Phase 2 study of pegylated liposomal doxorubicin in combination with interleukin-12 for AIDS-related Kaposi sarcoma.

Thirty-six patients with AIDS-associated Kaposi sarcoma (KS) requiring chemotherapy were treated for six 3-week cycles of pegylated liposomal doxorubicin (20 mg/m(2)) plus interleukin-12 (IL-12; 300 ng/kg subcutaneously twice weekly), followed by 500 ng/kg subcutaneous IL-12 twice weekly for up to 3 years. All received highly active antiretroviral therapy (HAART). Twenty-two had poor-prognosis KS (T(1)S(1)). Thirty patients had a major response, including 9 with complete response, yielding an 83.3% major response rate (95% confidence interval: 67.2%-93.6%). Median time to first response was 2 cycles. Median progression was not reached at median potential follow-up of 46.9 months. Of 27 patients with residual disease when starting maintenance IL-12, 15 had a new major response compared with this new baseline. The regimen was overall well tolerated; principal toxicities were neutropenia, anemia, transaminitis, and neuropsychiatric toxicity. Patients had increases in serum IL-12, interferon gamma, and inducible protein-10 (IP-10), and these remained increased at weeks 18 and 34. The regimen of IL-12 plus liposomal doxorubicin yielded rapid tumor responses and a high response rate in patients with AIDS-KS receiving HAART, and responses were sustained on IL-12 maintenance therapy. A randomized trial of IL-12 in this setting may be warranted. This study is registered at (http://www.clinicaltrials.gov) as no. NCT00020449.

Treatment of AIDS-related Kaposi's sarcoma with interleukin-12: rationale and preliminary evidence of clinical activity.

In this article, we review the preliminary evidence for the activity of interleukin-12 (IL-12) against Kaposi's sarcoma (KS) and discuss these results in the context of the biology of IL-12 and KS. IL-12 is a cytokine that enhances type 1 immunity, induces production of interferon gamma (IFN-gamma), and mediates antiangiogenic effects. In addition, it can downregulate a constitutively active G protein coupled receptor that is encoded by Kaposi's sarcoma-associated herpesvirus, the causative agent of KS. These factors suggested that IL-12 might be worth exploring as a potential anti-KS agent. In an initial phase I pilot study, IL-12 was found to have anti-KS activity when used alone in patients with AIDS-associated KS who were on a stable regimen of antiretroviral therapy. In preliminary results from a subsequent study of the combination of IL-12 plus liposomal doxorubicin along with highly active antiretroviral therapy, remissions were obtained in a substantial percentage of patients with advanced AIDS-associated KS. IL-12 has also been found active in patients with certain lymphomas. These results suggest that IL-12 may be worth exploring further as a potential antitumor agent in selected tumors.

Activity of subcutaneous interleukin-12 in AIDS-related Kaposi sarcoma.

Interleukin-12 (IL-12) enhances Th1-type T-cell responses and exerts antiangiogenic effects. We initiated a phase 1 pilot study of IL-12 in 32 patients with acquired immunodeficiency syndrome (AIDS)-related Kaposi sarcoma (KS) whose KS was progressing while on antiretroviral therapy. Fifteen patients had poor prognosis T(1)S(1) disease. IL-12 was administered subcutaneously twice weekly at doses from 100 to 625 ng/kg. The maximum tolerated dose was 500 ng/kg, and the principal toxicities were flulike symptoms, transaminase or bilirubin elevations, neutropenia, hemolytic anemia, and depression. No tumor responses were seen at the lowest dose (100 ng/kg), but 17 of 24 evaluable patients at the higher doses had partial or complete responses (response rate, 71%; 95% confidence interval, 48%-89%). Only 3 of 17 patients had a change in antiretroviral therapy before responding, and there were no significant differences between responders and nonresponders with regard to changes in CD4 counts or viral loads. Patients had increases in their serum IL-12, interferon-gamma, and inducible protein-10 (IP-10) after the first dose, and increases above baseline persisted after week 4. These results provide preliminary evidence that IL-12 has substantial activity against AIDS-related KS with acceptable toxicity and warrants further investigation for this indication.

Factors involved in the pharmacokinetics of COL-3, a matrix metalloproteinase inhibitor, in patients with refractory metastatic cancer: clinical and experimental studies.

COL-3 is an oral, lipophilic, tetracycline analog that has been administered to patients with metastatic cancer. Preliminary assessment of COL-3 in 35 patients with refractory metastatic carcinoma demonstrated apparent nonlinear pharmacokinetics with highly variable oral clearance (63.9% coefficient of variance [CV]). To elucidate possible sources of variability of COL-3 pharmacokinetics in vivo, in vitro plasma protein binding and in vitro metabolism were explored along with in vivo pharmacokinetics using compartmental modeling. The variability in the overall clearance and urinary excretion of COL-3 was also assessed. COL-3 had a long terminal half-life (median = 59.8 h), large apparent volume of distribution (median = 50.2 L), and low apparent clearance (median = 9.93 mL/min). Only adjusted ideal body weight decreased the variability in total apparent clearance. There was nonsaturable plasma protein binding of COL-3 (fu = 5.5%), with the majority of binding to albumin. The renal route of elimination is negligible, with 0.06% of unchanged COL-3 and 3.31% COL-3 glucuronide excreted in the first 6 days. COL-3 is not metabolized by phase I metabolism but does undergo glucuronidation in vitro by UGT1A1, UGT1A3, UGT1A9, and UGT2B7 and in vivo, as evidenced by COL-3 glucuronides in the urine (median = 13.6% of the total dose). COL-3 exhibits nonlinear pharmacokinetics, possibly due to dissolution rate-limited absorption.

Using positron emission tomography 2-deoxy-2-[18F]fluoro-D-glucose, 11CO, and 15O-water for monitoring androgen independent prostate cancer.

PURPOSE: Monitoring of androgen independent prostate cancer (AIPC) therapy involves monitoring prostate specific antigen (PSA) blood serum concentrations; however, the reliability of small changes in PSA values has been questioned. We performed a small pilot study to determine whether PET might be a useful monitor of changes during anti-angiogenic therapy in AIPC. PROCEDURES: Changes in tumor blood flow ([15O] water), blood volume ([11C]CO), 2-deoxy-2-[18F]fluoro-D-glucose (FDG) uptake and metabolic volume were measured before and during thalidomide treatment and compared with changes in PSA in six patients with AIPC. RESULTS: The percent change in PSA correlated with the FDG Delta%SUV(mean) (r=0.94, P<0.01) and Delta%metabolic tumor volume (r=0.91, P<0.01) but less well with Delta%blood volume (r=0.65, P=0.14). Percent change blood flow values showed an inverse correlation with percent changes in PSA (r=-0.83, P=0.032). CONCLUSIONS: PET measures of tumor blood flow and metabolism may have use in monitoring the physiologic changes occurring during anti-angiogenic therapy in AIPC.

A pilot study of cidofovir in patients with kaposi sarcoma.

A clinical trial was conducted to test the activity of cidofovir (CDV), a drug with in vitro activity against Kaposi sarcoma (KS)-associated herpesvirus (KSHV), in KS. Five patients with human immunodeficiency virus-associated KS (4 receiving antiretroviral therapy) and 2 patients with classical KS were administered CDV (5 mg/kg/dose) weekly for 2 weeks and then every other week. All 7 patients had progression of their KS at a median of 8.1 weeks (range, 5-27 weeks). Skin biopsy specimens of KS lesions showed no change in expression of latent or early lytic genes, but, in the 1 assessable patient, there was decreased expression of a late lytic gene. There was no decrease in the virus load of KSHV in peripheral blood mononuclear cells. This study does not provide proof of principle for the treatment of KS with CDV. However, it remains possible that antiherpesvirus therapy can be developed for herpes-induced tumors.

Matrix metalloproteinase inhibitor COL-3 in the treatment of AIDS-related Kaposi's sarcoma: a phase I AIDS malignancy consortium study.

PURPOSE: Matrix metalloproteinases (MMPs) are involved in tumor invasion and metastasis and are overexpressed in Kaposi's sarcoma (KS) cells. The primary aim was to define the safety and toxicity of the MMP inhibitor COL-3 in patients with AIDS-related KS. Secondary aims were to evaluate tumor response, pharmacokinetics, and changes in blood levels of MMP-2, MMP-9, vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF). PATIENTS AND METHODS: COL-3 was administered orally once daily, and doses were escalated in cohorts of three to six subjects. Patients with symptomatic visceral KS or severe tumor-associated edema were excluded. Antiretroviral therapy was permitted but not required. Study end points were grade 3 or 4 toxicity or progressive KS. Serial blood specimens were obtained for pharmacokinetics and levels of MMP-2, MMP-9, VEGF, and bFGF. RESULTS: Eighteen patients received COL-3 in dosing cohorts of 25, 50, and 70 mg/m(2)/d. Prior KS therapy was reported by 17 patients (94%). COL-3-related grade 3 or 4 adverse events were reported by six patients and included photosensitivity, rash, and headache. There was one complete response and seven partial responses, for an overall response rate of 44%, with a median response duration of 25+ weeks. The median COL-3 half-life was 39.3 hours (range, 4.1 to 251.1 hours). There was a significant difference between responders and nonresponders with respect to the change in MMP-2 serum levels from baseline to minimum value on treatment (P =.037). CONCLUSION: COL-3 administered orally once daily to patients with AIDS-related KS is reasonably well tolerated. The most common adverse event was dose-related photosensitivity. Antitumor activity was noted. Further evaluation of COL-3 for the treatment of KS is warranted.