Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high-risk, early breast cancer.

BACKGROUND: The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety. PATIENTS AND METHODS: One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015. RESULTS: With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome. CONCLUSION: With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

Renal impairment after ileostomy formation: a frequent event with long-term consequences.

AIM: High stoma output and dehydration is common following ileostomy formation. However, the impact of this on renal function, both in the short term and after ileostomy reversal, remains poorly defined. We aimed to assess the independent impact on kidney function of an ileostomy after rectal cancer surgery and subsequent reversibility after ileostomy closure. METHODS: This retrospective single-site cohort study identified patients undergoing rectal cancer resection from 2003 to 2017, with or without a diverting ileostomy. Renal function was calculated preoperatively, before ileostomy closure, and 6 months after ileostomy reversal (or matched times for patients without ileostomy). Demographics, oncological treatments and nephrotoxic drug prescriptions were assessed. Outcome measures were deterioration from baseline renal function and development of moderate/severe chronic kidney disease (CKD ≥ 3). Multivariate analysis was performed to assess independent risk factors for postoperative renal impairment. RESULTS: Five hundred and eighty-three of 1213 patients had an ileostomy. Postoperative renal impairment occurred more frequently in ileostomates (9.5% absolute increase in rate of CKD ≥ 3; P < 0.0001) vs no change in patients without an ileostomy (P = 0.757). Multivariate analysis identified ileostomy formation, age, anastomotic leak and renin-angiotensin system inhibitors as independently associated with postoperative renal decline. Despite stoma closure, ileostomates remained at increased risk of progression to new or worse CKD [74/438 (16.9%)] compared to patients without an ileostomy [36/437 (8.2%), P = 0.0001, OR 2.264 (1.49-3.46)]. CONCLUSIONS: Ileostomy formation is independently associated with kidney injury, with an increased risk persisting after stoma closure. Strategies to protect against kidney injury may be important in higher risk patients (elderly, receiving renin-angiotensin system antihypertensives, or following anastomotic leakage).

The Brain's Reward Response Occurs Even Without Actual Reward!

What if the brain's response to reward occurs even when there is no reward? Wouldn't that be a further concern for people prone to problem gambling and other forms of addiction, like those related to eating? Electroencephalography was employed to investigate this possibility using probabilistic feedback manipulations and measures of known event-related potentials (ERPs) related to reward processing. We tested the hypothesis-that reward-based ERPs would occur even in the absence of a tangible reward and when manipulations on expectation are implicit. The well-known P300 response potential was a key focus, and was assessed in non-gambling volunteer undergraduates on a task involving experimentally-manipulated probabilities of positive or negative feedback comprising three trial types-80, 50, or 20% positive feedback. A feedback stimulus (F1) followed a guess response between two possible outcomes (implicit win/loss), and then a second feedback stimulus (F2) was presented to confirm an alleged 'win' or 'loss' (explicit win/loss). Results revealed that amplitude of the P300 in F1-locked data (implicit manipulation) was larger (more positive) on average for feedback outcomes that were manipulated to be less likely than expected. The effect is pronounced after increased time on task (later trials), even though the majority of participants were not explicitly aware of our probability manipulations. For the explicit effects in F2-locked data, no meaningful or significant effects were observed. These findings point to the existence of proposed success-response mechanisms that operate not only explicitly but also with implicit manipulations that do not involve any direct indication of a win or loss, and are not associated with tangible rewards. Thus, there seems to be a non-explicit form of perception (we call 'implicit') associated with an internal experience of wins/losses (in the absence of actual rewards or losses) that can be measured in associated brain processes. The potential significance of these findings is discussed in terms of implications for problem gambling.

Cytomegalovirus pre-emptive therapy after hematopoietic stem cell transplantation in the era of real-time quantitative PCR: comparison with recipients of solid organ transplants.

BACKGROUND: Cytomegalovirus (CMV) continues to be an important complication of hematopoietic stem cell transplantation and solid organ transplantation. METHODS: In this study, 314 patients who underwent hematopoietic stem cell transplantation between January 2003 and October 2011 were tested serially for CMV DNA by real-time quantitative polymerase chain reaction (qPCR) for 90 days post transplantation. Patients with CMV viremia >3000 genomes/mL (equivalent to 2520 IU/mL) received pre-emptive therapy and were compared with previously published data from solid organ transplant (SOT) patients monitored and treated in exactly the same way. RESULTS: After stem cell transplant (SCT), 48% of patients developed at least 1 episode of viremia. The median duration of a viremic episode was 25 days and the peak viral load (VL) was 4784 genomes/mL whole blood (equivalent to 4019 IU/mL). The data demonstrated that recipients with positive CMV serostatus were at increased risk of developing viremia, with 0% of donor-negative/recipient-negative (D-R-), 3.7% of D+R-, 79.5% of D-R+, and 74.2% of D+R+ groups developing viremia over follow-up (adjusted hazard ratio for D+R- vs. D+R+ group 0.03; 95% confidence interval 0.004, 0.18; P = 0.0013). In contrast with SOT patients, where 58/74 (78%) D+R- patients had viremia, a low risk of CMV infection was seen after stem cell transplantation (1/27; 3.7%). CONCLUSION: As both groups of patients, the previously published SOT patients and the present hematopoietic SCT patients, were monitored using the same protocol and qPCR assay with pre-emptive therapy administered at the same VL cutoffs, the distinct differences seen cannot be explained by differences in testing or management and thus emphasize distinct aspects of the natural history of CMV infection post transplant in these 2 patient groups.

Phase I study of olaparib plus gemcitabine in patients with advanced solid tumours and comparison with gemcitabine alone in patients with locally advanced/metastatic pancreatic cancer.

BACKGROUND: Olaparib (Lynparza) is an oral poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitor that induces synthetic lethality in cancers with homologous recombination defects. PATIENTS AND METHODS: In this phase I, dose-escalation trial, patients with advanced solid tumours received olaparib (50-200 mg capsules b.i.d.) continuously or intermittently (days 1-14, per 28-day cycle) plus gemcitabine [i.v. 600-800 mg/m(2); days 1, 8, 15, and 22 (cycle 1), days 1, 8, and 15 (subsequent cycles)] to establish the maximum tolerated dose. A separate dose-escalation phase evaluated olaparib in tablet formulation (100 mg o.d./b.i.d.; days 1-14) plus gemcitabine (600 mg/m(2)). In an expansion phase, patients with genetically unselected locally advanced or metastatic pancreatic cancer were randomised 2 : 1 to the tolerated olaparib capsule combination dose or gemcitabine alone (1000 mg/m(2)). RESULTS: Sixty-six patients were treated [dose-escalation phase, n = 44 (tablet cohort, n = 12); dose-expansion phase, n = 22 (olaparib plus gemcitabine, n = 15; gemcitabine alone, n = 7)]. In the dose-escalation phase, four patients (6%) experienced dose-limiting toxicities (raised alanine aminotransferase, n = 2; neutropenia, n = 1; febrile neutropenia, n = 1). Grade ≥3 adverse events were reported in 38/47 patients (81%) treated with olaparib capsules plus gemcitabine; most common were haematological toxicities (55%). Tolerated combinations were olaparib 100 mg b.i.d. capsule (intermittently, days 1-14) plus gemcitabine 600 mg/m(2) and olaparib 100 mg o.d. tablet (intermittently, days 1-14) plus gemcitabine 600 mg/m(2). There were no differences in efficacy observed during the dose-expansion phase. CONCLUSIONS: Olaparib 100 mg b.i.d. (intermittent dosing; capsules) plus gemcitabine 600 mg/m(2) is tolerated in advanced solid tumour patients, with no unmanageable/unexpected toxicities. Continuous dosing of olaparib or combination with gemcitabine at doses >600 mg/m(2) was not considered to have an acceptable tolerability profile for further study. CLINICALTRIALSGOV: NCT00515866.

Engaging medical physics students in active and authentic learning through the use of monte-carlo simulation and inverse treatment planning.

PURPOSE: Engagement and participation of students with the learning process has been recognised as a growing problem across the higher education sector. The aim of this study was to investigate the value and impact of introducing Problem-based Learning (PBL) activities into a radiotherapy physics unit of a postgraduate medical physics course. METHODS: Computer-based problem solving activities on 1) monte-carlo modelling of a linear accelerator and 2) inverse radiotherapy treatment planning were designed and implemented into a one-semester unit on radiotherapy physics. The value and impact of the activities on the student learning were evaluated through student surveys, a focus group, and peer observation of the sessions by members of the learning design team. Student attendance and grade profile data are also reported. RESULTS: Overall the results indicated that students had a positive experience with the new problem solving activities that were implemented. Survey responses from a number of students indicated a desire for increased theoretical and technical support prior to and during activities. Another underlying theme that emerged from survey and focus group response was the perceived lack of reward in terms of marks for their efforts working on the learning activities. This may have influenced students' choices around attendance and participation. No significant changes were noted in the overall grades achieved in the unit. CONCLUSIONS: Students appreciated the more hands-on approach to learning in the form of more authentic activities that they could directly relate to clinical radiotherapy. Further work is required to update and integrate assessment into the new learning delivery model more directly.

Validation and automation of the DYNJAWS component module of the BEAMnrc Monte Carlo code.

The purpose of this work is to validate and automate the use of DYNJAWS; a new component module (CM) in the BEAMnrc Monte Carlo (MC) user code. The DYNJAWS CM simulates dynamic wedges and can be used in three modes; dynamic, step-and-shoot and static. The step-and-shoot and dynamic modes require an additional input file defining the positions of the jaw that constitutes the dynamic wedge, at regular intervals during its motion. A method for automating the generation of the input file is presented which will allow for the more efficient use of the DYNJAWS CM. Wedged profiles have been measured and simulated for 6 and 10 MV photons at three field sizes (5 cm × 5 cm, 10 cm × 10 cm and 20 cm × 20 cm), four wedge angles (15°, 30°, 45° and 60°), at d (max) and at 10 cm depth. Results of this study show agreement between the measured and the MC profiles to within 3% of absolute dose or 3 mm distance to agreement for all wedge angles at both energies and depths. The gamma analysis suggests that dynamic mode is more accurate than the step-and-shoot mode. The DYNJAWS CM is an important addition to the BEAMnrc code and will enable the MC verification of patient treatments involving dynamic wedges.

Modeling a complex micro-multileaf collimator using the standard BEAMnrc distribution.

PURPOSE: The component modules in the standard BEAMnrc istribution may appear to be insufficient to model micro-multileaf collimators that have trifaceted leaf ends and complex leaf profiles. This note indicates, however, that accurate Monte Carlo simulations of radiotherapy beams defined by a complex collimation device can be completed using BEAMnrc's standard VARMLC component module. METHODS: That this simple collimator model can produce spatially and dosimetrically accurate microcollimated fields is illustrated using comparisons with ion chamber and film measurements of the dose deposited by square and irregular fields incident on planar, homogeneous water phantoms. RESULTS: Monte Carlo dose calculations for on-axis and off-axis fields are shown to produce good agreement with experimental values, even on close examination of the penumbrae. CONCLUSIONS: The use of a VARMLC model of the micro-multileaf collimator, along with a commissioned model of the associated linear accelerator, is therefore recommended as an alternative to the development or use of in-house or third-party component modules for simulating stereotactic radiotherapy and radiosurgery treatments. Simulation parameters for the VARMLC model are provided which should allow other researchers to adapt and use this model to study clinical stereotactic radiotherapy treatments.

Characterization of Gamma Knife Perfexion™ source based on Monte Carlo simulation.

This study is aimed at characterizing a single Cobalt-60 source capsule of the Gamma Knife Perfexion™ unit using the BEAMnrc Monte Carlo code. The Gamma Knife Perfexion™ source capsule was modeled using the BEAMnrc user code according to the manufacturer's technical details. The modeled parts include the source, the area around the source, and the capsule. The cylindrical source is 1 mm in diameter and 17 mm in length, with a physical density (ρ) of 8.9 × 103 kg/m3. The simulation parameters were an electron cutoff energy (ECUT) of 0.7 meV and photon cutoff energy (PCUT) of 0.01 meV. Energy fluence was calculated on a 0.25 cm diameter scoring plane located 3.1 cm from the source. Simulations were performed with and without the encapsulation of the source to investigate its effect on the spectrum and fluence of emitted gamma rays. The results showed that the influence of source encapsulation on the gamma rays is an increase in the relative number of particles in each energy bin of aggregate gamma rays by 92.36% at 0.23 meV energy and 66.12% at 1.10 meV energy. The secondary gamma rays were found to increase by 94.17% at 0.23 meV energy and 63.74% at 1.10 meV energy. The encapsulation of the source attenuated the gamma rays, which altered the spectrum. The mean energy of the beam increased, thereby exhibiting a beam-hardening effect.

Radiobiological model comparison of 3D conformal radiotherapy and IMRT plans for the treatment of prostate cancer.

The main aim of radiotherapy is to deliver a dose of radiation that is high enough to destroy the tumour cells while at the same time minimising the damage to normal healthy tissues. Clinically, this has been achieved by assigning a prescription dose to the tumour volume and a set of dose constraints on critical structures. Once an optimal treatment plan has been achieved the dosimetry is assessed using the physical parameters of dose and volume. There has been an interest in using radiobiological parameters to evaluate and predict the outcome of a treatment plan in terms of both a tumour control probability (TCP) and a normal tissue complication probability (NTCP). In this study, simple radiobiological models that are available in a commercial treatment planning system were used to compare three dimensional conformal radiotherapy treatments (3D-CRT) and intensity modulated radiotherapy (IMRT) treatments of the prostate. Initially both 3D-CRT and IMRT were planned for 2 Gy/fraction to a total dose of 60 Gy to the prostate. The sensitivity of the TCP and the NTCP to both conventional dose escalation and hypo-fractionation was investigated. The biological responses were calculated using the Källman S-model. The complication free tumour control probability (P+) is generated from the combined NTCP and TCP response values. It has been suggested that the alpha/beta ratio for prostate carcinoma cells may be lower than for most other tumour cell types. The effect of this on the modelled biological response for the different fractionation schedules was also investigated.

Effects of collimator backscatter in an Elekta linac by Monte Carlo simulation.

The effects of radiation backscattered from the secondary collimators into the monitor chamber in an Elekta linac (producing 6 and 10 MV photon beams) are investigated using BEAMnrc Monte Carlo simulations. The degree and effects of this backscattered radiation are assessed by evaluating the changes to the calculated dose in the monitor chamber, and by determining a correction factor for those changes. Additionally, the fluence and energy characteristics of particles entering the monitor chamber from the downstream direction are evaluated by examining BEAMnrc phase-space data. It is shown that the proportion of particles backscattered into the monitor chamber is small (< 0.35%), for all field sizes studied. However, when the backscatter plate is removed from the model linac, these backscattered particles generate a noticeable increase in dose to the monitor chamber (up to approximately 2.4% for the 6 MV beam and up to 4.4% for the 10 MV beam). With its backscatter plate in place, the Elekta linac (operating at 6 and 10 MV) is subject to negligible variation of monitor chamber dose with field size. At these energies, output variations in photon beams produced by the clinical Elekta linear accelerator can be attributed to head scatter alone. Corrections for field-size-dependence of monitor chamber dose are not necessary when running Monte Carlo simulations of the Elekta linac operating at 6 and 10 MV.

Saturation of postsynaptic glutamate receptors after quantal release of transmitter.

Miniature excitatory postsynaptic currents (mEPSCs) were elicited from small numbers of release sites after brief microperfusion of Ba2+ and K+ onto proximal dendritic processes of hippocampal neurons in culture. Temporal summation of closely timed mEPSCs deviated significantly from linearity. The number of instances of closely timed mEPSCs that were also closely matched in terms of peak amplitudes was significantly greater than that expected by chance. Amplitude pairing became statistically more significant after prolongation of mEPSC duration and inhibition of glutamate receptor desensitization with cyclothiazide. These results are best explained by postsynaptic receptors that approach saturation after quantal release of transmitter.

Allogeneic haematopoietic stem cell transplant in Philadelphia-positive acute lymphoblastic leukaemia.

ALL in which the Philadelphia (Ph) chromosome is detected is one of the few diseases in which there is almost unequivocal agreement that a matched sibling allogeneic haematopoietic stem cell transplant in first CR is the most appropriate therapy for patients within certain age limits. Extension of allogeneic stem cell transplant to patients without matched sibling donors or to older individuals is increasingly possible due to unrelated donors, umbilical cord blood and reduced-intensity conditioning regimens. Here, we carefully review evidence supporting current practice and examine recent evidence relating to the use of newer allogeneic transplant technologies in Ph-pos ALL. We explore the burgeoning literature on the role of tyrosine kinase inhibitors in this disease and summarize their impact on the transplant practice.

Latent autoimmune diabetes in adults (LADA) in South Wales: incidence and characterization.

AIM: To define the incidence and characteristics of latent autoimmune diabetes in adults (LADA). METHODS: We estimated the incidence of LADA by examining the incidence of Type 2 diabetes and calculating the proportion that were antibody positive. The incidence of Type 2 diabetes was calculated by analysis of computer records of 35 out of 36 general practices in Swansea. In addition, thirty-two practices participated in recruiting people with Type 2 diabetes to have glutamic acid decarboxylase (GAD) antibody testing. RESULTS: The crude proportion of Type 2 patients testing positive for GAD antibodies (GADA) was 4.0% (28/683). This figure did not change when we analysed only the practices that tested more than 60% of all eligible patients. In these practices, 79% (387/487) of all eligible patients were GADA tested and 14/387 [3.6% (95% confidence interval: 2.1-6.1%)] were classified as having LADA. This gives an incidence of LADA of 9 per 100,000 (95% confidence interval: 4.4-17.8 per 100,000) people per year registered with a general practitioner. Patients testing positive for GADA were more likely to have a lower body mass index, other antibodies, to present with acute symptoms and to have higher glycated haemoglobin. CONCLUSIONS: This is the first study of the incidence of LADA in primary care. People with LADA make up a significant proportion of people with apparent Type 2 diabetes. Patients with LADA are likely to be symptomatic, have poorer glycaemic control and have other autoimmune antibodies.

Radiotherapy treatment verification using radiological thickness measured with an amorphous silicon electronic portal imaging device: Monte Carlo simulation and experiment.

This work validates the use of an amorphous-silicon, flat-panel electronic portal imaging device (a-Si EPID) for use as a gauge of patient or phantom radiological thickness, as an alternative to dosimetry. The response of the a-Si EPID is calibrated by adapting a technique previously applied to scanning liquid ion chamber EPIDs, and the stability, accuracy and reliability of this calibration are explored in detail. We find that the stability of this calibration, between different linacs at the same centre, is sufficient to justify calibrating only one of the EPIDs every month and using the calibration data thus obtained to perform measurements on all of the other linacs. Radiological thickness is shown to provide a reliable means of relating experimental measurements to the results of BEAMnrc Monte Carlo simulations of the linac-phantom-EPID system. For these reasons we suggest that radiological thickness can be used to verify radiotherapy treatment delivery and identify changes in the treatment field, patient position and target location, as well as patient physical thickness.

Altered Nuclear Expression of the Deubiquitylase BAP1 Cannot be Used as a Prognostic Marker for Canine Melanoma.

BRCA1-associated protein-1 (BAP1) is a nuclear localized deubiquitylating enzyme that belongs to the ubiquitin c-terminal hydrolase subfamily. The encoded protein is highly homologous between man and dogs, suggesting a functional significance preserved by evolution. BAP1 has multiple properties, including tumour suppressor activity. Loss of BAP1 function is implicated in the oncogenesis of several types of cancers including uveal, mucosal and some cutaneous melanomas in humans, as well as in mesothelioma. In this study we investigate the significance of BAP1 in canine melanoma. Nuclear BAP1 protein was detected in five canine oral melanoma cell lines using an antibody commonly used for analysis of human tissues. BAP1 loss of function mutations often lead to loss of nuclear BAP1 (nBAP1) expression in humans; this is associated with a poorer prognosis in uveal and mucosal melanoma. Therefore, as a prelude to a study evaluating the prognostic significance of nBAP1 expression in dogs, immunohistochemistry (IHC) was used to assess cases of canine melanoma for nBAP1 expression. In 89 cases where tumour cells were identified by melan-A labelling, 100% of tumour cells were positive for nBAP1 expression, including eight uveal tract and 29 oral mucosal melanomas. This finding indicates that BAP1 IHC cannot be used as a prognostic marker in canine uveal and mucosal melanoma. Moreover, this observation suggests that either BAP1 has a different functional significance in canine melanoma or that loss of BAP1 function is achieved by a different route. This is a novel finding that warrants further investigation to determine the comparative biological relevance.

Amorphous silicon EPID calibration for dosimetric applications: comparison of a method based on Monte Carlo prediction of response with existing techniques.

For EPID dosimetry, the calibration should ensure that all pixels have a similar response to a given irradiation. A calibration method (MC), using an analytical fit of a Monte Carlo simulated flood field EPID image to correct for the flood field image pixel intensity shape, was proposed. It was compared with the standard flood field calibration (FF), with the use of a water slab placed in the beam to flatten the flood field (WS) and with a multiple field calibration where the EPID was irradiated with a fixed 10x10 field for 16 different positions (MF). The EPID was used in its normal configuration (clinical setup) and with an additional 3 mm copper slab (modified setup). Beam asymmetry measured with a diode array was taken into account in MC and WS methods. For both setups, the MC method provided pixel sensitivity values within 3% of those obtained with the MF and WS methods (mean difference<1%, standard deviation<2%). The difference of pixel sensitivity between MC and FF methods was up to 12.2% (clinical setup) and 11.8% (modified setup). MC calibration provided images of open fields (5x5 to 20x20 cm2) and IMRT fields to within 3% of that obtained with WS and MF calibrations while differences with images calibrated with the FF method for fields larger than 10x10 cm2 were up to 8%. MC, WS and MF methods all provided a major improvement on the FF method. Advantages and drawbacks of each method were reviewed.

The evolving role of chemotherapy and hematopoietic cell transplants in Ph-positive acute lymphoblastic leukemia in adults.

The introduction of the tyrosine kinase inhibitors (TKI) into the treatment of patients with Ph or BCR-ABL1-positive acute lymphoblastic leukemia has revolutionized the treatment of this poor prognosis acute leukemia. The combination of TKI with chemotherapy has improved response rates and allowed more patients to proceed to allogeneic hematopoietic cell transplant (alloHCT). Older patients have excellent responses to TKI and corticosteroids or in combination with minimal chemotherapy. This raises the question as to whether patients require full-intensity chemotherapy with TKI to achieve molecular remissions. The pediatricians have proposed that cure is achievable without alloHCT in children. These results have suggested that many patients may not require traditional chemotherapy in addition to TKI to achieve remission, and that patients who achieve a negative minimal residual disease state may not require alloHCT. The data in support of these questions is presented here and a suggested future clinical trial design based on these data is proposed.

Pegylated-asparaginase during induction therapy for adult acute lymphoblastic leukaemia: toxicity data from the UKALL14 trial.

Safety and efficacy data on pegylated asparaginase (PEG-ASP) in adult acute lymphoblastic leukaemia (ALL) induction regimens are limited. The UK National Cancer Research Institute UKALL14 trial NCT01085617 prospectively evaluated the tolerability of 1000 IU/m2 PEG-ASP administered on days 4 and 18 as part of a five-drug induction regimen in adults aged 25-65 years with de novo ALL. Median age was 46.5 years. Sixteen of the 90 patients (median age 56 years) suffered treatment-related mortality during initial induction therapy. Eight of the 16 died of sepsis in combination with hepatotoxicity. Age and Philadelphia (Ph) status were independent variables predicting induction death >40 versus ⩽40 years, odds ratio (OR) 18.5 (2.02-169.0), P=0.01; Ph- versus Ph+ disease, OR 13.60 (3.52-52.36), P<0.001. Of the 74 patients who did not die, 37 (50.0%) experienced at least one grade 3/4 PEG-ASP-related adverse event, most commonly hepatotoxicity (36.5%, n=27). A single dose of PEG-ASP achieved trough therapeutic enzyme levels in 42/49 (86%) of the patients tested. Although PEG-ASP delivered prolonged asparaginase activity in adults, it was difficult to administer safely as part of the UKALL14 intensive multiagent regimen to those aged >40 years. It proved extremely toxic in patients with Ph+ ALL, possibly owing to interaction with imatinib.