Emma Dean

Phase I study to assess the safety and tolerability of olaparib in combination with bevacizumab in patients with advanced solid tumours

Background:Olaparib (AZD2281) is a potent oral poly(ADP-ribose) polymerase inhibitor with anti-tumour activity and acceptable toxicity as monotherapy in patients with BRCA-deficient cancers. The vascular endothelial growth factor receptor inhibitor bevacizumab has been incorporated into standard of care with chemotherapy in various tumours. This phase I study established the safety, tolerability and clinical pharmacokinetics of olaparib alone and in combination with bevacizumab.Methods:Patients with advanced solid tumours received increasing doses of continuous oral olaparib (100, 200 and 400 mg b.i.d. capsule formulation) in combination with bevacizumab (10 mg kg−1 intravenous q2w).Results:In all, 12 patients enrolled and received treatment. The most common adverse events (AEs) related to olaparib were grade 1/2 nausea and fatigue. No haematological parameters were reported as AEs. No serious AEs related to olaparib or dose-limiting toxicities (DLTs) were reported. Three patients discontinued due to AEs, two patients discontinued both olaparib and bevacizumab and one patient discontinued olaparib. Five patients received combination treatment for over 6 months. There was no evidence that bevacizumab affected olaparib.Conclusion:The combination of olaparib 400 mg b.i.d. with bevacizumab 10 mg kg−1 q2w was generally well tolerated with no DLTs. This combination could be considered for future clinical investigation.

Biomarkers of apoptosis.

Within the era of molecularly targeted anticancer agents, it has become increasingly important to provide proof of mechanism as early on as possible in the drug development cycle, especially in the clinic. Selective activation of apoptosis is often cited as one of the major goals of cancer chemotherapy. Thus, the present minireview focuses on a discussion of the pros and cons of a variety of methodological approaches to detect different components of the apoptotic cascade as potential biomarkers of programmed cell death. The bulk of the discussion centres on serological assays utilising the technique of ELISA, since here there is an obvious advantage of sampling multiple time points. Potential biomarkers of apoptosis including circulating tumour cells, cytokeratins and DNA nucleosomes are discussed at length. However, accepting that a single biomarker may not have the power to predict proof of concept and patient outcome, it is clear that in the future more emphasis will be placed on technologies that can analyse panels of biomarkers in small volumes of samples. To this end the increased throughput afforded by multiplex ELISA technologies is discussed.

IAPs as a Target for Anticancer Therapy

The avoidance of apoptosis is one of the hallmarks of cancer cells. In addition, failure to induce apoptosis by anticancer agents, either due to limitations of the drug or the tumour cell evading apoptosis, is a reason for chemotherapeutic failure. Two general pathways for apoptotic cell death have been characterised, the extrinsic and intrinsic pathways which merge in the final common pathway. X-linked inhibitor of apoptosis protein (XIAP) is an anti-apoptotic protein in the final common pathway that inhibits caspases and suppresses apoptosis. XIAP is over-expressed in many cancer cell lines and cancer tissues. High XIAP expression has been correlated with resistance to chemotherapy and radiotherapy and to poor clinical outcome by some investigators. Manipulation of apoptosis is an attractive therapeutic concept. Much effort has been spent on inhibiting the anti-apoptotic protein, B cell lymphoma gene 2 (Bcl-2) which is part of the intrinsic pathway. Now attention is turning to inhibition of XIAP as a cancer drug target. It has been argued that it is more effective to block the final common pathway rather than just the intrinsic arm. Inhibition of XIAP can be with either antisense oligonucleotides (ASO) or small molecule inhibitors. In vitro, XIAP antagonists produce XIAP knockdown and apoptosis which is associated with sensitisation of tumour cells to radiotherapy and cytotoxic drugs. In vivo, XIAP antagonists have antitumour effects and sensitise tumours to the effects of chemotherapy. This review will summarise the preclinical data for both ASO and small molecule inhibition of XIAP and discuss emerging Phase I data. Future strategies for manipulation of XIAP and the clinical development of XIAP inhibitors will be discussed.

X-linked inhibitor of apoptosis protein as a therapeutic target

Dysregulation of apoptosis has been shown to contribute to many diseases, including cancer formation, development and resistance, as well as neurodegenerative and autoimmune disorders. One mechanism through which tumour cells are believed to acquire resistance to apoptosis is by overexpression of X-linked inhibitor of apoptosis protein (XIAP), which belongs to a family of inhibitor of apoptosis proteins. When XIAP is overexpressed, cancer cells are rendered resistant to apoptosis, both intrinsically and in response to chemotherapy and radiotherapy. Significant progress has been made in targeting XIAP therapeutically, both directly and indirectly through the modulation of other molecules involved in the apoptotic pathway. This review introduces XIAP from its molecular origins, discusses its modulation and potential as a novel drug target, and considers future therapeutic perspectives.

First-in-human pharmacokinetic and pharmacodynamic study of the dual m-TORC 1/2 inhibitor, AZD2014.

Purpose: AZD2014 is a novel, oral, m-TORC 1/2 inhibitor that has shown in vitro and in vivo efficacy across a range of preclinical human cancer models. Experimental Design: A rolling six-dose escalation was performed to define an MTD (part A), and at MTD a further cohort of patients was treated to further characterize toxicities and perform pre- and posttreatment biopsies (part B). AZD2014 was administered orally twice a day continuously. Flow cytometry, ELISA, and immunohistochemistry were used to quantify pharmacodynamic biomarkers. Pharmacokinetic analysis was carried out by mass spectrometry. Results: A total of 56 patients were treated across a dose range of 25 to 100 mg. The MTD was 50 mg twice daily. The dose-limiting toxicities were fatigue and mucositis. At the MTD, the most common adverse events (AE) were fatigue (78%), nausea (51%), and mucositis (49%), but these were equal to or greater than grade 3 in only 5% of patients. Drug levels achieved at the MTD (AUCss 6686 ng·h/mL, Cmax ss 1,664 ng/mL) were consistent with activity in preclinical models. A reduction in p-S6 levels and Ki67 staining was observed in 8 of 8 and 5 of 9 evaluable paired biopsy samples. Partial responses were seen in a patient with pancreatic cancer and a patient with breast cancer, who were found to have a PDGFR and ERBB2 mutation, respectively. Conclusions: The recommended phase II dose for further evaluation of AZD2014 is 50 mg twice daily, and at this dose it has been possible to demonstrate pharmacologically relevant plasma concentrations, target inhibition in tumor, and clinical responses. Clin Cancer Res; 21(15); 3412–9. ©2015 AACR.

Erlotinib in combination with pemetrexed for patients with advanced non-small-cell lung cancer (NSCLC): a phase I dose-finding study

BACKGROUND Erlotinib and pemetrexed are approved single agents for second-line treatment of non-small-cell lung cancer (NSCLC) and, in combination, have shown synergistic antitumor activity in NSCLC cell lines. We investigated the safety, pharmacokinetics and preliminary efficacy of combined erlotinib-pemetrexed in patients with refractory advanced NSCLC. PATIENTS AND METHODS A nonrandomized, open-label, phase IB study was performed in patients with advanced NSCLC whose disease had progressed on or following first-line chemotherapy with a platinum-containing regimen or for whom the erlotinib-pemetrexed combination was considered appropriate. Patients received i.v. pemetrexed 500-700 mg/m² every 3 weeks and oral erlotinib 100-150 mg/day. RESULTS Twenty patients were recruited. The most common adverse events (AEs) were rash, diarrhea and fatigue. Serious AEs occurred in eight patients (three treatment related) and there were eight deaths (none treatment related). Dose-limiting toxic effects were not experienced up to erlotinib 150 mg/day plus pemetrexed 600 mg/m². Concurrent administration did not affect pharmacokinetic parameters. Two patients achieved partial responses and nine had stable disease. CONCLUSIONS Erlotinib-pemetrexed combination is well tolerated at doses equal to the licensed single-agent doses (150 mg/day and 500 mg/m², respectively). The good tolerability profile and promising efficacy indicate that this combination warrants further investigation for patients with advanced NSCLC.

A small molecule inhibitor of XIAP induces apoptosis and synergises with vinorelbine and cisplatin in NSCLC.

Background:Evasion of apoptosis contributes to the pathogenesis of solid tumours including non-small cell lung cancer (NSCLC). Malignant cells resist apoptosis through over-expression of inhibitor of apoptosis proteins (IAPs), such as X-linked IAP (XIAP).Methods:A phenylurea-based small molecule inhibitor of XIAP, XIAP antagonist compound (XAC) 1396-11, was investigated preclincally to determine its ability to sensitise to clinically relevant cytotoxics, potentially allowing dose reduction while maintaining therapeutic efficacy.Results:XIAP protein expression was detected in six NSCLC cell lines examined. The cytotoxicity of XAC 1396-11 against cultured NSCLC cell lines in vitro was concentration- and time-dependent in both short-term and clonogenic assays. XAC 1396-11-induced apoptosis was confirmed by PARP cleavage and characteristic nuclear morphology. XAC 1396-11 synergised with vinorelbine±cisplatin in H460 and A549 NSCLC cells. The mechanism of synergy was enhanced apoptosis, shown by increased cleavage of caspase-3 and PARP and by the reversal of synergy by a pan-caspase inhibitor. Synergy between XAC 1396-11 and vinorelbine was augmented by optimising drug scheduling with superior effects when XAC 1396-11 was administered before vinorelbine.Conclusion:These preclinical data suggest that XIAP inhibition in combination with vinorelbine holds potential as a therapeutic strategy in NSCLC.

Neuroendocrine and epithelial phenotypes in small-cell lung cancer: implications for metastasis and survival in patients

Background:Small-cell lung cancer (SCLC) has a very aggressive clinical course with early metastasis. This study investigated how the distinctive neuroendocrine characteristics contribute to disease progression and invasion in human SCLC.Methods:The neuroendocrine phenotype (pro-opiomelanocortin (POMC)) was quantified by ELISA in blood samples from 43 SCLC patients. The neuroendocrine (POMC, chromogranin A, neuron-specific enolase, NCAM) and epithelial (cytokeratin and E-cadherin) phenotypes were investigated, using ELISA and immunocytochemistry/immunohistochemistry.Results:In SCLC patients, 16% had elevated circulating POMC, which was associated with significantly worse survival (P=0.02) and liver metastases (P=0.004). In addition, POMC correlated with epithelial-positive circulating tumour cells (P=0.0002). In a panel of SCLC cell lines, all POMC-secreting cell lines expressed cytokeratin (40% of total). Even after cloning, DMS 79 cells expressed both neuroendocrine and epithelial markers. DMS 79 xenografts secreted POMC into the blood, which mirrored the tumour volume. These xenografts expressed both neuroendocrine and epithelial phenotypes in all tumours, with both phenotypes prevalent in cells invading the surrounding tissue.Conclusion:Both neuroendocrine and epithelial phenotypes coexist in human SCLC tumours in vitro and in vivo and this persists in invading tumour cells. In patients, POMC secretion predicts poor survival and liver metastases, suggesting a crucial role of the neuroendocrine phenotype.

AKT Inhibition in Solid Tumors With AKT1 Mutations

Purpose AKT1 E17K mutations are oncogenic and occur in many cancers at a low prevalence. We performed a multihistology basket study of AZD5363, an ATP-competitive pan-AKT kinase inhibitor, to determine the preliminary activity of AKT inhibition in AKT-mutant cancers. Patients and Methods Fifty-eight patients with advanced solid tumors were treated. The primary end point was safety; secondary end points were progression-free survival (PFS) and response according to Response Evaluation Criteria in Solid Tumors (RECIST). Tumor biopsies and plasma cell-free DNA (cfDNA) were collected in the majority of patients to identify predictive biomarkers of response. Results In patients with AKT1 E17K-mutant tumors (n = 52) and a median of five lines of prior therapy, the median PFS was 5.5 months (95% CI, 2.9 to 6.9 months), 6.6 months (95% CI, 1.5 to 8.3 months), and 4.2 months (95% CI, 2.1 to 12.8 months) in patients with estrogen receptor-positive breast, gynecologic, and other solid tumors, respectively. In an exploratory biomarker analysis, imbalance of the AKT1 E17K-mutant allele, most frequently caused by copy-neutral loss-of-heterozygosity targeting the wild-type allele, was associated with longer PFS (hazard ratio [HR], 0.41; P = .04), as was the presence of coincident PI3K pathway hotspot mutations (HR, 0.21; P = .045). Persistent declines in AKT1 E17K in cfDNA were associated with improved PFS (HR, 0.18; P = .004) and response ( P = .025). Responses were not restricted to patients with detectable AKT1 E17K in pretreatment cfDNA. The most common grade ≥ 3 adverse events were hyperglycemia (24%), diarrhea (17%), and rash (15.5%). Conclusion This study provides the first clinical data that AKT1 E17K is a therapeutic target in human cancer. The genomic context of the AKT1 E17K mutation further conditioned response to AZD5363.

Abstract LB-66: Results of two phase I multicenter trials of AZD5363, an inhibitor of AKT1, 2 and 3: Biomarker and early clinical evaluation in Western and Japanese patients with advanced solid tumors .

Background: AZD5363 is an oral, potent, and selective inhibitor of AKT1, 2 and 3, with activity in a wide range of tumor cell lines and xenografts dependent upon PI3K/AKT signaling. Methods: Two phase I studies (NCT01226316 [West], NCT01353781 [Japan]) were initiated to define the toxicity, pharmacokinetic (PK), and pharmacodynamic (PD) profile of AZD5363. Two schedules, continuous bid dosing (7/7) and an intermittent schedule bid dosing 4 days on 3 days off (4/7), were investigated. PD biomarkers of AKT signaling were assessed (using pre- and on-treatment samples) in plasma (pPRAS40, pGSK3β, pAKT, glucose, insulin), plucked hair (pPRAS40) and tumor tissue (pPRAS40, pGSK3β, pAKT). Results: At data cut-off (January 2013), 92 patients had been treated in the dose-escalation phases of both studies. In the Western study, the maximum tolerated dose (MTD) for each schedule was 320 mg bid (7/7) and 480 mg bid intermittent dosing (4/7). In the Japanese study, 320 mg bid (7/7) was not tolerated; the MTD for intermittent dosing (4/7) was 480 mg bid. The most commonly reported adverse events, of note, were hyperglycemia, rash, and diarrhea. The PK profile suggests a dose proportional increase in Cmax and AUC. Exposures achieved at doses of 320 mg bid (7/7) and 480 mg bid (4/7) and above are consistent with activity seen in xenograft models. At the doses described, target engagement was seen as evidenced by PD changes in normal tissue (>50% reduction in pPRAS40 in 7/10 patients on AZD5363 480 mg bid (4/7) in plucked hair samples and 30-50% reduction in pPRAS40 and >30% reduction in pGSK3β in platelet rich plasma). Importantly, 7/9 paired biopsies showed an increase in pAKT consistent with the non allosteric inhibition of AKT. Investigation of another intermittent schedule of AZD5363 bid, 2 days on/5 days off treatment, is ongoing. Exploratory mutation analyses of plasma samples are ongoing. Two partial responses were observed, one endometrioid cancer of the ovary and one cervical cancer, in patients on AZD5363 at 480 mg bid (4/7) and 400 mg bid (7/7), respectively. Mutation of either AKT1 or PIK3CA was identified in tumor tissue from both patients. A further patient, with endometrioid cancer of ovary (PIK3CA mutation), had stable disease (SD) for 156 days. Conclusions: AZD5363 administered at 480 mg bid (4/7) was generally well tolerated and showed a PK and PD profile consistent with activity in preclinical models. Partial responses were noted in patients with mutations driving the PI3K pathway. Footnote: AZD5363 was discovered by AstraZeneca subsequent to collaboration with Astex Therapeutics (and its collaboration with the Institute of Cancer Research and Cancer Research Technology Ltd). Citation Format: Udai Banerji, Malcolm Ranson, Jan HM Schellens, Taito Esaki, Emma Dean, Andrea Zivi, Ruud van der Noll, Paul K. Stockman, Marcelo Marotti, Michelle D. Garrett, Barry R. Davies, Paul Elvin, Andrew Hastie, Peter Lawrence, SY Amy Cheung, Christine Stephens, Kenji Tamura. Results of two phase I multicenter trials of AZD5363, an inhibitor of AKT1, 2 and 3: Biomarker and early clinical evaluation in Western and Japanese patients with advanced solid tumors . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-66. doi:10.1158/1538-7445.AM2013-LB-66