Phase I to II multicenter study of oblimersen sodium, a Bcl-2 antisense oligonucleotide, in patients with advanced chronic lymphocytic leukemia.

PURPOSE: To determine the maximum-tolerated dose (MTD), efficacy, safety, and pharmacokinetics of oblimersen sodium in patients with advanced chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS: Eligible patients had relapsed or refractory CLL after treatment with fludarabine. Oblimersen was administered at doses ranging from 3 to 7 mg/kg/d as a 5-day continuous intravenous infusion in cycle 1 and as a 7-day continuous intravenous infusion in subsequent cycles every 3 weeks in stable or responding patients. RESULTS: Forty patients were enrolled and treated (14 patients in phase I and 26 patients in phase II). Dose-limiting reactions in phase I included hypotension and fever, and the MTD for phase II dosing was established at 3 mg/kg/d. Two (8%) of 26 assessable patients achieved a partial response. Other evidence of antitumor activity included > or = 50% reduction in splenomegaly (seven of 17 patients; 41%), complete disappearance of hepatomegaly (two of seven patients; 29%), > or = 50% reduction of lymphadenopathy (seven of 22 patients; 32%), and > or = 50% reduction in circulating lymphocyte counts (11 of 22 patients; 50%). Adverse events included transient hypotension, fever, fatigue, night sweats, diarrhea, nausea, vomiting, hypokalemia, and cough. Plasma concentrations of oblimersen (parent drug) and its major metabolites were variable. Renal clearance represented only a small portion of total parent drug clearance. CONCLUSION: Dosing with oblimersen sodium in patients with CLL is limited by development of a cytokine release syndrome that is characterized by fever, hypotension, and back pain. Oblimersen sodium has modest single-agent activity in heavily pretreated patients with advanced CLL, and further evaluation of its activity in combination with cytotoxic drugs is warranted.

Pharmacokinetics and safety of ILX23-7553, a non-calcemic-vitamin D3 analogue, in a phase I study of patients with advanced malignancies.

PURPOSE: Differentiation therapy is an alternative to chemotherapy with potentially less toxicity, improved quality of life, and survival. We conducted a phase I trial of ILX23-7553, a formulation of 1,25-dihydroxy-16-ene-23-yne-vitamin D(3), a 1,25-dihydroxyvitamin D(3) analog with preclinically demonstrated antitumor and differentiating effects and diminished hypercalcemic effects. PATIENTS AND METHODS: The protocol consisted of five daily oral treatments during 14-day cycles at 15 dose levels from 1.3 to 45.0 mug/m(2)/day. We treated 42 heavily pretreated patients who had a variety of malignancies with 162 treatment cycles, and obtained pharmacokinetics from three patients at the two highest dose levels. RESULTS: There were no grade 3 or 4 toxicities. Grade 1-2 toxicities included diarrhea, nausea, fatigue, constipation, and one grade 1 hypercalcemia. Average day 6 calcium was 9.26 +/- 0.55 mg/dl in cycle 1 and 9.30 +/- 0.67 mg/dl in cycle 2. Pharmacokinetics at dose levels 14 (40 mug/m(2)/day) (1 patient) and 15 (45 mug/m(2)/day) (2 patients) demonstrated an average C(max) of 30.4 +/- 7.8 pg/ml (0.07 nM) and 104 +/- 38.2 pg/ml (0.25 nM), and AUCs of 222.5 +/- 225.2 pg.h/ml and 855 +/- 536 pg h/ml, respectively. Eight patients (19%) had stable disease. While in vitro effects have been reported at these concentrations, they were at least 10-fold lower than ED(50)s, and the study was terminated before an MTD was reached. CONCLUSION: The drug is safe and has potential benefits at serum concentrations where effects begin to be noted in vitro. Further study is needed with a reformulated higher unit dose compound to determine the safety and efficacy of higher serum concentrations.

Phase I trial of the proteasome inhibitor PS-341 in patients with refractory hematologic malignancies.

PURPOSE: To determine the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT), and pharmacodynamics (PD) of the proteasome inhibitor bortezomib (previously known as PS-341) in patients with refractory hematologic malignancies. PATIENTS AND METHODS: Patients received PS-341 twice weekly for 4 weeks at either 0.40, 1.04, 1.20, or 1.38 mg/m(2), followed by a 2-week rest. The PD of PS-341 was evaluated by measurement of whole blood 20S proteasome activity. RESULTS: Twenty-seven patients received 293 doses of PS-341, including 24 complete cycles. DLTs at doses above the 1.04-mg/m(2) MTD attributed to PS-341 included thrombocytopenia, hyponatremia, hypokalemia, fatigue, and malaise. In three of 10 patients receiving additional therapy, serious reversible adverse events appeared during cycle 2, including one episode of postural hypotension, one systemic hypersensitivity reaction, and grade 4 transaminitis in a patient with hepatitis C and a substantial acetaminophen ingestion. PD studies revealed PS-341 induced 20S proteasome inhibition in a time-dependent manner, and this inhibition was also related to both the dose in milligrams per meter squared, and the absolute dose of PS-341. Among nine fully assessable patients with heavily pretreated plasma cell dyscrasias completing one cycle of therapy, there was one complete response and a reduction in paraprotein levels and/or marrow plasmacytosis in eight others. In addition, one patient with mantle cell lymphoma and another with follicular lymphoma had shrinkage of nodal disease. CONCLUSION: PS-341 was well tolerated at 1.04 mg/m(2) on this dose-intensive schedule, although patients need to be monitored for electrolyte abnormalities and late toxicities. Additional studies are indicated to determine whether incorporation of dose/body surface area yields a superior PD model to dosing without normalization. PS-341 showed activity against refractory multiple myeloma and possibly non-Hodgkin's lymphoma in this study, and merits further investigation in these populations.