Kyriakos P. Papadopoulos

First-in-Man Clinical Trial of the Oral Pan-AKT Inhibitor MK-2206 in Patients With Advanced Solid Tumors

PURPOSE AKT signaling is frequently deregulated in human cancers. MK-2206 is a potent, oral allosteric inhibitor of all AKT isoforms with antitumor activity in preclinical models. A phase I study of MK-2206 was conducted to investigate its safety, maximum-tolerated dose (MTD), pharmacokinetics (PKs), pharmacodynamics (PDs), and preliminary antitumor efficacy. PATIENTS AND METHODS Patients with advanced solid tumors received MK-2206 on alternate days. Paired tumor biopsies were mandated at the MTD for biomarker studies. PD studies incorporated tumor and hair follicle analyses, and putative predictive biomarker studies included tumor somatic mutation analyses and immunohistochemistry for phosphatase and tensin homolog (PTEN) loss. RESULTS Thirty-three patients received MK-2206 at 30, 60, 75, or 90 mg on alternate days. Dose-limiting toxicities included skin rash and stomatitis, establishing the MTD at 60 mg. Drug-related toxicities included skin rash (51.5%), nausea (36.4%), pruritus (24.2%), hyperglycemia (21.2%), and diarrhea (21.2%). PKs (area under the concentration-time curve from 0 to 48 hours and maximum measured plasma concentration) were dose proportional. Phosphorylated serine 473 AKT declined in all tumor biopsies assessed (P = .015), and phosphorylated threonine 246 proline-rich AKT substrate 40 was suppressed in hair follicles at 6 hours (P = .008), on days 7 (P = .028) and 15 (P = .025) with MK-2206; reversible hyperglycemia and increases in insulin c-peptide were also observed, confirming target modulation. A patient with pancreatic adenocarcinoma (PTEN loss; KRAS G12D mutation) treated at 60 mg on alternate days experienced a decrease of approximately 60% in cancer antigen 19-9 levels and 23% shrinkage in tumor measurements. Two patients with pancreatic neuroendocrine tumors had minor tumor responses. CONCLUSION MK-2206 was well tolerated, with evidence of AKT signaling blockade. Rational combination trials are ongoing to maximize clinical benefit with this therapeutic strategy.

Phase I, Pharmacokinetic, and Pharmacodynamic Study of AMG 479, a Fully Human Monoclonal Antibody to Insulin-Like Growth Factor Receptor 1

PURPOSE To determine the maximum-tolerated dose (MTD) and to assess the safety, pharmacokinetics, and evidence of antitumor activity of AMG 479, a fully human monoclonal antibody to insulin-like growth factor receptor 1 (IGF-1R). PATIENTS AND METHODS Patients with advanced solid malignancies or non-Hodgkins lymphoma received escalating doses of AMG 479 intravenously (IV) every 2 weeks (Q2W). Blood samples were assayed to determine pharmacokinetic parameters and IGF-1R occupancy on neutrophils; fluorodeoxyglucose-positron emission tomography scans were used to assess tumor metabolic effects. RESULTS Fifty-three patients received 312 infusions of AMG 479 Q2W. Overall, the most common grades 1 to 2 toxicities were fatigue, thrombocytopenia, fever, rash, chills, and anorexia. One dose-limiting toxicity (ie, grade 3 thrombocytopenia) occurred in a patient at 20 mg/kg during course 1; grade 3 thrombocytopenia (n = 8) and grade 3 transaminitis elevations (n = 1) also were reported but not in the escalation phase. The maximum-planned dose of 20 mg/kg was safely administered; thus, an MTD was not reached. High levels of neutrophil IGF-1R binding and increases from baseline in serum IGF-1 levels were observed in the 12- and 20-mg/kg cohorts. Tumor responses included one durable complete response (CR) and one unconfirmed partial response (PR) in two patients with Ewing/primitive neuroectodermal tumors and included one PR and one minor response in two patients with neuroendocrine tumors. The patients with Ewing/PNET who had a CR have remained disease free on therapy after 28 months. CONCLUSION AMG 479 can be administered safely at 20 mg/kg IV Q2W. The absence of severe toxicities, attainment of serum concentrations associated with high levels of IGF-1R binding on neutrophils, and provocative antitumor activity warrant additional studies of this agent.

The Clinical Effect of the Dual-Targeting Strategy Involving PI3K/AKT/mTOR and RAS/MEK/ERK Pathways in Patients with Advanced Cancer

Purpose: This study evaluated the clinical relevance of the dual-targeting strategy involving PI3K/AKT/mTOR and RAF/MEK/ERK pathways. Experimental Design: We investigated safety, efficacy, and correlations between tumor genetic alterations and clinical benefit in 236 patients with advanced cancers treated with phase I study drugs targeting phosphoinositide 3-kinase (PI3K) and/or mitogen-activated protein kinase (MAPK) pathways in our Phase I Clinical Trials Program. Results: Seventy-six (32.2%) patients received a PI3K pathway inhibitor in combination with a MAPK pathway inhibitor (D), whereas 124 (52.5%) and 36 (15.3%), respectively, received an inhibitor of either the PI3K or MAPK pathways (S). The rates of drug-related grade >III adverse events were 18.1% for (S) and 53.9% for (D; P < 0.001); the rates of dose-limiting toxicities were 9.4% for (S) and 18.4% for (D; P = 0.06). The most frequent grade >III adverse events were transaminase elevations, skin rash, and mucositis. In our comprehensive tumor genomic analysis, of 9 patients who harbored coactivation of both pathways (colorectal cancer, n = 7; melanoma, n = 2), all 5 patients treated with (D) had tumor regression ranging from 2% to 64%. Conclusions: These results suggest that dual inhibition of both pathways may potentially exhibit favorable efficacy compared with inhibition of either pathway, at the expense of greater toxicity. Furthermore, this parallel pathway targeting strategy may be especially important in patients with coexisting PI3K pathway genetic alterations and KRAS or BRAF mutations and suggests that molecular profiling and matching patients with combinations of these targeted drugs will need to be investigated in depth. Clin Cancer Res; 18(8); 2316–25. ©2012 AACR.

Phase I Study of RO4929097, a Gamma Secretase Inhibitor of Notch Signaling, in Patients With Refractory Metastatic or Locally Advanced Solid Tumors

PURPOSE To determine the maximum-tolerated dose (MTD) and assess safety, pharmacokinetics, pharmacodynamics, and evidence of antitumor activity of RO4929097, a gamma secretase inhibitor of Notch signaling in patients with advanced solid malignancies. PATIENTS AND METHODS Patients received escalating doses of RO4929097 orally on two schedules: (A) 3 consecutive days per week for 2 weeks every 3 weeks; (B) 7 consecutive days every 3 weeks. To assess reversible CYP3A4 autoinduction, the expanded part of the study tested three dosing schedules: (B) as above; modified A, 3 consecutive d/wk for 3 weeks; and (C) continuous daily dosing. Positron emission tomography scans with [(18)F]fluorodeoxyglucose (FDG-PET) were used to assess tumor metabolic effects. RESULTS Patients on schedule A (n = 58), B (n = 47), and C (n = 5; expanded cohort) received 302 cycles of RO4929097. Common grade 1 to 2 toxicities were fatigue, thrombocytopenia, fever, rash, chills, and anorexia. Transient grade 3 hypophosphatemia (dose-limiting toxicity, one patient) and grade 3 pruritus (two patients) were observed at 27 mg and 60 mg, respectively; transient grade 3 asthenia was observed on schedule A at 80 mg (one patient). Tumor responses included one partial response in a patient with colorectal adenocarcinoma with neuroendocrine features, one mixed response (stable disease) in a patient with sarcoma, and one nearly complete FDG-PET response in a patient with melanoma. Effect on CYP3A4 induction was observed. CONCLUSION RO4929097 was well tolerated at 270 mg on schedule A and at 135 mg on schedule B; the safety of schedule C has not been fully evaluated. Further studies are warranted on the basis of a favorable safety profile and preliminary evidence of clinical antitumor activity.

Efficacy and Safety of Abemaciclib, an Inhibitor of CDK4 and CDK6, for Patients with Breast Cancer, Non-Small Cell Lung Cancer, and Other Solid Tumors.

UNLABELLED We evaluated the safety, pharmacokinetic profile, pharmacodynamic effects, and antitumor activity of abemaciclib, an orally bioavailable inhibitor of cyclin-dependent kinases (CDK) 4 and 6, in a multicenter study including phase I dose escalation followed by tumor-specific cohorts for breast cancer, non-small cell lung cancer (NSCLC), glioblastoma, melanoma, and colorectal cancer. A total of 225 patients were enrolled: 33 in dose escalation and 192 in tumor-specific cohorts. Dose-limiting toxicity was grade 3 fatigue. The maximum tolerated dose was 200 mg every 12 hours. The most common possibly related treatment-emergent adverse events involved fatigue and the gastrointestinal, renal, or hematopoietic systems. Plasma concentrations increased with dose, and pharmacodynamic effects were observed in proliferating keratinocytes and tumors. Radiographic responses were achieved in previously treated patients with breast cancer, NSCLC, and melanoma. For hormone receptor-positive breast cancer, the overall response rate was 31%; moreover, 61% of patients achieved either response or stable disease lasting ≥6 months. SIGNIFICANCE Abemaciclib represents the first selective inhibitor of CDK4 and CDK6 with a safety profile allowing continuous dosing to achieve sustained target inhibition. This first-in-human experience demonstrates single-agent activity for patients with advanced breast cancer, NSCLC, and other solid tumors. Cancer Discov; 6(7); 740-53. ©2016 AACR.See related commentary by Lim et al., p. 697This article is highlighted in the In This Issue feature, p. 681.

Multiepitope CD8+ T cell response to a NY-ESO-1 peptide vaccine results in imprecise tumor targeting

The cancer-testis antigen NY-ESO-1 is one of the most promising candidates for generic vaccination of cancer patients. Here we analyzed the CD8(+) T cell response to a NY-ESO-1 peptide vaccine composed of the two previously defined peptides 157-165 and 157-167, administered with GM-CSF as a systemic adjuvant. The NY-ESO-1 peptide vaccine elicited a CD8(+) T cell response directed against multiple distinct epitopes in the 157-167 region, as revealed by using A2/peptide multimers incorporating overlapping A2 binding peptides in this region. However, only a minor fraction of the elicited CD8(+) T cells, namely those recognizing the peptide 157-165 with sufficiently high functional avidity, recognized the naturally processed target on NY-ESO-1(+) tumor cells. In contrast, the majority of peptide 157-165-specific CD8(+) T cells exhibited lower functional avidity and no tumor reactivity. In addition, vaccine-elicited CD8(+) T cells specific for other overlapping epitopes in the 157-167 region failed to significantly recognize NY-ESO-1-expressing tumor targets. Thus, because of the complexity of the CD8(+) T cell repertoire that can be elicited by vaccination with synthetic peptides, a precise definition of the targeted epitope, and hence, of the corresponding peptide to be used as immunogen, is required to ensure a precise tumor targeting.

Clinical pharmacokinetics, metabolism, and drug-drug interaction of carfilzomib.

Carfilzomib, an irreversible proteasome inhibitor, has a favorable safety profile and significant antitumor activity in patients with relapsed and refractory multiple myeloma (MM). Here we summarize the clinical pharmacokinetics (PK), metabolism, and drug-drug interaction (DDI) profile of carfilzomib. The PK of carfilzomib, infused over 2–10 minutes, was evaluated in patients with solid tumors or MM. Metabolites of carfilzomib were characterized in patient plasma and urine samples. In vitro drug metabolism and DDI studies were conducted in human liver microsomes and hepatocytes. A clinical DDI study was conducted in patients with solid tumors to evaluate the effect of carfilzomib on CYP3A activity. Plasma concentrations of carfilzomib declined rapidly and in a biphasic manner after intravenous administration. The systemic half-life was short and the systemic clearance rate was higher than hepatic blood flow. Carfilzomib was cleared largely extrahepatically via peptidase cleavage and epoxide hydrolysis. Cytochrome P450–mediated metabolism played a minor role, suggesting that coadministration of P450 inhibitors or inducers is unlikely to change its PK profile. Carfilzomib showed direct and time-dependent inhibition of CYP3A in human liver microsome preparations and exposure to carfilzomib resulted in reductions in CYP3A and 1A2 gene expression in cultured human hepatocytes. However, administration of carfilzomib did not affect the PK of midazolam in patients with solid tumors, and there were no safety signals indicative of potential drug interactions. We conclude that the rapid systemic clearance and short half-life of carfilzomib limit clinically significant DDI.

Phase I Study of 30-Minute Infusion of Carfilzomib As Single Agent or in Combination With Low-Dose Dexamethasone in Patients With Relapsed and/or Refractory Multiple Myeloma

PURPOSE Carfilzomib is an irreversible inhibitor of the constitutive proteasome and immunoproteasome. This phase I study evaluated the maximum-tolerated dose (MTD), pharmacokinetics, and pharmacodynamics of carfilzomib administered as a 30-minute intravenous (IV) infusion. Safety and efficacy of carfilzomib as a single agent or in combination with low-dose dexamethasone were assessed. PATIENTS AND METHODS Patients with relapsed and/or refractory multiple myeloma (MM) were administered single-agent carfilzomib on days 1, 2, 8, 9, 15, and 16 of a 28-day cycle. Cycle one day 1 and 2 doses were 20 mg/m(2), followed thereafter by dose escalation to 36, 45, 56, or 70 mg/m(2). Additionally, carfilzomib was combined with low-dose dexamethasone (40 mg/wk). RESULTS Thirty-three patients were treated with single-agent carfilzomib. Dose-limiting toxicities in two patients at 70 mg/m(2) were renal tubular necrosis and proteinuria (both grade 3). The MTD was 56 mg/m(2). Nausea (51.5%), fatigue (51.5%), pyrexia (42.4%), and dyspnea and thrombocytopenia (each 39.4%) were the most common treatment-related toxicities. Overall response rate (ORR) was 50% (56-mg/m(2) cohort). Increasing carfilzomib dosing from 20 to 56 mg/m(2) resulted in higher area under the plasma concentration-time curve from time zero to last sampling and maximum plasma concentration exposure with short half-life (range, 0.837 to 1.21 hours) and dose-dependent inhibition of proteasome chymotrypsin-like activity. In 22 patients treated with 45 or 56 mg/m(2) of carfilzomib plus low-dose dexamethasone, the ORR was 55% with a safety profile comparable to that of single-agent carfilzomib. CONCLUSION Carfilzomib administered as a 30-minute IV infusion at 56 mg/m(2) (as single agent or with low-dose dexamethasone) was generally well tolerated and highly active in patients with relapsed and/or refractory MM. These data have provided the basis for the phase III randomized, multicenter trial ENDEAVOR.

Development of PARP inhibitors in oncology.

Poly (ADP-ribose) polymerase (PARP) plays a key role in DNA repair mechanisms by detecting and initiating repair after DNA strand breaks. Inhibition of PARP in DNA repair-defective tumors (like those with BRCA1 or BRCA2 mutations) can lead to gross genomic instability and cell death. Likewise, combining PARP inhibition with cytotoxic agents such as chemotherapy or radiation therapy is synergistic in many preclinical models. Several drugs designed to inhibit PARP are currently in clinical development, many following a development path different from that of typical anticancer agents. In this review we will focus on the early clinical data from PARP inhibitors that are entering clinical trials, the potential tumors they might target, their combination with other drugs and the different biomarkers that are being explored. Concepts such as ‘BRCAness’, synthetic lethality, Phase 0 trials and pharmacodynamic markers will be discussed in the context of the development of PARP inhibitors.

Antitumor activity in ras-driven tumors by blocking akt and mek

Purpose: KRAS is the most commonly mutated oncogene in human tumors. KRAS-mutant cells may exhibit resistance to the allosteric MEK1/2 inhibitor selumetinib (AZD6244; ARRY-142886) and allosteric AKT inhibitors (such as MK-2206), the combination of which may overcome resistance to both monotherapies. Experimental Design: We conducted a dose/schedule-finding study evaluating MK-2206 and selumetinib in patients with advanced treatment-refractory solid tumors. Recommended dosing schedules were defined as MK-2206 at 135 mg weekly and selumetinib at 100 mg once daily. Results: Grade 3 rash was the most common dose-limiting toxicity (DLT); other DLTs included grade 4 lipase increase, grade 3 stomatitis, diarrhea, and fatigue, and grade 3 and grade 2 retinal pigment epithelium detachment. There were no meaningful pharmacokinetic drug–drug interactions. Clinical antitumor activity included RECIST 1.0–confirmed partial responses in non–small cell lung cancer and low-grade ovarian carcinoma. Conclusion: Responses in KRAS-mutant cancers were generally durable. Clinical cotargeting of MEK and AKT signaling may be an important therapeutic strategy in KRAS-driven human malignancies (Trial NCT number NCT01021748). Clin Cancer Res; 21(4); 739–48. ©2014 AACR.