Mirela Hategan

PACMEL: A phase 1 dose escalation trial of trametinib (GSK1120212) in combination with paclitaxel

BACKGROUND We sought to determine the maximal tolerated dose of the MEK inhibitor trametinib with weekly paclitaxel, with a view to exploring the combinations activity in melanoma lacking a BRAF V600 mutation. METHODS In this phase 1 study we used a fixed dose of paclitaxel (80 mg/m2 intravenous (IV) on days 1, 8 and 15 of each 4 week cycle) and escalated the dose of trametinib (to a maximum 2mg orally (PO) daily), following a 3+3 design. Eligible patients had advanced melanoma and could have received up to two previous lines of treatment for metastatic disease. FINDINGS 15 patients were enrolled, all but one of whose melanoma was wild type for BRAF at codon 600. The maximal monotherapy dose of trametinib proved tolerable with weekly paclitaxel. The most frequent adverse events observed were rash and fatigue. Six (40%) partial responses were reported, including four of eight patients with NRAS mutations. Median progression free survival was 5.5 months (95% confidence interval (CI) 1.8-7.8 months) and overall survival, 14.1 months (95% CI 4.6-not reached). INTERPRETATION Trametinib can safely be given with weekly paclitaxel at the full monotherapy dose. In this small group promising progression free and overall survival were observed in patients with melanoma lacking a V600 BRAF mutation.

Management of melanoma

BACKGROUND Melanoma is a potentially curable cancer, but around 20% of patients will develop disease which is beyond surgical clearance. Rising incidence alongside breakthroughs in understanding the molecular biology of this disease identifying systemic therapies offering survival gains now demand a more proactive, integrated approach to melanoma management. SOURCES OF DATA PubMed references relating to aspects of melanoma research and treatment. AREAS OF AGREEMENT Rapidly rising incidence throughout the world. Effective surgery as well as new molecular targeted systemic biological agents and immunotherapies necessitating early diagnosis and multidisciplinary therapeutic interventions. AREAS OF CONTROVERSY Role of screening and prevention. Benefit of interventions for locoregional melanoma, including role of sentinel lymph node biopsy. Integration and sequencing of treatments for unresectable melanoma. GROWING POINTS Molecular determinants of melanoma influencing disease outcome and treatment decisions. AREAS TIMELY FOR DEVELOPING RESEARCH Education and training of patient and healthcare professionals. Role of screening, surveillance and follow-up strategies. Biology of melanoma guiding treatment decisions.

1094PDA PHASE 1, DOSE ESCALATION STUDY OF PACLITAXEL WITH GSK1120212 (TRAMETINIB) FOR THE TREATMENT OF ADVANCED MELANOMA

N. Coupe1, P. Corrie2, M. Hategan2, J. Larkin3, M.E. Gore3, A. Gupta1, A. Wise4, S. Suter1, C. Ciria5, S. Love5, L. Collins4, M.R. Middleton1 Medical Oncology, The Oxford Cancer Centre, Churchill Hospital, Oxford Radcliffe Hospitals NHS Trust, Oxford, UK Oncology Centre, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK Medicine, Royal Marsden Hospital NHS Foundation Trust, London, UK Department of Oncology, University of Oxford, Oncology Clinical Trials Office, Oxford, UK Centre for Statistics In Medicine, University of Oxford, Oxford Clinical Trials Research Unit, Oxford, UK

Abstract B23: A phase 1 study in patients with mesothelioma or non small cell lung tumours requiring arginine to assess ADI-PEG 20 with pemetrexed and cisplatin (TRAP study)

Background: Loss of the metabolic tumor suppressor, argininosuccinate synthetase (ASS1), the rate-limiting enzyme in arginine biosynthesis, sensitizes mesothelioma and lung carcinoma cells to apoptosis following arginine withdrawal. We have reported treatment with the arginine depletor pegylated arginine deiminase (ADI-PEG 20) in ASS1-negative tumor cells potentiates the cytotoxic effect of pemetrexed, accompanied by suppression of de novo pyrimidine synthesis and the pyrimidine salvage pathway (Allen et al, Cancer Res 2014. We have undertaken a phase I study (NCT02029690) of ADI-PEG 20 combined with first-line pemetrexed and cisplatin chemotherapy in patients (pt) with ASS1-deficient mesothelioma or non-squamous non-small cell lung cancer (NSCLC), primary objective was to recommend a dose for future study (RP2D). Methods: Main inclusion criteria: ≥ 18 years, PS ≤ 1, tumour ASS1 loss (≤ 50% ASS expression by IHC) with adequate organ function and written, informed consent. Exclusion criteria: symptomatic CNS metastases, significant concurrent morbidity, therapeutic anticoagulation, history of seizures, or allergy to trial medication(s). A 3+3+3 phase 1 dose escalation design was used with increasing doses of weekly ADI-PEG 20 (18, 27 and 36 mg/m2 IM) in each of three cohorts plus pemetrexed 500 mg/m2 and cisplatin 75 mg/m2 both given every 3 weeks (1 cycle), maximum 18 weeks. ADI-PEG 20 alone was allowed after 18 weeks if there was stable disease or better. Adverse events were graded using CTCAE v4.03 and dose limiting toxicities (DLT) were defined as: Grade 4 neutropenia (> 7 days), febrile neutropenia, Grade 4 anaemia or thrombocytopenia, other clinically significant Grade 3/4 non haematological toxicity that occurred during cycle 1. Radiological disease response was assessed every 6 weeks (modified RECIST for mesothelioma and RECIST 1.1 for NSCLC) and peripheral blood samples were collected to measure plasma arginine and citrulline levels and antibodies to ADI-PEG 20. Results: 42 pt were screened for tumor ASS1 expression and 15 (36%) were ASS1-deficient. Subsequently, 9 pt were eligible for DLT assessment. Demographics - 6 M:3 F, Age range 62 - 77, NSCLC (4): Mesothelioma (5), Prior therapy EGFRi (1 pt), External beam radiotherapy (2 pt) No DLT were observed at any dose level. Grade ≤ 3, AE related to pemetrexed and cisplatin were (5 pt): nausea (5), fatigue (2) and vomiting, peripheral neuropathy, dry mouth, mouth ulcers, dehydration and neutropenia (1 each). No AE were reported related to ADI PEG 20. Mean cycles of treatment: 9 (range 4 - 14) 1 pt was dose reduced after cisplatin toxicity. Arginine was depleted for ≥3 weeks (3-18 weeks in all treated patients. 7/9 pt had partial response (PR) and 2/9 had stable disease (SD) as best response. Conclusions: The combination was well tolerated, the RP2D is 36mg/m2 ADI-PEG 20 weekly with pemetrexed 500 mg/m2 and cisplatin 75 mg/m2 every 3 weeks. Robust clinical activity has been observed with 78% pt having PR as best response on CT scan, as well as PR and SD in2 pt with sarcomatoid mesothelioma. The tolerability and response / disease control rate suggest that this combination may have clinical utility as first line treatment for these malignancies in ASS1-deficient pt. RP2D expansion cohorts are ongoing for pt with pleural mesothelioma or non-squamous NSCLC. Citation Format: Simon Pacey, James F. Spicer, Pui Ying Chan, Mirela Hategan, Dimitra Repana, Jeremy Peter Steele, Peter Schmid, Gary J R Cook, Monica Diaz, Amanda Johnston, Richard Baird, Adelberto Barba, Ramsay Khadeir, Michael Sheaff, Jose Roca, Teresa Szyszko, John Bomalaski, Peter Wojciech Szlosarek. A phase 1 study in patients with mesothelioma or non small cell lung tumours requiring arginine to assess ADI-PEG 20 with pemetrexed and cisplatin (TRAP study). [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B23.

468PPHASE I MULTICENTRE TAX-TORC TRIAL OF THE DUAL MTORC1/2 INHIBITOR AZD2014 (A) PLUS WEEKLY PACLITAXEL (P) IN PATIENTS (PTS) WITH SOLID TUMOURS (CRUKD/12/013)

ABSTRACT Aim: Activation of the PI3 kinase-AKT-mTOR pathway is hypothesized to contribute to resistance to chemotherapy and targeted agents in many cancers. Enhanced PI3 kinase pathway signaling has been shown in ovarian cancer cell lines and ascitic cells from pts showing chemoresistance. In a previous phase I trial the maximum tolerated dose (MTD) of the dual mTORC1/2 inhibitor AZD2014 (A) as monotherapy was defined as 50 mg bd 7/7. Preclinically, when A is combined with P, additive apoptosis is observed. Therefore, the combination of A and P was evaluated in a multicentre Phase I trial in patients with solid tumours (EudraCT 2012-003896-20). Study aims were to determine the MTD and recommended dose for the combination of fixed dose weekly P with two intermittent schedules of A, based on safety, tolerability, pharmacokinetics (PK) profile, pharmacodynamics (PD) and antitumour activity. Methods: A was administered orally bd either 3 days on 4 days off (3/7 schedule) or 2 days on 5 days off (2/7 schedule) starting on the same day as fixed dose weekly intravenous P 80mg/m2. A cycle comprised 6 weekly treatments every 49 days. A 3 + 3 dose escalation design was employed. Results: 17 pts have been treated in the study so far. On the 3/7 schedule (12 treated), 2 pts had dose-limiting toxicities (DLT) of grade (Gr) 3 fatigue and mucositis at 75 mg bd of A. On the 2/7 schedule (5 treated), 2 pts had DLT of Gr 3 rash at 100mg bd of A. Frequently observed adverse events of any grade were fatigue, diarrhoea, anaemia, mucositis and anorexia. PK and PD data for the 2 schedules will be presented. To date, 3/5 pts with taxane-pretreated ovarian cancer have achieved RECIST and/or GCIG CA125 partial response (PR). 2/2 pts with taxane-pretreated squamous NSCLC and 1/2 pts with EGFR-mutant lung adenocarcinoma have shown significant necrosis of their tumours and PR by RECIST. Conclusions: The MTD for the 3/7 schedule is P 80 mg/m2 plus A 50 mg bd. For the 2/7 schedule, 100mg bd A + weekly P is declared non-tolerated, based on 2 DLTs of Gr 3 rash. Expansions in relapsed ovarian cancer and squamous cell lung cancer are now planned. The study is supported by AstraZeneca, Cancer Research UK, Experimental Cancer Medicine Centre and NIHR Biomedical Research Centre Initiatives. It is co-sponsored by the Institute of Cancer Research/Royal Marsden NHS Foundation Trust. Disclosure: S. Banerjee, S.B. Kaye and J.S. De Bono: Served on Advisory Board for AstraZeneca. All other authors have declared no conflicts of interest.