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Background: CDK7 inhibition is a promising therapeutic strategy in cancer; acting as a regulator of the cell cycle, transcription and endocrine receptor signalling [1]. Patients with HR+BC post CDK4/6 inhibitor treatment have a poor prognosis; median progression free survival (mPFS) of ~ 8 weeks for fulvestrant post CDK4/6i in HR+BC [2,3]. Pre-clinical HR+BC models indicate the potential for synergy when the CDK7 inhibitor samuraciclib is combined with the Selective Estrogen Receptor Degrader fulvestrant [4]Materials and Methods: This single arm cohort assessed the tolerability and efficacy of samuraciclib in combination with standard dose fulvestrant in patients with advanced HR+BC; all patients had previously received an aromatase inhibitor and a CDK4/6i for advanced disease.Results: 31 patients with HR+BC received the combination of standard dose with fulvestrant and samuraciclib. 6 patients received samuraciclib dose of 240mg once daily (QD) and 25 patients a dose of 360mg QD. The combination treatment was generally well tolerated, with adverse drug reactions (AE) of note being G1-2 nausea, vomiting and diarrhoea; the majority of patients staying on treatment until disease progression.RECIST evaluation indicates evidence of reduction in tumor disease burden, including a partial response in one patient who has been on treatment for ~ 1 year.Graphic illustrations of data, including ‘waterfall’ and ‘swimmer’ plots, will be presented along with stratification data based on demographic factors such as hepatic involvement and cfDNA analysis (ESR1m, PI3Km).Conclusions: Samuraciclib has demonstrated an acceptable safety profile with evidence of anti-tumour activity in combination with fulvestrant for patients with advanced HR+BC who have progressed on their prior CDK4/6i.References:1.Patel et al., Mol Cancer Therap. 20182.Juric et al., SABCS 20183.Lindeman et al., JCO 20214.Jeselsohn et al., SABCS 2019 Citation Format: Charles Coombes, Sasha J Howell, Matthew G Krebs, Simon Lord, Laura M Kenny, Ash Bahl, Glen Clack, Edward Ainscow, Paul A Dickinson, Raluca Fostea, Janine Mansi, Carlo Palmieri, Gianflippo Bertelli, Rinath Jeselsohn, Zahi Mitri, William J Gradishar, Sagar Sardesai, Joyce O'Shaughnessy, Patrick Ward, Pavani Chalasani, Manfred Lehnert, Simak Ali, Stuart McIntosh. Study of samuraciclib (CT7001), a first-in-class, oral, selective inhibitor of CDK7, in combination with fulvestrant in patients with advanced hormone receptor positive HER2 negative breast cancer (HR+BC) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS3-10.

Background: CDK7 inhibition is a promising therapeutic strategy in cancer. CDK7 is a key kinase, regulating cell division, transcription and nuclear receptor function [1]. Although recent advances have been made in the treatment of TNBC this disease is still one of significant unmet need. Materials and Methods: Tolerability and efficacy of Samuraciclib were assessed in a TNBC expansion cohort of the first in human study of Samuraciclib. These patients had metastatic or locally advanced TNBC and had received prior taxane and anthracycline therapy including at least one line of chemotherapy for metastatic or locally advanced disease. Results: From 29th January 2019 to 12th April 2021, 23 women with advanced TNBC were recruited and dosed with Samuraciclib 360mg OD. Treatment has generally been well tolerated with all patients remaining on treatment until disease progression. The most common adverse drug reactions (AE) were: G1-2 Nausea (96%), Vomiting (52%) and Diarrhea (91%). There were 4 dose reductions to manage upper GI adverse events of nausea and/or vomiting. G3 events were as follows: 2 Grade 3 Diarrhea, 1 Grade 3 Vomiting, 1 Grade 3 Fatigue, 1 Grade 3 Stomatitis, 1 Grade 3 Anaemia and 1 Grade 4 Thrombocytopenia21 patients have had follow-up evaluations for assessment of efficacy. Stable disease was achieved in 14 patients, 1 with partial response (being on treatment for 72 weeks) and 7 patients with progressive disease; two additional patients remain on compassionate use treatment, following disease progression by RECIST. 5 patients have been on treatment for at least 24 weeks of whom 3 have exceeded 1 year. Conclusions: Samuraciclib demonstrated an acceptable safety and tolerability profile with evidence of antitumour activity in advanced TNBC. References1.Patel et al. ICEC0942, an Orally Bioavailable Selective Inhibitor of CDK7 for Cancer Treatment. Mol Cancer Ther. 2018. doi: 10.1158/1535-7163.MCT-16-0847. PMID:29545334. Citation Format: Sacha J Howell, Laura M Kenny, Simon Lord, Matthew G Krebs, Tobias Arkenau, Richard Baird, Iain R MacPherson, Ash Bahl, Glen Clack, Edward Ainscow, Anthony GM Barrett, Paul A Dickinson, Matthew J Fuchter, Manfred Lehnert, Simak Ali, Stuart McIntosh, Charles Coombes. A clinical study of samuraciclib (CT7001), a first-in-class, oral, selective inhibitor of CDK7, in patients with advanced triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-18-10.

Background The continual reassessment method (CRM) identifies the maximum tolerated dose (MTD) more efficiently and identifies the true MTD more frequently compared to standard methods such as the 3 + 3 method. An initial estimate of the dose-toxicity relationship (prior skeleton) is required, and there is limited guidance on how to select this. Previously, we compared the CRM with six different skeletons to the 3 + 3 method by conducting post-hoc analysis on a phase 1 oncology study (AZD3514), each CRM model reduced the number of patients allocated to suboptimal and toxic doses. This manuscript extends this work by assessing the ability of the 3 + 3 method and the CRM with different skeletons in determining the true MTD of various “true” dose-toxicity relationships. Methods One thousand studies were simulated for each “true” dose toxicity relationship considered, four were based on clinical trial data (AZD3514, AZD1208, AZD1480, AZD4877), and four were theoretical. The 3 + 3 method and 2-stage extended CRM with six skeletons were applied to identify the MTD, where the true MTD was considered as the largest dose where the probability of experiencing a dose limiting toxicity (DLT) is ≤33%. Results For every true dose-toxicity relationship, the CRM selected the MTD that matched the true MTD in a higher proportion of studies compared to the 3 + 3 method. The CRM overestimated the MTD in a higher proportion of simulations compared to the 3 + 3 method. The proportion of studies where the correct MTD was selected varied considerably between skeletons. For some true dose-toxicity relationships, some skeletons identified the true MTD in a higher proportion of scenarios compared to the skeleton that matched the true dose-toxicity relationship. Conclusion Through simulation, the CRM generally outperformed the 3 + 3 method for the clinical and theoretical true dose-toxicity relationships. It was observed that accurate estimates of the true skeleton do not always outperform a generic skeleton, therefore the application of wide confidence intervals may enable a generic skeleton to be used. Further work is needed to determine the optimum skeleton.

Background Cutaneous angiosarcomas are highly aggressive malignant tumors with poor prognosis. Currently there is no FDA-approved treatment. oPac+E is a combination of oral paclitaxel and a novel oral P-glycoprotein inhibitor, Encequidar. Materials and Methods: This is a phase-2 study evaluating the activity, safety and tolerability of oPac 205mg/m2 + E 12.9 mg once daily for 3 consecutive days weekly for patients with unresectable cutaneous angiosarcoma. Tumour response was evaluated every 6 weeks using RECIST and photography. Results: From Aug-2018 to May-2020, 7 of 26 enrolled patients (pts) had breast cutaneous angiosarcoma. All had previous breast cancer, mastectomy and radiotherapy and/or adjuvant chemotherapy, no prior taxane for angiosacoma and no metastatic disease. Median age was 66 yrs (range 49-76). Best objective response rates were: complete response (CR) 43% (3/7 pts), partial response (PR) 14% (1/7 pts), stable disease (SD) 43% (3/7 pts), progressive disease (PD) 0%. Furthermore, 3 pts (43%) who had inoperable lesions were deemed operable after Oraxol treatment and received curative intent surgical resection. Median progression free survival (PFS) was 17 weeks. oPac+E was generally well tolerated. Grade-3 treatment related adverse events (AEs) occurred in 5 pts: diarrhea=1, fatigue=2, neutropenia =1, dyspnea=1, dehydration=1, pneumonitis=1. Grade-4 AE were neutropenia in 2 pts. Grade-2 paraesthesia=1. All pts fully recovered. Dose reductions were needed in 3 subjects. No patients discontinued treatment due to AEs. To date no patients died. Conclusions: oPac+E may provide an effective oral treatment for radiation-associated breast angiosarcoma, with a high clinical benefit rate (CR + PR+ SD=100%), durable response and enabled resection of unresectable tumors. It is generally well tolerated even in elderly patients; with low incidence of neuropathy. It may allow patients to avoid hospital IV chemotherapy visits and the option of home treatment. Citation Format: Vinod Ravi, Michael Wagner, Tom Wei-Wu Chen, Herbert H Loong, Robert Mennel, Cheuh-Chuan Yen, Glen Clack, David Cutler, Rudolf Kwan, Wing=Kai CHan. A phase 2 study of oral paclitaxel and encequidar (oPac+E) in the treatment of cutnaeous angiosarcoma: The breast angiosarcoma subgroup [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS13-05.

Purpose: This study reports the safety, tolerability, MTD, recommended phase II dose (RP2D), pharmacokinetic/pharmacodynamic profile, and preliminary antitumor activity of ceralasertib combined with carboplatin in patients with advanced solid tumors. It also examined exploratory predictive and pharmacodynamic biomarkers. Patients and Methods: Eligible patients (n = 36) received a fixed dose of carboplatin (AUC5) with escalating doses of ceralasertib (20 mg twice daily to 60 mg once daily) in 21-day cycles. Sequential and concurrent combination dosing schedules were assessed. Results: Two ceralasertib MTD dose schedules, 20 mg twice daily on days 4–13 and 40 mg once daily on days 1–2, were tolerated with carboplatin AUC5; the latter was declared the RP2D. The most common treatment-emergent adverse events (Common Terminology Criteria for Adverse Events grade ≥3) were anemia (39%), thrombocytopenia (36%), and neutropenia (25%). Dose-limiting toxicities of grade 4 thrombocytopenia (n = 2; including one grade 4 platelet count decreased) and a combination of grade 4 thrombocytopenia and grade 3 neutropenia occurred in 3 patients. Ceralasertib was quickly absorbed (tmax ∼1 hour), with a terminal plasma half-life of 8–11 hours. Upregulation of pRAD50, indicative of ataxia telangiectasia mutated (ATM) activation, was observed in tumor biopsies during ceralasertib treatment. Two patients with absent or low ATM or SLFN11 protein expression achieved confirmed RECIST v1.1 partial responses. Eighteen of 34 (53%) response-evaluable patients had RECIST v1.1 stable disease. Conclusions: The RP2D for ceralasertib plus carboplatin was established as ceralasertib 40 mg once daily on days 1–2 administered with carboplatin AUC5 every 3 weeks, with pharmacokinetic and pharmacodynamic studies confirming pharmacodynamic modulation and preliminary evidence of antitumor activity observed.

Highlights • Summary of a protocol for a phase I study combining the ATR inhibitor and palliative radiotherapy. • Study design is discussed. • Study aims and objectives, brief eligibility criteria, DLT criteria and dose escalation is discussed. • Brief summary of translational research to be carried out., PATRIOT is a phase I study of the ATR inhibitor, AZD6738, as monotherapy, and in combination with palliative radiotherapy. Here, we describe the protocol for this study, which opened in 2014 and is currently recruiting and comprises dose escalation of both drug and radiotherapy, and expansion cohorts.

First-in-human (FIH) studies with AZD3514, a selective androgen receptor (AR) down-regulator, showed decreases of >30% in the prostate-specific antigen (PSA) in some patients. A modeling approach was adopted to understand these observations and define the optimum clinical use hypothesis for AZD3514 for clinical testing. Initial empirical modeling showed that only baseline PSA correlated significantly with this biological response, whereas drug concentration did not. To identify the mechanistic cause of this observation, a mechanism-based model was first developed, which described the effects of AZD3514 on AR protein and PSA mRNA levels in LNCaP cells with and without dihydrotestosterone (DHT). Second, the mechanism-based model was linked to a population pharmacokinetic (PK) model; PSA effects of clinical doses were subsequently simulated under different clinical conditions. This model was used to adjust the design of the ongoing clinical FIH study and direct the backup program.

11517 Background: Oraxol is a combination of oral paclitaxel and a novel oral P-glycoprotein inhibitor, HM30181A. Cutaneous angiosarcomas are highly aggressive malignant tumors with poor prognosis. Currently there is no FDA-approved treatment. Methods: This is an open label study evaluating the activity, safety and tolerability of Oraxol 205mg/m2 administered orally, once daily, for 3 consecutive days per week. Planned treatment is for 25 weeks. Subjects included in this study had not received prior therapy with a taxane and did not have metastatic disease. Tumour response was evaluated at 6 weekly intervals using RECIST and photography. A Simon two stage design was used. Results: 18 of 24 enrolled patients (pts); male/female 11/7; median age 77 years (range 56-93), were evaluable at time of analysis. Subjects were recruited during an 18 month period, from Aug-2018 to Jan-2020. Best objective response rates were: CR 22% (n = 4), PR 11% (n = 2), SD 67% (n = 12), PD 0%. 42% of pts with SD had durability > 13 weeks (range 13-25). Median PFS was 38 weeks. All pts remain alive at time of reporting. Furthermore, 5 pts (28%) who had inoperable lesions were deemed operable after Oraxol and received surgical resection. Oraxol was generally well tolerated. Most common adverse events (AEs) G>3 were: diarrhea (n = 1), fatigue (n = 3), neutropenia (n = 9), leucopenia (n = 5), lymphopenia (n = 5). Serious AEs were G3 pneumonia in 2 subjects and G4 neutropenia in 2 subjects, one of which was febrile. All events fully resolved. Neuropathy was uncommon: n = 2 (G1 = 1 @ day 10, G2 = 1 @ day 64). Dose reductions were recorded in 7 subjects. 2 subjects discontinued treatment due to AEs; both asymptomatic pneumonitis seen on CT, which recovered after discontinuation. Following the initial positive results, the protocol has been amended to change the maximum recruitment of subjects from 25 to 43. Conclusions: Oraxol provides an orally administered treatment option for angiosarcoma, with a high and durable clinical benefit rate (CR + PR+ long SD). It is generally well tolerated even in an older patient population; particularly with respect to the the low incidence of neuropathy compared to IV paclitaxel. Recruitment is ongoing. Clinical trial information: NCT03544567 . [Table: see text]

We previously demonstrated that circulating tumour cells (CTCs) are detectable by the MelCAM and high molecular weight melanoma-associated antigen (HMW-MAA)-dependent CellSearch platform. However, CTCs which do not express these capture and detection markers are not detectable by CellSearch. Consequently, we explored the use of isolation by size of epithelial tumour cells (ISET), a marker independent, filtration-based device to determine the prevalence and heterogeneity of CTCs in metastatic cutaneous melanoma patients. Ninety patients were prospectively recruited and blood samples taken before treatment. Patients' blood was filtered using the ISET platform. CTCs were enumerated using dual immunohistochemistry with positive selection by S100 expression and exclusion of leucocytes and endothelial cells expressing CD45 or CD144, respectively. A panel of markers (Melan-A, MITF, MelCAM, high molecular melanoma-associated antigen, CD271 and MAGEC) was also examined. Fifty-one patients (57%) had CTCs (range 1-44 CTCs/4 ml blood) and 12 patients also had circulating tumour microemboli. Seven patients had S100- CTCs, 11 patients' CTCs were S100+ and 33 patients had S100+ and S100- CTCs. Substantial intrapatient and interpatient heterogeneity was observed for all other melanoma-associated markers. CTCs in metastatic cutaneous melanoma are detectable using the flexible marker-independent ISET platform. CTCs display significant marker expression heterogeneity implying that marker-dependent platforms would not detect all CTCs and multimarker assays are now required to reveal the biological significance of this CTC heterogeneity.

3062 Background: MET kinase is a therapeutic target in a range of cancer indications; it is a primary oncogenic driver and a mechanism of therapy resistance. OMO-1 is a highly potent, selective oral inhibitor of MET kinase and Organic Cation Transporter 2 (OCT2). Methods: This study assesses the safety, tolerability, pharmacokinetics (PK) and preliminary activity of OMO-1 in patients (pts) with advanced malignancies (NCT03138083). Module 1 data, evaluating ascending doses of OMO-1 monotherapy, are reported here. Results: As of January 16, 2019, 34 pts were enrolled at 5 twice-daily (BD) dose levels of OMO-1: 100, 200, 250, 350, and 400 mg, including 10 with MET gene amplified or mutated tumours. OMO-1 was generally well tolerated between 100 - 250 mg BD; pts were in the study for an average of 94 days (range: 15-291 days) and 20/34 pts discontinued due to disease progression. Most frequently-reported AEs were nausea (17/34), vomiting (14/34) and fatigue (14/34), mainly G1-2. Notably, no peripheral oedema, cardiovascular events or non-malignancy related LFT abnormalities were observed. A total of 36 SAEs were reported: 17 in 11 subjects were considered related to OMO-1, and included nausea (3/17), vomiting (4/17), chills, diarrhoea, influenza-like illness (2/17), increased blood bilirubin, blood creatinine (3/17) and neutrophil count, and sepsis. A dose of 250 mg BD was determined as the recommended Phase 2 dose (RP2D); doses ≥350mg BD were not in keeping with optimum long-term dosing: at 400 mg BD, 2/3 subjects experienced influenza-like illness (G2 and G3) and at 350 mg BD 2/5 subjects had G2 fatigue and nausea/vomiting. OMO-1 has a half-life of 2.5-3 hrs and plasma exposure is dose-proportional without accumulation. Elevated creatinine was observed across all dose levels, consistent with OCT2 inhibition. IHC analysis on paired tumour biopsies from a MET-mutated NSCLC pt dosed at 200 mg BD showed near-complete inhibition of phosphorylated MET, without affecting total MET. Conclusions: OMO-1 has a favourable safety profile at a RP2D of 250mg BD. Expansion cohorts for MET mutated/amplified tumour types are enrolling. Clinical trial information: NCT03138083.

e14674 Background: The MET kinase is an established therapeutic target in a range of cancer indications, being a primary oncogenic and therapy resistance driver. Methods: OMO-1 is a highly potent, selective oral inhibitor of MET kinase and Organic Cation Transporter 2 (OCT2) that is currently being explored in a Phase I/II study (NCT03138083). Results: Pre-clinical data for OMO-1 indicates that anti-tumor efficacy against MET driven tumor models does not require 24/7 exposure in the plasma. PK/PD assessments indicate that OMO-1 efficacy is AUC driven. Exposures above a trough concentration of ~600ng/ml for a period of 6-8hr and an AUC of 3000ng.h/ml result in complete target inhibition sufficient to induce regression or stasis of MET driven in-vivo models. Dosing of OMO-1 at 12.5mg/kg BD 4hr apart, or split over 4 doses 2hr apart, with a dosing-free period of 18-20hr was sufficient to obtain the effects preclinically. The ongoing Phase I/II study in patients with solid tumours utilised learnings from the pre-clinical and FIH study (NCT01964872) where ascending single doses and multiple doses were evaluated. The selected starting dose for the patient study (100mg BD, 4 hr apart) achieved exposures above the predicted MBAD. Paired tumor biopsies were obtained from a higher dose level (200mg BD). A MET exon 14 skipping mutation NSCLC patient at this dosed demonstrated near-complete inhibition of phospho MET accompanied by signs of clinical benefit and lesion shrinkage, thereby matching the preclinical data. Certain ‘class effect’ adverse events, such as edema, were not observed. Conclusions: OMO-1 is an oral, potent MET TKI with a novel dosing regime, identified during preclinical optimization (BD 4hr apart), that demonstrates encouraging signs of clinical activity without certain ‘class-specific’ adverse events. Further evaluation of this differentiated and efficacious agent is warranted and ongoing.

The incidence of melanoma is increasing worldwide. Advances in targeted agents and immunotherapy have improved outcomes in metastatic disease, but biomarkers are required to optimize treatment. We determined the prevalence of circulating tumor cells (CTCs) and explored their utility as prognostic and pharmacodynamic biomarkers. A total of 101 patients with metastatic cutaneous melanoma were recruited prospectively. CTC number was determined using the CellSearch platform and melanoma kits in samples taken at baseline and serially during treatment. CTC numbers ranged between 0 and 36 per 7.5 ml blood; 26% of patients had ≥ 2 CTCs. Baseline CTC number was prognostic for median overall survival (OS) in univariate analysis (2.6 vs. 7.2 months (P

Background The continual reassessment method (CRM) requires an underlying model of the dose-toxicity relationship (“prior skeleton”) and there is limited guidance of what this should be when little is known about this association. In this manuscript the impact of applying the CRM with different prior skeleton approaches and the 3 + 3 method are compared in terms of ability to determine the true maximum tolerated dose (MTD) and number of patients allocated to sub-optimal and toxic doses. Methods Post-hoc dose-escalation analyses on real-life clinical trial data on an early oncology compound (AZD3514), using the 3 + 3 method and CRM using six different prior skeleton approaches. Results All methods correctly identified the true MTD. The 3 + 3 method allocated six patients to both sub-optimal and toxic doses. All CRM approaches allocated four patients to sub-optimal doses. No patients were allocated to toxic doses from sigmoidal, two from conservative and five from other approaches. Conclusions Prior skeletons for the CRM for phase 1 clinical trials are proposed in this manuscript and applied to a real clinical trial dataset. Highly accurate initial skeleton estimates may not be essential to determine the true MTD, and, as expected, all CRM methods out-performed the 3 + 3 method. There were differences in performance between skeletons. The choice of skeleton should depend on whether minimizing the number of patients allocated to suboptimal or toxic doses is more important. Trial registration NCT01162395, Trial date of first registration: July 13, 2010. Electronic supplementary material The online version of this article (doi:10.1186/s12885-016-2702-6) contains supplementary material, which is available to authorized users.

Lipid profiles in women with early breast cancer receiving anastrozole with or without risedronate were examined within an international Phase III/IV study to assess for possible treatment related changes. Postmenopausal women with hormone receptor-positive breast cancer were assigned to 1 of 3 strata by risk of fragility fracture. Patients with the highest risk for fracture received anastrozole plus risedronate (A + R). Moderate-risk patients were randomized in a double-blind manner to A + R or anastrozole and placebo (A + P). Lower-risk patients received anastrozole (A) alone. Serial fasting blood samples were assessed for changes in lipid parameters relative to baseline after 12 months of treatment with anastrozole with or without risedronate. Samples were centrally analyzed for low-density lipoprotein cholesterol (LDL-cholesterol), high-density lipoprotein (HDL) cholesterol, total cholesterol (TC) and triglycerides (TG). Analysis was performed as primary analysis population for lipids (A plus A + P), lipid intention to treat population and secondary population (A + R). Of the 119 patients treated with A plus A + P, there were 66 patients eligible for inclusion in the primary analysis population. Of the 115 patients treated with secondary population (A + R) there were 65 patients eligible for lipid profiling. For LDL-cholesterol, HDL-cholesterol, TC and TG there were no significant changes between the baseline and 12 months assessments to suggest that any of these therapies have a negative impact on the lipid profile. In this study of postmenopausal women with early breast cancer receiving adjuvant anastrozole with or without risedronate, there was no adverse effect on LDL-cholesterol, HDL-cholesterol, TC or TG values over the 12 months monitoring period.

Saracatinib (AZD0530) is an orally active once-daily Src kinase inhibitor which modulates key signaling pathways in cancer cells. In a Phase I study in patients with advanced solid malignancies resistant to standard treatment we assessed the effect of saracatinib on bone turnover. Fifty-one patients were randomized into three parallel groups to receive saracatinib 50, 125 or 175 mg/day. After a single dose followed by a 7-day washout, patients received once-daily doses for 21 days. Bone turnover markers were measured in serum and urine samples collected before dosing on days 1, 2, 3, 17 and 28. Samples were available at baseline and more than one other time point for 44 patients. Bone resorption markers were significantly decreased by saracatinib. Serum cross-linked C-terminal telopeptide of type I collagen (sCTX) changed in the 50, 125 and 175 mg/day groups by -36% (95% CI -58, -4), -64% (95% CI -75, -48) and -75% (95% CI -83, -61), respectively, at day 28. Urinary cross-linked N-terminal telopeptide of type I collagen/creatinine ratio (uNTX/Cr) changed in the 50, 125 and 175 mg/day groups by; -13% (95% CI -33, 13), -48% (95% CI -59, -34) and -50% (95% CI -62, -35), respectively, at day 28. The significant decreases in bone resorption markers indicate that suppression of Src kinase inhibits osteoclast activity in patients with advanced cancer. This result suggests that saracatinib may have therapeutic benefit in metastatic bone disease.

Introduction: Epithelial circulating tumor cells (CTCs) are detectable in patients with non-small cell lung cancer (NSCLC). However, epithelial to mesenchymal transition, a widely reported prerequisite for metastasis, may lead to an underestimation of CTC number. We compared directly an epithelial marker-dependent (CellSearch) and a marker-independent (isolation by size of epithelial tumor cells [ISET]) technology platform for the ability to identify CTCs. Molecular characteristics of CTCs were also explored. Methods: Paired peripheral blood samples were collected from 40 chemonaive, stages IIIA to IV NSCLC patients. CTCs were enumerated by Epithelial Cell Adhesion Molecule-based immunomagnetic capture (CellSearch, Veridex) and by filtration (ISET, RareCell Diagnostics). CTCs isolated by filtration were assessed by immunohistochemistry for epithelial marker expression (cytokeratins, Epithelial Cell Adhesion Molecule, epidermal growth factor receptor) and for proliferation status (Ki67). Results: CTCs were detected using ISET in 32 of 40 (80%) patients compared with 9 of 40 (23%) patients using CellSearch. A subpopulation of CTCs isolated by ISET did not express epithelial markers. Circulating tumor microemboli (CTM, clusters of ≥3 CTCs) were observed in 43% patients using ISET but were undetectable by CellSearch. Up to 62% of single CTCs were positive for the proliferation marker Ki67, whereas cells within CTM were nonproliferative. Conclusions: Both technology platforms detected NSCLC CTCs. ISET detected higher numbers of CTCs including epithelial marker negative tumor cells. ISET also isolated CTM and permitted molecular characterization. Combined with our previous CellSearch data confirming CTC number as an independent prognostic biomarker for NSCLC, we propose that this complementary dual technology approach to CTC analysis allows more complete exploration of CTCs in patients with NSCLC.

Background: Obtaining tissue for pancreatic carcinoma diagnosis and biomarker assessment to aid drug development is challenging. Circulating tumour cells (CTCs) may represent a potential biomarker to address these unmet needs. We compared prospectively the utility of two platforms for CTC enumeration and characterisation in pancreatic cancer patients in a pilot exploratory study. Patients and methods: Blood samples were obtained prospectively from 54 consenting patients and analysed by CellSearch and isolation by size of epithelial tumour cells (ISET). CellSearch exploits immunomagnetic capture of CTCs-expressing epithelial markers, whereas ISET is a marker independent, blood filtration device. Circulating tumour cell expression of epithelial and mesenchymal markers was assessed to explore any discrepancy in CTC number between the two platforms. Results: ISET detected CTCs in more patients than CellSearch (93% vs 40%) and in higher numbers (median CTCs/7.5 ml, 9 (range 0–240) vs 0 (range 0–144)). Heterogeneity observed for epithelial cell adhesion molecule, pan-cytokeratin (CK), E-Cadherin, Vimentin and CK 7 expression in CTCs may account for discrepancy in CTC number between platforms. Conclusion: ISET detects more CTCs than CellSearch and offers flexible CTC characterisation with potential to investigate CTC biology and develop biomarkers for pancreatic cancer patient management.

Purpose Lung cancer is the leading cause of cancer-related death worldwide. Non–small-cell lung cancer (NSCLC) lacks validated biomarkers to predict treatment response. This study investigated whether circulating tumor cells (CTCs) are detectable in patients with NSCLC and what their ability might be to provide prognostic information and/or early indication of patient response to conventional therapy. Patients and Methods In this single-center prospective study, blood samples for CTC analysis were obtained from 101 patients with previously untreated, stage III or IV NSCLC both before and after administration of one cycle of standard chemotherapy. CTCs were measured using a semiautomated, epithelial cell adhesion molecule–based immunomagnetic technique. Results The number of CTCs in 7.5 mL of blood was higher in patients with stage IV NSCLC (n = 60; range, 0 to 146) compared with patients with stage IIIB (n = 27; range, 0 to 3) or IIIA disease (n = 14; no CTCs detected). In univariate analysis, progression-free survival was 6.8 v 2.4 months with P < .001, and overall survival (OS) was 8.1 v 4.3 months with P < .001 for patients with fewer than five CTCs compared with five or more CTCs before chemotherapy, respectively. In multivariate analysis, CTC number was the strongest predictor of OS (hazard ratio [HR], 7.92; 95% CI, 2.85 to 22.01; P < .001), and the point estimate of the HR was increased with incorporation of a second CTC sample that was taken after one cycle of chemotherapy (HR, 15.65; 95% CI, 3.63 to 67.53; P < .001). Conclusion CTCs are detectable in patients with stage IV NSCLC and are a novel prognostic factor for this disease. Further validation is warranted before routine clinical application.

Background This ‘Arimidex’, Tamoxifen, Alone or in Combination (ATAC) trial sub-study examined the effects of anastrozole and tamoxifen on bone mineral density (BMD) following 5 years of treatment. Patients and methods Lumbar spine and total hip BMD were assessed at years 6 and 7 in a total of 71 eligible patients. In total, 50 patients had evaluable data. Results Following anastrozole treatment, the lumbar spine median BMD increased by 2.35% (P = 0.04) and 4.02% (P = 0.0004) at years 6 and 7, while total hip median BMD increased by 0.71% (P = 0.3) and 0.5% (P = 0.8). After tamoxifen treatment, lumbar spine median BMD decreased by 0.79% (P = 0.2) and 0.30% (P = 0.9) at years 6 and 7, while total hip median BMD decreased by 2.09% (P = 0.0003) and 2.52% (P = 0.0002). Patients with a normal BMD or who were osteopenic at 5 years did not become osteoporotic. Conclusions Anastrozole treatment-related bone loss did not continue into the off-treatment follow-up period. The recovery in lumbar spine BMD and absence of further loss at the hip is consistent with the reduction in the annual rate of fracture observed after treatment cessation in the main ATAC trial.

Circulating tumor cell (CTC) number in metastatic cancer patients yields prognostic information consistent with enhanced cell migration and invasion via loss of adhesion, a feature of epithelial-to-mesenchymal transition (EMT). Tumor cells also invade via collective migration with maintained cell-cell contacts and consistent with this is the circulating tumor microemboli (CTM; contiguous groups of tumor cells) that are observed in metastatic cancer patients. Using a blood filtration approach, we examined markers of EMT (cytokeratins, E-cadherin, vimentin, neural cadherin) and prevalence of apoptosis in CTCs and CTM to explore likely mechanism(s) of invasion in lung cancer patients and address the hypothesis that cells within CTM have a survival advantage. Intra-patient and inter-patient heterogeneity was observed for EMT markers in CTCs and CTM. Vimentin was only expressed in some CTCs, but in the majority of cells within CTM; E-cadherin expression was lost, cytoplasmic or nuclear, and rarely expressed at the surface of the cells within CTM. A subpopulation of CTCs was apoptotic, but apoptosis was absent within CTM. This pilot study suggests that EMT is not prosecuted homogeneously in tumor cells within the circulation of lung cancer patients and that collective migration and enhanced survival of cells within CTM might contribute to lung cancer metastasis. Multiplex analysis and further detailed exploration of metastatic potential and EMT in CTCs/CTM is now warranted in a larger patient cohort.

Genetic alterations can determine the natural history of cancer and its treatment response. With further advances in DNA sequencing technology, multiple novel genetic alterations will be discovered which could be exploited as prognostic, predictive and pharmacodynamic biomarkers in the development and use of cancer therapeutics. As such, the importance in clinical practice of efficient and robust somatic mutation testing in solid tumours cannot be overemphasized in the current era of personalized medicine. However, significant challenges remain regarding the testing of genetic biomarkers in clinical practice. Reliance on archived formalin fixed, paraffin embedded tumour, obtained from diagnostic biopsies, for testing somatic genetic alterations could restrict the scientific community in asking relevant questions about a patient’s cancer biology. Problems inherent with using formalin fixed, archival tissue are well recognized and difficult to resolve. It could be argued that to achieve rapid and efficient incorporation of genetic biomarkers into clinical practice, somatic mutation testing in cancer patients should be simpler, less invasive using a readily available clinical sample, whilst maintaining robustness and reproducibility. In this regard, use of circulating free DNA (cfDNA) from plasma or serum as an alternative and/or additional source of DNA to test cancer specific genetic alterations is an attractive proposition. In light of encouraging results from recent studies, this mini review will discuss the current role and future potential of somatic mutation testing from circulating or cell free DNA derived from the blood of patients with solid tumours.

Activation of the MET/HGF pathway has been linked to tumor initiation, metastasis, angiogenesis and resistance to therapeutic agents. Here we present pharmacological characterization of OMO-1 (formerly JNJ-38877618), a potent, highly selective, orally bioavailable MET kinase inhibitor with nM binding affinity (Kd=1.4 nM) and enzyme inhibitory activity against wt and M1268T mutant MET (2 and 3 nM IC50). MET inhibitory effects were assessed in proliferation, colony formation and motility assays. OMO-1 displayed nM potency against MET Ampl/mutant and therapy resistant models. In vivo, OMO-1 induced complete inhibition of tumor growth in 3 models: the SNU5 MET amp gastric, U87-MG HGF autocrine glioblastoma and Hs746T MET exon 14 skipping mutant gastric cancer. OMO-1 induced regression of large MET amplified EBC-1 SqNSCLC where OMO-1 led to dose- and time-dependent inhibition of MET kinase activation, with the duration of target shut down considerably exceeding plasma exposure times. Combination treatments were well tolerated and improved EGFR targeted therapy. Although single agent OMO-1 had no effect on NSCLC HCC827 EGFR, combination with Erlotinib led to delayed onset of tumor recurrence. The acquired EGFR inhibitor resistant model HCC827-ER1 was determined to be MET amplified. OMO-1 and erlotinib both inhibited tumor growth of this model whilst combination induced tumor regression. In an EGFR inhibitor resistant PDX having MET amplification, single agent OMO-1 caused tumour stasis whereas MetMab/erlotinib only led to tumor growth delay. The potent preclinical activity we have observed, supports ongoing clinical development of OMO-1 in patients with MET pathway-driven tumors. Citation Format: Marion Libouban, Eleonora Jovcehva, Desiree De Lange, Boudewijn Janssens, Tinne Verhulst, Souichi Ogata, Berthold Wroblowski, Laurence Mevellec, Tianbao Lu, Glen Clack, Timothy Perera. OMO-1, a potent, highly selective, orally bioavailable, MET kinase inhibitor with a favorable preclinical toxicity profile, shows both monotherapy activity, against MET pathway-driven tumors, and EGFR TKI combination activity in acquired resistance models [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 4791.

TPS2614Background: OMO-1, a highly selective, oral, small molecule MET kinase/OCT2 inhibitor, demonstrated single agent cellular and in vivo anti-tumour activity, including regression in MET driven...

Biomarker measurements have become an essential component of oncology drug development, particularly so in this era of targeted therapies. Such measurements ensure that clinical studies are testing our biological hypotheses and can help make the difficult decisions required to choose which drugs to stop developing or de-prioritise. For those drugs taken forward, biomarker measurements may also help choose the appropriate dose, schedule and patient population. In this review we discuss the intrinsic properties of biological sample based efficacy measurements and how these relate to their implementation in oncology drug development by way of points to consider and examples.

Purpose The Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial (median follow-up, 68 months) has shown that adjuvant anastrozole has superior efficacy and better tolerability than tamoxifen. However, anastrozole reduces circulating estrogen, and low estradiol levels are associated with decreased bone mineral density (BMD) and increased fracture risk. It is therefore important to understand the effects of long-term aromatase inhibitor therapy on BMD. Patients and Methods This prospective substudy of the ATAC trial assessed BMD changes in postmenopausal women with invasive primary breast cancer receiving anastrozole (1 mg/d) or tamoxifen (20 mg/d) as adjuvant therapy for 5 years. Lumbar spine and total hip BMD were assessed at baseline and after 1, 2, and 5 years. Results One hundred ninety-seven women from the monotherapy arms of the ATAC trial were recruited onto the bone substudy, and 108 were included in the primary analysis. Among anastrozole-treated patients, there was a decrease in median BMD from baseline to 5 years in lumbar spine (−6.08%) and total hip (−7.24%) compared with the tamoxifen group (lumbar spine, +2.77%; total hip, +0.74%). No patients with normal BMD at baseline became osteoporotic at 5 years. Conclusion Anastrozole is associated with accelerated bone loss over the 5-year treatment period. However, although patients with pre-existing osteopenia are likely to require monitoring and bone-protection strategies, patients with normal BMD would not appear to require monitoring beyond the recommendation for healthy postmenopausal women. The effect of anastrozole on bone should be weighed against its superior efficacy and better tolerability profile versus tamoxifen in the main ATAC trial.

A framework for developing evidentiary standards for qualification of biomarkers is a key need identified in the Food and Drug Administration's Critical Path Initiative.1 This article describes a systematic framework that was developed by Pharmaceutical Research and Manufacturers of America (PhRMA) committees and tested at a workshop in collaboration with the Food and Drug Administration and academia. With some necessary refinements, this could be applied to create an appropriately individualized evidentiary standard for any biomarker purpose. Clinical Pharmacology & Therapeutics (2008); doi:10.1038/sj.clpt.6100451

A major step in targeted cancer drug discovery is demonstrating ‘proof of mechanism’. Tissue samples are an integral part of current drug development. At the Biotherapy Development Association Meeting in March 2007, the benefits and problems of tissue related endpoint inclusion in clinical drug development were discussed; Academic, Regulatory Authority and Pharmaceutical Industry representation being present. It was agreed that the public supports the use of human tissue in research; cooperation and collaboration are essential to ensure that tissue samples are collected and available for research; tissue sampling should be mandatory for clinical trials; and that tissue remaining from diagnostic, surgical and clinical trial based sampling should be made available for research. Until existing or new technologies provide utility for alternative sampling, access to human tissue samples of consistent quality will underpin the success of cancer drug pipelines in the era of molecular biological biomarkers and personalised medicine.

Demonstration of pharmacodynamic activity of new, targeted cancer drugs in tumour tissue is potentially important in guiding early drug development. However, delays between tumour sampling and sample fixation may result in variability of pharmacodynamic biomarkers. The aim of this study, was to assess the impact of delays in fixation on biomarkers of Src kinase activity. A total of 20 patients with locally advanced breast cancer and 5 with early bladder cancer had multiple tissue samples taken which were fixed at documented time points up to 60 min after biopsy. These were examined to determine if the amount of Paxillin, phospho-Paxillin, phospho-focal adhesion kinase (FAK) and total phospho-Tyrosine changed over time, using a quantitative lysate immunoassay. In breast cancer, there was an increase in the amount of phospho-Paxillin (60% per h; P = 0.019) up to 60 min after biopsy. The amount of total Paxillin decreased (28% per h; P = 0.034) over the same time course. In early bladder cancer, no changes were noted in any endpoints up to 45 min. Standardisation of the time taken between biopsy and fixation may be critical, particularly in studies using phosphorylated protein biomarkers.

Nausea and vomiting are components of a complex mechanism that signals food avoidance and protection of the body against the absorption of ingested toxins. This response can also be triggered by pharmaceuticals. Predicting clinical nausea and vomiting liability for pharmaceutical agents based on pre-clinical data can be problematic as no single animal model is a universal predictor. Moreover, efforts to improve models are hampered by the lack of translational animal and human data in the public domain. AZD3514 is a novel, orally-administered compound that inhibits androgen receptor signaling and down-regulates androgen receptor expression. Here we have explored the utility of integrating data from several pre-clinical models to predict nausea and vomiting in the clinic. Single and repeat doses of AZD3514 resulted in emesis, salivation and gastrointestinal disturbances in the dog, and inhibited gastric emptying in rats after a single dose. AZD3514, at clinically relevant exposures, induced dose-responsive "pica" behaviour in rats after single and multiple daily doses, and induced retching and vomiting behaviour in ferrets after a single dose. We compare these data with the clinical manifestation of nausea and vomiting encountered in patients with castration-resistant prostate cancer receiving AZD3514. Our data reveal a striking relationship between the pre-clinical observations described and the experience of nausea and vomiting in the clinic. In conclusion, the emetic nature of AZD3514 was predicted across a range of pre-clinical models, and the approach presented provides a valuable framework for predicition of clinical nausea and vomiting.

Aromatase inhibitors reduce estrogen levels in postmenopausal women with breast cancer. Residual estrogen is an important determinant of bone turnover. Adjuvant anastrozole was associated with significant BMD loss and increased bone remodeling, whereas tamoxifen reduced bone marker levels. Introduction: In the Anastrozole, Tamoxifen, Alone or in Combination (ATAC) trial after a median follow-up of 68 months, a significant improvement in disease-free survival was observed with anastrozole treatment (hazard ratio [HR], 0.87; 95% CI, 0.78–0.97; p = 0.01). Anastrozole was also associated with tolerability benefits compared with tamoxifen, but with higher fracture rates. The HR of anastrozole compared with tamoxifen after 60 months of treatment was 1.49 (95% CI, 1.25–1.77). Materials and Methods: This prospectively designed subprotocol (n = 308) of ATAC assessed changes in BMD and bone turnover markers in postmenopausal women with invasive primary breast cancer receiving anastrozole 1 mg/day, tamoxifen 20 mg/day, or combination treatment with both agents for 5 years. Patients with osteoporosis were excluded (osteopenia permitted at the investigators discretion). Lumbar spine and total hip BMD was assessed at baseline and after 1 and 2 years; bone turnover markers (serum C-telopeptide, urinary N-telopeptide [NTX], free deoxypyridinoline, serum procollagen type-1 N-propeptide, bone alkaline phosphatase [ALP]) were assessed at baseline and after 3, 6, and 12 months. Results were expressed as median percentage change. Results: After 2 years of anastrozole treatment, BMD was lost at lumbar spine (median 4.1% loss) and total hip (median 3.9% loss) sites; increases of 2.2% and 1.2%, respectively, were observed with tamoxifen. After 1 year of anastrozole treatment, increased bone remodeling was observed (NTX, +15%; 95% CI, 3–25%; bone ALP, +20%; 95% CI, 14–25%); decreased bone remodeling was observed with tamoxifen (NTX, −52%; 95% CI, −62% to −33%; bone ALP, −16%; 95% CI, −24% to −11%). Conclusions: Anastrozole is associated with significant BMD loss and a small increase in bone turnover, whereas tamoxifen (and the combination) is associated with increased BMD and decreased remodeling. These data may explain the increased fracture risk observed with anastrozole treatment in the ATAC trial. The impact of anastrozole on bone should be weighed against its overall superior efficacy and tolerability as observed in the main ATAC trial.

BRAF mutation testing from circulating free DNA (cfDNA) using the amplification refractory mutation testing system (ARMS) holds potential as a surrogate for tumor mutation testing. Robust assay validation is needed to establish the optimal clinical matrix for measurement and cfDNA-specific mutation calling criteria. Plasma- and serum-derived cfDNA samples from 221 advanced melanoma patients were analyzed for BRAF c.1799T>A (p.V600E) mutation using ARMS in two stages in a blinded fashion. cfDNA-specific mutation calling criteria were defined in stage 1 and validated in stage 2. cfDNA concentrations in serum and plasma, and the sensitivities and specificities of BRAF mutation detection in these two clinical matrices were compared. Sensitivity of BRAF c.1799T>A (p.V600E) mutation detection in cfDNA was increased by using mutation calling criteria optimized for cfDNA (these criteria were adjusted from those used for archival tumor biopsies) without compromising specificity. Sensitivity of BRAF mutation detection in serum was 44% (95% CI, 35% to 53%) and in plasma 52% (95% CI, 43% to 61%). Specificity was 96% (95% CI, 90% to 99%) in both matrices. Serum contains significantly higher total cfDNA than plasma, whereas the proportion of tumor-derived mutant DNA was significantly higher in plasma. Using mutation calling criteria optimized for cfDNA improves sensitivity of BRAF c.1799T>A (p.V600E) mutation detection. The proportion of tumor-derived cfDNA in plasma was significantly higher than in serum.

Tumour control rates from radiation therapy (RT) are limited by normal tissue toxicities. Novel strategies are required to selectively sensitize tumour cells to radiation-induced DNA damage. The G2 cell cycle checkpoint is an attractive target for this, as normal cells will be protected by their intact G1 checkpoint, which is lost in the majority of cancer cells. ATR is an important mediator of the G2 checkpoint. Preclinical data suggest that ATR inhibition will sensitise to DNA damaging therapies, including RT. This multi-part phase 1 trial aims to assess safety and tolerability and preliminary anti-tumour activity of the ATR inhibitor AZD6738 as monotherapy and in combination with palliative RT, escalating both drug and radiation dose at a dose-fractionation relevant to radical treatment. The design aims to test a novel agent at the earliest stage of clinical development and assess safety in combination with RT, with the aim of moving to a radically-treated population if tolerated. Methods: Participants have advanced solid tumours without standard systemic therapy options. The trial comprises three parts: parts A and B will assess AZD6738 as a single agent in dose escalation to MTD (part A), followed by expansion cohorts enriched for defective DNA damage response (part B). Part C will assess AZD6738 in combination with palliative RT in which participants will receive 20 Gy in 10 fractions, with per cohort escalation of drug dose to monotherapy MTD if tolerated. At the highest tolerated combination dose, the RT dose will be escalated to 30 Gy in 15 fractions. Maintenance AZD6738 post-RT will be tested at the highest tolerated combination dose. The study opened in August 2014. The study is dose escalating in part A and part C has opened and treated its first patient. Part B will open when dose escalation has completed. PATRIOT is sponsored by The Royal Marsden, funded by the Cancer Research UK/AstraZeneca Combinations Alliance and supported by supply of free drug and distribution costs from Astra Zeneca. Clinical trial information: NCT02223923

Prostate cancer is a leading cause of cancer death in men, with an estimate of about 241,000 new cases and 34,000 deaths due to prostate cancer in the United States in 2011 [1]. Prostate cancer is dependent on the androgen receptor (AR); the androgen axis shown to be a key driver of the disease [2]. This principle was first established more than 70 years ago by the demonstration that surgical castration will retard the progression of disease [3]. Prostate cancer typically responds well to suppression of testosterone. Surgical castration is effective in lowering testosterone production but suffers from its psychological impact and irreversibility; thus treatment of the early stages of advanced disease in the Western world is typically based on ‘chemical’ castration with luteinising hormone releasing hormone (LHRH) agonists. These agents suppress luteinising hormone release and markedly reduce testicular testosterone production. Even with effective surgical or chemical castration, however, some residual androgen production

A validated assay for the enumeration of circulating melanoma cells (CMCs) may facilitate the development of more effective therapies for metastatic melanoma patients. In this study CD146(+) cells were immunomagnetically enriched from 7.5 ml of blood. Isolated cells were fluorescently stained with DAPI, anti-molecular weight melanoma-associated antigen (HMW-MAA). anti-CD45 and CD34 and Ki67. CMCs were identified as CD146(+), HMW-MAA(+), CD45(-), CD34(-), Ki67(-/+) cells. Eighty-eight percent of spiked SK-MEL28 cells in 7.5 ml blood were recovered. In all 55 healthy donors = 2 CMCs per 7.5 ml of whole blood, as compared with the group with

Purpose To investigate the management of bone health in women with early breast cancer (EBC) who were scheduled to receive anastrozole. Patients and Methods Postmenopausal women with hormone receptor–positive EBC were assigned to one of three strata by risk of fragility fracture. Patients with the highest risk (H) received anastrozole 1 mg/d plus risedronate 35 mg/wk orally. Patients with moderate-risk (M) were randomly assigned in a double-blind manner to anastrozole and risedronate (A + R) or to anastrozole and placebo (A + P). Patients with lower-risk (L) received anastrozole (A) alone. Calcium and vitamin D were recommended for all patients. Lumbar spine and total hip bone mineral density (BMD) were assessed at baseline, 12 months, and 24 months. Results At 24 months, in the M group, treatment with A + R resulted in a significant increase in lumbar spine and total hip BMD compared with A + P treatment (2.2% v −1.8%; treatment ratio, 1.04; P < .0001; and 1.8% v −1.1%; treatment ratio, 1.03; P < .0001, respectively). In the H stratum, lumbar spine and total hip BMD increased significantly (3.0%; P = .0006; and 2.0%; P = .0104, respectively). Patients in the L stratum showed a significant decrease in lumbar spine BMD (−2.1%; P = .0109) and a numerical decrease in total hip BMD (−0.4%; P = .5988). Safety profiles for anastrozole and risedronate were similar to those already established. Conclusion In postmenopausal women at risk of fragility fracture who were receiving adjuvant anastrozole for EBC, the addition of risedronate at doses established for preventing and treating osteoporosis resulted in favorable effects in BMD during 24 months.

Src is a nonreceptor tyrosine kinase thought to be essential for osteoclast function and bone resorption. We investigated the effect of the orally available Src inhibitor saracatinib (AZD0530) on bone turnover in healthy men. The study was part of a randomized, double-blind, placebo-controlled multiple-ascending-dose phase I trial of saracatinib. Fifty-nine healthy men (mean age 34.6 years) were divided into five cohorts; four with 12 subjects and one with 11 subjects, and randomized within each cohort in the ratio 3:1 to receive a single dose of saracatinib or placebo, respectively, followed 7 to 10 days later with daily doses for a further 10 to 14 days. Dosing levels of saracatinib ascended by cohort (60 to 250 mg). Markers of bone turnover were measured predose and 24 and 48 hours after the initial single dose and immediately before and 24 and 48 hours and 10 to 14 days after the final dose. Data from 44 subjects were included in the analysis. There was a dose-dependent decrease in bone resorption markers [serum cross-linked C-telopeptide of type I collagen (sCTX) and urinary cross-linked N-telopeptide of type I collagen normalized to creatinine (uNTX/Cr)]. At a dose of 250 mg (maximum tolerated dose), sCTX decreased by 88% [95% confidence interval (CI) 84-91%] and uNTX/Cr decreased by 67% (95% CI 53-77%) from baseline 24 hours after the final dose. There was no significant effect on bone formation markers. There were no significant adverse events. We conclude that inhibition of Src reduces osteoclastic bone resorption in humans. Saracatinib is a potentially useful treatment for diseases characterized by increased bone resorption, such as metastatic bone disease and osteoporosis.

Given potential differences between the skeletal and other effects of the third generation aromatase inhibitors (AIs), we conducted an open, randomised Phase I study, comparing the effects of three licensed AIs on bone turnover markers, lipid profiles and adrenal function. Treatment comparisons were undertaken in 90 healthy postmenopausal women with normal bone mineral density who received once daily oral anastrozole (1mg, n=29), letrozole (2.5mg, n=29) or exemestane (25mg, n=32) for 24weeks with a subsequent 12week washout period. All three AIs induced increases in bone resorption markers, but no significant differences were observed in their effects on bone turnover markers. Greater differences were observed in lipid metabolism. Notably, exemestane, but not anastrozole or letrozole, significantly increased the LDL:HDL cholesterol ratio by 12weeks, largely mediated by a decrease in HDL-cholesterol. Further, long-term clinical studies are required to determine the impact, if any, of the differences observed between the AIs

AZD6738 is a potent and selective orally bio-available inhibitor of ataxia telangiectasia and rad3 related (ATR),a key serine/threonine protein kinase involved in DNA damage response signalling caused by DNA replication associated stress. Activation of ATR at stalled replication forks leads to suppression of replication fork origin firing, promotes repair and activates S/G1/G2-cell cycle checkpoints to prevent premature mitosis and maintain genomic integrity. Failure to resolve this damage leads to genomic instability and if sufficiently high, cell death. Cancer cells undergoing high levels of replication associated DNA damage or in cells with deficiencies in ATM-dependent repair pathways are hypothesised to be more reliant on ATR for survival and specific inhibition of ATR may lead to enhanced anti-tumour activity. In patients with malignant disease, an ATR inhibitor has the potential to: • Have monotherapy activity, through synthetic lethality or by exploiting on-going aberrant DNA replication structures leading to dependency on ATR • Act synergistically in combination with DNA damaging therapies, either systemic therapies or a localised DNA damaging therapy, such as radiotherapy which activate ATR • Act as a maintenance therapeutic after either of the above. AZD6738 monotherapy response across cell line panels in vitro shows a wide range of sensitivities and is well tolerated at efficacious doses in vivo. ATM-deficient cells are enriched for greater sensitivity to AZD6738 which offers a potential testable patient selection hypothesis. However, AZD6738 also shows enhanced activity in some (but not all) ATM-proficient cells such those from haematological malignancies. In addition, combination of AZD6738 with radiation induces regression in both ATM-deficient and ATM-proficient models (albeit at different AZD6738 doses). Anti-tumour activity of AZD6738 may, therefore, also be seen more broadly than ATM-deficiency particularly in combinations. Here we describe the 2 clinical studies with AZD6738 that will test the monotherapy and combination therapy (potentiation of DNA damage) hypotheses, along with an overview of the pre-clinical in vitro and in vivo data supporting this.

Background: Tamoxifen treatment results in a doubling of the risk of endometrial cancer after 1-2 years of treatment and a quadrupling after 5 years. Anastrozole, a third-generation aromatase inhibitor, with superior efficacy to tamoxifen, may also offer tolerability benefits in terms of effects on the endometrium. Methods and results: A sub-protocol of the ATAC trial compared the incidence/type of intrauterine changes following treatment with these agents in a subgroup of patients (n = 285) from the main trial. After 2 years anastrozole treatment, endometrial thickness remained ≤ 5 mm (baseline: 3.0 mm); in patients receiving tamoxifen, endometrial thickness increased by 3.2 mm to 7.0 mm, with a similar trend in the combination group. At baseline, 26/285 patients (9.1%) had endometrial abnormalities, most commonly polyps. After 2 years the number of endometrial abnormalities appeared lower with anastrozole treatment compared with tamoxifen although these differences were not statistically significant (odds ratio: 0.44; 95% confidence interval 0.146, 1.314; P = 0.14). Most abnormalities occurred within the first year of treatment (anastrozole: 4/6; tamoxifen: 7/10; combination: 10/16; total: 21/32). Fewer patients in the anastrozole group (1.4%) required medical intervention (tamoxifen 12.5%; combination 13.6%). Conclusions: Fewer endometrial abnormalities occurred during 2 years treatment with anastrozole compared with tamoxifen although statistical significance was not reached in this sub-protocol analysis.

BACKGROUND: The ‘Arimidex’, Tamoxifen, Alone or in Combination (ATAC) trial is a randomized, doubleblind trial comparing anastrozole (‘Arimidex’), alone or in combination with tamoxifen, relative to tamoxifen alone as 5 year adjuvant treatment for post-menopausal women with early breast cancer. Since tamoxifen is associated with endometrial pathology, the ATAC endometrial sub-protocol was initiated to establish the background prevalence of intrauterine pathology, and to assess prospectively the incidence and nature of intrauterine changes following endocrine therapy. Another aim was to provide data from which advice could be generated on the best endometrium screening method for patients receiving tamoxifen. METHODS: Patients underwent endometrial assessments at entry to the sub-protocol. The baseline investigations comprised transvaginal ultrasound scanning (TVUS), a hysteroscopy and an endometrial biopsy. RESULTS: A total of 285 gynaecologically asymptomatic women from 31 centres in 10 countries entered the endometrial sub-protocol. The mean uterine volume was 47.7 cm 3 . The median endometrial thickness overall was 3 mm. Twenty-four histologically confirmed, pathological changes were observed. Twenty-three pathologies were confirmed by TVUS, and 21 were identified by hysteroscopy and confirmed by histopathology. Women with or without intrauterine pathology had median endometrial thickness of 5 and 3 mm respectively. CONCLUSIONS: The presence of pathology was associated with increased endometrial thickness. The relative sensitivity and specificity of hysteroscopy and endometrial thickness for the diagnosis of endometrial pathology was comparable to other studies. If screening of the endometrium prior to treatment is appropriate, this study supports the use of an endometrial thickness of 3 mm, as assessed by TVUS, as a threshold for needing further investigation. This study demonstrates that if the endometrial thickness is >3 mm, hysteroscopy and biopsy is the optimal method of detecting intrauterine pathology in women with breast cancer who are about to commence endocrine treatment.

Objective The ATAC (Arimidex, Tamoxifen, Alone or in Combination) trial is a randomised, double-blind trial comparing ‘Arimidex’ (anastrozole), alone or in combination with tamoxifen, relative to tamoxifen alone as a five year adjuvant treatment for postmenopausal women with early breast cancer. Because tamoxifen is associated with endometrial pathology, the ATAC endometrial subprotocol was initiated to establish the background prevalence of pathology, and to assess prospectively the incidence and nature of intrauterine changes before and following endocrine therapy. Setting International. Population and Study Design Two hundred and eighty-five women entered the subprotocol: the mean age was 60 years (range 44–80 years); 113 women (40%) had taken hormone replacement therapy prior to randomisation, and 238 women were parous (84%). The age at onset of the menopause was 32–58 years, with the majority becoming menopausal between 46 and 55 years of age. Two hundred and seventy-two women had a hysteroscopy before they commenced trial medication. Hysteroscopy was performed successfully in 265 women. In six women, failure of hysteroscopy at baseline led to withdrawal from the study. Three of the women who withdrew had a pipelle biopsy taken. Therefore, the total number of endometrial biopsies at baseline was 268. Main outcome measures To assess the demographic characteristics of women entering the endometrial subprotocol and their hysteroscopic and histological findings before commencing trial medication. Results At hysteroscopy, there was a diagnosis of endometrial polyps in 34 women (13%), fibroids in 16 women (6%) and one case of suspicious endometrium, which was confirmed as a polyp on histology. Only 21 of the 34 polyps seen hysteroscopically were proven histologically (62% accuracy of hysteroscopy). Final histology found the prevalence of endometrial diagnostic categories as follows: 123 inactive endometrium (46%), 20 benign polyps (7%), 17 secretory endometrium (6%), 7 proliferative endometrium (3%), 3 atypical hyperplasia (2 in a polyp), 1 simple hyperplasia (in a polyp) and 1 fibroid. The remaining women had pipelle samples with insufficient tissue obtained, indicating a normal endometrial cavity. Conclusion This is the first study of such size in gynaecologically asymptomatic breast cancer patients. This paper describes the findings in individual patients before any trial treatment was given. In this baseline group, 82% (219/268) of women had a normal endometrial cavity; 18% (49/268) had endometrial activity (proliferative or secretory endometrium in 9%) or an intracavity abnormality (hyperplasia, polyps and a fibroid in 9%). In total, 36% of biopsies had insufficient tissue for diagnosis, which in combination with a normal hysteroscopy was classed as normal. The appearance of a polyp hysteroscopically in this group was not proven histologically in approximately 40% of cases. The development of uterine pathology over time in the ATAC study will subsequently be assessed against the findings of this baseline paper.

Background cfDNA is detectable in patients with metastatic cutaneous melanoma and its plasma concentration could potentially predict their clinical outcomes. We assessed the correlation between cfDNA concentration and patients' overall survival and clinical characteristics including known poor prognostic factors in melanoma. Prognostic value of CMCs number and its association with cfDNA level was also explored. Methods Pre-treatment blood samples from 50 patients with metastatic cutaneous melanoma were collected prospectively. cfDNA was extracted from 1 ml of plasma using QIAamp Circulating Nucleic Acids Kit (Qiagen, Hilden, Germany) and quantified by RNase P qPCR (ABI Life Technologies, Foster City, NJ, USA). CMC enumeration per 7.5 ml whole blood was performed within 96 hours of sample collection using the CellSearch Melanoma Kit (Veridex, NJ, USA). Correlation between cfDNA concentration and clinical characteristics and CMC number was performed using χ2-test and Fisher's exact test where appropriate. Survival curves were produced and compared by the Kaplan-Meier method and log-rank test respectively. Results The median concentration of cfDNA was 6.8 ng/ml (range 0-205.8) and median CMC number was 0/7.5ml (range 0-16). Patients with cfDNA concentration of >75% percentile had significantly shorter overall survival compared to those with cfDNA level Conclusions Plasma cfDNA concentration and presence of CMC in 7.5 ml whole blood can predict patient's survival outcomes in metastatic cutaneous melanoma. No association was found between these two biomarkers and this highlights the possibility that they may represent different tumour biological process. Disclosure G. Brady: has an advisory role in Epistem and owns shares in Epistem. G. Clack: employee of Astra-Zeneca pharamceuticals and ownes stock in Astra-zeneca. A. Hughes: Employee of Astra-Zeneca and ownes stock in Astra-Zeneca. All other authors have declared no conflicts of interest.

Summary Background: This study provides a direct randomized comparison of a new-generation, non-steroidal aromatase inhibitor, anastrozole (Arimidex®), with a steroidal aromatase inhibitor (formestane) with respect to oestrogen (oestradiol, oestrone, and oestrone sulphate) suppression and tolerability. Patients and methods: Sixty postmenopausal women with advanced breast cancer were randomized to receive either anastrozole 1 mg once daily orally (n = 29), or formestane 250 mg once every two weeks by intramuscular injection (n = 31). Treatment was continued until progression of disease or withdrawal from the study. The primary endpoints of this study were oestradiol suppression and tolerability. The secondary endpoints included oestrone and oestrone sulphate suppression. All laboratory analyses were conducted 'blind' of the randomized drug treatment. Results: Anastrozole produced a greater and more consistent suppression of oestradiol levels compared with formestane. Based on two- and four-week measurements, the mean fall from baseline (pre-dose) in oestradiol level was 79% and 58% in the anastrozole and formestane groups, respectively (P = 0.0001). After four weeks of treatment, oestrone and oestrone sulphate levels were also suppressed to a greater extent by anastrozole compared with formestane (oestrone: 85% versus 67%, respectively, P - 0.0043; oestrone sulphate: 92% versus 67%, respectively, P = 0.0007). No statistical differences were seen between the two drugs in the incidence of adverse events. Conclusions: Anastrozole provides a more consistent and significantly more effective suppression of oestradiol compared with formestane. Similar results were observed for oestrone and oestrone sulphate. The clinical significance of these differences in total oestrogen suppression remains to be established.