Phase I and pharmacokinetic study of lexatumumab (HGS-ETR2) given every 2 weeks in patients with advanced solid tumors

BACKGROUND

Lexatumumab (HGS-ETR2) is a fully human agonistic mAb to the tumor necrosis factor-related apoptosis-inducing ligand receptor 2 that activates the extrinsic apoptosis pathway and has potent preclinical antitumor activity.

MATERIALS AND METHODS

This phase 1, dose escalation study assessed the safety, tolerability, pharmacokinetics (PKs) and immunogenicity of lexatumumab administered i.v. every 14 days in patients with advanced solid tumors.

RESULTS

Thirty-one patients received lexatumumab over five dose levels (0.1-10 mg/kg). Most (26 of 31) received four or more cycles of treatment. One patient at 10 mg/kg experienced a possibly related dose-limiting toxicity of grade 3 hyperamylasemia. Nine patients achieved stable disease. One patient with chemotherapy-refractive Hodgkin's disease experienced a mixed response. Lexatumumab PKs were linear up to 10 mg/kg. At the 10 mg/kg dose, the mean (+/-standard deviation) t(1/2b) was 13.67 +/- 4.07 days, clearance was 4.95 +/- 1.93 ml/day/kg, V(1) was 45.55 ml/kg and V(ss) was 79.08 ml/kg, indicating that lexatumumab distributes outside the plasma compartment. No human antihuman antibodies were detected.

CONCLUSIONS

Lexatumumab can be safely administered every 14 days at 10 mg/kg. The PK profile supports this schedule. Further evaluation of lexatumumab at this dose schedule is warranted, including combination trials with other agents.

First-in-human, first-in-class, phase I study of a human monoclonal antibody CNTO 888 to the CC-chemokine ligand 2 (CCL2/MCP-1) in patients with solid tumors

e13500

Background: The chemokine CCL2 promotes angiogenesis, tumor proliferation, migration and metastasis through PI3K and NFkB signaling. CNTO 888 is a human IgG1κ monoclonal antibody with high binding affinity for CCL2 and documented preclinical antitumor activity. Methods: Patients were administered a 90 minute infusion of CNTO 888 on day 1, day 28 and subsequently on a q14 schedule. Exploratory PD assessments include diffusion contrast enhanced CT, circulating tumor and endothelial cells, free and bound CCL2 levels, bone markers and paired tumor biopsies. Results: 21 patients in cohorts of 3–6 patients received repeated CNTO 888 infusions at 5 dose levels (0.3mg/kg, 1mg/kg, 3mg/kg, 10mg/kg, 15 mg/kg). A further 23 patients are currently being evaluated in 2 expansion cohorts; 10mg/kg (n=12) and 15mg/kg (n=11). No dose limiting toxicities were seen up to 15 mg/kg q14. Preliminary pharmacokinetic (PK) data for doses ≤ 10 mg/kg showed linear kinetics with a bi-exponential decline and a t1/2 of 4.4 - 8.7 days. The 10 mg/kg dose level resulted in steady-state minimum concentrations above that needed to inhibit chemotaxis and calcium mobilization in preclinical studies. Dose-dependent increase in bound CCL2 levels of > 1000-fold seen following treatment, supports target modulation. 2 patients demonstrated stable disease (SD) > 6 months at 15mg/kg CNTO 888 (ocular melanoma and neuroendocrine tumor). Another patient at 0.3mg/kg CNTO 888 with ovarian cancer had 50% CA125 decline and SD for 10 months. Conclusions: CNTO 888 is well tolerated with no DLTs when administered up to 15mg/kg q14. Preliminary evidence of antitumor activity is reported.

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EZN-2968, a novel hypoxia-inducible factor-1α (HIF-1α) messenger ribonucleic acid (mRNA) antagonist: Results of a phase I, pharmacokinetic (PK), dose-escalation study of daily administration in patients (pts) with advanced malignancies

2564

Background: HIF-1 is a transcription factor that regulates expression of many key genes, notably those switching cell metabolism to anaerobic glycolysis and inducing neovascularization in response to hypoxia. Increased HIF-1α levels are associated with poor prognosis in several neoplasms. EZN-2968 is a potent locked nucleic acid antisense oligonucleotide suppressing HIF-1α mRNA translation in vitro (IC50 ∼1–5 nM). Methods: This study was designed to determine the safety, tolerability, PK, maximum tolerated dose, recommended dose, and preliminary evidence of antitumor activity of EZN-2968. Pts with advanced malignancies were treated with EZN-2968 administered as a daily 2-hr IV infusion x 5 days every 4 weeks using a 3+3 dose-escalating design. Dose escalation was based on toxicities observed during Cycle 1. Results: 19 pts (11 men; median age = 60 y [47–79 y]) were treated with EZN-2968 doses of 0.5 (3 pts), 0.8 (3 pts), 1.2 (3 pts), 1.8 (4 pts), 2.7 (3 pts), and 4.1 (3 pts) mg/kg/day. Tumor types included colorectal cancer (7 pts); renal cancer (4 pts); soft-tissue sarcoma (STS; 2 pts); angiosarcoma (1 pt); melanoma (1 pt); and breast, ovarian, pancreatic, and prostate cancers (1 pt each). No dose-limiting toxicities were observed. The most common adverse events (Aes) were vomiting (32%); fatigue (26%); and anemia, diarrhea, nausea, and tumor pain (each 21%). Most Aes were Grade 1 or 2. Plasma PK for Day 1 is tabulated below. Stable disease was observed for 1 pt with angiosarcoma (28 wks) and 1 pt with renal cancer (12 wks). Conclusions: EZN-2968 was well tolerated in previously treated pts with advanced malignancies. PK data do not show accumulation of EZN-2968. Dose escalation is ongoing; final results will be presented at the meeting. Durable stable disease has been observed.

[Table: see text]

[Table: see text]

A phase I dose-escalation study of the safety, pharmacokinetics (PK), and pharmacodynamics of XL765, a PI3K/TORC1/TORC2 inhibitor administered orally to patients (pts) with advanced solid tumors

3502

Background: XL765 is a potent and selective inhibitor of Class I PI3K isoforms, TORC1, and TORC2. XL765 has shown dose-dependent target modulation and tumor growth inhibition or shrinkage in multiple human xenografts. Methods: Pts receive XL765 bid or qd for 28-day cycles. PK and pharmacodynamic analyses are performed. Tumor response is assessed by RECIST every 8 weeks. Results: To date, 34 pts have been dosed with XL765; 26 pts on a bid regimen (15–120mg) and 8 pts on a qd regimen (70–100 mg). Maximum administered doses are 120 mg bid and 100 mg qd. Dose-limiting toxicities (DLTs) occurred at 120 mg bid and 60 mg bid and included elevated hepatic transaminases (2), anorexia/hypophosphatemia (1), rash (1), and nausea/vomiting (1). Grade > 2 increase in transaminases, including one possibly related serious adverse event of Grade 4, occurred in 3 of 7 pts at 120 mg bid. Non-specific neurological complaints (1) and rash (1) were the DLTs that occurred at 100 mg qd. The most common (> 10% of pts) related adverse events were elevated liver enzymes, nausea and diarrhea. XL765 exposure increased with increasing doses (15–120 mg bid). Median tmax was 1–3 h post-dose. Mean t1/2,z ranged from 3 to 9 h at steady-state. Repeat dosing (bid or qd) resulted in moderate to no drug accumulation. XL765 augmented food-induced increases in plasma insulin, but not glucose, in an exposure-dependent fashion. Robust pharmacodynamic modulation of PI3K pathway signaling in PBMCs, hair follicles, skin, and tumors was evident following administration of XL765. These effects were exposure-dependent for some biomarkers in PBMCs and hair. Five pts had durable stable disease (> 3 months): appendiceal cancer (15 mg bid) 8 cycles; RCC (15 mg bid) 4 cycles; NSCLC (30 mg bid) 4 cycles; mesothelioma (60 mg bid) 10 cycles; CRC (100 mg qd) 6 cycles. Conclusions: In this phase I study, XL765 has exhibited potent pharmacodynamic activity at generally well tolerated doses. PI3K pathway inhibition of ∼60–90% in hair and skin was seen at multiple tolerable doses.

[Table: see text]

Pharmacokinetics (PK) and safety of tesetaxel, an orally administered taxane, in a study examining a range of doses including the active phase II dose

e13535

Background: Tesetaxel is an orally active taxane with potent cytotoxic activity against various cancer cell lines in vitro, including cell lines and xenografts of human tumors that over-express P-glycoprotein. Tesetaxel displays markedly lower neurotoxicity than docetaxel in preclinical models. In Phase 2 studies, 2nd-line therapy with tesetaxel (27–35 mg/m2 every 3 weeks) was associated with overall response rates of 20% and 38% in patients (pts) with gastric and breast cancer, respectively. Neutropenia was the most common serious adverse event. We are conducting a dose-ranging study to examine the PK and safety of tesetaxel at doses including and just below the previously established MTD of 27 mg/m2. Methods: Eligibility criteria include advanced solid tumors, ECOG PS ≤ 2, and adequate organ function. The starting dose is 18 mg/m2, which is being escalated in increments of 3 mg/m2 to a maximum of 27 mg/m2. Tesetaxel is given for a minimum of 2 cycles; pts with response or stable disease may receive up to 2 more cycles. Plasma is assayed at various times to determine concentrations of parent drug and metabolites. A total of 12 patients will be entered into the dose-escalation phase, with sample expansion to 12 pts at the MTD. Results: Ongoing enrollment is expected to be completed in Q1 2009. Our group's prior study of tesetaxel 18 mg/m2 and 27 to 40 mg/m2 has shown that tesetaxel displays dose-proportional absorption and has a long terminal plasma half-life (mean approximately 180 hrs). We expect to confirm these data over a narrow dose range and to examine the data for correlations between PK and the duration and severity of neutropenia. Conclusions: Tesetaxel is an orally active taxane that eliminates infusion reactions and the associated need for premedication. It may overcome inherent or clinically acquired resistance to prototype taxanes and may prove to have reduced taxane-associated peripheral neuropathy in the clinical setting. Essential to future tesetaxel studies, this study will determine whether correlations between key PK parameters and dose-limiting reactions exist.

[Table: see text]

A phase II study of IMGN242 (huC242-DM4) in patients with CanAg-positive gastric or gastroesophageal (GE) junction cancer

e15625

Background: IMGN242 is a conjugate of the cytotoxic maytansinoid DM4 and the monoclonal antibody huC242, which binds to CanAg. In a Phase I study, the maximum tolerated dose for IMGN242 was determined to be 168 mg/m2, with ocular changes the primary dose-limiting toxicity. This Phase II study was initiated to assess IMGN242 for the treatment of gastric cancer. Methods: In this open-label, multi-center study, IMGN242 is given as a single IV infusion every three weeks to patients with CanAg-expressing metastatic or locally-advanced gastric or GE junction cancer. Patients must have been treated with at least one prior therapy to qualify for enrollment. The study has a 2-step design: If ≥1 objective response is achieved among the first 23 patients (Step 1), a total of 39 response-evaluable patients will be enrolled (Step 2). Results: Overall, 9 patients have received IMGN242. The first 6 were treated with 168 mg/m2, and 1 of these patients showed a marked biologic response by the FDG-PET scan in Cycle 1 followed by an unconfirmed partial response based on CT scan in Cycle 2. However, 3 of these 6 patients developed ocular toxicities assessed to be study drug related. Only patients with low plasma CanAg levels (<1000 U/ml) developed ocular toxicities, and clinical pharmacokinetic and pharmacodynamic (PK/PD) analyses revealed that plasma CanAg affects study drug exposures. The study was amended to differentiate the IMGN242 doses (126 mg/m2 or 168 mg/m2) administered based on the patient's plasma CanAg levels (< or >1000 U/mL). To date, 3 patients have received IMGN242 with this dosing strategy and no ocular toxicities have been reported. Conclusions: IMGN242 showed preliminary evidence of activity in this patient population. A novel Phase II dosing strategy is being used that should enhance tolerability. Patient enrollment is ongoing and updated results will be reported.

[Table: see text]

Pharmacology and safety factors affecting use of flat (rather than weight-based) dosing of tesetaxel, an orally administered taxane

2510

Background: As a class, taxanes have wide interpatient (pt) pharmacokinetic (PK) variability at their effective dose, which has been associated with adverse reactions, especially neutropenia. Tesetaxel is an oral taxane with Phase 2 activity in pretreated pts with colorectal, non-small cell lung, gastric, and breast cancers. Tesetaxel is not a substrate for P-glycoprotein; it is associated with lower neurotoxicity at equi-myelotoxic does, and it displays a long terminal half-life in plasma (∼180 hrs). We explored PK and clinical safety to determine the feasibility of using flat dosing in future studies. Methods: PK parameters were evaluated in 21 pts treated at the maximum tolerated dose (27 mg/m2) either alone or in combination with capecitabine. We then compared actual dose (total mg) with the weight-based dose and correlated the incidence and severity of Grade 3–4 neutropenia with weight-based vs. flat dosing. Results: A total of 174 pts were treated with tesetaxel in Phase 2 trials at doses of 27 or 35 mg/m2 once every 3 weeks. For pts prescribed with weight-based dosing (27 mg/m2), mean Cmax in 3 separate cohorts was 24.6, 42.5, and 47.9 μg/L, with AUC0-inf of 1363, 1592, and 1663 h*μg/L, respectively. In 103 pts prescribed a dose of 27 mg/m2, 17% and 16% of pts received doses of 40 mg or 60 mg, respectively, whereas 67% received 50 mg. Correlations between drug exposure AUC0-inf and actual dose (mg and mg/m2) across the entire range of administered doses showed r2 values of 0.455 and 0.492, respectively. Similar correlations after a second repeat dose showed r2 values of 0.731 and 0.653, respectively. The incidence of Grade 3–4 neutropenia at 27 mg/m2 was 33%. Conclusions: PK and clinical safety suggest that weight-based dosing offers no substantial advantage compared with flat dosing. Future studies could incorporate a starting dose of 50 mg administered once every 3 weeks. Flat dosing should also be tested using different schedules, including weekly x 3 weeks and “metronomic dosing” (1–2 mg/d).

[Table: see text]

A phase I study of q3W R1507, a human monoclonal antibody IGF-1R antagonist in patients with advanced cancer

3590

Background: Insulin-like growth factor receptor (IGF-1R) is a tyrosine kinase cell surface receptor overexpressed in cancer cells which mediates the mitogenic and anti-apoptotic actions of IGF, playing a key role in malignant transformation. The safety and pharmacokinetics of 3-weekly administration of R1507, a human monoclonal antibody selective for IGF-1R, were explored in this phase I dose escalation study in patients with advanced solid tumors or lymphomas. Materials and Methods: Multiple ascending doses of R1507 were administered as a 1 hour infusion every 3 weeks until the development of dose-limiting toxicity (DLT) or progressive disease. Inclusion criteria: ECOG PS 0–1, adequate hematologic, hepatic, and renal function, CD4 count >200/μl. Exclusion criteria: infection, immunosuppressive agents, diabetes mellitus, uncontrolled systemic disease, NYHA III/IV CHF. DLT defined as ≥ grade 2 hypersensitivity reaction; ≥ grade 3 non-hematologic toxicity; ≥ grade 2 cardiac toxicity; ≥ grade 3 hematologic toxicity = 7 days, or dose delay > 1 week due to toxicity. Blood samples were collected following 1st dose for non compartmental PK analysis and for future analysis of IGF-1R levels. Results: 21 patients (pts) (M:F 14:7) were enrolled in 1 of 4 dose levels (dose range 1–16 mg/kg). Mean pt age 57 yrs (range: 30–81), mean prior treatments 4.6 (range: 1–9). Mean treatment cycles 2.6 (range: 1- 6). Six pts remain on study. Adverse events (AE) included infection (6 pts), fatigue (4); rash, fever, arthralgia, cough, diarrhoea, abdominal and back pain (3 each). No DLT or serious AEs attributed to study drug were reported. Activity: 10 pts showed stable disease (median 33 days). PK: Clearance (CL) decreased from 812 mL/Day (Coefficient of Variation [CV] =19.9%) in the 1 mg/kg group to 418 mL/Day (CV=46.7%) in the 16 mg/kg group; Volume of distribution was in the range of 4.4 - 5.4 L (CV=10.9–34.8%). T1/2 increased from 4 to 9 days. Conclusions: Treatment with R1507 is tolerable at the dose of 16mg/kg q3W. Treatment-related toxicities are mild and clinically manageable. Decrease in CL across doses levels suggests a saturable elimination pathway. T1/2 value of ∼8 days supports a weekly dosing for future trials.

[Table: see text]

A phase I, pharmacokinetic and pharmacodynamic study of sorafenib (S), a multi-targeted kinase inhibitor in combination with temsirolimus (T), an mTOR inhibitor in patients with advanced solid malignancies

3512

Background: The combination of S and T is hypothesized to maximize pathway inhibition by concurrently targeting parallel signaling mechanisms and will abrogate potential resistance mechanisms directed towards the MAPK pathway through increased signaling via the survival pathway involving PI3K/Akt. Methods: Eligible patients (pts) were treated with escalating continuous oral doses of S (200 and 400 mg BID) and weekly T IV (15 mg, 25 mg). S began on day 8 of course 1 to permit PK evaluations of T. PD studies in PBMCs were performed serially in pts. Results: To date, 24 evaluable pts have received 85 courses [median 3;range1–12] in the following S/T dose cohorts; cohort 1: 200 mg/15 mg (n=6), cohort 2: 400 mg/15 mg (n=11), cohort 3: 400 mg/25 mg (n=6), and cohort 4: 200 mg/25 mg (n=1). Patients demographics were males/female 11/13, median age 54.5 [range 27–71] and PS of 0/1/2 : n=9/13/2. Dose limiting toxicities (DLT) were grade 3 typhlitis in 1/6 pts in cohort 1, and mucositis in 1/6 pts in cohort 2. Expansion of cohort 2 to 11 patients resulted in 4 additional DLTs (hand foot syndrome (HFS) x 2 pts, thrombycytopenia/rash x 1 pt, creatinine elevation x 1 pt). 3 of 6 pts in cohort 3 experienced DLT (HFS x 2 pts, thrombocytopenia x 1 pt). PK analyses show no evidence of S effect on T kinetics while Css,min values of S are consistent with those reported in single-agent studies (S 200mg BID median Css,min 4.42 μg/mL [SD 3.05], S 400 mg BID median Css,min 5.11 μg/mL [SD 4.35]). Apparent downregulation of 4E-BP1 and activated forms of p70S6 kinase and ERK was observed in some patients following treatment. Partial responses have occurred in NHL (1 pt) and papillary thyroid cancer (1 pt) and prolonged SD (> 12 mo) has been observed in RCC (1 pt). Conclusions: The combination of S and T demonstrate significant mucocutaneous toxicity at full doses of S, however preliminary PK analyses show no evidence of drug-drug interactions. Characterization of an intermediate dose of S 200 mg BID/T 25 mg IV is ongoing.

[Table: see text]

A phase I two arm trial of AS703569 (R763), an orally available aurora kinase inhibitor, in subjects with solid tumors: preliminary results

14130

Background: Aurora kinases are a family of kinases that play a crucial role in regulating segregation of chromosomes from parent to daughter cell and have been linked to tumorigenesis. Aurora kinase A is commonly amplified in solid tumors and has been established as an oncogene. Aurora B is often overexpressed and leads to defects in mitosis and increased tumor invasiveness. AS703569 is an orally available, highly potent inhibitor of aurora kinases A and B and several other kinases. AS703569 has been shown in vitro and in tumor xenograft models to inhibit proliferation and to trigger apoptosis of several tumor types. We report on the initial results of a phase I study of AS703569 in patients with solid tumors. The study objectives are to determine for each of 2 different dosing regimens the MTD and to evaluate safety, PK and pharmacodynamic effects. Methods: This is a phase I, two arm, dose-escalation study. Cohorts of 3 patients ≥18 years old with advanced solid tumors are being assigned to one of 2 dosing regimens. The dose escalation follows a modified Fibonacci scheme. The starting dose level is 6 mg/m2 p.o. per 21-day cycle divided in 2 or 3 doses (regimen 1: dosing on days 1, 8 or regimen 2: dosing on days 1, 2, 3). Patients with stable disease or response will be offered additional cycles. Results: A total of 15 patients have been included to date. The tumor types represent a typical widespread in phase I trials, including 3 cases of uterine/cervical cancer and 2 cases of breast cancer. The first 2 cohorts of 3 patients on dose level 1 (regimen 1 and 2) have been treated with no dose-limiting toxicities (DLTs) or serious adverse events (SAEs). Dose-escalation is proceeding for both regimens with 9 patients treated on dose level 2, 6 in regimen 1 where due to a DLT (likely disease-related and unlikely related to AS703569) the cohort was expanded, and 3 in regimen 2. Thus far, only two patients were withdrawn from the study due to disease progression and one patient withdrew consent. Two patients are ongoing at 4+ cycles and one at 3+. Conclusions: Treatment of patients in this phase I study of the aurora kinase inhibitor AS703569 at dose level 1 and 2 has been well tolerated over several cycles. Dose escalation is ongoing and analysis of PK and pharmacodynamics will be reported.

No significant financial relationships to disclose.

Semi-physiological pharmacokinetic-pharmacodynamic (PK/PD) models for troxacitabine-induced neutropenia and thrombocytopenia

13002

Background: Neutropenia and thrombocytopenia are the dose-limiting toxicities of troxacitabine in Phase 1 studies. The present study’s aim was to develop a novel semi-physiological PK/PD model that can simultaneously describe the time course of the absolute neutrophil and platelet count changes in cancer patients receiving troxacitabine. Methods: The mixed-effect modeling was performed using the Monte-Carlo Parametric Expectation Maximization algorithm implemented in SADAPT program. The analysis was based on PK/PD data from 31 subjects who received troxacitabine/cisplatin combination every 28 days at five different dose levels (4.8/50, 4.8/75, 6.4/50, 6.4/75, 8.0/75 mg/m2). The PD model consisted of 1) a troxicatabine-sensitive uncommitted progenitor cell compartment, which differentiates into committed neutrophil and platelet progenitor cells that are also sensitive to the troxacitabine, and 2) transit compartments for neutrophils and platelets that represent maturation stages in bone marrow. To capture the rebound phenomena and maintain the hemostasis, the model included a feedback mechanism for both neutrophils and platelets. The troxacitabine concentrationtion-time profiles affected the proliferation of sensitive progenitor cells through an inhibitory sigmoidal Emax model. A three-compartment linear pharmacokinetic model was developed to describe the troxaicibatine concentration-time profile. Results: The PD model described the time-course of troxacitabine- induced neutrophil and platelet cytopenias and accounted for the large observed inter-patient variability. The model predicted that neutrophil progenitor cells were more sensitive to troxacitabine therapy compared to platelet progenitor cells. Furthermore, the model suggested that the troxacitabine-induced neutropenia and thrombocytopenia are reversible and non-cumulative events. Conclusions: This novel model can describe both the intensity and duration of troxacitabine-induced thrombocytopenia and neutropenia rather than simply considering the nadir values. It may be valuable for selecting treatment regimens that minimize troxacitabine’s dose-limiting hematological toxicities.

No significant financial relationships to disclose.

Phase I pharmacokinetic (PK) and pharmacodynamic (PD) study of LBH589, a novel deacetylase (DAC) inhibitor given intravenously on a new once weekly schedule

14019

Background: LBH589 is a novel deacetylase inhibitor that inhibits proliferation of tumor cells at nanomolar levels. This phase I study tested the safety and tolerability of IV LBH589 once each week for 3 of 4 wks in pts with advanced solid tumors or lymphoma. Methods: LBH589 was administered IV over 30 min. on days 1, 8 and 15 of a 28-day cycle. Western blots on peripheral blood lymphocytes were used to study histone acetylation (HA). Plasma PK profiles were analyzed on Days 1 and 8. Results: Thirty five pts (median age: 70 yrs; 23M, 12F) have been treated on 3 dose levels [10 mg/m2 (8pts), 15 mg/m2 (8 pts), 20 mg/m2 (19 pts)] with the following tumor types: Cutaneous and peripheral T cell lymphoma (7 pts), prostate (6 pts), mesothelioma (4 pts), colon (3 pts) and other (15 pts). There was one dose-limiting toxicity (transient grade 4 thrombocytopenia) at 20 mg/m2, none at the lower doses. Other G3/G4 toxicities (all cycles) include: transient thrombocytopenia (G4–5 pts, G3–5 pts), neutropenia (G3–2 pts), anemia (G3–5 pts), G3 hypophosphatemia (1 pt), G3 hypokalemia (1 pt), G3 nausea (1 pt) and G3 pruritus (1 pt). Thrombocytopenia was transient. Of 2,042 ECGs, 1 pt had an increase in QTcF from baseline of > 60 msec another with a QTcF >500 msec, both at 20 mg/m2. There was a dose-dependent increase in HA 7 days after one dose with 43% (10 mg/m2), 50% (15 mg/m2) and 60% (20 mg/m2) of pts with increased acetylation. The LBH589 plasma conc. peaked at the end of the 0.5 hr infusion with a mean terminal half-life of 16 hr. Median Cmax achieved with 20 mg/m2 was 1,000 ng/mL (2.86 μM). The AUC0-inf increased linearly with IV doses of 10–20 mg/m2. One pt with CTCL achieved a complete response (CR) on cycle 3, Day 1; this pt had previously received oral LBH589 at 20 mg MWF, achieving a CR on cycle 6, Day 28 that lasted for 7 months. One peripheral T-Cell lymphoma pt achieved a partial response that has persisted for >7 months. One pt with prostate cancer has had a 26% reduction in nodal disease and > 50% drop in PSA in the first 2 cycles. Conclusions: The maximum tolerated dose of LBH589 given IV wkly on a 3 of 4 wk schedule is 20 mg/m2. This dose produced sustained PD effects and higher systemic exposure compared to oral LBH589. Preliminary evidence of antitumor activity has been observed.

No significant financial relationships to disclose.

Phase I study of oral LBH589, a novel deacetylase (DAC) inhibitor in advanced solid tumors and non-hodgkin’s lymphoma

3500

Background: LBH589 is a novel deacetylase inhibitor (DACi) which induces apoptosis of tumor cells at nanomolar levels. In this phase 1 study, we evaluated the safety and tolerability of LBH589 in pts with advanced solid tumors or non-hodgkins lymphoma. Methods: LBH589 was administered orally on Monday, Wednesday, and Friday (MWF) weekly. Western blots on peripheral blood lymphocytes were used to study histone acetylation (HA). Plasma PK profiles were analyzed on Days 1 and 15. Results: Thirty two pts have been treated (Median age 63 years; 18 M, 14 F). Pts received 15 mg (3), 30 mg (10), the dose-limiting toxicity level (DLT), or 20 mg (19), the maximum tolerated dose (MTD). Tumor types included: CTCL (10), renal cell (6), melanoma (6), prostate (4), hepatic (1), rhabodomyosarcoma (1), mesothelioma (1), colon (1), bladder (1), and parotid gland (1). Three DLTs were reported; G3 diarrhea and transient G4 thrombocytopenia at 30 mg and G3 fatigue at 20 mg. The most common adverse events were anorexia, nausea, fatigue, diarrhea and transient thrombocytopenia. Of the 1,057 ECGs, 1 pt (20 mg) had a QTcF of 503 msec, an isolated event after the first dose with no recurrence on continued therapy. The mean change in QTcF from baseline was < 10 msec during the first cycle in all cohorts. No increase in HA was seen at 15 mg, but did increase in 50% of pts at 72 hrs post dose in both the 20 mg and 30 mg cohorts. LBH589 was rapidly absorbed in plasma (Tmax 1.5 hr), then declined with a mean terminal half-life of 16 hrs. Cmax and AUC increased linearly with doses between 15–30 mg. Two cutaneous T- cell lymphoma (CTCL) pts achieved a complete response (5 and 7 months) and 4 CTCL pts attained a partial response (6.5, 8, 9 and 18+ months). Stable disease was achieved in 7 pts: CTCL-2 pts (2 and 3 months); RCC-2 pts (3.5 and 7 months); melanoma-1 pt (4 months), mesothelioma-1 pt (2.5 months) and parotid gland-1 pt (5 months). Fifteen pts progressed on treatment and 4 pts were not evaluable for response. Conclusions: At 20 mg MWF every week, LBH589 oral produced a sustained pharmacodynamic effect on HA for ≥72 hours post dose in 50% of pts. Cardiac data indicates no clinically-significant effect on QTcF. Preliminary evidence of tumor response was observed at this dose and schedule in CTCL pts.

No significant financial relationships to disclose.

A phase I study of a CanAg-targeted immunoconjugate, huC242-DM4, in patients with Can Ag-expressing solid tumors

3062

Background: HuC242-DM4 is a novel, targeted anti-cancer agent in development for the treatment of CanAg-expressing tumors such as carcinomas of the colon and pancreas. The compound is formed by the conjugation of the potent cytotoxic maytansinoid drug, DM4, to the humanized monoclonal antibody, huC242. This agent was highly active across a broad spectrum of CanAg-expressing human tumor xenograft models. Methods: Patients were enrolled with metastatic or inoperable colorectal, pancreatic, and other CanAg-expressing tumors who have failed standard therapy (about 95% of pts. had received = 4 prior chemotherapy regimens). Results: Thirty patients were treated with huC242-DM4, receiving a single intravenous (IV) infusion once every three weeks. Cohorts of 3 patients initially were enrolled on each dose level. Patients have received huC242-DM4 at 18, 36, 60, 90, 126, 168, 223, and 297 mg/m2. To date, dose limiting toxicity (DLT) was experienced by two of six patients treated at the 223 mg/m2 dose level during their second cycle of treatment. The patients experienced decreased visual acuity, corneal deposits and keratitis. Both patients were subsequently treated with lubricating eye drops. At present, these adverse events have markedly improved in one patient, while the other patient has completely returned to baseline. Of 10 patients treated at the168 mg/m2 dose level (including two patients who were dose reduced to 168 mg/m2), seven patients have received at least two cycles of treatment. One patient had grade 3 diarrhea and dehydration during his second cycle at 168 mg/m2. The latter improved with intravenous fluids. Preliminary pharmacokinetic data reveal a half-life of huC242-DM4 of about 5 days in patients with low plasma CanAg levels. In patients with high plasma CanAg levels (>900 units/mL), clearance of huC242-DM4 is increased. There has been no clinically significant myelosuppression and no formation of antibody to humanized antibody (HAHA) or drug (HADA). One patient had a 36% decline in CEA (not associated with tumor shrinkage). Conclusions: HuC242-DM4 was well tolerated at the 168 mg/m2 dose level. The MTD is not yet defined and approaches to prevent /ameliorate ocular toxicity are planned.

No significant financial relationships to disclose.

A phase I pharmacokinetic and pharmacodynamic study of AMG 479, a fully human monoclonal antibody against insulin-like growth factor type 1 receptor (IGF-1R), in advanced solid tumors

3002

Background: Increased IGF-1 signaling mediates tumor proliferation, reduces apoptosis, and correlates with higher incidence and progression of common cancers. AMG 479, a fully human monoclonal antibody against IGF-1R, exhibited broad antitumor activity in xenograft models, both as a monotherapy and with chemotherapy. Methods: Patients (pts) entered escalating dose cohorts of AMG 479 (from 1 to 20 mg/kg administered intravenously [IV] every two weeks [Q2W]). Study objectives were to determine safety, maximum tolerated dose (MTD), pharmacokinetic (PK) parameters, pharmacodynamic (PD) parameters of tumor glucose metabolism (FDG PET/CT), human anti- AMG 479 antibody formation, IGF-1R occupancy in neutrophils, and tumor response (CT RECIST, and PET/CT criteria). Results: Sixteen pts with advanced malignancies were treated with doses from 1 to 20 mg/kg. The median number of cycles was 3 (range 1 to 16). Grade 3 thrombocytopenia was considered dose limiting in 1 pt at 20 mg/kg. Other grade 3/4 non-hematologic toxicities were observed in 2 pts; no hyperglycemia greater than grade 2 was observed. Anti-AMG 479 antibodies, but not neutralizing antibodies, were detected in 1 pt. One pt had an infusion reaction (grade 2 chills/rigors resolving in 15 minutes) but could be retreated following premedication. AMG 479 exhibited dose-linear PK in the dose range from 1 to 20 mg/kg, reaching steady state after 3 doses; mean terminal t1/2 ranged from 7 to 11 days; mean serum clearance ranged from 9 to 14 mL/day/kg; Css exceeded IC90 measured in preclinical models. PD results indicated a trend to dose-proportional occupancy of IGF-1R in neutrophils and increased levels of serum IGF-1 and IGF-BP3 (40% and 20% on day 3, respectively). By CT RECIST criteria, 1 pt with a neuroendocrine tumor had a confirmed partial response and 5 pts had durable stable disease. By FDG-PET/CT criteria, 1 pt with breast cancer had a mixed response. Conclusions: AMG 479 appears to be well tolerated at doses up to 20 mg/kg IV Q2W; dose escalation is complete. AMG 479 administration resulted in PK values adequate for activity in preclinical models, saturable binding of IGF-1R in neutrophils, and preliminary anti-tumor activity.

[Table: see text]

Oblimersen can be administered by subcutaneous (SC) and brief intravenous (IV) infusion: Clinical pharmacokinetics and pharmacodynamics (PK/PD) in patients with advanced cancer

14083

Background: Oblimersen (OBL) is a phosphorothioate oligodeoxynucleotide that decreases Bcl-2 protein levels. OBL has been administered by continuous intravenous infusion (CIVI) in most clinical studies. However, recent preclinical data suggest that equivalent or superior antitumor efficacy can be achieved with intermittent administration. We conducted a dose-ranging PK/PD study of OBL given by bolus SC injection and brief IV infusion to evaluate the feasibility of intermittent dosing. Methods: In this within-subject dose-escalation study, OBL was administered subcutaneously (SC) at doses of 75, 150 and 225 mg. In part II of the study, OBL was administered by 2-hr IV infusion beginning at 150 mg on day 1, by single-dose SC injection on day 8, and 2-hr IV daily x 5 consecutive days. Pharmacokinetics were assessed by non-compartmental analysis. Pharmacodynamic measurements of Bcl-2 levels in peripheral blood mononuclear (PBM) cells were made using Western blot analysis. Results: OBL absorption after SC administration was rapid with a Tmax of ∼2 hours. Mean Cmax values were 0.76, 1.70 and 3.10 μg/ml for the 75, 150 and 225 mg SC doses, respectively. Mean AUC0- inf values were 7.78, 15.36 and 25.57 hr*μg/mL. Plots of dose-normalized Cmax and AUC vs. dose showed slopes close to zero, indicating approximate dose proportionality. AUC0–24 exposure with the 225 mg SC dose was similar to previously established 24-hr steady-state AUCs after 3 mg/kg CIVI. SC injection was associated with an inflammatory erythematous grade 1 rash at the injection site that resolved within 7 days. The 150 mg 2-hr IV infusion x 1 or daily x 5 has been well-tolerated. Conclusions: OBL exposure from a single SC injection is similar to a 24-hr 3 mg/kg CIVI, and the 2-hr IV infusion is currently being evaluated. Both schedules appear to be well- tolerated, may reduce requirements for CIVI, and could be incorporated into intermittent dosing regimens.

No significant financial relationships to disclose.

A phase I, pharmacokinetic (PK) and pharmacodynamic (PD) study of the combination of an oral antimicrotubular agent, DJ-927 (D), and capecitabine (C) in patients (Pts) with advanced cancers

2016

Background: DJ-927, an oral microtubule stabilizer, has impressive cytotoxic activity in taxane-resistant tumors and an acceptable toxicity profile. C and Taxane combinations are active in solid tumors such as breast cancer. Non-overlapping mechanism of action and toxicity profiles and the convenience of an orally administered therapy have prompted a phase I evaluation of the combination. D was given orally once on day 1 and C for 14-days (D1–14), every three weeks. Methods: Eligible pts had evaluable cancer, minimal prior therapy and PS 0 - 2 ECOG. D was started at 18 mg/m2 on day 1 along with 1,250 mg/m2 of C orally B.I.D for 14 days, of a 21-day cycle. Incremental doses of both drugs were explored until the maximum tolerated dose (MTD) was reached. PK samples were collected during cycles 1 and 2, for assays of C and for D when given concurrently with C during cycle 1 and D given alone during cycle 2. Results: Twenty-seven pts [18 Male/ 9 Female; median age (range)- 58 yrs (33–70); PS 0 (n=8) ; PS 1 (n=19)] received 81 cycles [median (range)- 3 (1–8)] in 5 cohorts, with D and C 18/ 1250 mg/m2 (n = 3), 27/ 1250 mg/m2 (n = 7), 27/ 1900 mg/m2 (n = 7), 35/ 1900 mg/m2 (n = 3),and 27/ 2500 mg/m2 (n = 7). Dose-limiting toxicity (DLT) was grade 4 neutropenia in 2 of 3 pts at 35/ 1900 mg/m2 dose. Other common drug-related toxicities were leukopenia, nausea & vomiting (12 pts each, 44.4%), neutropenia, diarrhea and hand-foot syndrome (11 pts each, 40.7%), and fatigue (7 pts, 25.9%). A pt with hepatocellular carcinoma had an unconfirmed partial response at cycle 2 and 10 pts experienced disease stabilization lasting ≥ 12 weeks. The median elimination half-life (t½) of D was 182 hrs for cycle 1 (with C) and 204 hrs for cycle 2 (without C). Median tmax values for D with and without C occurred at 2 hours. Median clearance values (CL/F) for D in plasma were similar with and without C at 18.4 L/h/m2 and 19.8 L/h/m2, respectively. Conclusions: The combination of D and C is feasible and safe at the MTD of 27 mg/m2 and 2500 mg/m2, respectively. Co-administering C with D did not alter the PK of either drug. Preliminary evidence of antitumor activity suggests that further studies of this combination are warranted.

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HGS-ETR2—A fully human monoclonal antibody to TRAIL-R2: Results of a phase I trial in patients with advanced solid tumors

3012

Background: HGS-ETR2 is a fully-human high-affinity monoclonal antibody that is agonistic to the Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand Receptor 2 (TRAIL-R2, DR5). TRAIL-R2 is expressed more widely on the surface of tumor cells than normal cells; binding of HGS-ETR2 to TRAIL-R2 leads to activation of the extrinsic apoptosis pathway. HGS-ETR2 shows anti-tumor activity at doses ≥ 0.3 mg/kg in xenograft models, both as a single agent and in combination with chemotherapeutic agents. Methods: This phase 1, dose-escalation study assessed the safety, tolerability, pharmacokinetics and immunogenicity of HGS-ETR2 administered IV every 14 days in patients with advanced solid tumors. Patients received HGS-ETR2 until disease progression or unacceptable toxicity. Tumor measurements were repeated every 2 months. Results: To date, 31 patients have received 167 courses of HGS-ETR2 over 5 dose levels: 0.1, 0.3, 1.0, 3.0 and 10.0 mg/kg q14 days. The majority (26 of 31) received at least 4 courses. One patient experienced a dose-limiting toxicity of grade 3 hyperamylasemia at the 10 mg/kg dose level. The event was determined to be possibly related to HGS-ETR2 and also possibly related to a nutritional supplement. Stable disease was achieved in 10 patients for 4 to 16 cycles. One patient with chemotherapy-refractive Hodgkin’s disease had a tumor regression of abdominal disease. HGS-ETR2 pharmacokinetics were linear up to 10 mg/kg. At the 10 mg/kg dose, the pharmacokinetics were characterized by a mean (SD) t1/2β of 11 (4) days, CL of 6.0 (0.7) mL/day, and V1 of 47 (8) mL/kg, slightly larger than the plasma volume. The 1.8-fold larger Vss of 85 (27) mL/kg indicates that HGS-ETR2 distributes outside the plasma compartment. Human anti-human antibody formation has not been detected. Conclusions: HGS-ETR2 can be safely administered every 14 days at doses up to and including 10 mg/kg. Further evaluation of HGS-ETR2 is planned, including studies of HGS-ETR2 in combination with chemotherapeutic agents.

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Phase I and pharmacokinetics (PK) study of sequential paclitaxel and trabectedin every 2 weeks in patients with advanced solid tumors

2029

Background: Trabectedin (ET-743) is a DNA minor-groove intercalating agent that blocks transcription factor activity, elicits G2/M cell cycle arrest, and induces apoptosis. Single agent activity has been demonstrated in soft tissue sarcoma (STS), breast, prostate and ovarian cancer. In preclinical studies sequential exposure of paclitaxel (P) followed by trabectedin (T) 24 hrs later resulted in synergy. The objectives of this phase I study were to determine the maximum tolerated dose (MTD) and recommended phase II dose (RD) of sequential P and T administered every 2 weeks in patients with advanced solid tumors. Methods: Escalating doses of P (80–120 mg/m2) over 1hr iv on day 1 and T ( 525–775 μg/m2) as 3 hrs iv day 2 every 2 weeks were administered. To evaluate drug:drug interactions, P was administered alone on day -7 in course 1 and PK studies performed courses 1 & 2. MTD was defined as ≥ 2/3 pts with dose limiting toxicity (DLT) in the 1st 2 courses. Results: 29 pts were enrolled and 27 were evaluable: median age was 48 yrs (19–82). M/F 16/13. Pts were treated over 5 dose levels: I 80/525 (n = 3), II 80/580 (n = 3), III 120/580 (n = 6), IV 120/650 (n = 11), V 120/775 (n = 4). A total of 213 courses of therapy were given, median number of course was 4 (range 1–28). There were 4 DLTs due to neutropenia delaying therapy > 1 week; one each at 120/580 (Grade 2) and 120/650 (Grade 4) and 2 at the MTD of 120/775 (Grade 4). Most common toxicities observed for P+T were neutropenia (24%), nausea (51%), vomiting (24%), transaminitis (23%), myalgia (24%) and alopecia (20%). One pt with PNET has an ongoing CR 16 months, one breast cancer pt (prior P failure) has PR 12 mo+ and 8 pts (6 STS) had SD > 3 mo (range 4–15 mo). There appear to be no marked drug:drug interactions for P and T. Preliminary non-compartmental PK results [geometric mean (CV%)] for T include t1/2 52.4 hr (43.6%); Cl l/hr/m2 31.6 (57.3%); Vss l/m2 1382 (69%) and for P are t1/2, 29.2 hr (39.1%); Cl l/hr/m2 15.3 (44.1%); Vss 213 l/m2 (72%). Conclusions: The recommended dose for this combination is paclitaxel 120 mg/m2 day 1 and trabectedin 650 μg/m2 day 2 administered every 2 weeks. Antitumor activity in STS and breast cancer, predictable PK parameters, and tolerable toxicity warrants further study of this combination.

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Multi-targeted inhibition of the epidermal growth factor (EGFR) and vascular endothelial growth factor receptor (VEGFR) pathways: A phase I study of cetuximab (C), erlotinib (E), and bevacizumab (B) in patients with solid tumors

3005

Background: Complex interrelationships exist between the EGFR and VEGFR pathways. EGFR activation elicits cell proliferation, and downstream effects increase expression of VEGF. In renal cell carcinoma, mutations increase hypoxia inducible factor-1alpha, stimulating VEGF and transforming growth factor expression. Moreover, there is additive tumor inhibition from combined EGFR targeting with C, and a tyrosine kinase inhibitor. To maximally inhibit EGFR, and then inhibit downstream VEGFR activity, this phase I study was initiated to determine the maximum tolerated dose (MTD) of E with a fixed dose of C, and then the MTD of B with combined E and C in patients with advanced malignancies. Methods: Patients with advanced malignancies likely to express EGFR were entered in part 1 to daily oral E (starting at 100mg, planned initially to increase to 150 mg), with fixed dose C (400 mg/m2 loading and 250 mg/m2 IV weekly). Once the MTD was determined for E in combination C, part 2 incorporated the addition of escalating doses of B (5 mg/kg IV every 2 weeks, to increase to 10 mg/kg) to the combination of E and C. Results: 27 patients were entered and received 84 courses over 3 dose levels. In part 1 grade 3 rash occurred in 2 patients at E at 100 mg daily, and the MTD of E for this combination was 50 mg daily with standard dose C (12 patients treated). Other adverse events included rash, diarrhea, hypomagnesemia, and nausea. Part 2: B at 5 mg/kg IV q14 days can be added to the MTD of E with C, with additional non-dose limiting toxicities of headache, proteinuria, and hypertension. Durable stable disease has been observed in 4 patients with metastatic disease for 7 (sqaumous cell); 10+, 12, and 12+ (renal cell) months. Conclusions: The MTD for E combined with standard C is 50 mg daily. B at 5mg/kg can be combined safely with this combination and dose escalation is ongoing.

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A phase I, pharmacokinetic and biologic correlative study of oblimersen sodium (Genasense, G3139) and irinotecan in patients with metastatic colorectal cancer

PURPOSE

To assess the feasibility and antitumor activity of oblimersen sodium, an antisense oligonucleotide directed to the Bcl-2 mRNA, combined with irinotecan in patients with advanced colorectal carcinoma, characterize the pharmacokinetic behavior of both oblimersen sodium and irinotecan, and examine Bcl-2 protein inhibition in peripheral blood mononuclear cells (PBMC).

PATIENTS AND METHODS

Patients were treated with escalating doses of oblimersen sodium administered by continuous intravenous infusion (CIVI) days 1-8, and irinotecan administered intravenously on day 6 once every 3 weeks.

RESULTS

Twenty patients received a total of 84 courses at doses ranging from 3 to 7 mg/kg/day for oblimersen sodium and from 280 to 350 mg/m2 for irinotecan. Febrile neutropenia and diarrhea limited escalation of oblimersen sodium and irinotecan to 5 mg/kg/day and 350 mg/m2, respectively. Other toxicities included nausea, vomiting, fever and fatigue. Steady-state plasma concentrations were achieved within 48 h of beginning oblimersen sodium treatment and the agent was undetectable 24 h after the discontinuation of the infusion. Reduction in levels of Bcl-2 protein in PBMC was documented following treatment with oblimersen sodium. One patient experienced a partial response and 10 additional patients had stable disease lasting 2.5-10 months.

CONCLUSIONS

The combination is well tolerated at the recommended phase II oblimersen sodium dose of 7 mg/kg/day CIVI days 1-8 with irinotecan 280 mg/m2 intravenously on day 6 every 3 weeks.