Proper understanding of recurrent stress urinary incontinence treatment in women (PURSUIT): a randomised controlled trial of endoscopic and surgical treatment

BACKGROUND

Women with stress urinary incontinence (SUI) experience urine leakage with physical activity. Currently, the interventional treatments for SUI are surgical, or endoscopic bulking injection(s). However, these procedures are not always successful, and symptoms can persist or come back after treatment, categorised as recurrent SUI. There are longstanding symptoms and distress associated with a failed primary treatment, and currently, there is no consensus on how best to treat women with recurrent, or persistent, SUI.

METHODS

A two-arm trial, set in at least 20 National Health Service (NHS) urology and urogynaecology referral units in the UK, randomising 250 adult women with recurrent or persistent SUI 1:1 to receive either an endoscopic intervention (endoscopic bulking injections) or a standard NHS surgical intervention, currently colposuspension, autologous fascial sling or artificial urinary sphincter. The aim of the trial is to determine whether surgical treatment is superior to endoscopic bulking injections in terms of symptom severity at 1 year after randomisation. This primary outcome will be measured using the patient-reported International Consultation on Incontinence Questionnaire - Urinary Incontinence - Short Form (ICIQ-UI-SF). Secondary outcomes include assessment of longer-term clinical impact, improvement of symptoms, safety, operative assessments, sexual function, cost-effectiveness and an evaluation of patients' and clinicians' views and experiences of the interventions.

DISCUSSION

There is a lack of high-quality, randomised, scientific evidence for which treatment is best for women presenting with recurrent SUI. The PURSUIT study will benefit healthcare professionals and patients and provide robust evidence to guide further treatment and improve symptoms and quality of life for women with this condition.

TRIAL REGISTRATION

International Standard Randomised Controlled Trials Number (ISRCTN) registry ISRCTN12201059. Registered on 09 January 2020.

Design of BET Inhibitor Bottlebrush Prodrugs with Superior Efficacy and Devoid of Systemic Toxicities

Prodrugs engineered for preferential activation in diseased versus normal tissues offer immense potential to improve the therapeutic indexes (TIs) of preclinical and clinical-stage active pharmaceutical ingredients that either cannot be developed otherwise or whose efficacy or tolerability it is highly desirable to improve. Such approaches, however, often suffer from trial-and-error design, precluding predictive synthesis and optimization. Here, using bromodomain and extra-terminal (BET) protein inhibitors (BETi)-a class of epigenetic regulators with proven anticancer potential but clinical development hindered in large part by narrow TIs-we introduce a macromolecular prodrug platform that overcomes these challenges. Through tuning of traceless linkers appended to a "bottlebrush prodrug" scaffold, we demonstrate correlation of in vitro prodrug activation kinetics with in vivo tumor pharmacokinetics, enabling the predictive design of novel BETi prodrugs with enhanced antitumor efficacies and devoid of dose-limiting toxicities in a syngeneic triple-negative breast cancer murine model. This work may have immediate clinical implications, introducing a platform for predictive prodrug design and potentially overcoming hurdles in drug development.

Strategies to Improve Recruitment to a De-escalation Trial: A Mixed-Methods Study of the OPTIMA Prelim Trial in Early Breast Cancer

AIMS

De-escalation trials are challenging and sometimes may fail due to poor recruitment. The OPTIMA Prelim randomised controlled trial (ISRCTN42400492) randomised patients with early stage breast cancer to chemotherapy versus 'test-directed' chemotherapy, with a possible outcome of no chemotherapy, which could confer less treatment relative to routine practice. Despite encountering challenges, OPTIMA Prelim reached its recruitment target ahead of schedule. This study reports the root causes of recruitment challenges and the strategies used to successfully overcome them.

MATERIALS AND METHODS

A mixed-methods recruitment intervention (QuinteT Recruitment Intervention) was used to investigate the recruitment difficulties and feedback findings to inform interventions and optimise ongoing recruitment. Quantitative site-level recruitment data, audio-recorded recruitment appointments (n = 46), qualitative interviews (n = 22) with trialists/recruiting staff (oncologists/nurses) and patient-facing documentation were analysed using descriptive, thematic and conversation analyses. Findings were triangulated to inform a 'plan of action' to optimise recruitment.

RESULTS

Despite best intentions, oncologists' routine practices complicated recruitment. Discomfort about deviating from the usual practice of recommending chemotherapy according to tumour clinicopathological features meant that not all eligible patients were approached. Audio-recorded recruitment appointments revealed how routine practices undermined recruitment. A tendency to justify chemotherapy provision before presenting the randomised controlled trial and subtly indicating that chemotherapy would be more/less beneficial undermined equipoise and made it difficult for patients to engage with OPTIMA Prelim. To tackle these challenges, individual and group recruiter feedback focussed on communication issues and vignettes of eligible patients were discussed to address discomforts around approaching patients. 'Tips' documents concerning structuring discussions and conveying equipoise were disseminated across sites, together with revisions to the Patient Information Sheet.

CONCLUSIONS

This is the first study illuminating the tension between oncologists' routine practices and recruitment to de-escalation trials. Although time and resources are required, these challenges can be addressed through specific feedback and training as the trial is underway.

Publisher Correction: Reduction of liver fibrosis by rationally designed macromolecular telmisartan prodrugs

In the version of this Article originally published, the author Peter Blume-Jensen was not denoted as a corresponding author; this has now been amended and the author's email address has been added. The 'Correspondence and requests for materials' statement was similarly affected and has now been updated with the author's initials 'P.B-J.'

Reduction of liver fibrosis by rationally designed macromolecular telmisartan prodrugs

At present there are no drugs for the treatment of chronic liver fibrosis that have been approved by the Food and Drug administration of the United States. Telmisartan, a small-molecule antihypertensive drug, displays antifibrotic activity, but its clinical use is limited because it causes systemic hypotension. Here, we report the scalable and convergent synthesis of macromolecular telmisartan prodrugs optimized for preferential release in diseased liver tissue. We optimized the release of active telmisartan in fibrotic liver to be depot-like (that is, a constant therapeutic concentration) through the molecular design of telmisartan brush-arm star polymers, and show that these lead to improved efficacy and to the avoidance of dose-limiting hypotension in both metabolically and chemically induced mouse models of hepatic fibrosis, as determined by histopathology, enzyme levels in the liver, intact-tissue protein markers, hepatocyte necrosis protection, and gene-expression analyses. In rats and dogs, the prodrugs are retained long-term in liver tissue and have a well-tolerated safety profile. Our findings support the further development of telmisartan prodrugs that enable infrequent dosing in the treatment of liver fibrosis.

Abstract LB-062: Development of macromolecular prodrugs of BET-bromodomain inhibitors with superior anti-tumor efficacy that are T-cell sparing and devoid of systemic toxicity

Small molecule BET inhibitors are promising anti-cancer agents, but their clinical development has been limited by hematological and gastrointestinal (GI) toxicity. For the prototype benzodiazepine-derived inhibitor (OTX-015), the dose-limiting toxicities (DLTs) are thrombocytopenia (96%), anemia (91%), and neutropenia (51%) with additional GI events (diarrhea, vomiting and mucositis) reported to limit patient compliance despite evidence of durable/objective tumor responses. Accordingly, based on a review of entries in www.clinicaltrials.gov from January 2017 to January 2018, 11 out of 12 programs are reporting protracted phase I/II development times and reduced patient enrollment targets. To improve the narrow therapeutic index of current BET inhibitors, we here report the development of macromolecular BET inhibitor prodrugs with a favorable bio-distribution and release of active drug in tumor compared to other tissues, including gut and bone marrow.

We successfully conjugated two structurally distinct BET inhibitors, including the OTX-015, to Brush polymers using an array of different linker chemistries and evaluated them for in vivo efficacy and toxicity using immunocompetent, orthotopically implanted mouse tumor models. Through rational design of drug conjugation and linker chemistry, we optimized the PK properties and drug release rates offering a ‘depot-like' release of drug in tumor tissue resulting in both improved efficacy and reduction of systemic dose-limiting toxicity. Specifically, these novel formulations were evaluated for myelosuppression and GI toxicity using an array of in vitro, clinical pathology and immunohistopathology techniques. Compared to non-conjugated BET inhibitors, which showed dose-dependent body weight loss, diarrhea, and suppression of white blood cells, the macromolecular BET-BRUSH prodrugs spared the lymphocytes, platelets and neutrophils and showed minimal suppression of the reservoir of myeloid cells in the bone marrow. The improved therapeutic index of the BET-Brush compounds was confirmed through detailed PK/PD/Efficacy studies correlating the concentration of both released and polymer-bound BET inhibitor in tumor and plasma with quantitative tissue biomarker modulation (c-MYC, HEXIM-1 and CD180). Whole organ bio-distribution studies using fluorophore-conjugated BET-Brush confirmed the favorable distribution into tumor over the gut and bone marrow, with BET-Brush showing profound modulation of biomarkers in tumor tissue, but not gut. Notably, the BET-Brush compounds showed suppression of PD-L1 expression in tumors, which in context of preserved T-cells, can make BET-Brush a promising combination with immuno-oncology therapy. Paired with an excellent safety profile of the polymer backbone in rat and non-human primates, these data support the further development of BET-Brush prodrugs as an infrequently dosed treatment for human cancers.

Citation Format: Farrukh Vohidov, Jannik N. Andersen, Kyriakos D. Economides, Michail V. Shipitsin, Olga Burenkova, Nolan M. Gallagher, Peyton Sheih, Matthew Golder, Jenny Liu, William K. Dahlberg, Hung V. Nguyen, Deborah J. Ehrlich, Julie Kim, Sung Jin Huh, Bhavatarini Vangamudi, Allison M. Neenan, James C. Ackley, Joelle Baddour, Sattanathan Paramasivan, Gaurab KC, David J. Turnquist, Jenny K. Saucier-Sawyer, Paul W. Kopesky, Samantha W. Brady, Michael J. Jessel, Lawrence A. Reiter, Donald E. Chickering, Jeremiah A. Johnson, Peter Blume-Jensen. Development of macromolecular prodrugs of BET-bromodomain inhibitors with superior anti-tumor efficacy that are T-cell sparing and devoid of systemic toxicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-062.

Adaptation of the By-Band randomized clinical trial to By-Band-Sleeve to include a new intervention and maintain relevance of the study to practice

Background

Recruitment into surgical RCTs can be threatened if new interventions available outside the trial compete with those being evaluated. Adapting the trial to include the new intervention may overcome this issue, yet this is not often done in surgery. This paper describes the challenges, rationale and methods for adapting an RCT to include a new intervention.

Methods

The By‐Band study was designed in the UK in 2009–2010 to compare the effectiveness of laparoscopic adjustable gastric band and Roux‐en‐Y gastric bypass for severe obesity. It contained a pilot phase to establish whether recruitment was possible, and the grant proposal specified that an adaptation to include sleeve gastrectomy would be considered if practice changed and recruitment was successful. Information on changing obesity surgery practice, updated evidence and expert opinion about trial design were used to inform the adaptation.

Results

The pilot phase recruited over 13 months in 2013–2014 and randomized 80 patients (79 anticipated). During this time, major changes in obesity practice in the UK were observed, with gastric band reducing from 32·6 to 15·8 per cent and sleeve gastrectomy increasing from 9·0 to 28·1 per cent. The evidence base had not changed markedly. The British Obesity and Metabolic Surgery Society and study oversight committees supported an adaptation to include sleeve gastrectomy, and a proposal to do so was approved by the funder.

Conclusion

Adaptation of a two‐group surgical RCT can allow evaluation of a third procedure and maintain relevance of the RCT to practice. It also optimizes the use of existing trial infrastructure to answer an additional important research question. Registration number: ISRCTN00786323 (http://www.isrctn.com/).

Something to consider

Mix and measure fluorescence screening for selective quadruplex binders

The human genome contains thousands of regions, including that of the telomere, that have the potential to form quadruplex structures. Many of these regions are potential targets for therapeutic intervention. There are many different folding patterns for quadruplex DNAs and the loops exhibit much more variation than do the quartets. The successful targeting of a particular quadruplex structure requires distinguishing that structure from all of the other quadruplex structures that may be present. A mix and measure fluorescent screening method has been developed, that utilizes multiple reporter molecules that bind to different features of quadruplex DNA. The reporter molecules are used in combination with DNAs that have a variety of quadruplex structures. The screening is based on observing the increase or decrease in the fluorescence of the reporter molecules. The selectivity of a set of test molecules has been determined by this approach.

Circular dichroism of quadruplex DNAs: applications to structure, cation effects and ligand binding

Circular dichroism, CD, spectra can be used to gain information about quadruplex structures of DNAs as well as the effects of sequence, cations, chemical modification and ligand binding on quadruplex structure. There is not yet a validated approach to calculate a CD spectrum from a quadruplex structure nor is their one to go from a CD spectrum to a structure. However, it is possible to empirically correlate CD spectra features with quadruplex structural type in many cases. In this article four case studies are presented to indicate the strengths and limitations of CD in investigations of the properties of quadruplex structures formed by telomere repeat sequences. The case studies include determination of the quadruplex structural type present as a function of potassium concentration, the effect of sequence on the equilibrium between quadruplex structural types as a function of potassium concentration, the effect of ligand binding on quadruplex structure and the effect of 5' phosphorylation on quadruplex structural type.