostate-specific antigen (PSA) concentration or other signs of disease progression despite androgen-deprivation therapy and serum testosterone concentrations at castrate levels (≤50 ng/dL), and with at least one metastatic lesion on bone scan, CT, or MRI. Eligible patients were randomly assigned (1:1) to receive oral olaparib (300 mg twice per day) plus oral abiraterone (1000 mg once a day) and oral prednisone or prednisolone (5 mg twice a day) or placebo plus abiraterone (1000 mg once a day) and prednisone or prednisolone (5 mg twice a day). Randomisation was done without stratification and by use of an interactive voice or web response system. A randomised treatment kit ID number was assigned sequentially to each patient as they became eligible. The primary endpoint (radiographic progression-free survival) has previously been reported. HRQOL was a prespecified exploratory patient-reported outcome. Patients were asked to complete the Brief Pain Inventory-Short Form (BPI-SF), single-item worst bone pain, Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire, and EuroQol-5 five-dimension five level (EQ-5D-5L) assessment at baseline, at weeks 4, 8, and 12, then every 12 weeks until treatment discontinuation. Prespecified outcomes were change from baseline in BPI-SF worst pain, single-item worst bone pain and FACT-P Total Outcome Index (TOI) scale scores, time to deterioration in BPI-SF worst pain and worst bone pain, and assessment of the EQ-5D-5L pain and discomfort domain. All analyses were exploratory and done in the full analysis set (all randomly assigned patients, including patients who were randomly assigned but did not subsequently go on to receive study treatment), with the exception of mean baseline and total change from baseline analyses, for which we used the population who had a valid baseline and at least one post-baseline assessment. This trial is registered with Clinicaltrials.gov, NCT01972217, and is no longer recruiting patients. Between Nov 25, 2014, and July 14, 2015, 171 patients were assessed for eligibility. 29 patients were excluded, and 142 were enrolled and randomly assigned to receive olaparib and abiraterone (n=71) or placebo and abiraterone (n=71). Data cutoff was Sept 22, 2017. Median follow-up was 15·9 months (IQR 8·1–25·5) in the olaparib plus abiraterone group and 24·5 months (8·1–27·6) in the placebo plus abiraterone group. Questionnaire compliance was generally high (43–100%). Least-squares mean changes from baseline in BPI-SF worst pain, single-item worst bone pain, and FACT-P TOI remained stable across all visits for patients in both treatment groups. Adjusted mean change in FACT-P TOI from baseline across all visits was −0·10 (95% CI −2·50 to 2·71) in the olaparib plus abiraterone group and −1·20 (−4·15 to 1·74) in the placebo plus abiraterone group (difference 1·30, 95% CI −2·70 to 5·30; p=0·52). Time to deterioration in pain was similar in both groups (BPI-SF worst pain HR 0·90 [95% CI 0·62–1·32], p=0·30; worst bone pain HR 0·85 [0·59–1·22], p=0·18). Improvement rates in the pain and discomfort domain of the EQ-5D-5L were similar in both groups from baseline to week 48, beyond which a higher proportion of patients in the olaparib plus abiraterone arm reported an improvement compared to the placebo plus abiraterone group. In these prespecified exploratory analyses, there was no significant difference in pain or HRQOL when olaparib was added to abiraterone. In this phase 2 trial, a statistically significant radiographic progression-free survival benefit was observed with the olaparib plus abiraterone combination. These results suggest that the improved survival benefits observed when combining olaparib with abiraterone does not result in different HRQOL compared with placebo plus abiraterone. Phase 3 studies are required to validate these results. AstraZeneca and Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA.
Survival with Olaparib in Metastatic Castration-Resistant Prostate Cancer
The PROfound trial showed that olaparib prolonged imaging-based progression-free survival among patients whose tumors contained defects in the homologous recombination repair genes BRCA1 , BRCA2 , or ATM . With longer follow-up, the trial now shows that olaparib prolonged overall survival in these patients. Toxic effects included anemia, nausea, and asthenia.
Exploring the Impact of Treatment Switching on Overall Survival from the PROfound Study in Homologous Recombination Repair (HRR)-Mutated Metastatic Castration-Resistant Prostate Cancer (mCRPC)
BackgroundIn oncology trials, treatment switching from the comparator to the experimental regimen is often allowed but may lead to underestimating overall survival (OS) of an experimental therapy.ObjectiveThis study evaluates the impact of treatment switching from control to olaparib on OS using the final survival data from the PROfound study and compares validated adjustment methods to estimate the magnitude of OS benefit with olaparib.Patients and methodsThe primary population from PROfound (Cohort A) was included, alongside two populations approved for treatment with olaparib by the European Medicines Agency and US Food and Drug Administration: BRCAm and Cohort A+B (excluding the PPP2R2A gene). Five methods were explored to adjust for switching: excluding or censoring patients in the control arm who receive subsequent olaparib, Rank Preserving Structural Failure Time Model (RPSFTM), Inverse Probability of Censoring Weights, and Two-Stage Estimation.ResultsThe RPSFTM was considered the most appropriate approach for PROfound as the results were robust to sensitivity analysis testing of the common treatment effect assumption. For Cohort A, the final OS hazard ratio reduced from 0.69 (95% CI 0.5–0.97) to between 0.42 (0.18–0.90) and 0.52 (0.31–1.00) for olaparib versus control, depending on the RPSFTM selected. Median OS reduced from 14.7 months to between 11.73 and 12.63 months for control.ConclusionsThe magnitude of the statistically significant (P < 0.05) survival benefit of olaparib versus control observed in Cohort A of PROfound is likely to be underestimated if adjustment for treatment switching from control to olaparib is not conducted. The RPSFTM was considered the most plausible method, although further development and validation of robust methods to estimate the magnitude of impact of treatment switching is needed.
Correlation between Cyclin Dependent Kinases and Artemisinin-Induced Dormancy in Plasmodium falciparum In Vitro
Artemisinin-induced dormancy provides a plausible explanation for recrudescence following artemisinin monotherapy. This phenomenon shares similarities with cell cycle arrest where cyclin dependent kinases (CDKs) and cyclins play an important role. Transcription profiles of Plasmodium falciparum CDKs and cyclins before and after dihydroartemisinin (DHA) treatment in three parasite lines, and the effect of CDK inhibitors on parasite recovery from DHA-induced dormancy were investigated. After DHA treatment, parasites enter a dormancy phase followed by a recovery phase. During the dormancy phase parasites up-regulate pfcrk1, pfcrk4, pfcyc2 and pfcyc4, and down-regulate pfmrk, pfpk5, pfpk6, pfcrk3, pfcyc1 and pfcyc3. When entering the recovery phase parasites immediately up-regulate all CDK and cyclin genes. Three CDK inhibitors, olomoucine, WR636638 and roscovitine, produced distinct effects on different phases of DHA-induced dormancy, blocking parasites recovery. The up-regulation of PfCRK1 and PfCRK4, and down regulation of other CDKs and cyclins correlate with parasite survival in the dormant state. Changes in CDK expression are likely to negatively regulate parasite progression from G1 to S phase. These findings provide new insights into the mechanism of artemisinin-induced dormancy and cell cycle regulation of P. falciparum, opening new opportunities for preventing recrudescence following artemisinin treatment.
Mitochondrial Membrane Potential in a Small Subset of Artemisinin-Induced Dormant Plasmodium falciparum Parasites In Vitro
Artemisinin-induced dormancy is a proposed mechanism for failures of monotherapy and is linked with artemisinin resistance in Plasmodium falciparum. The biological characterization and dynamics of dormant parasites are not well understood. Here we report that after dihydroartemisinin treatment in vitro, a small subset of morphologically dormant parasites was stained with rhodamine 123 (RH), a mitochondrial membrane potential marker, and persisted to recovery. RH-positive parasites sorted with fluorescence-activated cell sorting resumed growth at 10 000/well whereas RH-negative parasites failed to recover at 5 million/well. Furthermore, transcriptional activity for mitochondrial enzymes was detected only in RH-positive dormant parasites. Importantly, after treatment of dormant parasites with different concentrations of atovaquone, a mitochondrial inhibitor, the recovery of dormant parasites was delayed or stopped. This demonstrates that mitochondrial activity is critical for survival and regrowth of dormant parasites and that RH staining provides a means of identifying these parasites. These findings provide novel paths for studying and eradicating this dormant stage.