Adaptive Randomization Research Articles

Abstract PO-050: Precision Promise (PrP): An adaptive, multi-arm registration trial in metastatic pancreatic ductal adenocarcinoma (PDAC)

Abstract Background: Drug development in PDAC has been disappointing with an extremely low trial success rate despite considerable effort. PrP is a transformative, adaptive clinical trial platform that attempts to correct this by continuously and rapidly evaluating novel therapeutic options while maximizing the probability of patient (pt) randomization to an experimental treatment and nurturing enhanced cooperation among groups representing pt advocacy, pharmaceuticals, translational/clinical academia, and the FDA. This patient-centric study represents a fundamental shift in drug development for PDAC in the United States and aims to become the largest Phase 2/3 registrational study ever launched in this disease. Methods: PrP (NCT04229004) is a clinical trial platform sponsored by the Pancreatic Cancer Action Network (PanCAN) and funded solely through non-government sources. The protocol was finalized based on the FDA 2020 guidance document regarding "complex innovative designs" in registration trials https://www.fda.gov/media/130897/download. It utilizes adaptive randomization along with several trial design and Bayesian statistical innovations provided by Berry Consultants LLC. All pts undergo pre-and on-treatment biopsies with state-of-the-art genomic, transcriptomic, and immune analysis, along with collection of blood samples for research purposes throughout the study. Pts are managed using novel standardized supportive care techniques, and PrP contains 3 sub-protocols involving quality of life, sarcopenia and actigraphy. PrP was launched in 2020, and currently includes 20 US sites. Focused on both 1st and 2nd line treatment of metastatic PDAC, PrP uses an adaptive platform design with 30% of pts randomized between one of the 2 standard of care control arms (gemcitabine + nab-paclitaxel and mFOLFIRINOX) and 70% to experimental arms, currently either SM-88, a cancer metabolism-based agent (Tyme Inc); or Pamrevlumab, an antibody inhibiting the activity of the connective tissue growth factor (Fibrogen Inc.) The study is ongoing with >100 pts enrolled to date. The Data and Safety Monitoring Committee regularly reviews the data and continues to recommend that the trial proceeds as planned. New study arms will be added after review by an Arm Selection Committee that assesses the validity of the treatment target and the adequacy of the preexisting pre-clinical and clinical data. An additional experimental arm is anticipated in 2021. Conclusion: Compared to traditional trial designs, PrP offers several advantages: multiple investigational treatments can be evaluated in parallel over time; only ~ 175 pts per experimental arm required to initiate a regulatory registration; and increased learning from every patient during the trial, altogether resulting in both time saving and a 30-50% cost saving. In effect, PrP has created an entirely new “learning community” and can substantially accelerate drug development for PDAC. Citation Format: Vincent J. Picozzi, Anne-Marie Duliege, Anirban Maitra, Manuel Hidalgo, Andrew Eugene Hendifar, Gregory L. Beatty, Sudheer Doss Doss, Regina Deck, Lynn M. Matrisian, Julie Fleshman, Diane M. Simeone. Precision Promise (PrP): An adaptive, multi-arm registration trial in metastatic pancreatic ductal adenocarcinoma (PDAC) [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-050.

CTNI-40. EVALUATING FEASIBILITY AND EFFICIENCY OF PHASE II ADAPTIVE PLATFORM TRIAL DESIGNS BASED ON THE INDIVIDUALIZED SCREENING TRIAL OF INNOVATIVE GLIOBLASTOMA THERAPY (INSIGhT) EXPERIENCE

Abstract BACKGROUND The Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) is a phase II platform trial with Bayesian adaptive randomization and deep genomic profiling to more efficiently test experimental agents in newly diagnosed glioblastoma and to prioritize therapies for late-stage testing. METHODS In the ongoing INSIGhT trial, patients with newly diagnosed MGMT-unmethylated glioblastoma are randomized to the control arm or one of three experimental therapy arms (CC-115, abemaciclib, and neratinib). The control arm therapy is radiotherapy with concomitant and adjuvant temozolomide, and primary endpoint is overall survival. Randomization has been adapted based on Bayesian estimation of biomarker-specific probability of treatment impact on progression-free survival (PFS). All tumors undergo detailed molecular sequencing, and this is facilitated with the companion ALLELE protocol. To evaluate feasibility of this approach, we assessed the status of this ongoing trial. RESULTS Since INSIGhT was activated 4.3 years ago, it has expanded to include 12 sites across the United States. A total of 247 patients have been enrolled. Randomization probabilities have been repeatedly adjusted over time based upon early PFS results to alter the randomization ratio from standard 1:1:1:1 randomization. All three arms have completed accrual and efficacy estimates are available based upon comparison to the common control arm in context of relevant biomarkers. There are 87 patients alive and in follow-up, and there are ongoing plans to add additional arms to evaluate further treatments in the future. CONCLUSION The INSIGhT trial demonstrates that a multi-center Bayesian adaptive platform trial is a feasible and effective approach to help prioritize therapies and biomarkers for newly diagnosed GBM. The trial has maintained robust accrual, and the simultaneous testing of multiple agents, sharing a common control arm and adaptive randomization serve as features to increase trial efficiency relative to traditional clinical trial designs.

CTNI-05. PRELIMINARY RESULTS OF THE NERATINIB ARM IN THE INDIVIDUALIZED SCREENING TRIAL OF INNOVATIVE GLIOBLASTOMA THERAPY (INSIGHT): A PHASE II PLATFORM TRIAL USING BAYESIAN ADAPTIVE RANDOMIZATION

Abstract BACKGROUND EGFR is amplified in over 50% of glioblastoma and 20-30% have EGFRvIII mutations. Neratinib is a potent inhibitor of EGFR/HER2 approved for metastatic HER2+ breast cancer. To efficiently evaluate the potential impact of neratinib on overall survival (OS) in newly-diagnosed glioblastoma and to simultaneously develop information regarding potential genomic biomarker associations, neratinib was included as an arm on the Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) trial. INSIGhT is a phase II platform trial using response adaptive randomization and deep genomic profiling to more efficiently test experimental agents in MGMT unmethylated glioblastoma and accelerate identification of novel therapies for phase III testing. Initial randomization was equal between neratinib, control, and two other experimental arms but subsequent randomization was adapted based on efficacy as determined by progression-free survival (PFS). We report preliminary results for the neratinib arm. METHODS Patients with newly diagnosed MGMT-unmethylated glioblastoma were randomized to receive either radiotherapy with concomitant and adjuvant temozolomide or standard radiochemotherapy followed by adjuvant neratinib (240 mg daily). Treatment continued until progression or development of unacceptable toxicities. The primary endpoint was OS. Association between neratinib efficacy and EGFR amplification was also investigated. RESULTS There were 144 patients (70 control; 74 neratinib). Neratinib was reasonably well-tolerated with no new toxicity signals identified. PFS was compared (HR 0.84; p=0.38, logrank test – not significant) between the neratinib (median 6.05 months) and control (median 5.82 months) arms. For patients EGFR pathway activation the PFS HR was 0.53 (p-value=0.03 – significant, median PFS: neratinib, 6.21 months, control, 5.26 months). However, there was no significant improvement in OS in EGFR amplified/mutated patients (HR 1.05; p-value 0.87) between neratinib (median 14.2) compared to the control arm (median 14.6). CONCLUSION Neratinib prolonged PFS in the EGFR positive subpopulation but there was no overall PFS benefit, or any OS improvement.

Using biomarkers to allocate patients in a response-adaptive clinical trial

In this paper, we discuss a response adaptive randomization method, and why it should be used in clinical trials for rare diseases compared to a randomized controlled trial with equal fixed randomization. The developed method uses a patient’s biomarkers to alter the allocation probability to each treatment, in order to emphasize the benefit to the trial population. The method starts with an initial burn-in period of a small number of patients, who with equal probability, are allocated to each treatment. We then use a regression method to predict the best outcome of the next patient, using their biomarkers and the information from the previous patients. This estimated best treatment is assigned to the next patient with high probability. A completed clinical trial for the effect of catumaxomab on the survival of cancer patients is used as an example to demonstrate the use of the method and the differences to a controlled trial with equal allocation. Different regression procedures are investigated and compared to a randomized controlled trial, using efficacy and ethical measures.

A multi-center, adaptive, randomized, platform trial to evaluate the effect of repurposed medicines in outpatients with early coronavirus disease 2019 (COVID-19) and high-risk for complications: the TOGETHER master trial protocol

Background: There remains a need for an effective and affordable outpatient treatment for early COVID-19. Multiple repurposed drugs have shown promise in treating COVID-19. We describe a master protocol that will assess the efficacy of different repurposed drugs as treatments for early COVID-19 among outpatients at a high risk for severe complications. Methods: The TOGETHER Trial is a multi-center platform adaptive randomized, placebo-controlled, clinical trial. Patients are included if they are at least 18 years of age, have a positive antigen test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and have an indication for high risk of disease severity, including co-morbidities, older age, or high body mass index. Eligible patients are randomized with equal chance to an investigational product (IP) or to placebo.The primary endpoint is hospitalization defined as either retention in a COVID-19 emergency setting for greater than 6 hours or transfer to tertiary hospital due to COVID-19. Secondary outcomes include mortality, adverse events, adherence, and viral clearance. Scheduled interim analyses are conducted and reviewed by the Data and Safety Monitoring Committee (DSMC), who make recommendations on continuing or stopping each IP. The platform adaptive design go-no-go decision rules are extended to dynamically incorporate external evidence on COVID-19 interventions from ongoing independent randomized clinical trials. Discussion: Results from this trial will assist in the identification of therapeutics for the treatment of early diagnosed COVID-19. The novel methodological extension of the platform adaptive design to dynamically incorporate external evidence is one of the first of its kind and may provide highly valuable information for all COVID-19 trials going forward. Clinicaltrials.gov registration: NCT04727424 (27/01/2021)

Estimating Conditional Power for Sequential Monitoring of Covariate Adaptive Randomized Designs: The Fractional Brownian Motion Approach

Conditional power based on classical Brownian motion (BM) has been widely used in sequential monitoring of clinical trials, including those with the covariate adaptive randomization design (CAR). Due to some uncontrollable factors, the sequential test statistics under CAR procedures may not satisfy the independent increment property of BM. We confirm the invalidation of BM when the error terms in the linear model with CAR design are not independent and identically distributed. To incorporate the possible correlation structure of the increment of the test statistic, we utilize the fractional Brownian motion (FBM). We conducted a comparative study of the conditional power under BM and FBM. It was found that the conditional power under FBM assumption was mostly higher than that under BM assumption when the Hurst exponent was greater than 0.5.

Acupuncture for combat post-traumatic stress disorder: trial development and methodological approach for a randomized controlled clinical trial

BackgroundPost-traumatic stress disorder (PTSD) is a significant public health problem, affecting approximately 7% of the general population and 13–18% of the combat Veteran population. The first study using acupuncture for PTSD in a civilian population showed large pre- to post-treatment effects for an empirically developed verum protocol, which was equivalent to group cognitive behavior therapy and superior to a wait-list control. The primary objective of this study is to determine both clinical and biological effects of verum acupuncture for combat-related PTSD in treatment-seeking US Veterans.MethodsThis is a two-arm, parallel-group, prospective randomized placebo-controlled clinical trial. The experimental condition is verum acupuncture and the placebo control is sham (minimal) acupuncture in 1-h sessions, twice a week for 12 weeks. Ninety subjects will provide adequate power and will be allocated to group by an adaptive randomization procedure. The primary outcome is change in PTSD symptom severity from pre- to post-treatment. The secondary biological outcome is change from pre- to post-treatment in psychophysiological response, startle by electromyographic (EMG) eyeblink. Assessments will be conducted at pre-, mid-, post-, and 1-month post-treatment, blind to group allocation. Intent-to-treat analyses will be conducted.DiscussionThe study results will be definitive because both clinical and biological outcomes will be assessed and correlated. Issues such as the number needed for recruitment and improvement, use of sham acupuncture, choice of biological measure, and future research need will be discussed.Trial registrationClinicalTrials.gov NCT02869646. Registered on 17 August 2016.

MP13-05 IMPACT OF MICTURITION HABITS ON FUNCTIONAL OUTCOMES OF PATIENTS WITH ORTHOTOPIC NEOBLADDER: RESULTS FROM A SINGLE CENTER PROSPECTIVE RANDOMISED CONTROLLED TRIAL

You have accessJournal of UrologyBladder Cancer: Invasive I (MP13)1 Sep 2021MP13-05 IMPACT OF MICTURITION HABITS ON FUNCTIONAL OUTCOMES OF PATIENTS WITH ORTHOTOPIC NEOBLADDER: RESULTS FROM A SINGLE CENTER PROSPECTIVE RANDOMISED CONTROLLED TRIAL Riccardo Mastroianni, Gabriele Tuderti, Umberto Anceschi, Alfredo Maria Bove, Aldo Brassetti, Mariaconsiglia Ferriero, Leonardo Misuraca, Salvatore Guaglianone, Ashanti Zampa, Michele Gallucci, and Giuseppe Simone Riccardo MastroianniRiccardo Mastroianni More articles by this author , Gabriele TudertiGabriele Tuderti More articles by this author , Umberto AnceschiUmberto Anceschi More articles by this author , Alfredo Maria BoveAlfredo Maria Bove More articles by this author , Aldo BrassettiAldo Brassetti More articles by this author , Mariaconsiglia FerrieroMariaconsiglia Ferriero More articles by this author , Leonardo MisuracaLeonardo Misuraca More articles by this author , Salvatore GuaglianoneSalvatore Guaglianone More articles by this author , Ashanti ZampaAshanti Zampa More articles by this author , Michele GallucciMichele Gallucci More articles by this author , and Giuseppe SimoneGiuseppe Simone More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001994.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Functional outcomes of radical cystectomy (RC) with orthotopic ileal neobladder and their predictive variables remain underinvestigated. We aimed to evaluate the impact of voiding time-intervals on both day (d)- and night (n)-time continence in a randomised controlled trial (RCT) cohort of patients comparing open RC (ORC) and robot-assisted RC (RARC) with totally intracorporeal (i) urinary diversion (UD) (NCT03434132). METHODS: Patients were eligible if they had a diagnostic TURBt with cT2-4, cN0, cM0, or recurrent high-grade NMIBC and no anesthesiologic contraindications to robotic surgery. Between Jan 2018 and Sept 2020, 116 patients were enrolled with a covariate adaptive randomization process based on the following variables: BMI, ASA score, preoperative hgb, UD [Padua ileal bladder (PIB) or ileal conduit], neoadjuvant chemotherapy and cT-stage. Logistic regression (LR) was performed to build a model to predict d- and n-time continence using a voiding cut-off time. RESULTS: Out of 116 patients enrolled, 88 received PIB and 71 were included in the study (12 patients died, 1 was lost to follow-up, 1 was hypercontinent, 1 had a stroke and 2 had permanent catheter). Baseline clinical data were reported in Table 1. RARC with iPIB was performed with no need of open conversion. At a median follow-up of 16 months (IQR: 11-28), 60 patients (85%) were d-time continent, and 45 (63%) were n-time continent. Patients who had d-time voiding intervals <3h had higher probability to be d-time continent (88%vs64%;p=0.04); similarly, n-time continence probabilities were higher when n-time voiding intervals were <3h (76%vs47%;p=0.01). At LR analysis, for each hour increase in voiding intervals, d-time and n-time continence probabilities decreased of 41% (HR: 0.587; 95%CI 0.424-0.813;p=0.001). In d-time continent patients, LR demonstrated that for each hour increase n-time continence probability decreased of 49% (HR: 0.514; 95%CI 0.353-0.749; p=0.001). CONCLUSIONS: This study supports the key role of micturition habits on functional outcomes of neobladder patients. Patients should be preoperatively counseled about the need to respect voiding cut-off time of 3h to achieve optimal functional results. Source of Funding: none © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e244-e244 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Riccardo Mastroianni More articles by this author Gabriele Tuderti More articles by this author Umberto Anceschi More articles by this author Alfredo Maria Bove More articles by this author Aldo Brassetti More articles by this author Mariaconsiglia Ferriero More articles by this author Leonardo Misuraca More articles by this author Salvatore Guaglianone More articles by this author Ashanti Zampa More articles by this author Michele Gallucci More articles by this author Giuseppe Simone More articles by this author Expand All Advertisement Loading ...

Comparative Effectiveness Research using Bayesian Adaptive Designs for Rare Diseases: Response Adaptive Randomization Reusing Participants

Slow accrual rate is a major challenge in clinical trials for rare diseases and is identified as the most frequent reason for clinical trials to fail. This challenge is amplified in comparative effectiveness research where multiple treatments are compared to identify the best treatment. Novel efficient clinical trial designs are in urgent need in these areas. Our proposed response adaptive randomization (RAR) reusing participants trial design mimics the real-world clinical practice that allows patients to switch treatments when desired outcome is not achieved. The proposed design increases efficiency by two strategies: (i) Allowing participants to switch treatments so that each participant can have more than one observation and hence it is possible to control for participant specific variability to increase statistical power; and (ii) Using RAR to allocate more participants to the promising arms such that ethical and efficient studies will be achieved. Extensive simulations were conducted and showed that, compared with trials where each participant receives one treatment, the proposed participants reusing RAR design can achieve comparable power with a smaller sample size and a shorter trial duration, especially when the accrual rate is low. The efficiency gain decreases as the accrual rate increases.

One year on: The impact of COVID-19 on clinical research

One year on: The impact of COVID-19 on clinical research

A multi-center, adaptive, randomized, platform trial to evaluate the effect of repurposed medicines in outpatients with early coronavirus disease 2019 (COVID-19) and high-risk for complications: the TOGETHER master trial protocol

Background: Although vaccines are currently available for coronavirus disease 2019 (COVID-19), there remains a need for an effective and affordable outpatient treatment for early COVID-19. Multiple repurposed drugs have shown promise in treating COVID-19. We describe a master protocol that will assess the efficacy of different repurposed drugs as treatments for early COVID-19 among outpatients at a high risk for severe complications. Methods: The TOGETHER Trial is an international (currently in Brazil and Africa), multi-center platform adaptive randomized, placebo-controlled, clinical trial. Patients are included if they are at least 18 years of age, have a positive antigen test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and have an indication for high risk of disease severity, including co-morbidities, older age, or high body mass index. Eligible patients are randomized with equal chance to an investigational product (IP) or to placebo. The primary endpoint is hospitalization due to clinical worsening of COVID-19 or emergency room required observation for more than 6 hours up to 28 days after randomization. Key secondary endpoints include viral clearance, clinical improvement, hospitalization for any cause, mortality for any cause, and safety and tolerability of each IP. Scheduled interim analyses are conducted and reviewed by the Data and Safety Monitoring Committee (DSMC), who make recommendations on continuing or stopping each IP. The platform adaptive design go-no-go decision rules are extended to dynamically incorporate external evidence on COVID-19 interventions from ongoing independent randomized clinical trials. Discussion: Results from this trial will assist in the identification of therapeutics for COVID-19 that can easily be scaled in low- and middle-income settings. The novel methodological extension of the platform adaptive design to dynamically incorporate external evidence is one of the first of its kind and may provide highly valuable information for all COVID-19 trials going forward. Clinicaltrials.gov registration: NCT04727424 (27/01/2021)

Randomized phase II trial of durvalumab (anti-PDL1) and tremelimumab (anti-CTLA4) administered in combination versus sequentially for the treatment of recurrent platinum-resistant non-clear cell ovarian cancer (NCT03026062)

<h3>Objectives:</h3> Single agent immune checkpoint blockade (ICB) has demonstrated response rates of 5-15% in patients with recurrent high-grade ovarian cancer (HGOC), with another 15-40% of patients achieving stable disease. Combination ICB using ipilimumab and nivolumab resulted in improved response rates in a mixed population with platinum resistant and sensitive disease. The objective of the current trial was to evaluate sequential versus combination CTLA4 and PDL1 blockade strategies for extending progression free survival (PFS) in patients with platinum resistant/refractory HGOC. <h3>Methods:</h3> Patients were required to have pathologically confirmed platinum resistant or refractory epithelial ovarian cancer, no prior immunotherapy, and PS=0-1 for enrollment. The current abstract includes data only on subjects with high grade serous ovarian cancer (HGSOC), as enrollment of patients with clear cell histology is still ongoing. The primary endpoint was PFS and response was assessed using modified RECIST v1.1. Unlimited numbers of prior regimens were allowed. Patients were adaptively randomized to sequential arm: tremelimumab (3mg/kg q4 weeks x 4 doses) followed by durvalumab (1.5g IV q4 weeks for up to 9 doses) upon progression, or the combination arm: tremelimumab (1mg/kg IV plus durvalumab 1.5g IV q4wk for up to 4 doses followed by durvalumab monotherapy for up to 9 doses). For the Bayesian adaptive randomization, the probability of being assigned to an arm was proportional to the likelihood the arm had better PFS, such that patients were more likely to be randomized to the more effective arm. <h3>Results:</h3> A total of 61 subjects were adaptively randomized to sequential treatment (n=38) or combination therapy (n=23). 46 (79%) patients had wild-type breast cancer gene (<i>BRCA</i>). Median prior lines of therapy was 4 (range: 1-10). There was no difference in median PFS in the sequential arm (1.84 months; 95% CI: 1.77 – 2.17)) compared with the combination arm (1.87 months; 95% CI: 1.77 – 2.43), p=0.402. Similarly, median OS in the sequential and combination arms were 10.61 months (5.95 – 15.34) and 7.26 (4.24 – 15.57), respectively (p=0.810). In the sequential arm no objective responses were observed, although 12 patients (31.6%) exhibited stable disease. In the combination arm, 2 patients had partial response (8.7%) while one additional patient (4.4%) had stable disease. The adverse event profile was consistent with that previously reported for immune checkpoint therapy. <h3>Conclusions:</h3> There was no difference in the median PFS between the combination and sequential durvalumab plus tremelimumab treatment strategy arms in a heavily pretreated population of patients with platinum resistant/refractory HGOC. Response rates were comparable to prior reports, though the combination regimen did not add significant benefit as has been previously described with combination of ipilimumab/nivolumab. Further exploration into subpopulations that may have increased benefit from ICB is warranted.

PRINCIPLE: a community-based COVID-19 platform trial

PRINCIPLE: a community-based COVID-19 platform trial

Doxycycline for community treatment of suspected COVID-19 in people at high risk of adverse outcomes in the UK (PRINCIPLE): a randomised, controlled, open-label, adaptive platform trial

BackgroundDoxycycline is often used for treating COVID-19 respiratory symptoms in the community despite an absence of evidence from clinical trials to support its use. We aimed to assess the efficacy of doxycycline to treat suspected COVID-19 in the community among people at high risk of adverse outcomes.MethodsWe did a national, open-label, multi-arm, adaptive platform randomised trial of interventions against COVID-19 in older people (PRINCIPLE) across primary care centres in the UK. We included people aged 65 years or older, or 50 years or older with comorbidities (weakened immune system, heart disease, hypertension, asthma or lung disease, diabetes, mild hepatic impairment, stroke or neurological problem, and self-reported obesity or body-mass index of 35 kg/m2 or greater), who had been unwell (for ≤14 days) with suspected COVID-19 or a positive PCR test for SARS-CoV-2 infection in the community. Participants were randomly assigned using response adaptive randomisation to usual care only, usual care plus oral doxycycline (200 mg on day 1, then 100 mg once daily for the following 6 days), or usual care plus other interventions. The interventions reported in this manuscript are usual care plus doxycycline and usual care only; evaluations of other interventions in this platform trial are ongoing. The coprimary endpoints were time to first self-reported recovery, and hospitalisation or death related to COVID-19, both measured over 28 days from randomisation and analysed by intention to treat. This trial is ongoing and is registered with ISRCTN, 86534580.FindingsThe trial opened on April 2, 2020. Randomisation to doxycycline began on July 24, 2020, and was stopped on Dec 14, 2020, because the prespecified futility criterion was met; 2689 participants were enrolled and randomised between these dates. Of these, 2508 (93·3%) participants contributed follow-up data and were included in the primary analysis: 780 (31·1%) in the usual care plus doxycycline group, 948 in the usual care only group (37·8%), and 780 (31·1%) in the usual care plus other interventions group. Among the 1792 participants randomly assigned to the usual care plus doxycycline and usual care only groups, the mean age was 61·1 years (SD 7·9); 999 (55·7%) participants were female and 790 (44·1%) were male. In the primary analysis model, there was little evidence of difference in median time to first self-reported recovery between the usual care plus doxycycline group and the usual care only group (9·6 [95% Bayesian Credible Interval [BCI] 8·3 to 11·0] days vs 10·1 [8·7 to 11·7] days, hazard ratio 1·04 [95% BCI 0·93 to 1·17]). The estimated benefit in median time to first self-reported recovery was 0·5 days [95% BCI −0·99 to 2·04] and the probability of a clinically meaningful benefit (defined as ≥1·5 days) was 0·10. Hospitalisation or death related to COVID-19 occurred in 41 (crude percentage 5·3%) participants in the usual care plus doxycycline group and 43 (4·5%) in the usual care only group (estimated absolute percentage difference −0·5% [95% BCI −2·6 to 1·4]); there were five deaths (0·6%) in the usual care plus doxycycline group and two (0·2%) in the usual care only group.InterpretationIn patients with suspected COVID-19 in the community in the UK, who were at high risk of adverse outcomes, treatment with doxycycline was not associated with clinically meaningful reductions in time to recovery or hospital admissions or deaths related to COVID-19, and should not be used as a routine treatment for COVID-19.FundingUK Research and Innovation, Department of Health and Social Care, National Institute for Health Research.

A Novel Method for Mendelian Randomization Analyses With Pleiotropy and Linkage Disequilibrium in Genetic Variants From Individual Data.

Mendelian randomization makes use of genetic variants as instrumental variables to eliminate the influence induced by unknown confounders on causal estimation in epidemiology studies. However, with the soaring genetic variants identified in genome-wide association studies, the pleiotropy, and linkage disequilibrium in genetic variants are unavoidable and may produce severe bias in causal inference. In this study, by modeling the pleiotropic effect as a normally distributed random effect, we propose a novel mixed-effects regression model-based method PLDMR, pleiotropy and linkage disequilibrium adaptive Mendelian randomization, which takes linkage disequilibrium into account and also corrects for the pleiotropic effect in causal effect estimation and statistical inference. We conduct voluminous simulation studies to evaluate the performance of the proposed and existing methods. Simulation results illustrate the validity and advantage of the novel method, especially in the case of linkage disequilibrium and directional pleiotropic effects, compared with other methods. In addition, by applying this novel method to the data on Atherosclerosis Risk in Communications Study, we conclude that body mass index has a significant causal effect on and thus might be a potential risk factor of systolic blood pressure. The novel method is implemented in R and the corresponding R code is provided for free download.

The properties of entropy as a measure of randomness in a clinical trial

We study entropy as a measure of randomness in a sequential clinical trial. For any randomization design, we consider the well-known sequence of conditional treatment assignment probabilities, Pn, which complements the random allocation proportion. We then use Pn to formulate and prove a statement about conditions for the asymptotic mean entropy of a randomization design to achieve its optimum value. We compare both response-adaptive and non response adaptive randomization designs with respect to the asymptotic mean entropy, connecting the variance of Pn to the asymptotic mean entropy under normality. Then we explore whether both Pn, as well as the allocation proportion, may have zero asymptotic variance.

A practical response adaptive block randomization (RABR) design with analytic type I error protection

Response adaptive randomization (RAR) is appealing from methodological, ethical, and pragmatic perspectives in the sense that subjects are more likely to be randomized to better performing treatment groups based on accumulating data. However, applications of RAR in confirmatory drug clinical trials with multiple active arms are limited largely due to its complexity, and lack of control of randomization ratios to different treatment groups. To address the aforementioned issues, we propose a Response Adaptive Block Randomization (RABR) design allowing arbitrarily prespecified randomization ratios for the control and high-performing groups to meet clinical trial objectives. We show the validity of the conventional unweighted test in RABR with a controlled type I error rate based on the weighted combination test for sample size adaptive design invoking no large sample approximation. The advantages of the proposed RABR in terms of robustly reaching target final sample size to meet regulatory requirements and increasing statistical power as compared with the popular Doubly Adaptive Biased Coin Design are demonstrated by statistical simulations and a practical clinical trial design example.

Optimal protamine dosing after cardiopulmonary bypass: The PRODOSE adaptive randomised controlled trial

The dose of protamine required following cardiopulmonary bypass (CPB) is often determined by the dose of heparin required pre-CPB, expressed as a fixed ratio. Dosing based on mathematical models of heparin clearance is postulated to improve protamine dosing precision and coagulation. We hypothesised that protamine dosing based on a 2-compartment model would improve thromboelastography (TEG) parameters and reduce the dose of protamine administered, relative to a fixed ratio. We undertook a 2-stage, adaptive randomised controlled trial, allocating 228 participants to receive protamine dosed according to a mathematical model of heparin clearance or a fixed ratio of 1 mg of protamine for every 100 IU of heparin required to establish anticoagulation pre-CPB. A planned, blinded interim analysis was undertaken after the recruitment of 50% of the study cohort. Following this, the randomisation ratio was adapted from 1:1 to 1:1.33 to increase recruitment to the superior arm while maintaining study power. At the conclusion of trial recruitment, we had randomised 121 patients to the intervention arm and 107 patients to the control arm. The primary endpoint was kaolin TEG r-time measured 3 minutes after protamine administration at the end of CPB. Secondary endpoints included ratio of kaolin TEG r-time pre-CPB to the same metric following protamine administration, requirement for allogeneic red cell transfusion, intercostal catheter drainage at 4 hours postoperatively, and the requirement for reoperation due to bleeding. The trial was listed on a clinical trial registry (ClinicalTrials.gov Identifier: NCT03532594). Participants were recruited between April 2018 and August 2019. Those in the intervention/model group had a shorter mean kaolin r-time (6.58 [SD 2.50] vs. 8.08 [SD 3.98] minutes; p = 0.0016) post-CPB. The post-protamine thromboelastogram of the model group was closer to pre-CPB parameters (median pre-CPB to post-protamine kaolin r-time ratio 0.96 [IQR 0.78-1.14] vs. 0.75 [IQR 0.57-0.99]; p < 0.001). We found no evidence of a difference in median mediastinal/pleural drainage at 4 hours postoperatively (140 [IQR 75-245] vs. 135 [IQR 94-222] mL; p = 0.85) or requirement (as a binary outcome) for packed red blood cell transfusion at 24 hours postoperatively (19 [15.8%] vs. 14 [13.1%] p = 0.69). Those in the model group had a lower median protamine dose (180 [IQR 160-210] vs. 280 [IQR 250-300] mg; p < 0.001). Important limitations of this study include an unblinded design and lack of generalisability to certain populations deliberately excluded from the study (specifically children, patients with a total body weight >120 kg, and patients requiring therapeutic hypothermia to <28°C). Using a mathematical model to guide protamine dosing in patients following CPB improved TEG r-time and reduced the dose administered relative to a fixed ratio. No differences were detected in postoperative mediastinal/pleural drainage or red blood cell transfusion requirement in our cohort of low-risk patients. ClinicalTrials.gov Unique identifier NCT03532594.

Using pharmacopuncture for chronic tension-type headache treatment

Objective: assessing pharmacopuncture effect on pain syndrome and level of anxiety-depressive disorders in patients with chronic tension-type headache (CTTH). Materials and methods. An open-label controlled trial was conducted on 95 CTTH patients split among two groups by means of adaptive randomization. The comparison group subjects were receiving 35-70 mg/day of amitriptyline and 450 mg/day of tolperisone, while patients of the treatment group were assigned 2-4 courses of pharmacopuncture by the original method. The results were evaluated on the basis of the scores obtained via Visual Analogue Scale (VAS), McGill Pain Questionnaire, Beck Depression Inventory (BDI), and State-Trait Anxiety Inventory (STAI) sensu Ch. Spielberger and Yu. Khanin. Results. Patients in both clinical groups were inclined to a positive evaluation of received treatment. Based on the results of McGill Pain Questionnaire, we determined both affective and sensory pain descriptors, with a predominance of the latter. Both groups exhibited moderate depressive symptoms according to BDI of the psychological status. Prevalence of trait anxiety over reactive anxiety was determined by STAI. According to VAS, pain intensity after the treatment declined from 5.26±0.87 to 1.7±0.78 points (p&lt;0.05) and from 5.17±0.78 to 1.65±0.79 (p&lt;0.05) in the comparison group versus the treatment group. An improvement of anxiety and depression indicators was detected. Conclusion. Our results have demonstrated that pharmacopuncture is very promising in treating CTTH patients

Effect of a phone reminder system on patient-centered tuberculosis treatment adherence among adults in Northwest Ethiopia: a randomised controlled trial

ObjectivesThis study aimed to evaluate the effect of the phone reminder system on patient-centred TB treatment adherence during continuation phase, where patients are responsible for taking medication at home.MethodsWe conducted...