Efficacy and toxicity of the antisense oligonucleotide aprinocarsen directed against protein kinase C-alpha delivered as a 21-day continuous intravenous infusion in patients with recurrent high-grade astrocytomas.

Protein kinase C alpha (PKC-alpha) is a cytoplasmic serine threonine kinase involved in regulating cell differentiation and proliferation. Aprinocarsen is an antisense oligonucleotide against PKC-alpha that reduces PKC-alphain human cell lines and inhibits a human glioblastoma tumor cell line in athymic mice. In this phase 2 study, aprinocarsen was administered to patients with recurrent high-grade gliomas by continuous intravenous infusion (2.0 mg/kg/day for 21 days per month). Twenty-one patients entered this trial. Their median age was 46 years (range, 28-68 years), median Karnofsky performance status was 80 (range, 60-100), median tumor volume was 58 cm3 (range, 16-254 cm3), and histology included glioblastoma multiforme (n = 16), anaplastic oligodendroglioma (n = 4), and anaplastic astrocytoma (n = 1). The number of prior chemotherapy regimens included none (n = 3), one (n = 10), and two (n = 8). No tumor responses were observed. Patients on this therapy rapidly developed symptoms of increased intracranial pressure with increased edema, enhancement, and mass effect on neuroimaging. The median time to progression was 36 days, and median survival was 3.4 months. The observed toxicities were mild, reversible, and uncommon (grade 3 thrombocytopenia [n = 3] and grade 4 AST [n = 1]), and no coagulopathy or CNS bleeding resulted from this therapy. Plasma concentrations of aprinocarsen during the infusion exhibited significant interpatient variability (mean = 1.06 mug/ml; range, 0.34-6.08 mug/ml). This is the first study to use an antisense oligonucleotide or a specific PKC-alpha inhibitor in patients with high-grade gliomas. No clinical benefit was seen. The rapid deterioration seen in these patients could result from tumor growth or an effect of aprinocarsen on bloodbrain barrier integrity.

Phase I clinical and pharmacokinetic study of protein kinase C-alpha antisense oligonucleotide ISIS 3521 administered in combination with 5-fluorouracil and leucovorin in patients with advanced cancer.

The present study was designed to determine the maximum tolerated dose (MTD), toxicity profile, pharmacokinetics (PKs), and antitumor activity of the protein kinase C-alpha antisense oligonucleotide ISIS 3521 (ISIS Pharmaceuticals, Inc., Carlsbad, CA) when administered in combination with 5-fluorouracil (5-FU) and leucovorin (LV). Patients with refractory solid tumors received ISIS 3521 as a 21-day continuous infusion administered simultaneously with 5-FU and LV given daily for 5 days repeated every 4-5 weeks (one cycle). 5-FU and ISIS 3521 PK analysis were performed on samples taken during the first cycle in all patients. Fifteen patients received ISIS 3521 at one of three dose levels: (a) 1.0 (n = 3 patients); (b) 1.5 (n = 3 patients); and (c) 2.0 (n = 9 patients) mg/kg/day. All patients simultaneously received 5-FU (425 mg/m(2)/day) and LV (20 mg/m(2)/day) for 5 consecutive days. Grade 1-2 toxicities included alopecia, fatigue, mucositis, diarrhea, anorexia, nausea/vomiting, and tumor pain. One patient had grade 3 chest pain considered to be related to 5-FU therapy, another patient had dose-limiting grade 3 mucositis resolving in <7 days, and one patient with a history of gastritis had an acute upper gastrointestinal bleed thought to be 5-FU-induced toxicity. Five patients developed cycle 1 grade 4 neutropenia, which resolved without colony-stimulating factors before the next treatment cycle. There were no effects on prothrombin time and activated partial thromboplastin time. A clinically defined MTD was not reached. The character and severity of these toxicities do not seem to be dose related, and, as such, there was no classical dose-limiting toxicity defining the MTD. ISIS 3521 PKs in the presence of 5-FU was consistent with those reported previously. 5-FU PK parameters were also similar in the presence or absence of ISIS 3521. Six of 14 patients ( approximately 43%) across all dose cohorts had an improvement in measurable tumor response ranging from minor reduction in tumor size (4 patients) to objective partial response (>50% reduction in tumor size, 2 patients). ISIS 3521 is tolerable at its recommended single-agent dose when given with 5-FU and LV. There is no apparent PK interaction between ISIS 3521 and 5-FU and LV. Antitumor activity was observed with the combination; however, it is uncertain whether clinical activity is a result of enhanced drug interaction. Our study warrants further exploration of efficacy in a Phase II and/or Phase III clinical trial setting.

A phase I trial of ISIS 2503, an antisense inhibitor of H-ras, in combination with gemcitabine in patients with advanced cancer.

PURPOSE: The purpose of this study was to define the toxicity, pharmacokinetics, and clinical activity of the combination of ISIS 2503, an oligodeoxynucleotide antisense inhibitor of H-ras, and gemcitabine in patients with advanced solid tumors. EXPERIMENTAL DESIGN: The target dose of ISIS 2503 on this study was 6 mg/kg/day. Twenty-seven patients (16 male, 11 female) received 97 treatment courses (median, 2; range, 1-13). Nineteen patients were treated with a fixed gemcitabine dose of 1000 mg/m(2) on days 1 and 8 and two escalating doses of ISIS 2503 (4 and 6 mg/kg/day) as a 14-day continuous infusion starting on day 1. In addition, 8 patients (5 male, 3 female) received a flat dose of ISIS 2503 based on ideal body weight. Cycles were repeated every 3 weeks. Toxicities, graded according to the National Cancer Institute Common Toxicity Criteria, were recorded as maximum grade/patient for all treatment cycles. Pharmacokinetic analyses were performed to evaluate any interaction between these two agents. RESULTS: The most common nondose-limiting toxicity was hematological, manifested as neutropenia (5 grade 2, 7 grade 3, and 1 grade 4) and thrombocytopenia (10 grade 1, 5 grade 2, 5 grade 3, and 1 grade 4). Nonhematological toxicities included anorexia (7 grade 1, 3 grade 2, and 1 grade 3), nausea (10 grade 1 and 1 grade 3), fatigue (6 grade 1, 5 grade 2, and 3 grade 3), fever (6 grade 1, 2 grade 2, 1 and grade 3), and thrombosis associated with central lines (5). The plasma concentration of gemcitabine at the end of infusion was altered in the presence of ISIS 2503, leading to alterations on other pharmacokinetic parameters, but the observed differences were not clinically relevant. The plasma disposition of ISIS 2503 was not altered by gemcitabine coadministration. One partial response was documented in a heavily pretreated patient with metastatic breast cancer. Disease stabilization for greater than six cycles of treatment was observed in 5 patients. CONCLUSIONS: The combination of gemcitabine and ISIS 2503 was well tolerated and clinically active in this group of heavily pretreated patients. The recommended Phase II dose of gemcitabine (1000 mg/m(2)) and ISIS 2503 (6 mg/kg/day) warrants additional evaluation.

Virological effects of ISIS 14803, an antisense oligonucleotide inhibitor of hepatitis C virus (HCV) internal ribosome entry site (IRES), on HCV IRES in chronic hepatitis C patients and examination of the potential role of primary and secondary HCV resistance in the outcome of treatment.

Antisense oligonucleotides represent a promising class of antiviral agents. ISIS 14803 is a 20-unit phosphorothioate oligodeoxynucleotide that inhibited hepatitis C virus (HCV) replication and protein expression in cell culture and mouse models. A Phase I dose-escalation clinical study of ISIS 14803 was performed in 24 patients with HCV genotype 1 chronic hepatitis C. The patients received 0.5, 1.0, 2.0 or 3.0 mg/kg of ISIS 14803 for 4 weeks. Two of them receiving 2.0 mg/kg, experienced a significant (>1.0 log10) viral load reduction and nine other patients experienced minor (<1.0 log10) viral load reductions that were difficult to definitively distinguish from assay or patient variations. The aims of this study were to examine the effect of ISIS 14803 on its target site and neighbouring region quasispecies evolution, and to determine whether primary and secondary HCV resistance contributed to the observed virological response rate. The HCV internal ribosome entry site (IRES), including the ISIS 14803 target site in virus specimens collected from patients at baseline and end-of-treatment, was sequenced. An extensive IRES quasispecies analysis was performed in 10 of the patients at various time points before, during and after ISIS 14803 treatment. A significant IRES genetic evolution was found in three out of 10 patients through quasispecies analysis suggesting that treatment with ISIS 14803, a drug designed to bind to HCV RNA, exerted a selective pressure on HCV IRES. However, no mutations in the ISIS 14803 target site, which would inhibit binding of the oligonucleotide to HCV RNA, were detected before (primary resistance) or after treatment (secondary resistance) with the oligonucleotide. Furthermore, no obvious nucleotide changes in the surrounding IRES region that might possibly affect oligonucleotide binding were detected.

A phase II trial of ISIS 3521 in patients with metastatic colorectal cancer.

This phase II study was designed to characterize the clinical activity of ISIS 3521 in patients with metastatic colorectal cancer (CRC). Sixteen patients with pretreated or refractory CRC were treated with ISIS 3521. Eleven patients were given a dose of 2.0 mg/kg per day, and 5 patients received 3.0 mg/kg per day given over 21 days followed by a 7-day rest period. Patients continued with study until evidence of disease progression or unacceptable toxicity was detected. Patients underwent baseline tumor biopsies followed by a second biopsy during the last week of the first 21-day infusion. All 16 patients underwent baseline tumor biopsies, and 12 of the 16 patients underwent on-study tumor biopsies. No evidence of tumor response was observed. One patient had stable disease after 2 cycles and remained on for 1 additional cycle only to demonstrate progression of disease at that time. No dose-limiting or other significant toxicities were observed at both dosages, which could not be explained by progression of disease. Fatigue was common in all patients treated but was not dose limiting, and there was no evidence of coagulopathy. Analysis of the tumor biopsies obtained from the 11 evaluable samples showed marked uptake of ISIS 3521 in the normal liver parenchyma. However, there was minimal uptake within the tumor cells. In addition, no evidence of any alteration in protein kinase C-a within the tumors or any downstream effects leading to apoptosis were observed. ISIS 3521 demonstrated no clinical activity or target modulation in refractory metastatic CRC.

A phase I trial of an antisense inhibitor of hepatitis C virus (ISIS 14803), administered to chronic hepatitis C patients.

BACKGROUND/AIMS: ISIS 14803 is a 20-unit antisense phosphorothioate oligodeoxynucleotide that binds to hepatitis C virus (HCV) RNA at the translation initiation region of the internal ribosome entry site (IRES) and inhibits protein expression in cell culture and mouse models. This Phase I, open-label, dose-escalation trial of ISIS 14803 was performed in chronic HCV patients. METHODS: At least 7 days after receiving an initial single dose, twenty-eight patients received 0.5-3 mg/kg ISIS 14803 thrice weekly for 4 weeks by intravenous infusion or subcutaneous injection. RESULTS: In most patients, the 4-week treatment did not reduce plasma HCV RNA. However, 3 patients receiving > or =2 mg/kg had transient HCV reductions of 1.2-1.7 log(10) that persisted < or =32 days. These reductions were accompanied by asymptomatic, self-resolving elevations in serum alanine transaminase (ALT) levels to >10x the upper limit of normal. Two other patients had ALT flares without plasma HCV reduction. No clinical signs, symptoms of hepatic dysfunction, or laboratory changes in albumin or prothrombin time accompanied ALT elevations. CONCLUSIONS: ISIS 14803 treatment was associated with HCV reductions in only 3/28 patients. ALT flares in 5 patients also occurred. Further studies to evaluate ISIS 14803 treatment and the mechanisms of the ALT flares are now required.

A phase I trial of aprinocarsen (ISIS 3521/LY900003), an antisense inhibitor of protein kinase C-alpha administered as a 24-hour weekly infusion schedule in patients with advanced cancer.

PURPOSE: A phase I study was performed to determine the maximum tolerated dose (MTD), safety profile and pharmacology of aprinocarsen (ISIS 3521), an antisense oligonucleotide to protein kinase C-alpha, in patients with refractory solid tumors. EXPERIMENTAL DESIGN: Fourteen patients were treated in sequential cohorts of aprinocarsen by 24-hour continuous infusion (CIV), weekly, at doses of 6, 12, 18 and 24 mg/kg. RESULTS: One grade 4 toxicity was observed, transient grade 4 neutropenia at 18 mg/kg. Grade 3 toxicities included neutropenia at 12 mg/kg, fever and hemorrhage at 18 mg/kg, and neutropenia, nausea, and chills at 24 mg/kg. Grade 2 toxicities included thrombocytopenia myalgias, chills, headache, fatigue, fever and nausea/vomiting. Mean prothrombin times and activated partial thromboplastin times (aPTT) increased by 10% and 29% from baseline (p = 0.006 and 0.005). Mean complement split products (Bb and C3a) increased 1.6-fold and 3.6-fold (from p = 0.014 and 0.004, respectively). These changes correlated with dose and were transient with recovery to baseline by day 7. Steady state plasma concentrations (Css) of aprinocarsen were achieved within four hours. Css better described changes in aPTT than dose. Clinical evidence of complement activation was not observed. CONCLUSIONS: In contrast to 21-day protracted infusion schedules, delivery of aprinocarsen over a 24-hour infusion schedule showed concentration-dependent effects on coagulation and complement, which are consistent with nonclinical toxicology studies performed in the phosphorothioate DNA antisense drug class. These coagulation and complement changes resulted in a maximum tolerated dose 24 mg/kg.

Phase I trial of ISIS 104838, a 2'-methoxyethyl modified antisense oligonucleotide targeting tumor necrosis factor-alpha.

ISIS 104838 is a 20-mer phosphorothioate antisense oligonucleotide (ASO) that binds tumor necrosis factor-alpha (TNF-alpha) mRNA. It carries a 2'-methoxyethyl modification on the five 3' and 5' nucleotide sugars, with 10 central unmodified deoxynucleotides. ISIS 104838 was identified from a 264 ASO screen in phorbol myristate acetate-activated keratinocytes, and the dose response was assessed in lipopolysaccharide (LPS)-activated monocytes. Healthy males received multiple intravenous (i.v.) ISIS 104838 infusions in a placebo-controlled dose escalation trial (0.1-6 mg/kg). Additional volunteers received single or multiple subcutaneous (s.c.) injections. ISIS 104838 suppressed TNF-alpha protein by 85% in stimulated keratinocytes. The IC50 for TNF-alpha mRNA inhibition in stimulated monocytes was <1 microM. For i.v., C(max) occurred at the end of infusion. The effective plasma half-life was 15 to 45 min at 0.1 to 0.5 mg/kg and 1 to 1.8 h for higher doses. The apparent terminal plasma elimination half-life approximated 25 days. Obese subjects had higher plasma levels following equivalent mg/kg doses. For s.c. injections, C(max) occurred at 2 to 4 h and was lower than with equivalent i.v. dosing. Plasma bioavailability compared with i.v. was 82% following a 200 mg/ml s.c. injection. Transient activated partial thromboplastin time prolongation occurred after i.v. infusions and minimally after s.c. injections. Two subjects experienced rash, one a reversible platelet decrease, and mild injection site tenderness was noted. TNF-alpha production by peripheral blood leukocytes, induced ex vivo by LPS, was decreased by ISIS 104838 (p < 0.01). ISIS 104838, a second-generation antisense oligonucleotide, was generally well tolerated intravenously and subcutaneously. The pharmacokinetics support an infrequent dosing interval. Inhibition of TNF-alpha production ex vivo was demonstrated.