Sherry A. Goodner

A Phase 1 Escalating Single-Dose and Weekly Fixed-Dose Study of Cetuximab: Pharmacokinetic and Pharmacodynamic Rationale for Dosing

Purpose: This phase 1 study evaluated the pharmacokinetic and pharmacodynamic effects of cetuximab on patients with epithelial malignancies. Experimental Design: Following a skin and tumor biopsy, patients with advanced epithelial malignancies were randomized to receive a single dose of cetuximab at 50, 100, 250, 400, or 500 mg/m2 i.v. Repeat skin (days 2, 8, 15, and 22) and tumor (day 8) biopsies were obtained. Immunohistochemical expression of epidermal growth factor receptor (EGFR) and its pathway members was done on biopsies. Blood samples were obtained over 22 days for pharmacokinetic analyses. After day 22, all patients received weekly 250 mg/m2 cetuximab until disease progression or unacceptable toxicity. Results: Thirty-nine patients enrolled. Rash was noted in 26 (67%) patients. Three patients (two with colon cancer and one with laryngeal cancer) achieved a partial response and 13 patients had stable disease. Pharmacokinetic data revealed mean maximum observed cetuximab concentrations and mean area under the concentration-time curve from time zero to infinity increased in a dose-dependent manner up to 400 mg/m2 cetuximab. Mean clearance was similar at cetuximab doses ≥100 mg/m2, supporting saturation of EGFR binding at 250 mg/m2. Pharmacodynamic evaluation revealed that patients with partial response/stable disease had a higher-grade rash and higher cetuximab trough levels than those with progressive disease (P = 0.032 and 0.002, respectively). Administration of single doses (250-500 mg/m2) of cetuximab resulted in a dose-dependent decrease in EGFR protein expression levels in skin over time, supporting a minimal dose of cetuximab at 250 mg/m2 for a pharmacodynamic effect. Conclusion: This study provides a pharmacokinetic and pharmacodynamic rationale for the dosing of cetuximab.

Phase I Study of Docetaxel in Combination with the P-Glycoprotein Inhibitor, Zosuquidar, in Resistant Malignancies

Purpose: To determine the maximum tolerated dose, dose-limiting toxicity, and pharmacokinetics of docetaxel infused over 1 hour when given in combination with oral zosuquidar to patients with resistant solid tumors. Experimental Design: In cycle 1, patients received docetaxel alone. In subsequent cycles, zosuquidar was administered with docetaxel, which was escalated from 75 to 100 mg/m2. Zosuquidar was escalated from 100 to 300 mg/m2 every 8 hours on days 1 to 3 for a total of 7 doses, or from 400 to 500 mg every 12 hours for 2 doses administered 2 hours before docetaxel. The pharmacokinetics of docetaxel with and without zosuquidar administration were obtained. Results: Thirty-six of 41 patients completed at least one cycle of docetaxel and zosuquidar. The maximum tolerated dose was docetaxel 100 mg/m2 and zosuquidar 500 mg every 12 hours for 2 doses. The most common toxicity was neutropenia. In 35 patients, zosuquidar produced minimal increases in the docetaxel peak plasma concentrations and area under the curve. Dosing over 3 days with zosuquidar (7 doses) did not show benefit over the 1-day dosing. Of the 36 patients, one patient had a partial response, and 14 patients had disease stabilization. Conclusions: Docetaxel at 75 or 100 mg/m2 and zosuquidar 500 mg 2 hours before docetaxel and 12 hours later is well tolerated. Zosuquidar minimally alters the pharmacokinetics of docetaxel, allowing full dose docetaxel to be given with this P-glycoprotein modulator. A Phase II study with this combination in advanced breast carcinoma is underway.

Phase 1 and pharmacokinetic study of weekly docosahexaenoic acid-paclitaxel, Taxoprexin ® , in resistant solid tumor malignancies

PURPOSE To determine the maximum tolerated dose, dose-limiting toxicity (DLT), and pharmacokinetics of weekly docosahexaenoic acid-paclitaxel (DHA-paclitaxel), a taxane fatty acid conjugate. EXPERIMENTAL DESIGN Docosahexaenoic acid-paclitaxel was administered by 2-hour i.v. infusion weekly for three out of four weeks. DHA-paclitaxel 200 mg/m(2) was dose escalated by 100 mg/m(2) per cohort to 600 mg/m(2). Blood samples for pharmacokinetics of DHA-paclitaxel and paclitaxel derived from DHA-paclitaxel were collected. RESULTS Twenty-one patients received 42 cycles of treatment over five dose levels. Grade 3/4 neutropenia occurred in five patients but was not dose limiting. Grade 3 hyperbilirubinemia, a DLT, and grade 1 sensory neuropathy occurred at the highest dose level. PK analyses demonstrated dose proportional C (max) and AUC(0-24). Limited accumulation of DHA-paclitaxel or paclitaxel occurred with weekly treatment. Increased DHA-paclitaxel and paclitaxel AUC(0-24) were associated with increased neutropenia. Of the 19 patients evaluable for response, three patients with esophageal, melanoma and colon carcinoma had stable disease for 11, 16, and 17 weeks, respectively. CONCLUSION Docosahexaenoic acid-paclitaxel administered weekly to a maximum dose of 600 mg/m(2) was well-tolerated. The slow release of paclitaxel from DHA-paclitaxel and the weekly schedule approximates continuous infusion paclitaxel which may be more active than every 3 week or weekly taxanes.

Phase I study of pegylated liposomal doxorubicin and the multidrug-resistance modulator, valspodar

Valspodar, a P-glycoprotein modulator, affects pharmacokinetics of doxorubicin when administered in combination, resulting in doxorubicin dose reduction. In animal models, valspodar has minimal interaction with pegylated liposomal doxorubicin (PEG-LD). To determine any pharmacokinetic interaction in humans, we designed a study to determine maximum tolerated dose, dose-limiting toxicity (DLT), and pharmacokinetics of total doxorubicin, in PEG-LD and valspodar combination therapy in patients with advanced malignancies. Patients received PEG-LD 20–25 mg m−2 intravenously over 1 h for cycle one. In subsequent 2-week cycles, valspodar was administered as 72 h continuous intravenous infusion with PEG-LD beginning at 8 mg m−2 and escalated in an accelerated titration design to 25 mg m−2. Pharmacokinetic data were collected with and without valspodar. A total of 14 patients completed at least two cycles of therapy. No DLTs were observed in six patients treated at the highest level of PEG-LD 25 mg m−2. The most common toxicities were fatigue, nausea, vomiting, mucositis, palmar plantar erythrodysesthesia, diarrhoea, and ataxia. Partial responses were observed in patients with breast and ovarian carcinoma. The mean (range) total doxorubicin clearance decreased from 27 (10–73) ml h−1 m−2 in cycle 1 to 18 (3–37) ml h−1 m−2 with the addition of valspodar in cycle 2 (P=0.009). Treatment with PEG-LD 25 mg m−2 in combination with valspodar results in a moderate prolongation of total doxorubicin clearance and half-life but did not increase the toxicity of this agent.

Phase I dose and sequencing study of pegylated liposomal doxorubicin and docetaxel in patients with advanced malignancies

Pegylated liposomal doxorubicin (PEG‐LD) and docetaxel have single‐agent activity in several malignancies. The authors conducted a Phase I trial to evaluate the maximum tolerated dose (MTD), toxicities, and effect of dose sequencing of this combination in patients with advanced malignancies.

Coaching Intervention As a Strategy for Minority Recruitment to Cancer Clinical Trials

PURPOSE Lack of trust and rapport with health care providers has been identified in the under-representation of racial/ethnic minorities within clinical trials. Our study used a coach to promote trust among minority patients with advanced cancer. PATIENTS AND METHODS Minority patients with advanced breast, colorectal, lung, or prostate carcinoma were randomly assigned to receive a coach Intervention (CI) or usual care (UC). All patients completed baseline and 6-month telephone interviews to assess demographics, trust in health care providers, attitudes toward clinical trials, and quality of life. Patients randomly assigned to CI were assigned a coach, who made biweekly contacts for 6 months to address general issues, progress or development in cancer care, and available resources. Patients randomly assigned to UC received the standard of care, without this intervention. Clinical trial enrollment was assessed. RESULTS Over 21 months, we screened 268 patients and enrolled 73 African Americans and two Asian Americans. Patients were randomly assigned to CI (n = 38) or to UC (n = 37). Longitudinal analyses were conducted on 69 patients who completed the 6-month follow-up assessment. Trial enrollment was 16 and 13 patients for the CI and UC groups, respectively. This difference was not significant (P = .351). Higher quality of life (1-point odds ratio on Functional Assessment of Cancer Treatment-General = 1.033, P = .036) and positive attitudes toward trials predicted enrollment. There was no significant difference between these groups in quality of life, attitudes toward clinical trials, perceptions of racism, trust in doctors, or depression. CONCLUSIONS Quality of life and positive attitude toward trials predicted trial enrollment, regardless of assignment to CI or UC.