Anastasios Stathis

The BET Bromodomain Inhibitor OTX015 Affects Pathogenetic Pathways in Preclinical B-cell Tumor Models and Synergizes with Targeted Drugs.

Purpose: In cancer cells, the epigenome is often deregulated, and inhibition of the bromodomain and extra-terminal (BET) family of bromodomain-containing proteins is a novel epigenetic therapeutic approach. Preliminary results of an ongoing phase I trial have reported promising activity and tolerability with the new BET bromodomain inhibitor OTX015. Experimental Design: We assessed the preclinical activity of OTX015 as single agent and in combination in mature B-cell lymphoma models and performed in vitro and in vivo experiments to identify the mechanism of action and the genetic features associated with sensitivity to the compound. Results: OTX015 showed antiproliferative activity in a large panel of cell lines derived from mature B-cell lymphoid tumors with median IC50 of 240 nmol/L, without significant differences among the different histotypes. In vitro and in vivo experiments showed that OTX015 targeted NFKB/TLR/JAK/STAT signaling pathways, MYC- and E2F1-regulated genes, cell-cycle regulation, and chromatin structure. OTX015 presented in vitro synergism with several anticancer agents, especially with mTOR and BTK inhibitors. Gene expression signatures associated with different degrees of sensitivity to OTX015 were identified. Although OTX015 was mostly cytostatic, the compound induced apoptosis in a genetically defined subgroup of cells, derived from activated B-cell–like diffuse large B-cell lymphoma, bearing wtTP53, mutations in MYD88, and CD79B or CARD11. Conclusions: Together with the data coming from the ongoing phase I study, the in vitro and in vivo data presented here provide the basis for further clinical investigation of OTX015 as single agent and in combination therapies. Clin Cancer Res; 21(7); 1628–38. ©2015 AACR.

Long-term outcome following Helicobacter pylori eradication in a retrospective study of 105 patients with localized gastric marginal zone B-cell lymphoma of MALT type

BACKGROUND Treatment aimed at eradicating Helicobacter pylori infection results in lymphoma remission in most localized gastric mucosa-associated lymphoid tissue (MALT) lymphomas. The aim of this survey is to investigate the long-term effect of this therapeutic approach in a large series of patients. METHODS One hundred and five patients with localized gastric MALT lymphoma were initially treated only with H. pylori eradication regimens. Lymphoma responses were graded using the Wotherspoon score. RESULTS Helicobacter pylori, detected by histology in 81% of cases, was eradicated in all positive patients. Histological regression of the lymphoma was achieved in 78 of 102 assessable patients [76%, 95% confidence interval (CI): 67% to 84%] with complete remission (score 0-2) in 66 and partial remission (score 3) in 12. At a median follow-up time of 6.3 years, histological remission was consistently confirmed in 33 of 74 assessable patients, while 25 had score fluctuations (from 0 to 4) and 13 presented a lymphoma relapse (score 5). Only one patient had a distant progression. Transformation to a large-cell lymphoma was seen in two cases. The 5- and 10-year overall survival is 92% (95% CI: 84% to 96%) and 83% (95% CI: 70% to 91%), respectively. Only one patient died of lymphoma after transformation to a high-grade lymphoma. CONCLUSIONS Helicobacter pylori eradication resulted in complete lymphoma remission in the majority of cases. Long-term clinical disease control was achieved in most patients. A watch and wait policy appears to be safe in patients with minimal residual disease or histological-only local relapse.

Bromodomain inhibitor OTX015 in patients with lymphoma or multiple myeloma: a dose-escalation, open-label, pharmacokinetic, phase 1 study

BACKGROUND The first-in-class small molecule inhibitor OTX015 (MK-8628) specifically binds to bromodomain motifs BRD2, BRD3, and BRD4 of bromodomain and extraterminal (BET) proteins, inhibiting them from binding to acetylated histones, which occurs preferentially at super-enhancer regions that control oncogene expression. OTX015 is active in haematological preclinical entities including leukaemia, lymphoma, and myeloma. We aimed to establish the recommended dose of OTX015 in patients with haematological malignancies. We report the results from a cohort of patients with lymphoma or multiple myeloma (non-leukaemia cohort). METHODS In this dose-escalation, open-label, phase 1 study, we recruited patients from seven university hospital centres (in France [four], Switzerland [one], UK [one], and Italy [one]). Adult patients with non-leukaemia haematological malignancies who had disease progression on standard therapies were eligible to participate. Patients were treated with oral OTX015 once a day continuously over five doses (10 mg, 20 mg, 40 mg, 80 mg, and 120 mg), using a conventional 3 + 3 design, with allowance for evaluation of alternative administration schedules. The primary endpoint was dose-limiting toxicity (DLT) in the first treatment cycle (21 days). Secondary objectives were to evaluate safety, pharmacokinetics, and preliminary clinical activity of OTX015. The study is ongoing and is registered with ClinicalTrials.gov, number NCT01713582. FINDINGS Between Feb 4, 2013, and Sept 5, 2014, 45 patients (33 with lymphoma and 12 with myeloma), with a median age of 66 years (IQR 55-72) and a median of four lines of prior therapy (IQR 3-5), were enrolled and treated. No DLTs were observed in the doses up to and including 80 mg once a day (first three patients). We then explored a schedule of 40 mg twice a day (21 of 21 days). DLTs were reported in five of six patients receiving OTX015 at this dose and schedule (all five patients had grade 4 thrombocytopenia). We explored various schedules at 120 mg once a day but none was tolerable, with DLTs of thrombocytopenia, gastrointestinal events (diarrhoea, vomiting, dysgeusia, mucositis), fatigue, and hyponatraemia in 11 of 18 evaluable patients. At this point, the Safety Monitoring Committee decided to establish the feasibility of 80 mg once a day on a continuous basis, and four additional patients were enrolled at this dose. DLTs (grade 4 thrombocytopenia) was noted in two of the patients. In light of these DLTs and other toxicities noted at 120 mg, the dose of 80 mg once a day was selected, although on a schedule of 14 days on, 7 days off. Common toxic effects reported in the study were thrombocytopenia (43 [96%] patients), anaemia (41 [91%]), neutropenia (23 [51%]), diarrhoea (21 [47%]), fatigue (12 [27%]), and nausea (11 [24%]). Grade 3-4 adverse events were infrequent other than thrombocytopenia (26 [58%]). OTX015 plasma peak concentrations and areas under the concentration versus time curve increased proportionally with dose. Trough concentrations increased less than proportionally at lower doses, but reached or exceeded the in-vitro active range at 40 mg twice a day and 120 mg once a day. Three patients with diffuse large B-cell lymphoma achieved durable objective responses (two complete responses at 120 mg once a day, and one partial response at 80 mg once a day), and six additional patients (two with diffuse large B-cell lymphoma, four with indolent lymphomas) had evidence of clinical activity, albeit not meeting objective response criteria. INTERPRETATION The once-daily recommended dose for oral, single agent oral OTX015 in patients with lymphoma is 80 mg on a 14 days on, 7 days off schedule, for phase 2 studies. OTX015 is under evaluation in expansion cohorts using this intermittent administration (14 days every 3 weeks) to allow for recovery from toxic effects. FUNDING Oncoethix GmbH (a wholly owned subsidiary of Merck Sharp & Dohme Corp).

Clinical Response of Carcinomas Harboring the BRD4–NUT Oncoprotein to the Targeted Bromodomain Inhibitor OTX015/MK-8628

UNLABELLED The antineoplastic, prodifferentiative effects of bromodomain and extra-terminal (BET) bromodomain (BRD) inhibitors were initially discovered in NUT midline carcinoma (NMC), an aggressive subtype of squamous cancer driven by the BRD4-NUT fusion oncoprotein. BRD4-NUT blocks differentiation and maintains tumor growth through a potent chromatin-modifying mechanism. OTX015/MK-8628, a novel oral BET inhibitor, targets BRD2/3/4/T with preclinical activity in NMC and several other tumor types and is currently in clinical development. Antitumor activity was evaluated in four patients with advanced-stage NMC with confirmed BRD4-NUT fusions who were treated with 80 mg OTX015/MK-8628 once daily in a compassionate-use context. Two patients responded rapidly with tumor regression and symptomatic relief, and a third had meaningful disease stabilization with a minor metabolic response. The main side effects were mild to moderate gastrointestinal toxicity and fatigue, and reversible grade 3 thrombocytopenia. This is the first proof-of-concept evidence of clinical activity of a BRD inhibitor in targeting BRD4-NUT. SIGNIFICANCE We present the first clinical proof-of-concept that targeting BRD4-NUT with a BET inhibitor results in impressive and rapid antitumor activity in NMC. It offers strong potential for future clinical application in this rare patient population as either a single agent or in combination with other agents. Cancer Discov; 6(5); 492-500. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 461.

A Phase Ib Dose-Escalation Study of the Oral Pan-PI3K Inhibitor Buparlisib (BKM120) in Combination with the Oral MEK1/2 Inhibitor Trametinib (GSK1120212) in Patients with Selected Advanced Solid Tumors

Purpose: MAPK and PI3K/AKT/mTOR pathways play important roles in many tumors. In this study, safety, antitumor activity, and pharmacokinetics of buparlisib (pan class PI3K inhibitor) and trametinib (MEK inhibitor) were evaluated. Experimental Design: This open-label, dose-finding, phase Ib study comprised dose escalation, followed by expansion part in patients with RAS- or BRAF-mutant non–small cell lung, ovarian, or pancreatic cancer. Results: Of note, 113 patients were enrolled, 66 and 47 in dose-escalation and -expansion parts, respectively. MTD was established as buparlisib 70 mg + trametinib 1.5 mg daily [5/15, 33% patients with dose-limiting toxicities (DLT)] and recommended phase II dose (RP2D) buparlisib 60 mg + trametinib 1.5 mg daily (1/10, 10% patients with DLTs). DLTs included stomatitis (8/103, 8%), diarrhea, dysphagia, and creatine kinase (CK) increase (2/103, 2% each). Treatment-related grade 3/4 adverse events (AEs) occurred in 73 patients (65%); mainly CK increase, stomatitis, AST/ALT (aspartate aminotransferase/alanine aminotransferase) increase, and rash. For all (21) patients with ovarian cancer, overall response rate was 29% [1 complete response, 5 partial responses (PR)], disease control rate 76%, and median progression-free survival was 7 months. Minimal activity was observed in patients with non–small cell lung cancer (1/17 PR) and pancreatic cancer (best overall response was SD). Relative to historical data, buparlisib exposure increased and trametinib exposure slightly increased with the combination. Conclusions: At RP2D, buparlisib 60 mg + trametinib 1.5 mg daily shows promising antitumor activity for patients with KRAS-mutant ovarian cancer. Long-term tolerability of the combination at RP2D is challenging, due to frequent dose interruptions and reductions for toxicity. Clin Cancer Res; 21(4); 730–8. ©2014 AACR.

Phase I Study of Decitabine in Combination with Vorinostat in Patients with Advanced Solid Tumors and Non-Hodgkin's Lymphomas

Purpose: This phase I study evaluated the safety, tolerability, pharmacokinetics, and preliminary efficacy of the combination of decitabine with vorinostat. Patients and Methods: Patients with advanced solid tumors or non-Hodgkins lymphomas were eligible. Sequential and concurrent schedules were studied. Results: Forty-three patients were studied in 9 different dose levels (6 sequential and 3 concurrent). The maximum tolerated dose (MTD) on the sequential schedule was decitabine 10 mg/m2/day on days 1 to 5 and vorinostat 200 mg three times a day on days 6 to 12. The MTD on the concurrent schedule was decitabine 10 mg/m2/day on days 1 to 5 with vorinostat 200 mg twice a day on days 3 to 9. However, the sequential schedule of decitabine 10 mg/m2/day on days 1 to 5 and vorinostat 200 mg twice a day on days 6 to 12 was more deliverable than both MTDs with fewer delays on repeated dosing and it represents the recommended phase II (RP2D) dose of this combination. Dose-limiting toxicities during the first cycle consisted of myelosuppression, constitutional and gastrointestinal symptoms and occurred in 12 of 42 (29%) patients evaluable for toxicity. The most common grade 3 or higher adverse events were neutropenia (49% of patients), thrombocytopenia (16%), fatigue (16%), lymphopenia (14%), and febrile neutropenia (7%). Disease stabilization for 4 cycles or more was observed in 11 of 38 (29%) evaluable patients. Conclusion: The combination of decitabine with vorinostat is tolerable on both concurrent and sequential schedules in previously treated patients with advanced solid tumors or non-Hodgkins lymphomas. The sequential schedule was easier to deliver. The combination showed activity with prolonged disease stabilization in different tumor types. Clin Cancer Res; 17(6); 1582–90. ©2011 AACR.

Incidence, risk factors and outcome of histological transformation in follicular lymphoma

Histological transformation (HT) into diffuse large B‐cell lymphoma (DLBCL) was documented in 37 of the 281 (13%; 95% CI, 9–18) follicular lymphoma (FL) patients treated at our institute from 1979 to 2007. HT occurred at a median of 2·75 years from initial FL diagnosis and HT rate was 15% at 10 years and 26% at 14 years, with a plateau from that point onward. Patients with bulky or extranodal disease, or those diagnosed before 1990 had a significantly higher risk of HT. When initial treatment strategies were taken into account, a reduced HT risk was seen in the patients initially managed with a ‘watch and wait’ policy, while the risk appeared significantly increased in the small subset of 18 patients initially managed with rituximab plus chemotherapy (P = 0·0005). HT was associated with a significantly shorter cause‐specific survival (P = 0·0002). Predictors of survival after HT were the Follicular Lymphoma International Prognostic Index at diagnosis, as well as age and performance status at the time of HT. Our data confirm the adverse clinical outcome of FL after HT. In keeping with previous isolated reports, our findings suggest that there is a subgroup of patients in whom HT may not occur.

Marginal Zone Lymphomas

In the World Health Organization classification of tumors of hematopoietic and lymphoid tissues, the group of marginal zone lymphomas comprises three different entities, namely the extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue, the nodal marginal zone B-cell, and the splenic marginal zone B-cell lymphoma (with or without circulating villous lymphocytes). This article addresses each of the marginal zone lymphomas.

Utility of baseline 18FDG PET/CT functional parameters in defining prognosis of primary mediastinal (thymic) large B-cell lymphoma

The International Extranodal Lymphoma Study Group (IELSG) 26 study was designed to evaluate the role of (18)F-fluorodeoxyglucose (18FDG) positron emission tomography/computed tomography (PET/CT) in the management of primary mediastinal (thymic) large B-cell lymphoma (PMBCL). We examined the prognostic impact of functional PET parameters at diagnosis. Metabolic activity defined by the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) was measured on baseline 18FDG PET/CT following a standard protocol in a prospectively enrolled cohort of 103 PMBCL patients. All received combination chemoimmunotherapy with doxorubicin- and rituximab-based regimens; 93 had consolidation radiotherapy. Cutoff values were determined using the receiver-operating characteristic curve. At a median follow-up of 36 months, progression-free survival (PFS) and overall survival (OS) were 87% and 94%, respectively. In univariate analysis, elevated MTV and TLG were significantly associated with worse PFS and OS. Only TLG retained statistical significance for both OS (P = .001) and PFS (P < .001) in multivariate analysis. At 5 years, OS was 100% for patients with low TLG vs 80% for those with high TLG (P = .0001), whereas PFS was 99% vs 64%, respectively (P < .0001). TLG on baseline PET appeared to be a powerful predictor of PMBCL outcomes and warrants further validation as a biomarker. The IELSG 26 study was registered at www.clinicaltrials.gov as #NCT00944567.

Choice of Starting Dose for Molecularly Targeted Agents Evaluated in First-in-Human Phase I Cancer Clinical Trials

PURPOSE One tenth of the lethal dose to 10% of mice is one of the conventional parameters used to derive a safe starting dose in phase I trials of cytotoxic agents. There is no consensus on which preclinical models and parameters should define the starting dose for molecularly targeted agents. PATIENTS AND METHODS Reports of 81 first-in-human phase I trials evaluating 60 different molecularly targeted agents administered as monotherapy were reviewed. The maximum-tolerated dose (MTD) was defined as the highest safe dose administered to patients, whereas the maximum-administered dose (MAD) was recorded if the MTD was not reached. RESULTS Fifty-seven of the 81 trials specified the animal model used to determine the starting dose, with 29 (51%) of 57 based on rodent data and 28 (49%) of 57 based on non-rodent data. A wide range of toxicologic parameters was used to select the starting dose. The starting dose exceeded the human MTD in three (3.7%) of 81 trials, and in all three trials, nonhematologic toxicity was dose limiting. The median number of dose levels to reach MTD or MAD from starting dose was five (range, one to 14 dose levels), and the median ratio of MTD or MAD to starting dose was 12 (range, < 1 to 300). Hypothetical doubling of the starting dose appeared to be safe, whereas tripling of the starting dose was unsafe. CONCLUSION The derivation of starting dose for first-in-human phase I trials of molecularly targeted agents in patients with cancer is safe but is based on diverse practices using a variety of preclinical toxicologic parameters.