Voreloxin, a first-in-class anticancer quinolone derivative, in relapsed/refractory solid tumors: a report on two dosing schedules.

PURPOSE: Voreloxin, a novel replication-dependent DNA-damaging agent, intercalates DNA and inhibits topoisomerase II. Voreloxin induces site-selective DNA double-strand breaks and apoptosis. We report the phase 1 experience of voreloxin in patients with relapsed/refractory solid tumors, including dose-limiting toxicity (DLT), maximum-tolerated dose (MTD), pharmacokinetics, and clinical activity. EXPERIMENTAL DESIGN: Two dose-escalation studies evaluated voreloxin administered i.v. every 3 weeks (SPO-0001) or weekly for 3 weeks every 28 days (SPO-0002). In SPO-0001, patients were classified as heavily pretreated (HP) or minimally pretreated (MP) based on therapeutic history. RESULTS: In the SPO-0001 study, 41 patients (24 HP/17 MP) were treated in eight dose cohorts (3-75 mg/m(2)). At 60 mg/m(2), four HP patients experienced DLTs: grade 4 neutropenia (n = 3, one with fever) and grade 3 febrile neutropenia/pneumonia (n = 1). At 75 mg/m(2), two MP patients experienced DLTs: grade 4 neutropenia/thrombocytopenia (n = 1) or grade 2 oral thrush for >29 days (n = 1). Therefore, the MTD was 48 mg/m(2) (HP patients) and 60 mg/m(2) (MP patients). In the SPO-0002 study, 21 patients were treated in six dose cohorts (3-24 mg/m(2)). At 18 mg/m(2), two patients experienced DLTs: grade 3 neutropenia, one with pleural effusion (>14 days each). The MTD was 15 mg/m(2). Voreloxin exhibited low clearance (2 L/h/m(2)), a long terminal half-life (22 hours), and dose-proportional exposure. Overall, 31 of 62 patients had stable disease and 1 patient (ovarian cancer) had a partial response per Rustin criteria. CONCLUSIONS: Voreloxin showed an acceptable safety profile with clinical activity in patients with relapsed/refractory solid tumors. The MTD was schedule-dependent. Voreloxin is currently in clinical studies of ovarian cancer and acute myeloid leukemia.

Radioimmunotherapy of non-Hodgkin's lymphoma: clinical development of the Zevalin regimen.

Zevalin (ibritumomab tiuxetan; IDEC Pharmaceuticals Corporation, San Diego, CA, USA) was approved by the United States Food and Drug Administration on February 19, 2002, following 9 years of clinical development. Six clinical studies supported the Zevalin Biologics License Application. The Zevalin regimen is indicated for the treatment of patients with relapsed or refractory low-grade, follicular, or transformed B-cell non-Hodgkin's lymphoma (NHL), and for those with follicular NHL refractory to Rituxan (rituximab, MabThera; IDEC Pharmaceuticals Corporation, San Diego, CA and Genentech, South San Francisco, CA). In the year following FDA approval, approximately 1300 patients were treated in clinical trials or with the commercially available product.

The beta3 nicotinic receptor subunit: a component of alpha-conotoxin MII-binding nicotinic acetylcholine receptors that modulate dopamine release and related behaviors.

Nigrostriatal dopaminergic neurons express many nicotinic acetylcholine receptor (nAChR) subunits capable of forming multiple nAChR subtypes. These subtypes are expressed differentially along the neuron and presumably mediate diverse responses. beta3 subunit mRNA has restricted expression but is abundant in the substantia nigra and ventral tegmental areas. To investigate the potential role(s) of nicotinic receptors containing the beta3 subunit in dopaminergic tracts, we generated mice with a null mutation in the beta3 gene. We were thereby able to identify a population of beta3-dependent alpha-conotoxin MII-binding nAChRs that modulate striatal dopamine release. Changes were also observed in locomotor activity and prepulse inhibition of acoustic startle, behaviors that are controlled, in part, by nigrostriatal and mesolimbic dopaminergic activity, respectively, suggesting that beta3-containing nAChRs modulate these behaviors.

Clinical and histologic response to single-dose treatment of moderate to severe psoriasis with an anti-CD80 monoclonal antibody.

Pathologic T-cell activation is implicated in psoriasis progression. CD80, a costimulatory molecule involved in T-cell activation, likely plays a key role. IDEC-114, an IgG(1) anti-CD80 antibody, was evaluated for safety, pharmacokinetics, and preliminary clinical activity in this open-label, single-dose, dose-escalating study in patients with moderate to severe chronic plaque psoriasis. Twenty-four patients received IDEC-114 (0.05 mg/kg, 0.25 mg/kg, 1 mg/kg, 5 mg/kg, 10 mg/kg, or 15 mg/kg). Psoriasis Area and Severity Index, Physician's Global Psoriasis Assessment, and Psoriasis Severity Scale scores improved in the highest-dose groups. Average plaque thickness and plaque CD3+ and CD8+ T-cell counts decreased in the 10 mg/kg dose group. Adverse events were primarily mild, transient, constitutional symptoms; the most common related events were mild asthenia (29% of patients), chills (25%), and headache (21%). The serum half-life of IDEC-114 was approximately 13 days. A single dose of IDEC-114 appears to be safe and well tolerated and has promising clinical activity in psoriasis.

Ibritumomab tiuxetan radioimmunotherapy for patients with relapsed or refractory non-Hodgkin lymphoma and mild thrombocytopenia: a phase II multicenter trial.

Mildly thrombocytopenic patients with relapsed or refractory low-grade non-Hodgkin lymphoma (NHL) have an increased risk of chemotherapy-induced myelosuppression following treatment. The safety and efficacy of radioimmunotherapy with a reduced dose of (90)Y ibritumomab tiuxetan (0.3 mCi/kg [11 MBq/kg]; maximum 32 mCi [1.2 GBq]) was evaluated in 30 patients with mild thrombocytopenia (100-149 x 10(9) platelets/L) who had advanced, relapsed or refractory, low-grade, follicular, or transformed B-cell NHL. The ibritumomab tiuxetan regimen included an infusion of rituximab (250 mg/m(2)) and injection of (111)In ibritumomab tiuxetan (5 mCi [185 MBq]) for dosimetry evaluation, followed 1 week later with rituximab (250 mg/m(2)) and (90)Y ibritumomab tiuxetan (0.3 mCi/kg [11 MBq/kg]). Patients (median age, 61 years; 90% stage III/IV at study entry; 83% follicular lymphoma; and 67% with bone marrow involvement) had a median of 2 prior therapy regimens (range, 1-9). Estimated radiation-absorbed doses were well below the study-defined maximum allowable for all 30 patients. With the use of the International Workshop criteria for NHL response assessment, the overall response rate was 83% (37% complete response, 6.7% complete response unconfirmed, and 40% partial response). Kaplan-Meier estimated median time to progression (TTP) was 9.4 months (range, 1.7-24.6). In responders, Kaplan-Meier estimated median TTP was 12.6 months (range, 4.9-24.6), with 35% of data censored. Toxicity was primarily hematologic, transient, and reversible. The incidence of grade 4 neutropenia, thrombocytopenia, and anemia was 33%, 13%, and 3%, respectively. Reduced-dose ibritumomab tiuxetan is safe and well tolerated and has significant clinical activity in this patient population.