Real-world outcomes of patients with relapsed/refractory large B-cell lymphoma receiving second-line therapy in England.

Autologous stem-cell transplantation (ASCT) is standard therapy for relapsed/refractory large B-cell lymphoma (R/R LBCL), but many patients are either ineligible or unable to receive it. This retrospective study characterized outcomes in R/R LBCL, delineated by eligibility for, and receipt of, ASCT. Median progression-free survival (PFS) and event-free survival (EFS) for patients undergoing ASCT were 35.2 and 31.6 months (overall survival [OS] not reached). Median PFS, EFS, and OS were 4.3, 4.3, and 6.9 months for ineligible patients, and 2.7, 2.6, and 9.4 months for those eligible for but unable to receive ASCT. This highlights an unmet need for alternative therapies in patients unable to receive ASCT.

Treatment outcomes in patients with large B-cell lymphoma after progression to chimeric antigen receptor T-cell therapy.

Over 60% of relapsed/refractory (R/R) large B-cell lymphoma (LBCL) patients who receive chimeric antigen receptor (CAR) T cells will experience disease progression. There is no standard next line of therapy and information in this setting is scarce and heterogeneous. We analyzed 387 R/R LBCL patients who progressed after CAR T cells from July 2018 until March 2022 in Spain and the United Kingdom. Median overall survival (OS) was 5.3 months, with significant differences according to the interval between infusion and progression (<2 months [1.9 months], 2-6 months [5.2 months], and >6 months [not reached]). After progression, 237 (61%) patients received treatment. Focusing on the first subsequent therapy, overall (complete) response rates were 67% (38%) for polatuzumab-bendamustine-rituximab (POLA), 51% (36%) for bispecific antibodies (BsAb), 45% (35%) for radiotherapy (RT), 33% (26%) for immune checkpoint inhibitors (ICIs), 25% (0%) for lenalidomide (LENA), and 25% (14%) for chemotherapy (CT). In terms of survival, 12-month progression-free survival and OS was 36.2% and 51.0% for POLA, 32.0% and 50.1% for BsAb, 30.8% and 37.5% for RT, 29.9% and 27.8% for ICI, 7.3% and 20.8% for LENA, and 6.1% and 18.3% for CT. Thirty-two (14%) patients received an allogeneic hematopoietic cell transplant with median OS not reached after a median follow-up of 15.1 months. In conclusion, patients with R/R LBCL who progress within the first 2 months after CAR T-cell therapy have dismal outcomes. Novel targeted agents, such as polatuzumab and BsAbs, can achieve prolonged survival after CAR T-cell therapy failure.

Ibrutinib as part of risk-stratified treatment for posttransplant lymphoproliferative disorder: the phase 2 TIDaL trial.

ABSTRACT: Posttransplant lymphoproliferative disorder (PTLD) is a rare complication of solid organ transplantation, and cytotoxic chemotherapy is associated with treatment-related morbidity and mortality. Current treatment takes a sequential, risk-stratified approach, and patients with low-risk disease after initial immunotherapy can avoid escalation to immunochemotherapy. TIDaL is a prospective, single-arm phase 2 trial investigating the activity and tolerability of ibrutinib combined with risk-stratified therapy for first-line treatment of PTLD. Eligible patients were adults with newly diagnosed CD20+ B-cell PTLD after solid organ transplant and performance status 0 to 2. Initial treatment comprised 49 days of ibrutinib 560 mg once daily, with 4 doses of weekly rituximab. Treatment response on interim scan and baseline International Prognostic Index were used to allocate patients to either a low-risk arm (who continued ibrutinib, alongside 4 further doses of 3-weekly rituximab) or high-risk (escalation to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone [R-CHOP] immunochemotherapy, with ibrutinib continuing in patients aged <65 years). The primary outcome was complete response on interim scan, achieved by 11 of 38 patients (29%; 95% confidence interval [CI], 15-46). This did not reach the prespecified threshold for clinically significant activity. Secondary outcomes included allocation to the low-risk arm (41% of patients), 2-year progression-free survival (58%; 95% CI, 44-76), and 2-year overall survival (76%; 95% CI, 63-91). Adverse events were mostly hematological, gastrointestinal, and infective. Although TIDaL does not support adding ibrutinib into first-line treatment of PTLD, increasing the proportion of patients who can be treated without cytotoxic chemotherapy remains an important aim of future research. This trial was registered at www.clinicaltrials.gov as #ISRCTN32667607.

Central Venous Access Devices for the Delivery of Systemic Anticancer Therapy: An Economic Evaluation.

OBJECTIVES: Patients undergoing long-term anticancer therapy typically require one of 3 venous access devices: Hickman-type device (HICK), peripherally inserted central catheter (PICC), or implantable chest wall port (PORT). Recent evidence has shown PORT is safer and improves patient satisfaction. However, PORT did not show improvement in quality-adjusted life-years and was more expensive. Decisions regarding cost-effectiveness in the United Kingdom are typically informed by a cost-per-quality-adjusted life-year metric. However, this approach is limited in its ability to capture the full range of relevant outcomes, especially in the context of medical devices. This study assessed the potential cost-effectiveness of HICK, PICC, and PORT in routine clinical practice. METHODS: This is a cost-consequence analysis to determine the trade-offs between the following outcomes: complication, infection, noninfection, chemotherapy interruption, unplanned device removals, health utilities, device insertion cost, follow-up cost, and total cost, using data from the Cancer and Venous Access clinical trial. We conducted value of implementation analysis of a PORT service. RESULTS: PORT was superior in terms of overall complication rate compared with both HICK (incidence rate ratio 0.422; 95% CI 0.286-0.622) and PICC (incidence rate ratio 0.295; 95% CI 0.189-0.458) and less likely to lead to an unplanned device removal. There was no difference in chemotherapy interruption or health utilities. Total cost with device in situ was lower on PORT than HICK (-£98.86; 95% CI -189.20 to -8.53) and comparable with PICC -£48.57 (95% CI -164.99 to 67.86). Value of implementation analysis found that PORT was likely to be considered cost-effective within the National Health Service. CONCLUSION: Decision makers should consider including PORT within the suite of venous access devices available within in the National Health Service.

Tafasitamab for patients with relapsed or refractory diffuse large B-cell lymphoma: final 5-year efficacy and safety findings in the phase II L-MIND study.

Tafasitamab, an anti-CD19 immunotherapy, is used with lenalidomide for patients with autologous stem cell transplant-ineligible relapsed/refractory diffuse large B-cell lymphoma based on the results of the phase II L-MIND study (NCT02399085). We report the final 5-year analysis of this study. Eighty patients ≥18 years who had received one to three prior systemic therapies, and had Eastern Cooperative Oncology Group performance status 0-2 received up to 12 cycles of co-administered tafasitamab and lenalidomide, followed by tafasitamab monotherapy until disease progression or unacceptable toxicity. The primary endpoint was the best objective response rate. Secondary endpoints included duration of response, progression-free survival, overall survival, and safety. Exploratory analyses evaluated efficacy endpoints by prior lines of therapy. At data cutoff on November 14, 2022, the objective response rate was 57.5%, with a complete response rate of 41.3% (n=33), which was consistent with prior analyses. With a median follow-up of 44.0 months, the median duration of response was not reached. The median progression-free survival was 11.6 months (95% confidence interval [95% CI]: 5.7-45.7) with a median follow-up of 45.6 months. The median overall survival was 33.5 months (95% CI: 18.3-not reached) with a median follow-up of 65.6 months. Patients who had received one prior line of therapy (n=40) showed a higher objective response rate (67.5%; 52.5% complete responses) compared to patients who had received two or more prior lines of therapy (n=40; 47.5%; 30% complete responses), but the median duration of response was not reached in either subgroup. Other exploratory analyses revealed consistent long-term efficacy results across subgroups. Adverse events were consistent with those described in previous reports, were manageable, and their frequency decreased during tafasitamab monotherapy, with no new safety concerns. This final 5-year analysis of L-MIND demonstrates that the immunotherapy combination of tafasitamab and lenalidomide is well tolerated and has long-term clinical benefit with durable responses.

Bendamustine plus rituximab for the treatment of Waldenström Macroglobulinemia: Patient outcomes and impact of bendamustine dosing.

Bendamustine and rituximab (BR) therapy is commonly used in the treatment of Waldenström Macroglobulinemia (WM). The impact dose of Bendamustine dose on response and survival outcomes is not well-established, and the impact of its use in different treatment settings is not clear. We aimed to report response rates and survival outcomes following BR, and clarify the impact of depth of response and bendamustine dose on survival. A total of 250 WM patients treated with BR in the frontline or relapsed settings were included in this multicenter, retrospective cohort analysis. Rates of partial response (PR) or better differed significantly between the frontline and relapsed cohorts (91.4% vs 73.9%, respectively; p < 0.001). Depth of response impacted survival outcomes: two-year predicted PFS rates after achieving CR/VGPR vs PR were 96% versus 82%, respectively (p = 0.002). Total bendamustine dose was predictive of PFS: in the frontline setting, PFS was superior in the group receiving ≥1000 mg/m2 compared with those receiving 800-999 mg/m2 (p = 0.04). In the relapsed cohort, those who received doses of <600 mg/m2 had poorer PFS outcomes compared with those who received ≥600 mg/m2 (p = 0.02). Attaining CR/VGPR following BR results in superior survival, and total bendamustine dose significantly impacts response and survival outcomes, in both frontline and relapsed settings.

Use of a real-world synthetic control arm for direct comparison of lisocabtagene maraleucel and conventional therapy in relapsed/refractory large B-cell lymphoma.

This study used a real-world population as a synthetic comparator for the single-arm TRANSCEND NHL 001 study (TRANSCEND; NCT02631044) to evaluate the efficacy of lisocabtagene maraleucel (liso-cel) compared with conventional (noncellular) therapies in patients with relapsed/refractory (R/R) large B-cell lymphoma (LBCL). Inclusion and exclusion criteria for the real-world study closely matched the enrollment criteria in TRANSCEND. The analytic comparator cohort was created by matching and balancing observed baseline characteristics of real-world patients with those in TRANSCEND using propensity score methodology. Efficacy outcomes comparing liso-cel- (n = 257) and conventional therapy-treated (n = 257) patients, respectively, significantly favored liso-cel: overall response rate (74% vs 39%; p < 0.0001), complete response rate (50% vs 24%; p < 0.0001), median overall survival (23.5 vs 6.8 months; p < 0.0001), and median progression-free survival (3.5 vs 2.2 months; p < 0.0001). These results demonstrated a statistically significant and clinically meaningful benefit of liso-cel in patients with third- or later-line R/R LBCL relative to conventional therapies.Clinical trial registration: ClinicalTrials.gov identifier: NCT02631044.

Biallelic TET2 mutations confer sensitivity to 5'-azacitidine in acute myeloid leukemia.

Precision medicine can significantly improve outcomes for patients with cancer, but implementation requires comprehensive characterization of tumor cells to identify therapeutically exploitable vulnerabilities. Here, we describe somatic biallelic TET2 mutations in an elderly patient with acute myeloid leukemia (AML) that was chemoresistant to anthracycline and cytarabine but acutely sensitive to 5'-azacitidine (5'-Aza) hypomethylating monotherapy, resulting in long-term morphological remission. Given the role of TET2 as a regulator of genomic methylation, we hypothesized that mutant TET2 allele dosage affects response to 5'-Aza. Using an isogenic cell model system and an orthotopic mouse xenograft, we demonstrate that biallelic TET2 mutations confer sensitivity to 5'-Aza compared with cells with monoallelic mutations. Our data argue in favor of using hypomethylating agents for chemoresistant disease or as first-line therapy in patients with biallelic TET2-mutated AML and demonstrate the importance of considering mutant allele dosage in the implementation of precision medicine for patients with cancer.

A qualitative service evaluation of patient and caregiver experiences of CAR-T therapy: Recommendations for service development and implications for palliative care teams.

BACKGROUND: Chimeric Antigen-Receptor-T-cell (CAR-T) therapy is a potentially life-saving treatment for refractory haematological malignancies. Internationally, CAR-T services are undergoing rapid development. Despite this, research on the lived experiences of patients receiving novel immunotherapies is limited. Little is known about their supportive care needs. Consequently, dedicated palliative and supportive care services may not be considered. AIM: To explore the patient and caregiver experience of CAR-T therapy and identify unmet needs to inform service development. DESIGN: A qualitative longitudinal service evaluation. Sixteen interviews were conducted between December 2020 and March 2021 with patients (n = 10) and family caregivers (n = 4). Thematic analysis was underpinned by a constructivist approach. SETTING/PARTICIPANTS: All patients and caregivers attending one UK centre for CAR-T therapy were eligible. Semi-structured interviews were conducted at specific time points: prior to infusion, one month after infusion and follow-up post-treatment (5-18 months). RESULTS: Identified themes described the unique challenges of CAR-T therapy. From the point of referral patients had a wide range of supportive care needs. Initially, this was attributed to prior receipt of multiple failed treatments. Subsequently, CAR-T side-effects impacted on quality-of-life and physical function. Significant psychological morbidity from prognostic uncertainty was described throughout. Patients and caregivers reported that a dedicated nurse specialist - an expert, consistent point of contact - was essential. CONCLUSION: Patients and caregivers would benefit from early and ongoing support from palliative care, allied-health professionals and psychology. As indications for CAR-T therapy expand, there is an urgent need for multi-centre studies incorporating patient-reported outcome data to ensure patient-centred service delivery.

A national service for delivering CD19 CAR-Tin large B-cell lymphoma - The UK real-world experience.

CD19 CAR-T have emerged as a new standard treatment for relapsed/refractory (r/r) large B-cell lymphoma (LBCL). CAR-T real-world (RW) outcomes published to date suggest significant variability across countries. We provide results of a large national cohort of patients intended to be treated with CAR-T in the UK. Consecutive patients with r/r LBCL approved for CAR-T by the National CAR-T Clinical Panel between December 2018 and November 2020 across all UK CAR-T centres were included. 404/432 patients were approved [292 axicabtagene ciloleucel (axi-cel), 112 tisagenlecleucel (tisa-cel)], 300 (74%) received the cells. 110/300 (38.3%) patients achieved complete remission (CR) at 6 months (m). The overall response rate was 77% (52% CR) for axi-cel, 57% (44% CR) for tisa-cel. The 12-month progression-free survival was 41.8% (axi-cel) and 27.4% (tisa-cel). Median overall survival for the intention-to-treat population was 10.5 m, 16.2 m for infused patients. The incidence of grade ≥3 cytokine release syndrome and neurotoxicity were 7.6%/19.6% for axi-cel and 7.9%/3.9% for tisa-cel. This prospective RW population of CAR-T eligible patients offers important insights into the clinical benefit of CD19 CAR-T in LBCL in daily practice. Our results confirm long-term efficacy in patients receiving treatment similar to the pivotal trials, but highlight the significance of early CAR-T failure.

Addition of four doses of rituximab to standard induction chemotherapy in adult patients with precursor B-cell acute lymphoblastic leukaemia (UKALL14): a phase 3, multicentre, randomised controlled trial.

BACKGROUND: Treatment for adults with acute lymphoblastic leukaemia requires improvement. UKALL14 was a UK National Cancer Research Institute Adult ALL group study that aimed to determine the benefit of adding the anti-CD20 monoclonal antibody, rituximab, to the therapy of adults with de novo B-precursor acute lymphoblastic leukaemia. METHODS: This was an investigator-initiated, phase 3, randomised controlled trial done in all UK National Health Service Centres treating patients with acute lymphoblastic leukaemia (65 centres). Patients were aged 25-65 years with de-novo BCR-ABL1-negative acute lymphoblastic leukaemia. Patients with de-novo BCR-ABL1-positive acute lymphoblastic leukaemia were eligible if they were aged 19-65 years. Participants were randomly assigned (1:1) to standard-of-care induction therapy or standard-of-care induction therapy plus four doses of intravenous rituximab (375 mg/m2 on days 3, 10, 17, and 24). Randomisation used minimisation and was stratified by sex, age, and white blood cell count. No masking was used for patients, clinicians, or staff (including the trial statistician), although the central laboratory analysing minimal residual disease and CD20 was masked to treatment allocation. The primary endpoint was event-free survival in the intention-to-treat population. Safety was assessed in all participants who started trial treatment. This study is registered with ClincialTrials.gov, NCT01085617. FINDINGS: Between April 19, 2012, and July 10, 2017, 586 patients were randomly assigned to standard of care (n=292) or standard of care plus rituximab (n=294). Nine patients were excluded from the final analysis due to misdiagnosis (standard of care n=4, standard of care plus rituximab n=5). In the standard-of-care group, median age was 45 years (IQR 22-65), 159 (55%) of 292 participants were male, 128 (44%) were female, one (<1%) was intersex, and 143 (59%) of 244 participants had high-risk cytogenetics. In the standard-of-care plus rituximab group, median age was 46 years (IQR 23-65), 159 (55%) of 294 participants were male, 130 (45%) were female, and 140 (60%) of 235 participants had high-risk cytogenetics. After a median follow-up of 53·7 months (IQR 40·3-70·4), 3-year event-free survival was 43·7% (95% CI 37·8-49·5) for standard of care versus 51·4% (45·4-57·1) for standard of care plus rituximab (hazard ratio [HR] 0·85 [95% CI 0·69-1·06]; p=0·14). The most common adverse events were infections and cytopenias, with no difference between the groups in the rates of adverse events. There were 11 (4%) fatal (grade 5) events in induction phases 1 and 2 in the standard-of-care group and 13 (5%) events in the standard-of-care plus rituximab group). 3-year non-relapse mortality was 23·7% (95% CI 19·0-29·4) in the standard-of-care group versus 20·6% (16·2-25·9) in the standard-of-care plus rituximab group (HR 0·88 [95% CI 0·62-1·26]; p=0·49). INTERPRETATION: Standard of care plus four doses of rituximab did not significantly improve event-free survival over standard of care. Rituximab is beneficial in acute lymphoblastic leukaemia but four doses during induction is likely to be insufficient. FUNDING: Cancer Research UK and Blood Cancer UK.

In-vivo T-cell depleted reduced-intensity conditioned allogeneic haematopoietic stem-cell transplantation for patients with acute lymphoblastic leukaemia in first remission: results from the prospective, single-arm evaluation of the UKALL14 trial.

BACKGROUND: The outcome of chemotherapy in patients older than 40 years with acute lymphoblastic leukaemia is poor and myeloablative allogeneic haematopoietic stem-cell transplantation (HSCT) has a high transplant-related mortality (TRM) in this age cohort. The aim of this study was to assess the activity and safety of reduced-intensity conditioned allogeneic HSCT in this patient population. METHODS: This was a single-arm, prospective study within the UKALL14 trial done in 46 centres in the UK, which recruited patients to the transplantation substudy. Participants in UKALL14 had B-cell or T-cell acute lymphoblastic leukaemia, were aged 25-65 years (BCR-ABL1-negative) or 18-65 years (BCR-ABL1-positive), and for this subcohort had a fit, matched sibling donor or an 8 out of 8 allelic matched unrelated donor (HLA-A, HLA-B, HLA-C, and HLA-DR). On June 20, 2014, the protocol was amended to allow 7 out of 8 matched unrelated donors if the patient had high risk cytogenetics or was minimal residual disease (MRD)-positive after the second induction course. Patients were given fludarabine, melphalan, and alemtuzumab (FMA; intravenous fludarabine 30 mg/m2 on days -6 to -2, melphalan 140 mg/m2 on day -2, and alemtuzumab 30 mg on day -1 [sibling donor] and days -2 and -1 [unrelated donor]) before allogeneic HSCT (aged ≥41 years patient pathway). Donor lymphocyte infusions were given from 6 months for mixed chimerism or MRD. The primary endpoint was event-free survival and secondary and transplantation-specific endpoints included overall survival, relapse incidence, TRM, and acute and chronic graft-versus-host disease (GVHD). This study is registered with ClinicalTrials.gov, NCT01085617. FINDINGS: From Feb 22, 2011, to July 26, 2018, 249 patients (236 aged ≥41 years and 13 younger than 41 years) considered unfit for a myeloablative allograft received an FMA reduced-intensity conditioned HSCT. 138 (55%) patients were male and 111 (45%) were female. 88 (35%) participants received transplantations from a sibling donor and 160 (64%) received transplantations from unrelated donors. 211 (85%) participants had B-precursor acute lymphoblastic leukaemia. High-risk cytogenetics were present in 43 (22%) and another 63 (25%) participants were BCR-ABL1-positive. At median follow-up of 49 months (IQR 36-70), 4-year event-free survival was 46·8% (95% CI 40·1-53·2) and 4-year overall survival was 54·8% (48·0-61·2). 4-year cumulative incidence of relapse was 33·6% (27·9-40·2) and 4-year TRM was 19·6% (15·1-25·3). 27 (56%) of 48 patients with TRM had infection as the named cause of death. Seven (15%) of 48 patients had fungal infections, 13 (27%) patients had bacterial infections (six gram-negative), and 11 (23%) had viral infections (three cytomegalovirus and two Epstein-Barr virus). Acute GVHD grade 2-4 occurred in 29 (12%) of 247 patients and grade 3-4 occurred in 12 (5%) patients. Chronic GVHD incidence was 84 (37%) of 228 patients (50 [22%] had extensive chronic GVHD). 49 (30%) of 162 patients had detectable end-of-induction MRD, which portended worse outcomes with event-free survival (HR 2·40 [95% CI 1·46-3·93]) and time-to-relapse (HR 2·41 [1·29-4·48]). INTERPRETATION: FMA reduced-intensity conditioned allogeneic HSCT in older patients with acute lymphoblastic leukaemia in first complete remission provided good disease control with moderate GVHD, resulting in better-than-expected event-free survival and overall survival in this high-risk population. Strategies to reduce infection-related TRM will further improve outcomes. FUNDING: Cancer Research UK.

Immune responses against SARS-CoV-2 variants after two and three doses of vaccine in B-cell malignancies: UK PROSECO study.

Patients with hematological malignancies are at increased risk of severe COVID-19 outcomes due to compromised immune responses, but the insights of these studies have been compromised due to intrinsic limitations in study design. Here we present the PROSECO prospective observational study ( NCT04858568 ) on 457 patients with lymphoma that received two or three COVID-19 vaccine doses. We show undetectable humoral responses following two vaccine doses in 52% of patients undergoing active anticancer treatment. Moreover, 60% of patients on anti-CD20 therapy had undetectable antibodies following full vaccination within 12 months of receiving their anticancer therapy. However, 70% of individuals with indolent B-cell lymphoma displayed improved antibody responses following booster vaccination. Notably, 63% of all patients displayed antigen-specific T-cell responses, which increased after a third dose irrespective of their cancer treatment status. Our results emphasize the urgency of careful monitoring of COVID-19-specific immune responses to guide vaccination schemes in these vulnerable populations.

Selumetinib in combination with dexamethasone for the treatment of relapsed/refractory RAS-pathway mutated paediatric and adult acute lymphoblastic leukaemia (SeluDex): study protocol for an international, parallel-group, dose-finding with expansion phase I/II trial.

INTRODUCTION: Event-free survival rates at 15 years for paediatric patients with relapsed/refractory acute lymphoblastic leukaemia (ALL) are 30%-50%, with 5-year survival for adult patients only 20%. Many patients with newly diagnosed and relapsed ALL harbour somatic RAS-signalling activation mutations. Induction therapy for ALL involves steroids, with preclinical data suggesting the combination of dexamethasone with the MEK1/2 inhibitor, selumetinib (ARRY-142886) has a synergistic anticancer effect. METHODS AND ANALYSIS: The SeluDex trial is an international, parallel-group, dose-finding with expansion, phase I/II trial to assess the selumetinib/dexamethasone combination in adult and paediatric patients with relapsed/refractory, RAS pathway mutant ALL. The Cancer Research UK Clinical Trials Unit at University of Birmingham is the UK Coordinating Centre, with national hubs in Copenhagen, Denmark; Monza, Italy; Münster, Germany; Paris, France; and Utrecht, Netherlands. Patients with morphologically proven relapsed/refractory or progressive B-cell precursor or T-cell ALL, with demonstrated RAS pathway activating mutations are eligible. Adult patients are >18 years old, ECOG <2 and paediatric <18 years old, Lansky play scale ≥60% or Karnofsky score ≥60%. Phase I primary objective is the recommended phase II dose of selumetinib as defined by occurrence/non-occurrence of dose limiting toxicities using the continual reassessment method; phase II will evaluate preliminary antileukaemic activity of the combination, as defined by morphological response 28 days post-treatment using a Bayesian approach. Target recruitment is between 26 and 42 patients (minimum 13 and maximum 21 per group), depending the number of phase I patients included in phase II. ETHICS AND DISSEMINATION: Medical ethical committees of all the participating countries have approved the study protocol; initial (UK) ethics approval (17/YH/0123) was granted by Yorkshire & The Humber-Leeds West Research Ethics Committee. Participants are required to provide written informed consent/assent. Results will be disseminated through national and international presentations and peer-reviewed publications. TRIAL REGISTRATION NUMBER: ISRCTN92323261.