Phase I pharmacokinetic (PK) and pharmacodynamic (PD) study of PF-00337210, a highly selective VEGFR inhibitor

3519

Background: PF-00337210 potently inhibits VEGFR2 phosphorylation and is >10-fold more selective, based on IC50, for VEGFR2 than other kinases (eg, KIT and PDGFRs). In vitro, PF-00337210 inhibits VEGF-mediated HUVEC survival (IC50 = 0.53 nM). In vivo, it inhibits tumor angiogenesis and human xenograft growth. Methods: The primary objectives were to determine the safety profile and MTD of PF-00337210. PK and PD (DCE-MRI at baseline and cycle [C] 1, day [D] 2) were also evaluated. The volume rate transfer constant (Ktrans) assessed VEGFR inhibitory effects on vascular permeability and perfusion. Results: To date, 29 patients (pts) with advanced solid tumors were treated with PF-00337210 at doses of 0.67–9 mg QD, 13 of whom (45%) had received prior VEGF/VEGFR inhibitors. No dose-limiting toxicities (DLTs) occurred at 0.67–8 mg QD. Two DLTs occurred at 9 mg QD: one pt had chest pain, G3 troponin I, and G3 myocardial ischemia; a second pt had significant hypertension (HTN) at the anticipated Tmax after the first dose (systolic ≥180 mmHg over 3 hrs). HTN and fatigue were the most common treatment-related adverse events (AEs). HTN occurred in 8 pts (28%); incidence and intensity corresponded with dose, but was well controlled with antihypertensive agents. Fatigue was reported in 9 pts (31%) and occurred most frequently in pts receiving ≥6 mg QD. Other AEs included nausea, anorexia, proteinuria, and diarrhea. PK data indicated that mean (%CV) t1/2 at 8 mg QD was 8.60 (81) h (n=4) and AUC0–24 was 309 (45) ng.h/mL at steady-state (SS) on C1D15. Exposures (AUC0–24) were generally linear and variability ranged from 21 to 44% across doses. The observed accumulation ratio (Rac) at SS was 1.22 (15) (n=21), which was predicted by t1/2. PF-00337210 decreased mean Ktrans (1/min) values by 22.5±11.8 (n=2), 15.2 (n=1), 5.4±4.8 (n=3), and 25.3±8.5% (n=4) at 4, 6, 8, and 9 mg QD, respectively. No objective responses were observed but 7/29 pts (24%) had stable disease. Conclusions: PF-00337210 was well tolerated with the DLTs being HTN and myocardial ischemia. The QD MTD was determined to be 8 mg. Preliminary evidence of VEGFR inhibition was shown by DCE-MRI at ≥4 mg QD. The trial is now evaluating BID dosing which may allow increased drug exposures and fewer hypertensive effects that may be related to Cmax.

[Table: see text]

Population pharmacokinetics of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone in cancer patients

2508

Background: 3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3AP) is an inhibitor of ribonucletoide reductatse with activity in hematological malignancies as well as melanoma and prostate cancer. This study describes the population PK of 3AP and the relationship between 3AP disposition and patient covariates. Methods: 40 pts with advanced cancer from two phase 1 studies were included in the PK model building. Pts received 3AP 25–105 mg/m2 IV on day 1. 3AP plasma and erythrocyte levels were sampled at 10 timepoints over a 24-hour period and measured by a validated HPLC method. Data were analyzed by a nonlinear mixed- effects modeling approach with NONMEM system Version V. Xpose10 and S-PLUS were used for goodness-of-fit assessment and model evaluation to obtain clearance (CL), volume of distribution (V) for compartment (C) 1, plasma (V1); V for C2, erythrocytes (V2); and V for C3 (V3). 15 covariates were evaluated, including: weight, BSA, gender, PS, age, ABCB1[C1236T, G2667T, C3436T] genotypes, toxicity, concurrent chemotherapy [irinotecan, doxorubicin], response and number of cycles administered. Normal renal and hepatic function were required for study entry and were not included as covariates. Response was assessed after 2 cycles of therapy. Results: 3AP PK were described as a 3-compartment model with first-order elimination. Estimated paramaters were: V1 =5.68 L/m2 (95%CI 4.3–7.1); V2=18.9 L/m2 (95%CI 14.6–23.2); V3= 40.0 L/m2 (95%CI 23.8–55.4); CL 25.4 L/hr/m2 (95%CI 22.4–28.4). Gender was associated with V; women had a lower V2 (p<0.05). This may be related to a lower hemoglobin in women. The number of cycles administered was associated with decreased CL; those with decreased CL received less than 2 cycles before going off study. Conclusions: Women had a lower V2 than men and pts with decreased CL received less than 2 cycles of therapy, suggesting PK may be helpful in individualizing dosing. ABCB1 genotypes and concurrent irinotecan or doxorubicin do not influence 3AP disposition. Supported by: U01CA062491 “Early Clinical Trials of Anti-Cancer Agents with Phase I Emphasis” NCI; CTEP TRI Funding 24XS090, and 1ULRR025011 Clinical and Translational Science Award of the National Center for Research Resources, NIH.

No significant financial relationships to disclose.

A phase II clinical and biological study of lithium carbonate (Li) in patients with low-grade neuroendocrine tumors

e15662

Background: Low-grade neuroendocrine tumors (NETs), such as carcinoid, islet cell tumors, and medullary thyroid carcinomas, respond poorly to chemotherapy, and effective, less toxic therapies are needed. Glycogen Synthase Kinase (GSK)-3β, a multifunctional protein kinase, has been shown to regulate growth and hormone production in NETs. Use of lithium carbonate (Li) in murine models suppressed carcinoid cell growth, reduced GSK-3β levels and reduced expression of chromogranin A. This study assessed the efficacy of Li in patients with NETs. Methods: Eligible pts had pathologically-proven, measurable low-grade NETs. Prior treatment was allowed if completed >4wks prior to registration. Standard eligibility criteria were used, and use of medications affecting Li metabolism or levels were prohibited. A single-arm, open-label, two-stage Phase II design was used. Li was dosed at 300mg orally TID with meals, titrated to a target serum level of 0.8–1.0mmol/L. The primary endpoint was objective tumor response by RECIST. Secondary endpoints included overall survival, progression-free survival, decrease of serum tumor markers, toxicity, and quality of life. Results: 15 pts were enrolled between 10/3/07and 7/17/08; 6 men, 9 women. The median age was 58 (range 47–74). Patients’ diagnoses were carcinoid tumor for 8 subjects, islet cell tumor for 5 subjects, and 2 unknown primary sites. ECOG PS was 0 (6 patients) or 1 (9 patients). Two pts came off study due to side effects (tremor, dizziness/abdominal pain). There were no radiographic responses. Due to an early stopping rule requiring at least 1 objective response in the first 13 evaluable pts, the study was closed to further accrual. 13 patients had pre- and post-therapy biopsies. Evaluation of quality of life and GSK-3β levels in tumor tissue is ongoing. Conclusions: Li was ineffective at obtaining a radiographic response in our 13 evaluable patients who were treated as part of this study. We will determine from tumor biopsies whether Li was effective at phosphorylating GSK-3β in order to make conclusions about GSK-3β as a therapeutic target for future NET treatment strategies. Funded through NIH grant R21CA117117- 01A2 and CTRC grant 1ULRR025011.

No significant financial relationships to disclose.

A phase I study of capecitabine, oxaliplatin (CapOx), and lapatinib (L) in metastatic or advanced solid tumors

2579

Background: CapOx is a standard treatment for patients (pts) with metastatic colorectal cancer (mCRC) and has been shown to be equivalent to FOLFOX in a phase III study. L is a tyrosine kinase inhibitor with targeting of the EGF and Her-2 receptors. Preclinical data suggest there may be synergy between L and Cap as well as L and Ox. This phase I study was designed to determine the maximum tolerated dose (MTD) of CapOx and L. Methods: Pts eligible for treatment included those with advanced or metastatic cancers, ECOG PS 2 or less, adequate renal and liver function, and ≤ 3 prior chemotherapy regimens. Treatment over a 21-day cycle was as follows: Ox, single IV infusion on Day 1; Cap, twice-daily oral administration on Days 1 through 14; L, continuous once-daily oral administration. Pts were treated with escalating doses of L (starting at 1000 mg daily) and Cap (starting at 1500 mg/m2/day), while Ox was kept at 130 mg/m2. The primary endpoint was determination of MTD. Results: Ten pts (9/10 female, median age 62 yrs.) were enrolled. One pt had breast cancer and the remainder had non- colorectal GI malignancies (esophagus, hepatobiliary, and pancreas). One pt at dose level 0 experienced dose-limiting toxicity (DLT) (dehydration, elevated bilirubin, hypokalemia). Two pts at dose level 1 (L 1000, Ox 130, Cap 2000) had DLTs of hypokalemia and diarrhea. At an intermediate dose level of L 1000, Cap 1700, Ox 130, two pts experienced DLTs (grade 2 fatigue/anorexia, grade 3 fatigue and dizziness). The MTD was determined to be L 1000 mg daily, Cap 1500 mg/m2/day, Ox 130 mg/m2. There were no treatment-related grade 4 toxicities. The most common grade 3 toxicity was diarrhea (4 pts). There were no grade 3 neuropathies, hematologic toxicities, or rash, and only one case of grade 3 fatigue. One pt with pancreatic cancer had a confirmed partial response (PR) to treatment, and 3 others had stable disease for > 90 days. Conclusions: The regimen of CapOx and L has efficacy in the treatment of solid tumors with established responsiveness to fluoropyrimidines or Ox. The MTD was L 1000 mg daily, Ox 130 mg/m2, and Cap 1500 mg/m2/day. This regimen will be investigated further in a Phase II study involving pts with mCRC.

[Table: see text]

MC044h, a phase II trial of sorafenib in patients (pts) with metastatic neuroendocrine tumors (NET): A Phase II Consortium (P2C) study

4504

Background: Treatment options for metastatic NET, including islet cell carcinoma (ICC) and carcinoid tumor (CT), are limited. These tumors frequently express vascular endothelial growth factor receptor-2 (VEGFR-2) and platelet derived growth factor receptor receptor-β (PDGFR-β). Sorafenib, a small-molecule inhibitor of the VEGFR-2 and PDGFR-β tyrosine kinase domains, is a rational targeted therapy to evaluate in NET. Methods: Eligibility criteria included: ECOG PS = 2, = 1 prior chemotherapy, good organ function and signed informed consent. Prior interferon and prior or concurrent octreotide at a stable dose were allowed. Pts unable to take oral medications, with uncontrolled hypertension or with symptomatic coronary artery disease were excluded. Pts received sorafenib 400 mg po BID. Primary endpoint was response by RECIST in two cohorts (ie, CT and ICC) using separate 2-stage phase II designs. Results: 93 pts were enrolled: (50 CT, 43 ICC). For pts evaluable for the primary endpoint, 4 of 41 (10%) CT pts and 4 of 41 (10%) ICC pts had a PR. There were 3 minor responses (MR = 20–29% decrease in sum of target lesion diameters) in CT pts and 9 MRs in ICC pts for PR+MR rate of 17% for CT pts and 32% for ICC pts. For pts evaluable, 6-month progression-free survival was observed in 8/20 CT and 14/23 ICC pts. Grade 3–4 toxicity occurred in 43% of pts, with skin (20%), GI (7%) and fatigue (9%) most common. Translational studies from tumor tissue will be presented. Conclusions: Sorafenib at 400 mg po BID has modest activity in metastatic neuroendocrine tumors, with frequent grade = 3 toxicity. Supported by NOI CM6225.

No significant financial relationships to disclose.

Phase I clinical and pharmacokinetic (PK) trial of the kinesin spindle protein (KSP) inhibitor MK-0731 in patients with solid tumors

2548

Background: KSP is essential for the separation of spindle poles during mitosis and inhibition results in mitotic arrest. MK- 0731 is a potent inhibitor of KSP, with an IC50 of 2.2 nM, and >20,000 fold selectivity against other kinesins. MK-0731 causes mitotic arrest with an EC50 in several tumor cell lines of 3–5 nM. Methods: Phase I study to determine the safety and tolerability, MTD, and PK of MK-0731 administered IV over 24 hrs every 21 days. In part 1, dosing started at 6 mg/m2/24 hr and was escalated until the MTD was reached. In part 2, pts with measurable taxane-resistant cancer were treated at the MTD established in Part 1 (target accrual =22 pts in part 2). Interim Results: 35 pts with solid tumors (M/F 23/12), median age 63 yrs (23 - 79), were treated at doses of 6 to 48 mg/ m2/24hrs (median cycles 3, range 1–10, total cycles=128). Frequent tumor types included prostate (8), ovarian (4), colon (3), bladder (2), neuroendocrine (2), lung (2), breast (2). Prolonged (>5 days) grade 4 neutropenia was observed in 2 pts at 48 mg/m2/24hrs (11 days duration) and 2 pts at 24 mg/m2/24hrs (7 days duration) leading to expansion of cohorts at lower dose levels. At the MTD of 17 mg/ m2/24, there were no DLTs. 14 patients have been enrolled at the MTD in part 2 of the study. Drug related grade 3/4 toxicities were anemia (1), AST (1), hyperglycemia (1), nausea/vomiting (1), neutropenia (7), syncope (1). PK results from the first 20 patients suggest that MK- 0731 concentrations appear to decline monoexponentially or biexponentially following the infusion with terminal t1/2 from ∼4 to 22 hrs. In some patients, steady-state concentrations may not be achieved by the end of the 24 hr infusion. Mean values at the 17 mg/m2/24hrs dose level were Cmax=599 nM, AUC8=14.56 μM·hr, and CL=119 mL/min. AUC, exposures, and end of infusion concentrations appear to increase proportionally with dose. Stable disease for = 4 cycles (range 4- 10) was seen in 16 patients. Conclusion: Treatment with MK-0731 at the MTD of 17 mg/m2/day every 21 days in patients with advanced solid tumors was well tolerated with consistent dose limiting toxicity of myelosuppression.

No significant financial relationships to disclose.

Phase I clinical and pharmacokinetic (PK) trial of the kinesin spindle protein (KSP) inhibitor MK-0731 in cancer patients

2001

Background: KSP is essential for the separation of spindle poles during mitosis and inhibition results in mitotic arrest. Function is thought to be limited to mitosis and inhibitors should not cause the peripheral neuropathy seen with other mitotic-inhibitors. MK-0731 is a potent inhibitor of KSP, with an IC50 of 2.2 nM, and >20,000 fold selectivity against other kinesins. MK-0731 causes mitotic arrest with an EC50 in several tumor cell lines of 3−5 nM. Methods: Phase I study to determine the safety and tolerability, MTD, and PK of MK-0731 administered IV over 24 hrs every 21 (Q21) ds. Results: Eight pts with solid tumors (M/F 6/2), median age 55 yrs (45–72 yrs), were treated at doses of 6 to 48 mg/m2/24hrs. Prolonged (≥5 ds) Grade 4 neutropenia was observed in 2 pts at 48 mg/m2/24 hrs leading to expansion of cohorts at lower dose levels. Other drug related toxicities include diarrhea, alopecia, nail changes, nausea/vomiting, mucositis, abdominal pain, anorexia, phlebitis. PK results suggest that steady-state concentrations may not be achieved by the end of the 24 hr infusion and MK-0731 concentrations appear to decline monoexponentially or biexponentially following the infusion with terminal t1/2 from ∼4 to 11 hrs. Median values at the 48 mg/m2/24 hrs dose level were Cmax = 1223 nM, AUC∞ = 26.585 μM · hr, and CL=122 mL/min. AUC, exposures, and end of infusion concentrations appear to increase proportionally with dose. Conclusions: This is the first study of MK-0731. The MTD was exceeded at 48 mg/m2/24 hrs Q21. Further evaluation will continue at lower doses.

[Table: see text]

A phase II trial of gefitinib in patients (pts) with progressive metastatic neuroendocrine tumors (NET): A Phase II Consortium (P2C) study

4043

Background: Systemic treatment options for progressive metastatic NET, including islet cell carcinoma (ICC) and carcinoid tumor (CT), are limited. These tumors frequently express the epidermal growth factor receptor (EGFR). Gefitinib, a small-molecule inhibitor of the EGFR tyrosine kinase, has been shown to inhibit the growth of NET cell lines. Methods: Eligibility criteria included: radiographic progression by RECIST criteria, ECOG PS ≤ 2, ≤ 1 prior chemotherapy, and good organ function. Prior interferon and prior or concurrent octreotide (if disease progression documented on stable dose) were allowed. Pts received gefitinib 250 mg po daily. We evaluated 6 month (mos) progression-free survival (PFS) in two cohorts (ie, CT and ICC) using separate 2-stage phase II designs. 6 mos PFS rates of 30% (CT) and 10% (ICC) were considered promising. Results: 96 pts were enrolled: (57 CT, 39 ICC). For pts evaluable for the primary endpoint, 23 of 38 (61%) CT pts and 9 of 29 (31%) pts with ICC were progression-free at 6 mos. 1 PR and one minor response (MR = 20–29% decrease in sum of target lesion diameters) were observed in 40 CT pts; 2 PR and 1 MR in 31 ICC pts. In addition, 32% (12/38) of CT and 14% (4/29) of ICC pts had stable disease on study for a duration that exceeded by at least 4 months the time to progression documented prior to study entry. Grade 3–4 toxicity was infrequent with fatigue (6%), diarrhea (5%) and rash (3%) most common. Evaluation of markers of the EGFR pathway on tumor tissue will be presented. Conclusions: Gefitinib is well-tolerated and results in prolonged disease stabilization in pts with prior documented objective progression of CT and ICC, with rare objective responses. Supported by NOI CM17104.

No significant financial relationships to disclose.

A phase I study of triapine in combination with irinotecan in refractory tumors

12011

Background: Triapine is a small molecule inhibitor of ribonucleotide reductase and has anti-tumor activity alone and in combination with other agents in advanced solid tumors. Based on its ability to limit DNA repair, Triapine has been postulated to act synergistically with irinotecan. This study was conducted to determine the toxicities and efficacy of Triapine with irinotecan. Correlative studies included: pharmacokinetics, MDR polymorphisms, and the effects of Triapine on cell cycle and electron paramagnetic resonance spectroscopy. Methods: This study used standard eligibility criteria with the following exceptions: patients must have had no prior irinotecan and no G6PD deficiency. The treatment plan consisted of irinotecan on day 1 with Triapine on days 1- 3 of a 21-day cycle. Starting dose (level 1) was irinotecan (150 mg/m2) and Triapine (85 mg/m2/day). RECIST was used to measure response. Results: 10 patients have been enrolled; 5 men, 5 women. Tumor types: 4 pancreatic, 2 cholangio, 1 esophageal, 1 sarcoma, 1 lung, 1 ovarian. Grade 3–4 toxicities at least possibly related to Triapine at any dose level were as follows: neutropenia (3), leukopenia (2), fatigue, hypoxia, nausea, vomiting, thrombocytopenia, abdominal cramping, hypocalcemia, and thrombosis. The first patient enrolled at level 1 developed a DLT (Grade 3 hypoxia). Consequently, irinotecan and Triapine doses were reduced to 100 mg/m2 and 60 mg/m2/day, respectively (level -1). One of 6 patients experienced a DLT at this dose level. Further patients were then enrolled at level 1. There were 2 DLTs of 4 patients at level 1. One partial response (NSCLC) was seen. Conclusions: Unacceptable toxicities were seen at dose level 1; however, dose level -1 was well tolerated. The trial has therefore been amended in order to evaluate a higher dose of irinotecan (150 mg/m2) with the level -1 dose of Triapine (60 mg/m2/day). Accrual continues at this dose level. Antitumor activity in NSCLC was noted at level 1.

[Table: see text]

TAT results in a longitudinal study of bereaved college students

The authors analyzed projective data obtained from 141 college students who wrote stories on three separate occasions to selected cards from the Thematic Apperception Test (TAT). The students included 46 members of support groups for bereaved college students, 34 members of a bereavement control group, and 61 nonbereaved students. The study used a repeated-measures pretest-posttest control group design to gather longitudinal data about the trajectory of bereavement with and without support group intervention. Coders, who reached consistently high interrater reliability, looked for themes of death, grief, coping, and affiliation in the stories. Multivariate analysis of variance (MANOVA) and repeated-measures MANOVA tests were applied to analyze coding results. Overall MANOVA results indicated significant group differences in the responses to the TAT cards. Repeated-measures MANOVA found group differences in use of themes of death and grief and found Group x Time differences in maintaining a sense of self-efficacy while in a crisis. A majority of the stories contained affiliation imagery but without any group differences in the use of such imagery.

Isokinetic muscle performance in healthy female handball players and players with a unilateral anterior cruciate ligament reconstruction

A total of 114 healthy female European team handball players in the elite to second division with no previous ACL injury, and the uninjured legs of 22 females with a unilaterally reconstructed ACL (the injury sustained while playing handball; mean time from reconstruction 15 months) were examined with a Biodex isokinetic testing device. Five extensions and flexions at lower speed (60 degrees/s) and 15 repetitions at higher speed (240 degrees/s) were performed. Gravity-corrected peak torque values for flexion and extension were obtained, and hamstrings-to-quadriceps ratios (H/Q) were calculated at both speeds. Compared with the control group, the uninjured legs of the injury group showed 8% weaker quadriceps muscles and 14% higher H/Q ratios at higher speed. The other between-group comparisons were not significant. These differences could have been developed by strength reduction after the injury in the noninjured limb due-to-insufficient rehabilitation, by a weaker musculature in the patient group already initially, or by both mechanisms. If the second option is true, the finding may indicate that weak quadriceps musculature is one of the risk factors for anterior cruciate ligament injuries. The study establishes additional normative data on hamstrings and quadriceps torque on high-level female handball players.