Phase I dose-escalation trial of the oral investigational Hedgehog signaling pathway inhibitor TAK-441 in patients with advanced solid tumors.

PURPOSE: This first-in-human study assessed safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary clinical activity of single and multiple doses of TAK-441, an investigational inhibitor of the Hedgehog signaling pathway. EXPERIMENTAL DESIGN: Patients with advanced, solid tumors received daily oral TAK-441 (50-1,600 mg/day); daily dose was doubled in each subsequent cohort until the maximum tolerated/feasible dose (MTD/MFD) was reached. Blood was collected to evaluate TAK-441 plasma concentrations. Skin biopsies were obtained to evaluate suppression of the Hedgehog-regulated gene Gli1. RESULTS: Thirty-four patients were enrolled (median age 59). The most common diagnoses were colorectal cancer (26%), basal cell carcinoma (BCC, 21%), and pancreatic cancer (9%). The MFD of 1,600 mg/day (based on tablet size and strength) was considered the MTD. Dose-limiting toxicities included muscle spasms and fatigue. Grade ≥3 treatment-emergent adverse events, regardless of causality, occurred in 15 patients (44%), of which hyponatremia (n = 4) and fatigue (n = 3) were most common. Oral absorption was fairly rapid; median Tmax was 2.0 to 4.0 hours after a single dose. Mean elimination half-life was 13.5 to 22.6 hours. Systemic exposure of TAK-441 based on the area under the plasma concentration-time curve was linear across the dose range. Gli1 expression in skin biopsies was strongly inhibited at all dose levels. Best response was partial response (1 patient with BCC) and stable disease (7 patients with various solid tumors). CONCLUSIONS: TAK-441 was generally well tolerated up to MFD of 1,600 mg/day, with preliminary antitumor activity. Further study of TAK-441 may be appropriate in populations selected for tumors with ligand-dependent or independent Hedgehog signaling.

Phase I Study of Topotecan, Ifosfamide, and Etoposide (TIME) with autologous stem cell transplant in refractory cancer: pharmacokinetic and pharmacodynamic correlates.

PURPOSE: To determine the maximum tolerated dose (MTD) of topotecan in combination with ifosfamide, mesna, and etoposide (TIME), followed by autologous hematopoietic cell transplant (HCT), in patients with chemotherapy-refractory malignancies. EXPERIMENTAL DESIGN: Patients were treated with (in mg/m(2)/d) ifosfamide 3,333, mesna 3,333, and topotecan 3.3 to 28.3 during days -8 through -6 and etoposide 500 (days -5 through -3) followed by HCT on day 0. Once MTD was defined, we expanded this dosing cohort to include patients with high-risk lymphoma due to activity seen during dose escalation. Topotecan pharmacokinetic analyses were carried out, and topoisomerase I levels and activity were measured. RESULTS: The topotecan MTD in this regimen was 64 mg/m(2) (21.3 mg/m(2)/d). Mucositis was dose limiting and correlated with topotecan dose level and area under the curve (AUC). Dose level was also correlated with length of hospitalization, number of days of parenteral nutrition, and neutrophil and platelet engraftment. Topotecan AUC was significantly correlated with time to platelet recovery. The baseline peripheral blood mononuclear cell topoisomerase I level was found to be a significant positive predictor for overall and progression-free survival. Topotecan AUC was positively correlated with dose level, with a trend toward decreasing clearance with increasing dose. CONCLUSION: Topotecan can be a useful drug in the high-dose setting given its activity in some malignancies when given in standard dose. Pharmacokinetic monitoring may be a valuable tool for optimizing the use of topotecan and to avoid toxicity seen with high-systemic exposures. Baseline topoisomerase I levels may have an important role in predicting topotecan efficacy.