The clinical effect of the dual-targeting strategy involving PI3K/AKT/mTOR and RAS/MEK/ERK pathways in patients with advanced cancer.

PURPOSE: This study evaluated the clinical relevance of the dual-targeting strategy involving PI3K/AKT/mTOR and RAF/MEK/ERK pathways. EXPERIMENTAL DESIGN: We investigated safety, efficacy, and correlations between tumor genetic alterations and clinical benefit in 236 patients with advanced cancers treated with phase I study drugs targeting phosphoinositide 3-kinase (PI3K) and/or mitogen-activated protein kinase (MAPK) pathways in our Phase I Clinical Trials Program. RESULTS: Seventy-six (32.2%) patients received a PI3K pathway inhibitor in combination with a MAPK pathway inhibitor (D), whereas 124 (52.5%) and 36 (15.3%), respectively, received an inhibitor of either the PI3K or MAPK pathways (S). The rates of drug-related grade >III adverse events were 18.1% for (S) and 53.9% for (D; P < 0.001); the rates of dose-limiting toxicities were 9.4% for (S) and 18.4% for (D; P = 0.06). The most frequent grade >III adverse events were transaminase elevations, skin rash, and mucositis. In our comprehensive tumor genomic analysis, of 9 patients who harbored coactivation of both pathways (colorectal cancer, n = 7; melanoma, n = 2), all 5 patients treated with (D) had tumor regression ranging from 2% to 64%. CONCLUSIONS: These results suggest that dual inhibition of both pathways may potentially exhibit favorable efficacy compared with inhibition of either pathway, at the expense of greater toxicity. Furthermore, this parallel pathway targeting strategy may be especially important in patients with coexisting PI3K pathway genetic alterations and KRAS or BRAF mutations and suggests that molecular profiling and matching patients with combinations of these targeted drugs will need to be investigated in depth.

Phase I, pharmacokinetic, and pharmacodynamic study of intravenously administered Ad5CMV-p53, an adenoviral vector containing the wild-type p53 gene, in patients with advanced cancer.

PURPOSE: The purpose of this study was to assess the feasibility of administering Ad5CMV-p53, an adenoviral vector containing the wild-type p53 gene to patients with advanced malignancies, characterize the pertinent pharmacokinetic parameters, identify evidence of viral uptake in both normal and tumor tissue, and seek evidence of antitumor activity. METHODS: Patients were treated with escalating doses of Ad5CMV-p53 intravenously over 30 minutes on days 1, 2, and 3, every 28 days. The clearance of circulating Ad5CMV-p53 (INGN 201) DNA was characterized in the plasma and paired tumor and skin biopsies were performed in patients treated at the two highest dose levels to assess vector uptake into tissues. RESULTS: Seventeen patients received 36 courses of Ad5CMV-p53 at doses ranging from 3 x 10(10) to 3 x 10(12) virus particles (vp). Fatigue, nausea, vomiting, and fever were common, but rarely severe. Abnormalities of coagulation parameters, including decreases in fibrinogen and increases in fibrin degradation products at 3 x 10(12)vp, precluded additional dose escalation. Ad5CMV-p53 DNA could be detected in the plasma by polymerase chain reaction assay in the majority of patients at 14 days and 28 days at doses of 3 x 10(10) and higher. Six patients treated at 1 x 10(12)vp and 3 x 10(12)vp dose levels had Ad5CMV-p53 DNA detected within paired tumor tissue collected day 4. CONCLUSION: Ad5CMV-p53 can be safely and repetitively administered up to 1 x 10(12)vp intravenously daily for 3 consecutive days. The absence of severe toxicities, the presence of circulating adenovirus 24 hours after administration, and detectable p53 transgene within tumor tissue distant from the site of administration demonstrates that systemic therapy with this adenoviral vector containing p53 is feasible.

A Phase I pharmacokinetic and biological correlative study of oblimersen sodium (genasense, g3139), an antisense oligonucleotide to the bcl-2 mRNA, and of docetaxel in patients with hormone-refractory prostate cancer.

PURPOSE: To assess the feasibility of administering oblimersen sodium, a phosphorothioate antisense oligonucleotide directed to the Bcl-2 mRNA, with docetaxel to patients with hormone-refractory prostate cancer; to characterize the pertinent pharmacokinetic parameters, Bcl-2 protein inhibition in peripheral blood mononuclear cell(s) (PBMC) and tumor; and to seek preliminary evidence of antitumor activity. EXPERIMENTAL DESIGN: Patients were treated with increasing doses of oblimersen sodium administered by continuous i.v. infusion on days 1 to 6 and docetaxel administered i.v. over 1 h on day 6 every 3 weeks. Plasma was sampled to characterize the pharmacokinetic parameters of both oblimersen and docetaxel, and Bcl-2 protein expression was measured from paired collections of PBMCs pretreatment and post-treatment. RESULTS: Twenty patients received 124 courses of the oblimersen and docetaxel combination at doses ranging from 5 to 7 mg/kg/day oblimersen and 60 to 100 mg/m(2) docetaxel. The rate of severe fatigue accompanied by severe neutropenia was unacceptably high at doses exceeding 7 mg/kg/day oblimersen and 75 mg/m(2) docetaxel. Nausea, vomiting, and fever were common, but rarely severe. Oblimersen mean steady-state concentrations were 3.44 +/- 1.31 and 5.32 +/- 2.34 at the 5- and 7-mg/kg dose levels, respectively. Prostate-specific antigen responses were observed in 7 of 12 taxane-naïve patients, but in taxane-refractory patients no responses were observed. Preliminary evaluation of Bcl-2 expression in diagnostic tumor specimens was not predictive of response to this therapy. CONCLUSIONS: The recommended Phase II doses for oblimersen and docetaxel on this schedule are 7 mg/kg/day continuous i.v. infusion days 1 to 6, and 75 mg/m(2) i.v. day 6, respectively, once every 3 weeks. The absence of severe toxicities at this recommended dose, evidence of Bcl-2 protein inhibition in PBMC and tumor tissue, and encouraging antitumor activity in HPRC patients warrant further clinical evaluation of this combination.

A phase I and pharmacokinetic study of ILX-295501, an oral diarylsulfonylurea, on a weekly for 3 weeks every 4-week schedule in patients with advanced solid malignancies.

PURPOSE: This study was conducted to assess the feasibility of administering the oral diarylsulfonylurea (DSU) ILX-295501 on a weekly for 3 weeks every 4-week schedule. The study also sought to determine the maximum tolerated dose (MTD) of ILX-295501 on this schedule, characterize its pharmacokinetic behavior, and seek preliminary evidence of anticancer activity. EXPERIMENTAL DESIGN: The initial starting dose of ILX-295501 was 100 mg/m(2), which was equivalent to one-sixth of the highest dose that did not induce irreversible toxicity in dogs, and, using a modified Fibonnaci search scheme to guide dose level selection, the following dose levels were evaluated: 100, 200, 400, 600, 900, 1350, and 1800 mg/m(2). Because severe toxicities were being reported in other trials at doses that encompassed this range and a cumulative toxicity profile was emerging, the study was suspended and then reinitiated to further reevaluate the lower dosing range. In the second part of the study, the following dose levels were selected a priori for evaluation: 400, 800, 1000, 1250, and 1500 mg/m(2); and a modified continual reassessment model was used for dose assignment to determine the MTD, which was defined a priori as the highest dose in which the incidence of dose-limiting toxicity in the first course did not exceed 20%. RESULTS: Forty-nine patients were treated with 142 courses of ILX-295501 at doses ranging from 100 to 1800 mg/m(2). The incidences of dose-limiting toxicity, principally neutropenia and thrombocytopenia, were unacceptably high at ILX-295501 doses exceeding 1000 mg/m(2), which was determined to be the MTD for both minimally pretreated and heavily pretreated (HP) patients. In contrast to the first generation of DSUs, particularly sulofenur, clinically relevant levels of oxidized hemoglobin (methemoglobin) and secondary hemolytic anemia, were not noted. One HP patient with non-small cell lung carcinoma experienced a partial response. Pharmacokinetic studies revealed that ILX-295501 was absorbed slowly, with peak plasma concentrations (C(max)) achieving 6.02 h, on average, after oral administration. The pharmacokinetic behavior of ILX-295501 was characterized by dose proportionality, a relatively small apparent volume of distribution at steady state (V(ss)/F), averaging 8.02 +/- 14.08 liters, and low apparent total body clearance (CL(t)/F) rate (mean, 0.036 +/- 0.116 liters/h). The initial drug distribution phase was rapid [harmonic mean half-life (t(1/2alpha)), 2.1 +/- 7.0 min], whereas the terminal elimination phase was slow (harmonic mean t(1/2beta,) 150.6 +/- 80.2 h). CONCLUSIONS: The recommended dose for Phase II studies of the oral DSU ILX-295501 administered weekly for 3 weeks every 4 weeks is 1000 mg/m(2)/day for both minimally pretreated and HP patients. The characteristics of the myelosuppressive effects of ILX-295501, the paucity of severe nonhematological toxicities, and preliminary antitumor activity warrant disease-directed evaluations of ILX-295501.

A Phase I and pharmocokinetic study of exatecan mesylate administered as a protracted 21-day infusion in patients with advanced solid malignancies.

PURPOSE: The purpose of this study was to assess the feasibility of administering exatecan, a water-soluble, potent camptothecin analogue, as a protracted 21-day continuous i.v. infusion (CIVI). The study also sought to determine the maximum tolerated dose (MTD) of exatecan on a 21-day CIVI schedule, characterize its pharmacokinetic behavior, and seek preliminary evidence of anticancer activity. EXPERIMENTAL DESIGN: Exatecan dose-schedule development was performed in two stages using the modified Continual Reassessment Method and single patient cohorts. First, patients with advanced solid malignancies were treated with exatecan (0.15 mg/m(2)/day) as a CIVI for 5 days, and the duration of the CIVI was incrementally increased from 5 to 21 days. In the second stage of the study, the dose was incrementally increased to derive a tolerable dose of exatecan administered as 21-day CIVI. The MTD was defined for both minimally pretreated (MP) and heavily pretreated (HP) patients as the highest dose level at which the incidence of dose-limiting toxicity does not exceed 20%. RESULTS: Thirty-one patients were treated with 100 courses of exatecan at 6 dose-schedule levels. The incidence of the principal dose-limiting toxicities, neutropenia and thrombocytopenia, was unacceptably high at exatecan doses exceeding 0.15 mg/m(2)/day as a 21-day CIVI, which was determined to be the MTD for both MP and HP patients. The pharmacokinetics of exatecan were dose-proportional, and mean [coefficient of variation (percentage) steady-state concentration (plasma concentration at steady-state)] values ranged from 6.88 (80.6) to 19.41 (74.2) ng/ml at exatecan dose levels ranging from 0.15 to 0.30 mg/m(2)/day, which are similar to IC(50) values against human tumor cell lines treated for shorter periods. Mean pharamacokinetic parameters for total exatecan derived from a compartmental model included clearance and volume of distribution values of 1.39 (86.9) liters/h/m(2) and 39.66 (197.4) liters, respectively. Two HP patients with non-small cell lung and unknown primary carcinomas had partial responses, and objective evidence of anticancer activity and clinical benefit were noted in several other individuals. CONCLUSIONS: The administration of exatecan as a 21-day CIVI at doses as high as 0.15 mg/m(2)/day is safe and feasible for both MP and HP patients. The characteristics of the myelosuppressive effects of exatecan on this schedule, the paucity of severe nonhematological toxicities, and documented anticancer activity in several drug-refractory malignancies warrant further evaluation of the merits of administering exatecan by either a CIVI or alternate drug delivery systems to achieve protracted systemic exposure.