Durvalumab (MEDI 4736) in combination with extended neoadjuvant regimens in rectal cancer: a study protocol of a randomised phase II trial (PRIME-RT).

BACKGROUND: Advances in multi-modality treatment of locally advanced rectal cancer (LARC) have resulted in low local recurrence rates, but around 30% of patients will still die from distant metastatic disease. In parallel, there is increasing recognition that with radiotherapy and systemic treatment, some patients achieve a complete response and may avoid surgical resection, including in many cases, the need for a permanent stoma. Extended neoadjuvant regimes have emerged to address these concerns. The inclusion of immunotherapy in the neoadjuvant setting has the potential to further enhance this strategy by priming the local immune microenvironment and engaging the systemic immune response. METHODS: PRIME-RT is a multi-centre, open label, phase II, randomised trial for patients with newly diagnosed LARC. Eligible patients will be randomised to receive either: short course radiotherapy (25 Gray in 5 fractions over one week) with concomitant durvalumab (1500 mg administered intravenously every 4 weeks), followed by FOLFOX (85 mg/m2 oxaliplatin, 350 mg folinic acid and 400 mg/m2 bolus 5-fluorouracil (5-FU) given on day 1 followed by 2400 mg/m2 5-FU infusion over 46-48 h, all administered intravenously every 2 weeks), and durvalumab, or long course chemoradiotherapy (50 Gray to primary tumour in 25 fractions over 5 weeks with concomitant oral capecitabine 825 mg/m2 twice per day on days of radiotherapy) with durvalumab followed by FOLFOX and durvalumab. The primary endpoint is complete response rate in each arm. Secondary endpoints include treatment compliance, toxicity, safety, overall recurrence, proportion of patients with a permanent stoma, and survival. The study is translationally rich with collection of bio-specimens prior to, during, and following treatment in order to understand the molecular and immunological factors underpinning treatment response. The trial opened and the first patient was recruited in January 2021. The main trial will recruit up to 42 patients with LARC and commence after completion of a safety run-in that will recruit at least six patients with LARC or metastatic disease. DISCUSSION: PRIME-RT will explore if adding immunotherapy to neoadjuvant radiotherapy and chemotherapy for patients with LARC can prime the tumour microenvironment to improve complete response rates and stoma free survival. Sequential biopsies are a key component within the trial design that will provide new knowledge on how the tumour microenvironment changes at different time-points in response to multi-modality treatment. This expectation is that the trial will provide information to test this treatment within a large phase clinical trial. Trial registration Clinicaltrials.gov NCT04621370 (Registered 9th Nov 2020) EudraCT number 2019-001471-36 (Registered 6th Nov 2020).

Venous access devices for the delivery of long-term chemotherapy: the CAVA three-arm RCT.

BACKGROUND: Venous access devices are used for patients receiving long-term chemotherapy. These include centrally inserted tunnelled catheters or Hickman-type devices (Hickman), peripherally inserted central catheters (PICCs) and centrally inserted totally implantable venous access devices (PORTs). OBJECTIVES: To evaluate the clinical effectiveness, safety, cost-effectiveness and acceptability of these devices for the central delivery of chemotherapy. DESIGN: An open, multicentre, randomised controlled trial to inform three comparisons: (1) peripherally inserted central catheters versus Hickman, (2) PORTs versus Hickman and (3) PORTs versus peripherally inserted central catheters. Pre-trial and post-trial qualitative research and economic evaluation were also conducted. SETTING: This took place in 18 UK oncology centres. PARTICIPANTS: Adult patients (aged ≥ 18 years) receiving chemotherapy (≥ 12 weeks) for either a solid or a haematological malignancy were randomised via minimisation. INTERVENTIONS: Hickman, peripherally inserted central catheters and PORTs. PRIMARY OUTCOME: A composite of infection (laboratory confirmed, suspected catheter related and exit site infection), mechanical failure, venous thrombosis, pulmonary embolism, inability to aspirate blood and other complications in the intention-to-treat population. RESULTS: Overall, 1061 participants were recruited to inform three comparisons. First, for the comparison of peripherally inserted central catheters (n = 212) with Hickman (n = 212), it could not be concluded that peripherally inserted central catheters were significantly non-inferior to Hickman in terms of complication rate (odds ratio 1.15, 95% confidence interval 0.78 to 1.71). The use of peripherally inserted central catheters compared with Hickman was associated with a substantially lower cost (-£1553) and a small decrement in quality-adjusted life-years gained (-0.009). Second, for the comparison of PORTs (n = 253) with Hickman (n = 303), PORTs were found to be statistically significantly superior to Hickman in terms of complication rate (odds ratio 0.54, 95% confidence interval 0.37 to 0.77). PORTs were found to dominate Hickman with lower costs (-£45) and greater quality-adjusted life-years gained (0.004). This was alongside a lower complications rate (difference of 14%); the incremental cost per complication averted was £1.36. Third, for the comparison of PORTs (n = 147) with peripherally inserted central catheters (n = 199), PORTs were found to be statistically significantly superior to peripherally inserted central catheters in terms of complication rate (odds ratio 0.52, 95% confidence interval 0.33 to 0.83). PORTs were associated with an incremental cost of £2706 when compared with peripherally inserted central catheters and a decrement in quality-adjusted life-years gained (-0.018) PORTs are dominated by peripherally inserted central catheters: alongside a lower complications rate (difference of 15%), the incremental cost per complication averted was £104. The qualitative work showed that attitudes towards all three devices were positive, with patients viewing their central venous access device as part of their treatment and recovery. PORTs were perceived to offer unique psychological benefits, including a greater sense of freedom and less intrusion in the context of personal relationships. The main limitation was the lack of adequate power (54%) in the non-inferiority comparison between peripherally inserted central catheters and Hickman. CONCLUSIONS: In the delivery of long-term chemotherapy, peripherally inserted central catheters should be considered a cost-effective option when compared with Hickman. There were significant clinical benefits when comparing PORTs with Hickman and with peripherally inserted central catheters. The health economic benefits were less clear from the perspective of incremental cost per quality-adjusted life-years gained. However, dependent on the willingness to pay, PORTs may be considered to be cost-effective from the perspective of complications averted. FUTURE WORK: The deliverability of a PORTs service merits further study to understand the barriers to and methods of improving the service. TRIAL REGISTRATION: This trial is registered as ISRCTN44504648. FUNDING: This project was funded by the National Institute for Health Research (NHIR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 47. See the NIHR Journals Library website for further project information.

For patients who need long-term chemotherapy delivered through a vein, there are currently three options: (1) a Hickman-type device, which is a flexible tube (central line) inserted underneath the skin on the chest into a large vein; (2) a peripherally inserted central catheter, which is a long line tube inserted into a vein in the arm and passed through a large vein in the chest; and (3) a totally implantable device, which is a small chamber (accessed externally by a needle) that sits underneath the skin, usually in the chest, and goes into a large vein. The Cancer And Venous Access (CAVA) trial compared these devices in > 1000 patients and looked at complications, quality of life, acceptability and value for money. We found that totally implantable devices halved the risk of complications compared with the other two options (which had similar complication rates to each other). We found that patients' quality of life was similar for all three devices, although a quality-of-life measure specific to these devices showed some emotional and psychological benefits in favour of totally implantable devices. All three devices work, although the totally implantable devices are associated with fewer complications and are less intrusive for patients. In the CAVA trial, we found that totally implantable devices are the most costly device to use, followed by the Hickman-type device, with the peripherally inserted central device being the cheapest. This is partly because of the tendency for totally implantable devices to remain in patients for a longer period of time than the other two options. The costs could potentially be reduced by training nurse-led teams to insert totally implantable devices, as already happens with the other two devices. Totally implantable devices can be considered value for money depending on how people value avoiding complications and the quality-of-life benefits for patients.

Central venous access devices for the delivery of systemic anticancer therapy (CAVA): a randomised controlled trial.

BACKGROUND: Hickman-type tunnelled catheters (Hickman), peripherally inserted central catheters (PICCs), and totally implanted ports (PORTs) are used to deliver systemic anticancer treatment (SACT) via a central vein. We aimed to compare complication rates and costs of the three devices to establish acceptability, clinical effectiveness, and cost-effectiveness of the devices for patients receiving SACT. METHODS: We did an open-label, multicentre, randomised controlled trial (Cancer and Venous Access [CAVA]) of three central venous access devices: PICCs versus Hickman (non-inferiority; 10% margin); PORTs versus Hickman (superiority; 15% margin); and PORTs versus PICCs (superiority; 15% margin). Adults (aged ≥18 years) receiving SACT (≥12 weeks) for solid or haematological malignancy from 18 oncology units in the UK were included. Four randomisation options were available: Hickman versus PICCs versus PORTs (2:2:1), PICCs versus Hickman (1:1), PORTs versus Hickman (1:1), and PORTs versus PICCs (1:1). Randomisation was done using a minimisation algorithm stratifying by centre, body-mass index, type of cancer, device history, and treatment mode. The primary outcome was complication rate (composite of infection, venous thrombosis, pulmonary embolus, inability to aspirate blood, mechanical failure, and other) assessed until device removal, withdrawal from study, or 1-year follow-up. This study is registered with ISRCTN, ISRCTN44504648. FINDINGS: Between Nov 8, 2013, and Feb 28, 2018, of 2714 individuals screened for eligibility, 1061 were enrolled and randomly assigned, contributing to the relevant comparison or comparisons (PICC vs Hickman n=424, 212 [50%] on PICC and 212 [50%] on Hickman; PORT vs Hickman n=556, 253 [46%] on PORT and 303 [54%] on Hickman; and PORT vs PICC n=346, 147 [42%] on PORT and 199 [58%] on PICC). Similar complication rates were observed for PICCs (110 [52%] of 212) and Hickman (103 [49%] of 212). Although the observed difference was less than 10%, non-inferiority of PICCs was not confirmed (odds ratio [OR] 1·15 [95% CI 0·78-1·71]) potentially due to inadequate power. PORTs were superior to Hickman with a complication rate of 29% (73 of 253) versus 43% (131 of 303; OR 0·54 [95% CI 0·37-0·77]). PORTs were superior to PICCs with a complication rate of 32% (47 of 147) versus 47% (93 of 199; OR 0·52 [0·33-0·83]). INTERPRETATION: For most patients receiving SACT, PORTs are more effective and safer than both Hickman and PICCs. Our findings suggest that most patients receiving SACT for solid tumours should receive a PORT within the UK National Health Service. FUNDING: UK National Institute for Health Research Health Technology Assessment Programme.

Whole-Slide Imaging of Pap Cellblock Preparations Is a Potentially Valid Screening Method.

OBJECTIVE: To date, the impact of digital imaging on routine cytology remains far from perfect. Cellblock (CB) preparations from Pap samples have been shown to be diagnostically valuable. We evaluated the validity of utilizing whole-slide imaging (WSI) prepared from Pap CBs as a screening tool. STUDY DESIGN: A total of 1,110 CB slides prepared from residual Pap samples were analyzed - 563 normal, 282 atypical squamous cells of undetermined significance (ASCUS), 12 atypical squamous cells-cannot exclude high-grade squamous intraepithelial lesion, 188 low-grade squamous intraepithelial lesions (LSIL), 36 high-grade squamous intraepithelial lesions (HSIL), 25 atypical glandular cells of undetermined significance, 1 adenocarcinoma in situ, 2 invasive adenocarcinomas, and 1 squamous cell carcinoma. Virtual slides were obtained using the Aperio system. Test performance characteristics of liquid-based samples and WSI from CB samples were compared. RESULTS: Average sensitivity and specificity of the five WSI reviewers was 58.3 and 85.1% for ASCUS, respectively, 54.1 and 93.9% for LSIL, and 51.8 and 98.8% for HSIL. Overall WSI sensitivity and specificity for detecting lesions was 82.1 and 86.2%, respectively. Agreement (kappa values) between WSI reviewers was 0.56 for ASCUS, 0.69 for LSIL, 0.67 for HSIL, and 0.74 for negative samples. CONCLUSIONS: WSI of CB preparations is a feasible method to achieve high-quality specimen preparations. It is as sensitive as liquid-based methods and appears to be highly specific for the detection of LSIL and HSIL.

Whole Slide Imaging of Pap Cell Block Preparations versus Liquid-Based Thin-Layer Cervical Cytology: A Comparative Study Evaluating the Detection of Organisms and Nonneoplastic Findings.

OBJECTIVE: Cervical cancer is one of the most common malignancies worldwide, yet it is preventable by population screening. In a previous study, we confirmed the feasibility of utilizing whole slide imaging (WSI) of cell block (CB) preparations to overcome the limitations of digitizing cytologic samples. In this study, we evaluated the accuracy of WSI in identifying various organisms and nonneoplastic findings. STUDY DESIGN: A total of 335 WS images from Pap CB preparations were analyzed using the Aperio system. The test performance characteristics of ThinPrep (TP) and WSI samples were compared for adequacy, for the presence of bacterial vaginosis (BV), fungi, Trichomonas vaginalis (TV) and herpes simplex virus (HSV) and for nonneoplastic findings. RESULTS: The WSI samples contained optimal material from all preparations. BV was diagnosed in 33 WSI versus 36 TP samples. Budding yeasts and/or pseudohyphal forms were noted in 18 WSI versus 19 TP samples. TV organisms (10 of 11 samples) and 1 HSV case were accurately identified in the WSI and TP samples. Squamous metaplasia, keratosis and reactive/reparative and inflammatory changes were easily identified by WSI. CONCLUSIONS: The concept of WSI from Pap CB preparations is potentially feasible for adoption. Digital remote web-based technology eliminates the need for an individual on site, saving time and resources.

Discovery and characterization of a selective, nonpeptidyl thrombopoietin receptor agonist.

OBJECTIVE: Peptide and other small molecule agonists have been described for several cytokines and growth factors. Hydrazone compounds described here as thrombopoietin receptor agonists were identified as activating STAT proteins in a Tpo responsive cell line. METHODS: STAT activation and analysis of signal transduction pathways in cell lines and normal human platelets was elucidated by Western blot and electrophoretic mobility shift assays. Proliferation assays in cell types responsive to other cytokines determined specificity for Tpo receptor. Flow cytometry quantified differentiation of CD34(+) cells into CD41(+) megakaryocytes and platelet production in vitro. RESULTS: Activation of STAT5, mitogen-activated protein kinase, p38, and early response genes by SB 394725 was similar to that induced by Tpo. SB 394725 induced a reporter gene response under a STAT activation promoter as well as the megakaryocyte-specific gpIIb promoter. The compound induced proliferation of Tpo responsive lines but demonstrated no activity in cell lines responding to other cytokines, i.e., erythropoietin, granulocyte-colony stimulating factor, interleukin-3, interferon-gamma. The response of normal human Tpo receptors was elucidated by measuring growth and differentiation of human bone marrow in vitro. Activation of endogenous Tpo receptors by SB 394725 was demonstrated in human and chimp platelets, but not in platelets of other species including mouse, dog, rabbit, or cynomolgus monkey. CONCLUSIONS: SB 394725, a small molecule with a molecular weight of 452 Da, is capable of activating Tpo-specific signal transduction, proliferation, and differentiation responses similar to the responses and functions of the protein growth factor, Tpo.

Toll-like receptor 9 can be expressed at the cell surface of distinct populations of tonsils and human peripheral blood mononuclear cells.

Unmethlylated CpG dinucleotides induce a strong T-helper-1-like inflammatory response, presumably mediated by Toll-like receptor 9 (TLR9). However, the nature and cellular localization of TLR9 in primary human cells remain controversial. Here we demonstrate, using flow cytometry and immunofluorescence microscopy techniques, that TLR9 can be expressed at the cell surface. The primary human cell subsets that were positive for TLR9 expression were distinct depending on the tissues analyzed. Specifically, in human peripheral blood mononuclear cells (PBMC) the majority of cell surface TLR9(+) cells were confined to the major histocompatibility complex (MHC) class II(+) CD19(-) populations that express CD11c and/or CD14, whereas in tonsils the same gated population contained primarily MHC class II(+) CD19(+) cells. Cells positive for surface expression represented a minor fraction of the total cell populations examined, varying between 2 and 10%. In addition, we found that TLR9 expression at the surface of PBMC was up-regulated approximately fourfold following stimulation with the gram-negative bacterial cell wall component lipopolysaccharide, suggesting a potential modulatory role of TLR4 agonists on TLR9 expression. Taken together, these data validate human TLR9 expression at the surface of primary cells, in addition to the previously described intracellular localization. Further, our results suggest that human antigen-presenting cells comprise the major cell populations expressing cell surface TLR9.

Selective binding and oligomerization of the murine granulocyte colony-stimulating factor receptor by a low molecular weight, nonpeptidyl ligand.

Granulocyte colony-stimulating factor regulates neutrophil production by binding to a specific receptor, the granulocyte colony-stimulating factor receptor, expressed on cells of the granulocytic lineage. Recombinant forms of granulocyte colony-stimulating factor are used clinically to treat neutropenias. As part of an effort to develop granulocyte colony-stimulating factor mimics with the potential for oral bioavailability, we previously identified a nonpeptidyl small molecule (SB-247464) that selectively activates murine granulocyte colony-stimulating factor signal transduction pathways and promotes neutrophil formation in vivo. To elucidate the mechanism of action of SB-247464, a series of cell-based and biochemical assays were performed. The activity of SB-247464 is strictly dependent on the presence of zinc ions. Titration microcalorimetry experiments using a soluble murine granulocyte colony-stimulating factor receptor construct show that SB-247464 binds to the extracellular domain of the receptor in a zinc ion-dependent manner. Analytical ultracentrifugation studies demonstrate that SB-247464 induces self-association of the N-terminal three-domain fragment in a manner that is consistent with dimerization. SB-247464 induces internalization of granulocyte colony-stimulating factor receptor on intact cells, consistent with a mechanism involving receptor oligomerization. These data show that small nonpeptidyl compounds are capable of selectively binding and inducing productive oligomerization of cytokine receptors.

Identification of a pharmacophore for thrombopoietic activity of small, non-peptidyl molecules. 1. Discovery and optimization of salicylaldehyde thiosemicarbazone thrombopoietin mimics.

High-throughput screening has resulted in the discovery of thiosemicarbazone thrombopoietin mimics. A shared pharmacophore hypothesis between this series and a previously identified class, the pyrazol-4-ylidenehydrazines, led to the rapid optimization of both potency and efficacy of the thiosemicarbazones. The application of high-throughput chemistry and purification techniques allowed for the rapid elucidation of structure-activity relationships.

Identification of a pharmacophore for thrombopoietic activity of small, non-peptidyl molecules. 2. Rational design of naphtho[1,2-d]imidazole thrombopoietin mimics.

The invention of a new class of naphtho[1,2-d]imidazole thrombopoietin mimics based on a pharmacophore hypothesis for small-molecule thrombopoietic agonists is discussed. Parallel array synthesis and purification techniques allowed for the rapid exploration of structure-activity relationships within this class and for the improvement in TPO mimetic potencies and efficacies.

Stable expression of a synthetic gene for the human motilin receptor: use in an aequorin-based receptor activation assay.

A synthetic gene for the human motilin receptor containing 33 unique restriction sites was designed and stably coexpressed in HEK293 cells with the bioluminescent Ca(2+) indicator protein aequorin. The dose-dependent response of the receptor to motilin was demonstrated using transient transfections, and a stable cell line was selected. [(125)I]Motilin binding was used to estimate receptor expression level for the stable cell line, and titration of a membrane preparation indicated a K(d) value of 0.8 nM. The same cell line was used to evaluate a panel of erythromycin-derived agonists and provided EC(50) values for receptor activation that agree closely with data obtained in contractility assays. The peptide antagonist ANQ11125 (Phe3Leu13 motilin 1-14) inhibited motilin induced response with a K(i) value of 10 nM. The system is well-suited for the screening of compound libraries and receptor mutagenesis studies.