Phase I expansion study of the first-in-class monocarboxylate transporter 1 (MCT1) inhibitor AZD3965 in patients with diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL)

3115

Background: Tumours rely on lactate transporters (MCT1-4) to maintain glycolytic flux and avoid intracellular acidification. In haematological tumours the MCT1 transporter acts as a lactate and pyruvate exporter. AZD3965 is a potent and specific inhibitor of MCT1 causing intracellular lactate accumulation. In vivo efficacy was observed in xenografts of DLBCL and BL, expressing high levels of MCT1 and no or low levels of MCT4. In the AZD3965 phase I (NCT01791595) dose-escalation an oral recommended phase 2 dose (RP2D) of 10mg twice-daily (bd) was determined. Pharmacokinetic (PK) showed exposure estimated to produce a minimum MCT1 occupancy of 90% (based on modelling). DLTs were primarily on-target dose-dependent, reversible, asymptomatic alterations in retinal function seen on ERG. Methods: This expansion cohort enrolled patients with relapsed/refractory DLBCL and BL. Expression of MCT1/MCT4 was assessed by immunohistochemistry. Pharmacokinetic (PK) sampling was performed and pharmacodynamic assessments included [18F]FDG-PET/CT imaging and plasma/urine metabolomics. Results: 11 DLBCL patients were treated with AZD3965 10mg bd. PK showed exposure to be broadly in line with the escalation cohort. No significant ERG changes were observed. One patient experienced a dose-limiting SUSAR of Troponin I increase. MCT1 is expressed in erythrocytes, however no serious events of anaemia were seen, with one non-clinically significant episode of grade 3 anaemia reported. Urine analysis showed increased excretion of lactate and ketone bodies post AZD3965 treatment consistent with renal target engagement. No alteration was detected in plasma. Ongoing stable disease at cycle 5 was observed in one patient and an additional patient had a confirmed complete response (CR) lasting 15 months, with no significant toxicity. In the patient showing CR a reduction in tumour FDG uptake was observed on day 3 of cycle 1. The other four patients who consented to research imaging did not have a clinical response and no changes were observed on FDG-PET. Conclusions: AZD3965 can be safely administered at 10mg bd. In one DLBCL patient monotherapy activity was observed with changes in FDG-PET providing evidence indicative of proof of mechanism. These changes in FDG uptake as early as on day 3 in the responding patient warrant further investigation of FDG-PET as a predictive biomarker. Further biomarker analysis and preclinical studies are ongoing to understand the biology and explore effective combinations with other agents targeting tumour cell metabolism Clinical trial information: NCT01791595.

Results of the OPARATIC trial: A phase I dose escalation study of olaparib in combination with temozolomide (TMZ) in patients with relapsed glioblastoma (GBM)

2022

Background: Olaparib, a small molecule inhibitor of poly (ADP-ribose) polymerase (PARP), may improve GBM outcomes by enhancing cytotoxic effects of ionising radiation and TMZ. Clinical development of PARP inhibitors has been restricted by exacerbation of hematological toxicity. We investigated tumor pharmacokinetics (PK) of olaparib and safety and tolerability of its combination with TMZ. Methods: Dose escalation explored different schedules of olaparib (tablet formulation) with 42 day cycles of daily low dose TMZ. A dose expansion cohort evaluated the maximum tolerated schedule. PK analysis was performed on tumor and blood samples from patients undergoing neurosurgical resection, who received 4 olaparib doses pre-operatively. Results: 48 patients were recruited (median age 51(18-68); 29 male, 19 female) of whom 27 underwent surgery and 35 received olaparib/TMZ and were evaluable. 13 evaluable patients received expansion dose schedule (median age 54(21-67); 9 male, 4 female). Olaparib was detected in 73 of 74 tumor core specimens from 27 patients; mean conc. 588nM (97-1374nM), and in 27 of 28 tumor margin specimens from 10 patients; mean conc. 500nM (97-1237nM). Margin: core ratios ranged from 0.2–3.9(mean 1.2); tumor: plasma ratios ranged from 0.01 to 0.9 (mean 0.25). Olaparib dosing on days 1-5 was hindered by myelosuppression. Expansion cohort dose was defined as TMZ 75 mg/m2daily plus olaparib 150 mg (OD) days 1-3 weekly. Of 13 evaluable patients receiving expansion dose-schedule, 9 completed cycle 1, 2 completed cycle 2 and 2 completed cycle 3. Currently 45% of the evaluable patients remain progression-free at 6 months, with 2 still on treatment (full data set May2017). Of 35 evaluable patients, 24 experienced AE Grade ≥3 (see Table). Conclusions: Olaparib penetrates both core and margins of recurrent GBM despite failing to penetrate the intact brain barrier in pre-clinical heathy rodent models. Combination with extended low dose TMZ is safe and well tolerated, yielding encouraging 6 month progression-free survival rates. Clinical trial information: NCT01390571. [Table: see text]

A first-in-human first-in-class (FIC) trial of the monocarboxylate transporter 1 (MCT1) inhibitor AZD3965 in patients with advanced solid tumours

2516

Background: A key metabolic alteration in tumour cells is an increased dependency on the glycolysis, resulting in the production of lactate, which is transported out of cells by MCTs. Inhibition of MCT-1 leads to a profound inhibition of cancer cell growth in preclinical models. AZD3965 is a FIC inhibitor of MCT-1, and we report results from the phase I study of this agent. Methods: Patients with advanced solid tumours were treated with oral (po) AZD3965 at total daily doses of 5-30mg given once (od) and twice daily (bd). Exclusion criteria included a history of retinal or cardiac disease due to preclinical toxicology findings in the eye and heart (which express MCT-1). The primary objectives were to determine the safety, dose limiting toxicities (DLT) and maximum tolerated dose (MTD) of AZD3965. Intensive pharmacokinetic (PK) profiling was performed with subsequent modelling for receptor occupancy. Pharmacodynamic profiling included imaging to detect pH changes and tumour glucose uptake; plasma/urine metabolomics and MCT-1 and MCT-4 tumour expression by immunohistochemistry. Results: 35 patients (20M:15F median age 65) were treated at dose levels 5, 10, 20, and 30mg od and 15 and 10mg bd. AZD3965 was generally well tolerated with nausea and fatigue (CTCAE Gr1-2) the most commonly reported side effects. A single DLT of cardiac troponin rise was observed at 20mg od. Asymptomatic, reversible retinal ERG changes were observed in all but the lowest dose levels, with DLTs observed at doses above 20mg od. PK data indicate exposures in the preclinical efficacy range. Metabolomic changes in urinary lactate and urinary ketones correlate with on-target activity. The increase in urinary ketones is likely to be attributable to the role of MCT1 in physiological ketone transport. Conclusions: The MCT1 inhibitor AZD3965 can be administered to patients at doses which engage the drug target, with a MTD of 20mg od po. DLTs seen were primarily dose dependent, asymptomatic and reversible changes in retinal function, which were an expected on-target effect. Investigation of the activity of AZD3965 is ongoing in tumours known to express MCT1. Clinical trial information: NCT01791595.

A phase I trial of AT9283 (a selective inhibitor of aurora kinases) in children and adolescents with solid tumors: a Cancer Research UK study

PURPOSE

A phase I trial of AT9283 (a multitargeted inhibitor of Aurora kinases A and B) was conducted in children and adolescents with solid tumors, to identify maximum-tolerated dose (MTD), safety, efficacy, pharmacokinetics, and pharmacodynamic (PD) activity.

EXPERIMENTAL DESIGN

AT9283 was administered as a 72-hour continuous intravenous infusion every 3 weeks. A rolling-six design, explored six dose levels (7, 9, 11.5, 14.5, 18.5, and 23 mg/m(2)/d). Pharmacokinetic and PD assessments, included inhibition of phospho-histone 3 (pHH3) in paired skin punch biopsies.

RESULTS

Thirty-three patients were evaluable for toxicity. There were six dose-limiting toxicities and the MTD was 18.5 mg/m(2)/d. Most common drug-related toxicities were hematologic (neutropenia, anemia, and thrombocytopenia in 36.4%, 18.2%, and 21.2% of patients), which were grade ≥3 in 30.3%, 6.1%, and 3% of patients. Nonhematologic toxicities included fatigue, infections, febrile neutropenia and ALT elevation. One patient with central nervous system-primitive neuroectodermal tumor (CNS-PNET) achieved a partial response after 16 cycles and 3 cases were stable for four or more cycles. Plasma concentrations were comparable with those in adults at the same dose level, clearance was similar although half-life was shorter (4.9 ± 1.5 hours, compared with 8.4 ± 3.7 hours in adults). Inhibition of Aurora kinase B was shown by reduction in pHH3 in 17 of 18 patients treated at ≥11.5 mg/m(2)/d.

CONCLUSION

AT9283 was well tolerated in children and adolescents with solid tumors with manageable hematologic toxicity. Target inhibition was demonstrated. Disease stabilization was documented in intracranial and extracranial pediatric solid tumors and a phase II dose determined.

A randomised, phase II trial of the DNA-hypomethylating agent 5-aza-2'-deoxycytidine (decitabine) in combination with carboplatin vs carboplatin alone in patients with recurrent, partially platinum-sensitive ovarian cancer

BACKGROUND

Our previous laboratory and clinical data suggested that one mechanism underlying the development of platinum resistance in ovarian cancer is the acquisition of DNA methylation. We therefore tested the hypothesis that the DNA hypomethylating agent 5-aza-2'-deoxycytodine (decitabine) can reverse resistance to carboplatin in women with relapsed ovarian cancer.

METHODS

Patients progressing 6-12 months after previous platinum therapy were randomised to decitabine on day 1 and carboplatin (AUC 6) on day 8, every 28 days or carboplatin alone. The primary objective was response rate in patients with methylated hMLH1 tumour DNA in plasma.

RESULTS

After a pre-defined interim analysis, the study closed due to lack of efficacy and poor treatment deliverability in 15 patients treated with the combination. Responses by GCIG criteria were 9 out of 14 vs 3 out of 15 and by RECIST were 6 out of 13 vs 1 out of 12 for carboplatin and carboplatin/decitabine, respectively. Grade 3/4 neutropenia was more common with the combination (60% vs 15.4%) as was G2/3 carboplatin hypersensitivity (47% vs 21%).

CONCLUSIONS

With this schedule, the addition of decitabine appears to reduce rather than increase the efficacy of carboplatin in partially platinum-sensitive ovarian cancer and is difficult to deliver. Patient-selection strategies, different schedules and other demethylating agents should be considered in future combination studies.

A phase I pharmacokinetic (PK) and pharmacodynamic (PD) study of the selective aurora kinase inhibitor GSK1070916A

2525

Background: GSK1070916A is a potent and selective inhibitor of Aurora B and C. This phase I study in collaboration with GlaxoSmithKline was part of the Cancer Research UK Clinical Development Programme. Methods: Patients (pts) with advanced/metastatic solid cancers for whom there was no standard therapy, with adequate performance status and organ function were eligible for GSK1070916A (1 hour i.v. infusion days 1 – 5, every 21 days). The primary objectives were to determine the safety profile, dose limiting toxicity (DLT) and maximum tolerated dose (MTD) of GSK1070916A. The starting dose was 5mg/m2/day, with initial single pt cohorts, followed by “3 + 3” cohorts and expansion at the MTD. DLTs included prolonged (> 5 days) or complicated grade 4 neutropenia; the MTD was the highest dose at which < 1 of 3 - 6 pts experienced DLT. Cycle 1 blood and healthy skin biopsies were obtained for PK and PD assays. The expanded cohort included 6 pts having pre- and post-treatment functional imaging studies (FDG PET-CT and MRI), and a further 6 having paired tumour biopsies for PD studies. Results: Nine single pt cohorts received up to 73mg/m2/day of GSK1070916A with no grade 3 or 4 related adverse events. At 102.2mg/m2/day, 1 pt had a DLT (febrile neutropenia) and 2 pts non-DLT grade 4 neutropenia; this dose was considered unacceptably toxic and 23 pts received a lower dose of 85mg/m2/day; 7/23 pts had prolonged/complicated grade 4 neutropenia, 5 of whom continued GSK1070916A with dose reduction +/- delay. There were no treatment related deaths. A pt with ovarian cancer (102.2mg/m2/day) had a RECIST PR; 19 pts had stable disease for < 223 days. GSK1070916A PK were linear with a strong correlation between exposure (AUC) and reduction in neutrophils (r2 0.91). At the 85 mg/m2 dose, mean day 1 t1/2 was 8.98 hours and Cl 9.2 l/h; AUCinf was 10% higher on day 5 than day 1. PD results in healthy skin (phosphoHistone-H3, Ki 67 and cleaved caspase-3) were inconsistent. Conclusions: The MTD of GSK1070916A as a 1 hour i.v. infusion on days 1 – 5, every 21 days is 85mg/m2/day, with predictable and manageable neutropenia as the DLT and evidence of clinical activity. Serum levels of cytokeratin-18, tumour PD and functional imaging data will be presented. Clinical trial information: NCT01118611.

A phase I trial of AT9283 (a selective inhibitor of Aurora kinases) given for 72 hours every 21 days via intravenous infusion in children and adolescents with relapsed and refractory solid tumours

9542

Background: AT9283, is a multi-targeted inhibitor, against Aurora A and B, JAK & ABL kinases. Aurora kinases are potential therapeutic targets in paediatric solid cancers. Methods: A phase I dose escalation study was performed using a 72 hour intravenous infusion repeated 3 weekly using a rolling 6 design for patients aged >2 to <19 years with relapsed/ refractory solid tumours. Results: Eighteen patients treated with a median age of 10 (range 3 to 16) years. Four dose cohorts of 7, 9, 11.5 and 14.5 mg/m2/day. The diagnoses included; 5 high grade glioma, 4 rhabdoid tumours, 3 neuroblastomas, 3 sarcomas & 3 others. There has been only one dose limiting toxicity; Grade 3 febrile neutropenia at 11.5 mg/m2/day. The majority of adverse events (AEs) have been grade 1/2 & considered unrelated/ unlikely related to study drug. Two patients have experienced Grade 3 or 4 AEs considered at least possibly related to study drug: Grade 3 haemoglobin and Grade 4 neutrophils in a patient treated at 9 mg/m2/day & Grade 3 lymphopenia, neutrophils, infection with normal neutrophil count and aspartate transaminase in a patient treated at 11.5 mg/m2/day. Pharmacokinetics of AT9283 in this population are largely in keeping with those seen in adult patients at similar doses (Arkenau et al., 2011) although there may be greater variability. Pharmacodynamic evidence of aurora B inhibition, as manifested by a reduction in histone H3 phosphorylation in normal skin biopsies pre & post infusion, has been documented at all dose levels tested. Stable disease (up to 6 cycles) has been observed in 3 patients. Conclusions: This paediatric phase I study has demonstrated AT9283 administered as a 72 hour continuous infusion can be given at a dose level of 11.5 mg/m2/day which is higher than the maximum tolerated dose observed in adult patients (9 mg/m2/day) with advanced solid tumours. Myelosuppresion is the main toxicity but the regimen is well tolerated with preliminary anticancer activity seen in heavily pre-treated paediatric patients. [Table: see text]

MSI-low, a real phenomenon which varies in frequency among cancer types

This study assessed whether low-level microsatellite instability (MSI-L) is a phenomenon specific to colorectal cancers or is also present in other tumour types. Breast (grade III ductal and lobular), endometrial and ovarian carcinomas, as well as colorectal cancers, were analysed for MSI-L using eight microsatellite markers. The markers were selected from a panel that had previously been shown to be sensitive for the detection of MSI-L in colorectal cancers. It was found that MSI-L was present in 30 of 87 (35%) colorectal cancers, 2 of 59 (3%) grade III breast carcinomas, 1 of 35 (3%) lobular breast cancers, 16 of 50 (32%) endometrial cancers, and 9 of 34 (26%) ovarian cancers. These results suggest that MSI-L is a very rare occurrence in breast carcinomas, but does occur as a real phenomenon in colorectal, endometrial, and ovarian carcinomas, which are all part of the hereditary non-polyposis colon cancer (HNPCC) syndrome. PCR artefact was also found to masquerade as MSI-L; criteria for the assessment of MSI-L are suggested to eliminate this problem.

Germline mutations but not somatic changes at the MYH locus contribute to the pathogenesis of unselected colorectal cancers

MYH-associated polyposis is a recently described, autosomal recessive condition comprising multiple colorectal adenomas and cancer. This disease is caused by germline mutations in the base excision repair (BER) gene MYH. Genes involved in the BER pathway are thus good candidates for involvement in the pathogenesis of sporadic tumors of the large bowel. We have screened a set of 75 sporadic colorectal cancers for mutations in MYH, MTH1, and OGG1. Allelic loss at MYH was also assessed. Selected samples were screened for mutations and allele loss at APC and mutations in p53, K-ras, and beta-catenin. A panel of 35 colorectal cancer cell lines was screened for MYH mRNA and protein expression. One of 75 cancers had bi-allelic germline mutations in MYH and on retrospective analysis of medical records this patient was found to have synchronous multiple small adenomas in addition to carcinoma. No somatic MYH mutations were found and mRNA and protein were expressed in all of our cell lines. There were no clearly pathogenic mutations in MTH1 or OGG1 in any tumor. Bi-allelic germline MYH mutations cause approximately 1 to 3% of unselected colorectal cancers, but appear always to be associated with multiple adenomas. Somatic inactivation of the DNA glycosylases involved in the BER pathway however does not appear to be involved in colorectal tumorigenesis.