Recombinant fragment of human surfactant protein D to prevent neonatal chronic lung disease (RESPONSE): a protocol for a phase I safety trial in a tertiary neonatal unit.

INTRODUCTION: Chronic respiratory morbidity from bronchopulmonary dysplasia (BPD) remains the most common complication of preterm birth and has consequences for later respiratory, cardiovascular and neurodevelopmental outcomes. The early phases of respiratory illness are characterised by rapid consumption of endogenous surfactant and slow replenishment. Exogenous surfactant is routinely administered to infants born before 28 weeks of gestation as prophylaxis. Endogenous surfactant includes four proteins, known as surfactant proteins (SPs) A, B, C and D. Current bovine-derived and porcine-derived surfactant preparations only contain SPs B and C. SP-D has a key role in lung immune homeostasis as part of the innate immune system. Laboratory studies using recombinant SP-D have demonstrated reduced inflammation, which may be a pathway to reducing the associated morbidity from BPD. RESPONSE uses a recombinant fragment of human SP D (rfhSP-D), in a phase I safety and dose-escalation trial as the first stage in determining its effect in humans. METHODS AND ANALYSIS: This is a single-centre, dose-escalation, phase I safety study aiming to recruit 24 infants born before 30 weeks gestation with respiratory distress syndrome. In addition to routine surfactant replacement therapy, participants will receive three doses of rfhSP-D via endotracheal route at either 1 mg/kg, 2 mg/kg or 4 mg/kg. The study uses a Bayesian continual reassessment method to make dose escalation decisions. Dose-limiting events (DLE) in this trial will be graded according to the published Neonatal Adverse Event Severity Score. The primary outcome of this study is to evaluate the safety profile of rfhSP-D across each dose level based on the profile of DLE to establish the recommended phase 2 dose (RP2D) of rfhSP-D. ETHICS AND DISSEMINATION: The RESPONSE study has received ethical approval from London-Brent NHS Research Health Authority ethics committee. Results from the study will be published in peer-reviewed journals and presented at national and international conferences. TRIAL REGISTRATION NUMBERS: ISRCTN17083028, NCT05898633. PROTOCOL VERSION: RESPONSE Protocol V.4.0 24th July 2024.

Predicting radiotherapy response, Toxicities and quality-of-life related functional outcomes in soft tissue sarcoma of the extremities (PredicT) using dose-volume constraints development: a study protocol.

INTRODUCTION: Radiotherapy improves local tumour control in patients with soft tissue sarcoma of the extremities (STSE) but it also increases the probability of long-term toxicities such as tissue fibrosis, joint stiffness and lymphoedema. The use of radiation dose and volume thresholds, called dose constraints, may potentially reduce the development of toxicities in STSE. The aim of this study is to determine predictors of radiotherapy-related side effects for STSE. METHODS AND ANALYSIS: Predicting radiotherapy response, Toxicities and quality-of-life related functional outcomes in soft tissue sarcoma of the extremities (PredicT) is a multicentre observational study comprising two cohorts (PredicT A and B). PredicT A, a retrospective analysis of the UK VorteX (NCT00423618) and IMRiS clinical trials (NCT02520128), is aimed at deriving a statistical model for development of dose-volume constraints. This model will use receiving operator characteristics and multivariate analysis to predict radiotherapy side effects and patient-reported outcomes. PredicT B, a prospective cohort study of 150 patients with STSE, is aimed at testing the validity of those dose-volume constraints. PredicT B is open and planned to complete recruitment by September 2024. ETHICS AND DISSEMINATION: PredicT B has received ethical approval from North West - Liverpool Central Research Ethics Committee (20/NW/0267). Participants gave informed consent to participate in the study before taking part. We will disseminate our findings via publications, presentations, national and international conference meetings and engage with local charities. TRIAL REGISTRATION NUMBER: NCT05978024.

Elicitation of expert prior opinion to design the BARJDM trial in juvenile dermatomyositis.

OBJECTIVES: To elicit and quantify expert opinion concerning the relative merits of two treatments for a rare inflammatory disease: Juvenile dermatomyositis (JDM). The formal expression of expert opinion reported in this paper will be used in a Bayesian analysis of a forthcoming randomised controlled trial known as BARJDM (baricitinib for juvenile dermatomyositis). METHODS: A Bayesian prior elicitation meeting was convened, following a previously described methodological template. Opinion was sought on the probability that a patient in the BARJDM trial would achieve clinically inactive disease, off glucocorticoids (GC) within a 12-month period with either methotrexate (standard of care); or baricitinib (a Janus kinase inhibitor, JAKi), with GC schedules identical in both arms of the trial. Experts' views were discussed and refined following presentation and further discussion of summated published data regarding efficacy of methotrexate or JAKi for JDM. RESULTS: Ten UK paediatric rheumatology consultants (including one adolescent paediatric rheumatologist) participated in the elicitation meeting. All had expertise in JDM, leading active National Health Service clinics for this disease. Consensus expert prior opinion was that the most likely probability of clinically inactive disease off GC within 12 months was 0.55 on baricitinib and 0.23 on methotrexate, with a greater degree of uncertainty for baricitinib. CONCLUSION: Experts currently think that baricitinib is superior to MTX for the treatment of JDM, although there is uncertainty around this. BARJDM will therefore integrate randomised trial data with this expert prior opinion to derive a posterior distribution for the relative efficacy of baricitinib compared with MTX.

Feasibility of a new 'balanced binocular viewing' treatment for unilateral amblyopia in children aged 3-8 years (BALANCE): results of a phase 2a randomised controlled feasibility trial.

OBJECTIVES: This study aimed to evaluate the safety of dichoptic balanced binocular viewing (BBV) for amblyopia in children, plus feasibility, adherence, acceptability, trial methodology and clinical measures of visual function. DESIGN: We carried out an observer-masked parallel-group phase 2a feasibility randomised controlled trial. SETTING: Two study sites, a secondary/tertiary and a community site. PARTICIPANTS: We enrolled 32 children aged 3-8 years with unilateral amblyopia who had completed optical adaptation where indicated. 20 children attended the 16-week exit visit (retention 63%). INTERVENTIONS: Children were randomised to BBV (movies customised to interocular acuity difference at baseline) for 1 hour a day (active intervention) or standard management as per parental choice (part-time occlusion or atropine blurring, control). All interventions were used at home, daily for 16 weeks. PRIMARY OUTCOME MEASURE: 'VacMan suppression test' of interocular balance at 16 weeks from randomisation. SECONDARY OUTCOME MEASURES: feasibility outcomes (recruitment and retention ratios, adherence with the allocated intervention); safety outcomes at other time points (changes in prevalence of diplopia, manifest strabismus, suppression/interocular balance on a range of tests); efficacy outcomes (clinical measures of visual function, such as best-corrected visual acuity, BCVA). Outcome measures were identical to those planned in the protocol. RESULTS: Primary outcome: At baseline, values for the interocular balance point were higher (indicating greater suppression of the amblyopic eye) in the occlusion group than in the BBV group. These values shifted downwards on average for the occlusion group, significantly decreasing from baseline to week 16 (t8=4.49, p=0.002). Balance values did not change between baseline and week 16 for the BBV group (t9=-0.82, p=0.435). At 16 weeks, there was no statistical difference in interocular balance/suppression change over time between the two arms. The difference at follow-up between the arms, adjusted for baseline, was -0.02 (95% CI -0.28 to 0.23, p=0.87). FEASIBILITY: We prescreened 144 records of potentially eligible children. Between 28 October 2019 and 31 July 2021, including an interruption due to the COVID-19 pandemic, 32 children were screened and randomised (recruitment rate 22%), 16 to BBV and 16 to standard treatment. 20 children attended the 16-week exit visit (retention 63%). Mean adherence with BBV as proportion of viewing time prescribed was 56.1% (SD36) at 8 and 57.9% (SD 30.2) at 16 weeks. Mean adherence with prescribed occlusion time was 90.1% (SD 19.7) at 8 and 59.2% (SD 24.8) at 16 weeks. SECONDARY SAFETY/EFFICACY OUTCOMES: One child in the BBV arm reported transient double vision, which resolved; two reported headaches, which led to withdrawal. BCVA improved from mean 0.47 (SD0.18) logMAR at randomisation to 0.26 (0.14) with standard treatment, and from 0.55 (0.28) to 0.32 (0.26) with BBV. Outcomes at 16 weeks did not differ between treatments. PARTICIPANT EXPERIENCE: Families were generally positive about BBV, but families found both patching and BBV difficult to integrate into family routines. CONCLUSIONS: Recruitment rates indicate that a future phase 3 trial will require multiple sites or a longer enrolment period. Retention and adherence rates were lower than anticipated, which will influence future study designs. Dichoptic treatment may be equal to occlusion treatment in safety and efficacy; headaches may lead to discontinuation. Integration into family routines may constitute a barrier to implementation. TRIAL REGISTRATION NUMBER: NCT03754153.

Implementing and assessing Bayesian response-adaptive randomisation for backfilling in dose-finding trials.

Traditional approaches in dose-finding trials, such as the continual reassessment method, focus on identifying the maximum tolerated dose. In contemporary early-phase dose-finding trials, especially in oncology with targeted agents or immunotherapy, a more relevant aim is to identify the lowest dose level that maximises efficacy whilst remaining tolerable. Backfilling, defined as the practice of assigning patients to dose levels lower than the current highest tolerated dose, has been proposed to gather additional pharmacokinetic, pharmacodynamic and biomarker data to recommend the most appropriate dose to carry forward for subsequent studies. The first formal framework [5] for backfilling proposed randomising backfill patients with equal probability among those doses below the dose level where the study is currently at. Here, we propose to use Bayesian response-adaptive randomisation to backfill patients. This patient-oriented approach to backfilling aims to allocate more patients to dose levels in the backfill set with higher expected efficacy based on emerging data. The backfill set constitutes of the doses below the dose the dose-finding algorithm is at. At study completion, collective patient data inform the dose-response curve, suggesting an optimal dose level balancing toxicity and efficacy. Our simulation study across diverse clinical trial settings demonstrates that a backfilling strategy using Bayesian response-adaptive randomisation can result in a patient-oriented patient assignment procedure which simultaneously enhances the likelihood of correctly identifying the most appropriate dose level. This contribution offers a methodological framework and practical implementation for patient-oriented backfilling, encompassing design and analysis considerations in early-phase trials.

Safety and Efficacy of Metabolic Modulation With Ninerafaxstat in Patients With Nonobstructive Hypertrophic Cardiomyopathy.

BACKGROUND: In nonobstructive hypertrophic cardiomyopathy (nHCM), there are no approved medical therapies. Impaired myocardial energetics is a potential cause of symptoms and exercise limitation. Ninerafaxstat, a novel cardiac mitotrope, enhances cardiac energetics. OBJECTIVES: This study sought to evaluate the safety and efficacy of ninerafaxstat in nHCM. METHODS: Patients with hypertrophic cardiomyopathy and left ventricular outflow tract gradient <30 mm Hg, ejection fraction ≥50%, and peak oxygen consumption <80% predicted were randomized to ninerafaxstat 200 mg twice daily or placebo (1:1) for 12 weeks. The primary endpoint was safety and tolerability, with efficacy outcomes also assessed as secondary endpoints. RESULTS: A total of 67 patients with nHCM were enrolled at 12 centers (57 ± 11.8 years of age; 55% women). Serious adverse events occurred in 11.8% (n = 4 of 34) in the ninerafaxstat group and 6.1% (n = 2 of 33) of patients in the placebo group. From baseline to 12 weeks, ninerafaxstat was associated with significantly better VE/Vco2 (ventilatory efficiency) slope compared with placebo with a least-squares (LS) mean difference between the groups of -2.1 (95% CI: -3.6 to -0.6; P = 0.006), with no significant difference in peak VO2 (P = 0.90). The Kansas City Cardiomyopathy Questionnaire Clinical Summary Score was directionally, though not significantly, improved with ninerafaxstat vs placebo (LS mean 3.2; 95% CI: -2.9 to 9.2; P = 0.30); however, it was statistically significant when analyzed post hoc in the 35 patients with baseline Kansas City Cardiomyopathy Questionnaire Clinical Summary Score ≤80 (LS mean 9.4; 95% CI: 0.3-18.5; P = 0.04). CONCLUSIONS: In symptomatic nHCM, novel drug therapy targeting myocardial energetics was safe and well tolerated and associated with better exercise performance and health status among those most symptomatically limited. The findings support assessing ninerafaxstat in a phase 3 study.

The 3 + 3 design in dose-finding studies with small sample sizes: Pitfalls and possible remedies.

In the last few years, numerous novel designs have been proposed to improve the efficiency and accuracy of phase I trials to identify the maximum-tolerated dose (MTD) or the optimal biological dose (OBD) for noncytotoxic agents. However, the conventional 3+3 approach, known for its and poor performance, continues to be an attractive choice for many trials despite these alternative suggestions. The article seeks to underscore the importance of moving beyond the 3+3 design by highlighting a different key element in trial design: the estimation of sample size and its crucial role in predicting toxicity and determining the MTD. We use simulation studies to compare the performance of the most used phase I approaches: 3+3, Continual Reassessment Method (CRM), Keyboard and Bayesian Optimal Interval (BOIN) designs regarding three key operating characteristics: the percentage of correct selection of the true MTD, the average number of patients allocated per dose level, and the average total sample size. The simulation results consistently show that the 3+3 algorithm underperforms in comparison to model-based and model-assisted designs across all scenarios and metrics. The 3+3 method yields significantly lower (up to three times) probabilities in identifying the correct MTD, often selecting doses one or even two levels below the actual MTD. The 3+3 design allocates significantly fewer patients at the true MTD, assigns higher numbers to lower dose levels, and rarely explores doses above the target dose-limiting toxicity (DLT) rate. The overall performance of the 3+3 method is suboptimal, with a high level of unexplained uncertainty and significant implications for accurately determining the MTD. While the primary focus of the article is to demonstrate the limitations of the 3+3 algorithm, the question remains about the preferred alternative approach. The intention is not to definitively recommend one model-based or model-assisted method over others, as their performance can vary based on parameters and model specifications. However, the presented results indicate that the CRM, Keyboard, and BOIN designs consistently outperform the 3+3 and offer improved efficiency and precision in determining the MTD, which is crucial in early-phase clinical trials.

WAFER trial: a study protocol for a feasibility randomised controlled trial comparing wide-awake local anaesthesia no tourniquet (WALANT) to general and regional anaesthesia with tourniquet for flexor tendon repair.

INTRODUCTION: Flexor tendons are traditionally repaired under either general anaesthesia (GA) or regional anaesthesia (RA), allowing for the use of an arm tourniquet to minimise blood loss and establish a bloodless surgical field. However, the use of tourniquets exposes the patient to certain risks, including skin, muscle and nerve injuries. A recent advancement in anaesthesia delivery involves the use of a wide-awake approach where no sedation nor tourniquets are used (wide-awake local anaesthesia no tourniquet (WALANT)). WALANT uses local anaesthetic with epinephrine to provide pain relief and vasoconstriction, reducing operative bleeding. Several studies revealed potential benefits for WALANT compared with GA or RA. However, there remains a paucity of high-quality evidence to support the use of WALANT. As a result of this uncertainty, the clinical practice varies considerably. We aim to evaluate the feasibility of WALANT as an alternative to GA and RA in patients undergoing surgical repair of flexor tendon injuries. This involves addressing factors such as clinician and patient support for a trial, clinical equipoise, trial recruitment and dropout and the most relevant outcomes measures for a future definitive trial. METHODS AND ANALYSIS: WAFER is a multicentre, single-blinded, parallel group, randomised controlled trial (RCT) to assess the feasibility of WALANT versus RA and GA. The target population is patients with acute traumatic flexor tendon injuries, across 3 major hand surgery units in England involving a total of 60 participants. Outcome assessors will be blinded. The primary outcome will be the ability to recruit patients into the trial, while secondary outcomes include difference in functional outcome, patient-reported outcome measures, health-related quality of life, cost-effectiveness and complication rates. ETHICS AND DISSEMINATION: Ethical approval was obtained from the London-City and East Research Ethics Committee (22/PR/1197). Findings will be disseminated through peer-reviewed publication, conferences, patient information websites and social media networks. TRIAL REGISTRATION NUMBER: ISRCTN identifier: 15052559.