The suggested phase II dose on a continuous 42-day dosing schedule is 1,331 mg/m2/d. Linear pharmacologic parameters of the parent compound and metabolites are demonstrated.

Seventy-four previously untreated patients with metastatic colorectal adenocarcinoma were prospectively randomized into one of three treatment regimens: (1) 5-fluorouracil (5-FU) 450 mg/m2 as an intravenous (IV) bolus daily for five days or toxicity, then 200 mg/m2 IV bolus every other day for six doses; (2) methotrexate (MTX) 50 mg/m2 in normal saline by IV infusion over four hours followed by an IV bolus of 5-FU 600 mg/m2. This was administered weekly for 4 weeks and then every 2 weeks. (3) Leucovorin 500 mg/m2 in a two-hour IV infusion of normal saline with 5-FU 600 mg/m2 as an IV bolus one hour after the Leucovorin began every week for 6 weeks. The combined complete and partial response rates in the three regimens were 11%, 5%, and 48%, respectively (P = .0009). The median duration of response in the 5-FU and Leucovorin regimen was 10 months. There was no statistically significant difference between the treatment regimens with respect to survival time (P = .6). Toxicity in the 5-FU and Leucovorin regimen was predominantly diarrhea (13 of 30 patients, 40%). In this regimen, eight of 13 patients (52%) who developed diarrhea not only required a dose reduction of 5-FU, but also hospitalization for IV hydration. The predominant toxicity in the 5-FU alone regimen and the 5-FU and MTX regimen was leukopenia. One drug-related death occurred in each regimen.

Purpose: In preclinical models, calcitriol and the tyrosine kinase inhibitor gefitinib are synergistic and modulate extracellular signal-regulated kinase (Erk) and Akt pathways. Therefore, we conducted a phase I study of calcitriol and gefitinib to determine the maximum tolerated dose (MTD) of this combination. Experimental Design: Calcitriol was given i.v. over 1 h on weeks 1, 3, and weekly thereafter. Gefitinib was given at a fixed oral daily dose of 250 mg starting at week 2 (day 8). Escalation occurred in cohorts of three patients until the MTD was defined. Pharmacokinetic studies were done for calcitriol and gefitinib. Serial skin biopsies were done to investigate epidermal growth factor receptor (EGFR) pathway pharmacodynamic interactions. Results: Thirty-two patients were treated. Dose-limiting hypercalcemia was noted in two of four patients receiving 96 Ag/wk of calcitriol. One of seven patients developed dose-limiting hypercalcemia at the MTD 74 Ag/wk calcitriol dose level.The relationship between calcitriol dose and peak serum calcitriol (C max ) and systemic exposure (AUC) was linear. Mean (FSD) serum calcitriol C max at the MTD was 6.68 F 1.42 ng/mL. Gefitinib treatment inhibited EGFR, Akt, and Erk phosphorylation in the skin. Calcitriol did not have consistent effects on skin EGFR or its downstream elements. The combination of gefitinib and calcitriol did not modulate tumor EGFR pathway in patients with serial tumor biopsies. Conclusions: High doses of weekly i.v. calcitriol can be administered safely in combination with gefitinib. Calcitriol concentrations achieved at the MTD 74 Ag calcitriol exceed in vivo concentrations associated with antitumor activity in preclinical models.

Matrix metalloproteinases (MMPs) are a family of zinc-dependent proteinases that are associated with the tumorigenic process. MMPs degrade the extracellular matrix, promoting tumor invasion and metastasis. They also regulate host defense mechanisms and normal cell function; blocking all MMPs may not lead to a positive therapeutic outcome. Most clinical trials of MMP inhibitors (MMPIs) have yielded disappointing results, perhaps due to inappropriate study design or tumor staging, or to lack of selectivity. Positive results have been seen in gastric cancer with marimastat and in Kaposi's sarcoma with metastat. This review summarizes the current status of MMPIs.

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