A phase Ib dose-escalation and expansion study of the oral MEK inhibitor pimasertib and PI3K/MTOR inhibitor voxtalisib in patients with advanced solid tumours

BACKGROUND

This phase Ib study evaluated the safety, maximum-tolerated dose (MTD), pharmacokinetics, pharmacodynamics, and preliminary efficacy of pimasertib (MSC1936369B), a MEK1/2 inhibitor, in combination with voxtalisib (SAR245409), a pan-PI3K and mTORC1/mTORC2 inhibitor, in patients with advanced solid tumours.

METHODS

This study included a dose escalation and expansion in patients with select tumour types and alterations in the MAPK or PI3K pathways. A 3 + 3 design was used to determine MTD. Patients were evaluated for adverse events and tumour response.

RESULTS

146 patients were treated, including 63 in dose escalation and 83 in expansion. The MTD was pimasertib 90 mg and voxtalisib 70 mg daily. Based on the safety profile, the recommended phase 2 dose (RP2D) was pimasertib 60 mg and voxtalisib 70 mg. The most frequent treatment-emergent adverse events (TEAEs) were diarrhoea (75%), fatigue (57%), and nausea (50%). Responses included a complete response in one patient (1%), partial response in five (5%), and stable disease in 51 (46%). At the RP2D, 74 patients required dose interruption (73%), 20 required dose reduction (20%), and 26 discontinued treatment due to TEAEs (26%).

CONCLUSIONS

The combination of pimasertib and voxtalisib showed poor long-term tolerability and limited anti-tumour activity in patients with advanced solid tumours.

A Phase II Study of Pelareorep (REOLYSIN®) in Combination with Gemcitabine for Patients with Advanced Pancreatic Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, with 1 and 5-year survival rates of ~18% and 7% respectively. FOLFIRINOX or gemcitabine in combination with nab-paclitaxel are standard treatment options for metastatic disease. However, both regimens are more toxic than gemcitabine alone. Pelareorep (REOLYSIN®), a proprietary isolate of reovirus Type 3 Dearing, has shown antitumor activity in clinical and preclinical models. In addition to direct cytotoxic effects, pelareorep can trigger antitumor immune responses. Due to the high frequency of RAS mutations in PDAC, we hypothesized that pelareorep would promote selective reovirus replication in pancreatic tumors and enhance the anticancer activity of gemcitabine. Chemotherapy-naïve patients with advanced PDAC were eligible for the study. The primary objective was Clinical Benefit Rate (complete response (CR) + partial response (PR) + stable disease (SD) ≥ 12 weeks) and secondary objectives include overall survival (OS), toxicity, and pharmacodynamics (PD) analysis. The study enrolled 34 patients; results included one partial response, 23 stable disease, and 5 progressive disease. The median OS was 10.2 months, with a 1- and 2-year survival rate of 45% and 24%, respectively. The treatment was well tolerated with manageable nonhematological toxicities. PD analysis revealed reovirus replication within pancreatic tumor and associated apoptosis. Upregulation of immune checkpoint marker PD-L1 suggests future consideration of combining oncolytic virus therapy with anti-PD-L1 inhibitors. We conclude that pelareorep complements single agent gemcitabine in PDAC.

Phase 1 Study of Monotherapy with KHK2866, an Anti-Heparin-Binding Epidermal Growth Factor-Like Growth Factor Monoclonal Antibody, in Patients with Advanced Cancer

BACKGROUND

KHK2866 is a recombinant, humanized, non-fucosylated, monoclonal antibody directed at heparin-binding epidermal growth factor-like growth factor (HB-EGF).

OBJECTIVE

To determine the safety, tolerability, maximum tolerated dose (MTD), pharmacokinetics, pharmacodynamics, potential immunogenicity, and preliminary clinical efficacy of KHK2866 monotherapy in patients with advanced and refractory cancer in a first-in-human, phase 1 study.

MATERIALS AND METHODS

Using a standard 3 + 3 dose-escalation design, 20 patients received KHK2866 (0.3, 1, and 3 mg/kg) intravenously once weekly. Two additional patients received 0.1 mg/kg in a cohort which was subsequently added following protocol amendment.

RESULTS

The first three patients enrolled experienced grade 2 hypersensitivity (acute infusion reactions) after the first dose of KHK2866. After prophylactic treatment with an H1-blocker and corticosteroids in subsequently recruited patients, two grade 2 hypersensitivity reactions were observed in the remaining 19 patients. Grade 2/3 neurotoxicity appeared to be dose-limiting at 3 mg/kg in the original dose-escalation cohorts (n = 2), at 1 mg/kg in the MTD dose expansion cohort (n = 1), and at 0.1 mg/kg (n = 1). Neurotoxicity was manifested as complex partial seizure activity, aphasia, and confusion after first-dose administration. Pharmacokinetic exposure to KHK2866 increased proportionally to dose. Mean elimination half-life was 71.9-118 h over the dose range from 0.3 to 3 mg/kg. All KHK2866 doses decreased serum free HB-EGF levels, generally below the lower limit of quantification.

CONCLUSIONS

The study was terminated because of neuropsychiatric toxicity. The only predictive factor for neuropsychiatric toxicity was administration of KHK2866. These effects were reversible, but were not predictable. Their etiology is not presently understood. [Study registered at ClinicalTrials.gov #NCT0179291].

Phase 1 safety, pharmacokinetic and pharmacodynamic study of the cyclin-dependent kinase inhibitor dinaciclib administered every three weeks in patients with advanced malignancies

Background:

Dinaciclib is a potent inhibitor of cell cycle and transcriptional cyclin-dependent kinases. This Phase 1 study evaluated the safety, tolerability and pharmacokinetics of various dosing schedules of dinaciclib in advanced solid tumour patients and assessed pharmacodynamic and preliminary anti-tumour activity.

Methods:

In part 1, patients were enrolled in escalating cohorts of 2-h infusions administered once every 3 weeks, utilising an accelerated titration design until a recommended phase 2 dose (RP2D) was defined. In part 2, 8- and 24-h infusions were evaluated. Pharmacokinetic parameters were determined for all schedules. Pharmacodynamic effects were assessed with an ex vivo stimulated lymphocyte proliferation assay performed in whole blood.

Effects of dinaciclib on retinoblastoma (Rb) phosphorylation and other CDK targets were evaluated in skin and tumour biopsies. In addition to tumour size, metabolic response was evaluated by 18F-fluorodeoxyglucose-positron emission tomography.

Results:

Sixty-one patients were enrolled to parts 1 and 2. The RP2Ds were 50, 7.4 and 10.4 mg m⁻² as 2- 8- and 24-hour infusions, respectively. Dose-limiting toxicities included pancytopenia, neutropenic fever, elevated transaminases, hyperuricemia and hypotension. Pharmacokinetics demonstrated rapid distribution and a short plasma half-life. Dinaciclib suppressed proliferation of stimulated lymphocytes. In skin and tumour biopsies, dinaciclib reduced Rb phosphorylation at CDK2 phospho-sites and modulated expression of cyclin D1 and p53, suggestive of CDK9 inhibition. Although there were no RECIST responses, eight patients had prolonged stable disease and received between 6 and 30 cycles. Early metabolic responses occurred.

Conclusions:

Dinaciclib is tolerable at doses demonstrating target engagement in surrogate and tumour tissue.

Abstract 137: FT-1518, a new generation selective and potent mTORC1 and mTORC2 inhibitor: an in vitro and in vivo profile

Mammalian target of rapamycin (mTOR) is a clinically validated target in the treatment of cancer. mTOR forms two distinct multiprotein complexes, mTORC1 and mTORC2 which regulate cell growth, metabolism, proliferation, and survival. Rapamycin analogues target only the mTORC1 complex but do not affect the mTORC2 complex, which is an important driver for cancer cell growth and survival. The new generation of “Selective” mTOR inhibitors, blocking both mTORC1 and mTORC2 signaling might increase the efficacy and safety while expanding the therapeutic potential of these anticancer agents. Herein we describe FT-1518, a low nanomolar potent, kinase and PI3K sub family selective mTOR inhibitor. FT-1518 not only exhibited high oral bioavailability in preclinical species but has demonstrated excellent microsomal stability with no inhibitory activity towards undesired CYPs. FT-1518 showed high sustained tumor exposure and target Inhibition in a single oral dose xenograft model. FT-1518 depicted very good growth inhibitory activity across a large panel of hematologic and solid tumor cell lines with most activities falling into low nanomolar range. mTOR kinase inhibition in cells, by FT-1518, resulted in more potent inhibition of the mTOR pathway biomarkers (mTORC 1 & 2 biomarkers [pAkt(S473) and pS6(S240/244) or p70 S6K), no inhibition of PI3K biomarker [pAkt(T308)], and improved anti-proliferative activity as compared with rapamycin. FT-1518 exhibited dose-dependent and higher tumor growth inhibition (TGI) in multiple solid tumor xenografts compared with rapalogs and is poised to enter the clinic with a favorable toxicology profile.

Citation Format: Alain C. Mita, Monica M. Mita, Anthony D. William, Khalid Pasha, Chandra Siddamadappa, Kevin Zikaras, Felix T. Garzon. FT-1518, a new generation selective and potent mTORC1 and mTORC2 inhibitor: an in vitro and in vivo profile [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 137. doi:10.1158/1538-7445.AM2017-137

A phase Ia study of CC-90003, a selective extracellular signal-regulated kinase (ERK) inhibitor, in patients with relapsed or refractory BRAF or RAS-mutant tumors

2577

Background: CC-90003 is an irreversible inhibitor of ERK 1/2 with potent anti-proliferative activity in KRAS and BRAF mutant tumor models. We conducted a first-in-human study of CC-90003 in patients with RAS or BRAF mutant tumors. Methods: Patients received escalating doses of oral CC-90003 on a 21/28 day cycle. Standard safety (adverse events, chemistry/hematology, physical findings, ECGs and cardiac ECHO/MUGA scans) and PK parameters were assessed. Response was assessed per RECIST 1.1. A proprietary ELISA-based assay measured ERK levels unbound to CC-90003 in peripheral blood mononuclear cells. Results: Nineteen patients (median age: 60 yrs) harboring KRAS (n = 15), NRAS (n = 1), or BRAF (n = 3) mutant tumors received CC-90003 doses from 20 to 160 mg /day. The MTD was 120 mg based on the occurrence of Grade 3 transaminase elevations (n = 2) and hypertension (n = 1) observed at 160 mg (the NTD). Patients completed a median of 2 cycles (range: 1 to 5). AEs (mostly Grade 1 or 2) reported in ≥ 3 patients included constitutional (asthenia, fatigue), gastrointestinal (anorexia, nausea/vomiting, diarrhea), hepatic (transaminase elevations) and neurologic (dizziness, gait disturbance, paresthesias) toxicities. Grade 1-3 neurotoxicity was observed primarily at doses from 80 to 160 mg/day and resolved with dose reduction/interruption. PK parameters were highly variable, with AUC and Cmax increasing overall, with increasing dose. CC-90003 accumulation was observed after multiple doses. There were no objective responses. Levels of free ERK were reduced by ≥80% compared to baseline by C1D8 at doses ≥ 80 mg/day. Conclusions: ERK inhibition may be an attractive target for the management of mutant RAS or BRAF-driven tumors, however proof-of-concept demonstration for CC-90003 was limited by a lack of objective responses, an unfavorable PK profile and unanticipated neurotoxicity. Clinical trial information: NCT02313012.

Statins and pancreatic cancer

Pancreatic cancer remains among the most lethal cancers, despite ongoing advances in treatment for all stages of the disease. Disease prevention represents another opportunity to improve patient outcome, with metabolic syndrome and its components, such as diabetes, obesity and dyslipidemia, having been recognized as modifiable risk factors for pancreatic cancer. In addition, statins have been shown to potentially reduce pancreatic cancer risk and to improve survival in patients with a combination of metabolic syndrome and pancreatic cancer. Furthermore, preclinical studies have demonstrated that statins exhibit antitumor effects in pancreatic cancer cell lines in vitro and animal models in vivo, in addition to delaying the progression of pancreatic intraepithelial neoplasia to pancreatic ductal adenocarcinoma (PDAC) and inhibiting PDAC formation in conditional K-Ras mutant mice. The mechanisms by which statins produce anticancer effects remain poorly understood, although appear to involve inhibition of the mevalonate/cholesterol synthesis pathway, thus blocking the synthesis of intermediates important for prenylation and activation of the Ras/mitogen-activated protein kinase 1 signaling pathway. Furthermore, statins have been identified to modulate the phosphoinositide 3-kinase/Akt serine/threonine kinase 1 and inflammation signaling pathways, and to alter the expression of genes involved in lipid metabolism, which are important for PDAC growth and proliferation. In addition, statins have been demonstrated to exhibit further antitumor mechanisms in a number of other cancer types, which are beyond the scope of the present review. In the present review, current evidence highlighting the potential of statins as chemopreventive agents in pancreatic cancer is presented, and the antitumor mechanisms of statins elucidated thus far in this disease are discussed.

Phase I Study of PSMA-Targeted Docetaxel-Containing Nanoparticle BIND-014 in Patients with Advanced Solid Tumors

PURPOSE

First-in-human phase I trial to determine the safety, pharmacokinetics, and antitumor activity of BIND-014, a novel, tumor prostate-specific membrane antigen (PSMA)-targeted nanoparticle, containing docetaxel.

EXPERIMENTAL DESIGN

Patients with advanced solid tumors received BIND-014 every three weeks (n = 28) or weekly (n = 27), with dose levels ranging from 3.5 to 75 mg/m(2) and 15 to 45 mg/m(2), respectively.

RESULTS

BIND-014 was generally well tolerated, with no unexpected toxicities. The most common drug-related toxicities (>20% of patients) on either schedule included neutropenia, fatigue, anemia, alopecia, and diarrhea. BIND-014 demonstrated a dose-linear pharmacokinetic profile, distinct from docetaxel, with prolonged persistence of docetaxel-encapsulated circulating nanoparticles. Of the 52 patients evaluable for response, one had a complete response (cervical cancer on the every three week schedule) and five had partial responses (ampullary adenocarcinoma, non-small cell lung, and prostate cancers on the every-three-week schedule, and breast and gastroesophageal cancers on the weekly schedule). Responses were noted in both PSMA-detectable and -undetectable tumors.

CONCLUSIONS

BIND-014 was generally well tolerated, with predictable and manageable toxicity and a unique pharmacokinetic profile compared with conventional docetaxel. Clinical activity was noted in multiple tumor types. The recommended phase II dose of BIND-014 is 60 mg/m(2) every three weeks or 40 mg/m(2) weekly. Clin Cancer Res; 22(13); 3157-63. ©2016 AACR.

Clinical development of reovirus for cancer therapy: An oncolytic virus with immune-mediated antitumor activity

Reovirus is a double-stranded RNA virus with demonstrated oncolysis or preferential replication in cancer cells. The oncolytic properties of reovirus appear to be dependent, in part, on activated Ras signaling. In addition, Ras-transformation promotes reovirus oncolysis by affecting several steps of the viral life cycle. Reovirus-mediated immune responses can present barriers to tumor targeting, serve protective functions against reovirus systemic toxicity, and contribute to therapeutic efficacy through antitumor immune-mediated effects via innate and adaptive responses. Preclinical studies have demonstrated the broad anticancer activity of wild-type, unmodified type 3 Dearing strain reovirus (Reolysin^®) across a spectrum of malignancies. The development of reovirus as an anticancer agent and available clinical data reported from 22 clinical trials will be reviewed.

Abstract B144: Evaluation of total and encapsulated drug pharmacokinetics for BIND-014 (docetaxel nanoparticles for injectable suspension) in a phase 1 study

Background: BIND-014 is a novel, prostate-specific membrane antigen (PSMA) targeted AccurinTM (polymeric nanoparticle) containing docetaxel. PSMA is expressed on prostate cancer cells and on vasculature of many solid tumors. In a phase 1 study in patients with solid tumors BIND-014 was generally well-tolerated and displayed anti-tumor activity across a range of tumor types. Evaluation of total drug pharmacokinetics (PK) for BIND-014 in this study demonstrated differentiated plasma profiles compared to docetaxel, which is likely attributable to the vascular retention of the nanoparticle. Total docetaxel quantitation does not distinguish between docetaxel that remains encapsulated or that is released from the nanoparticle. Here we describe a method for separation of encapsulated docetaxel and characterization of the PK of total and encapsulated BIND-014 docetaxel in the phase 1 study.

Material and Methods: PK evaluation of BIND-014 was performed in 28 patients on Day 1 of a 21-day cycle (Q3W) over a dose range of 3.5 to 75 mg/m2. On Cycle 1, Day 1, blood was collected at pre-dose and at 30 minutes, 1, 2, 4, 6, 8, 24, 36, and 48 hours post-dose. A solid phase separation method in which released docetaxel binds to the matrix was developed for quantitation of encapsulated docetaxel. Encapsulated and total docetaxel were measured by LCMS. Peak concentration (Cmax), percent encapsulated, minimum concentration (Cmin), time to peak concentration (Tmax), area under the concentration-time curve (AUC), half-life (t1/2), clearance (CL) and volume of distribution (Vd) were determined for each patient using encapsulated and total plasma concentration data.

Results: Plasma concentrations of BIND-014 persisted for at least 48 hours at the higher dose levels. Clearance was independent of the administered dose, indicating a linear dose-concentration relationship following a single intravenous administration. Evaluation of encapsulated docetaxel plasma concentrations at all dose levels and all timepoints studied demonstrated mean values between 91% and 98% of total docetaxel, indicating that most circulating docetaxel was encapsulated in nanoparticles.

Conclusions: The total concentration of BIND-014 found in circulation compared to the concentration of encapsulated docetaxel was similar, indicating that the majority of docetaxel likely remains contained within the polymeric particle over the time course evaluated, and that the differentiated PK properties of BIND-014 compared to docetaxel, including greater Cmax and AUC and lower Vd and CL, are likely due largely to retention of encapsulated docetaxel within the vascular compartment. These results are consistent with the favorable tolerability profile of BIND-014 despite the markedly higher plasma concentrations for total BIND-014 compared to docetaxel at similar doses.

Citation Format: Jason M. Summa, Daniel D. Von Hoff, Jasgit C. Sachdev, Monica M. Mita, Patricia M. LoRusso, Peter D. Eisenberg, Howard A. Burris, Lowell L. Hart, Hagop Youssoufian, Donald M. Parsons, Susan C. Low. Evaluation of total and encapsulated drug pharmacokinetics for BIND-014 (docetaxel nanoparticles for injectable suspension) in a phase 1 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 B144.

Activated ras signaling pathways and reovirus oncolysis: an update on the mechanism of preferential reovirus replication in cancer cells

The development of wild-type, unmodified Type 3 Dearing strain reovirus as an anticancer agent has currently expanded to 32 clinical trials (both completed and ongoing) involving reovirus in the treatment of cancer. It has been more than 30 years since the potential of reovirus as an anticancer agent was first identified in studies that demonstrated the preferential replication of reovirus in transformed cell lines but not in normal cells. Later investigations have revealed the involvement of activated Ras signaling pathways (both upstream and downstream) and key steps of the reovirus infectious cycle in promoting preferential replication in cancer cells with reovirus-induced cancer cell death occurring through necrotic, apoptotic, and autophagic pathways. There is increasing evidence that reovirus-induced antitumor immunity involving both innate and adaptive responses also contributes to therapeutic efficacy though this discussion is beyond the scope of this article. Here, we review our current understanding of the mechanism of oncolysis contributing to the broad anticancer activity of reovirus. Further understanding of reovirus oncolysis is critical in enhancing the clinical development and efficacy of reovirus.

Abstract A68: Activity of the TORC 1/2 kinase inhibitor, CC-223, in hormone receptor positive (HR+) breast cancer cell lines and patients (pts) with genetically characterized HR+ breast cancer in a Phase I clinical trial

Introduction: PIK3CA and PTEN are among the top five most frequently mutated genes in breast cancer. Activating mutation of PIK3CA or loss of function mutation in PTEN leads to constitutive activation of AKT and mTOR driving multiple downstream metabolic and proliferative pathways important to oncogenesis. There is also cross-talk between the PI3K/AKT/mTOR pathway and ER signaling and activation of the PI3K/AKT/mTOR pathway is associated with resistance to endocrine therapy. CC-223 is a potent and selective ATP-competitive mTOR kinase inhibitor, targeting both TORC1 and TORC2 complexes.

Results: Pre-clinically, CC-223 potently inhibits the growth of breast cancer cell lines with GI50 values below 1 uM in 38 of 43 lines. Luminal-derived cell lines are more sensitive to CC-223 than basal-derived lines. Within the luminal subset, ER+, HER2+, PIK3CA mutant, or wild-type TP53 cell lines are more sensitive to CC-223; PTEN loss is not associated with increased CC-223 sensitivity. During the dose escalation part of the phase I clinical trial, 3 pts with breast cancer were enrolled. One pt with HR+/Her2- breast cancer had a durable PR (31 weeks). An expansion cohort of HR+/Her2- breast cancer enrolled 17 pts at a CC-223 dose of 45 mg QD in 28-day cycles and 13 pts were evaluable for tumor response. Deep sequencing of tumors for multiple cancer-related genes was performed. The most common (> 20%) related adverse events (all grades) reported in the breast cancer cohort were nausea, stomatitis, fatigue, anorexia, diarrhea, vomiting, hyperglycemia, rash, and thrombocytopenia. Exposure-dependent TORC1 (p4EBP1) and TORC2 (pAKT) inhibition was observed in blood cells; analysis of paired tumor biopsies is ongoing. Reduction in glucose uptake (> 25% decrease in SUV) on PET imaging at day 15 was observed in 4 of 8 patients with PET imaging data currently available. Three pts demonstrated RECIST PR in target lesions (one categorized as PD due to a new bone lesion); PIK3CA mutations were present in all 3 subjects. Of the two additional pts with PIK3CA mutations, one had SD > 6 months. The one PIK3CA mutated subject with PD at first restaging had a concurrent p53 mutation. Additional genetic abnormalities in mTOR and related pathways in subjects with target lesion PR involved PTEN, Rictor, and IGFR1 genes. Six subjects had SD after 2 cycles, with minor target lesion regression (0 to -30%) in 5 of 6, and with SD > 24 weeks in 1 of 6.

Conclusion: The safety profile of CC-223 is typical for drugs targeting the mTOR pathway. Preclinical and clinical data support the activity of CC-223 in HR+ positive breast cancer, particularly in tumors with PIK3CA mutations.

Breast Cancer Accrual: Cedars-Sinai (Mita): 4; SCRIL (Arkenau): 4; IGR (Varga): 4; SCRI (Bendell): 3 (all Part A); Moffitt (Mahipal): 2; UCSF (Munster): 1; JSOM (Paz-Ares): 1; ICR (DeLord): 1.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A68.

Citation Format: Monica M. Mita, Hendrik-Tobias Arkenau, Johanna C. Bendell, Pamela N. Munster, Amit Mahipal, Jean-Pierre Delord, Luis G. Paz-Ares, Jean-Charles Soria, Shuichan Xu, Tam Tran, Tao Shi, Xiaoling Wu, Rajesh Chopra, Kristen Hege, Andrea Varga. Activity of the TORC 1/2 kinase inhibitor, CC-223, in hormone receptor positive (HR+) breast cancer cell lines and patients (pts) with genetically characterized HR+ breast cancer in a Phase I clinical trial. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A68.