ABSTRACT
The development and clinical testing of drug combinations for the treatment of Non-Hodgkin Lymphoma (NHL) and other cancers has recently shown great promise. However, determining the optimum combination and its associated dosages for maximum efficacy and minimum side effects is still a challenge. This paper describes a parametric analysis of the dynamics of malignant B-cells and the effects of an anti-sense oligonucleotide targeted to BCL-2 (as-bcl-2), anti-CD-20 (rituximab) and their combination, for a SCID mouse human lymphoma xenograft model of NHL. Our parametric model is straightforward. Several mechanisms of malignant B-cell birth and death in the nodal micro-environment are simulated. Cell death is accelerated by hypoxia and starvation induced by tumor scale, by modification of anti-apoptosis with as-bcl-2, and by direct kill effects of rituximab (cell kill by cytotoxic immune cells is not included, due to the absence of an immune system in the corresponding experiments). We show that the cell population dynamics in the control animals are primarily determined by K*, the ratio of rate constants for malignant cell death, K(d), and cell birth, K(b). Tumor growth with independent treatments is reproduced by the model, and is used to predict their effect when administered in combination. Malignant cell lifetimes are derived to provide a quantitative comparison of the efficacy of these treatments. Future experimental and clinical applications of the model are discussed.
Subject(s)
Antibodies, Monoclonal/administration & dosage , Antineoplastic Agents/administration & dosage , Lymphoma, Non-Hodgkin/drug therapy , Models, Biological , Oligonucleotides/administration & dosage , Animals , Combined Modality Therapy , Disease Models, Animal , Drug Therapy, Combination , Humans , Lymphoma, Non-Hodgkin/diagnosis , Mice , Xenograft Model Antitumor AssaysABSTRACT
PURPOSE: We conducted a Phase II trial of bryostatin-1, an inhibitor of protein kinase C, in advanced renal cell carcinoma to measure toxicity, response rate, time to progression, and induction of cytokines. EXPERIMENTAL DESIGN: A total of 32 patients (26 male and 6 female) received bryostatin-1 at 35-40 microg/m(2) i.v. over 1 h on days 1, 8, and 15 of each 4-week cycle. Plasma interleukin-6, tumor necrosis factor-alpha, and C-reactive protein levels were assayed pretreatment, 1 and 23 h after completion of bryostatin-1 infusion at weeks 1 and 5. RESULTS: Cycles (102) of bryostatin-1 were given (median 2, range 1-8). The most common grade 1 or 2 toxicities were myalgias (46.8%), fatigue (59.3%), and dyspnea (18.8%). Grade 3-4 toxicity included myalgias (40.6%), ataxia (9.3%), and dyspnea (15.6%). Four (12%) patients experienced cardiac events while on study (cardiac arrhythmias and congestive heart failure occurred in 2 patients, and 2 patients had fatal cardiac arrests). Of 32 patients evaluable for response, 2 (6.3%) had partial responses lasting 9 with 6 months. A total of 15 patients (46.8%) had stable disease, and 6 (18.8%) patients had stable disease for >or=6 months. Plasma interleukin-6 increased >or=2-fold over baseline measurements in 5 of 17 patients (29.4%) but did not correlate with response or toxicity. CONCLUSIONS: Although weekly bryostatin-1 at 35-40 microg/m(2) produced a low proportion of objective responses, prolonged (>6 months) stable disease or partial remission in 25% of patients suggests that this agent, or other inhibitors of protein kinase C, may have a role in the treatment of renal cell carcinoma, perhaps in combination with other agents.
