Klaus Mross

Phase II Study of Temsirolimus (CCI-779), a Novel Inhibitor of mTOR, in Heavily Pretreated Patients With Locally Advanced or Metastatic Breast Cancer

PURPOSE In this study, two doses of temsirolimus (CCI-779), a novel inhibitor of the mammalian target of rapamycin, were evaluated for efficacy, safety, and pharmacokinetics in patients with locally advanced or metastatic breast cancer who had been heavily pretreated. PATIENTS AND METHODS Patients (n = 109) were randomly assigned to receive 75 or 250 mg of temsirolimus weekly as a 30-minute intravenous infusion. Patients were evaluated for tumor response, time to tumor progression, adverse events, and pharmacokinetics of temsirolimus. RESULTS Temsirolimus produced an objective response rate of 9.2% (10 partial responses) in the intent-to-treat population. Median time to tumor progression was 12.0 weeks. Efficacy was similar for both dose levels but toxicity was more common with the higher dose level, especially grade 3 or 4 depression (10% of patients at the 250-mg dose level, 0% at the 75-mg dose level). The most common temsirolimus-related adverse events of all grades were mucositis (70%), maculopapular rash (51%), and nausea (43%). The most common, clinically important grade 3 or 4 adverse events were mucositis (9%), leukopenia (7%), hyperglycemia (7%), somnolence (6%), thrombocytopenia (5%), and depression (5%). CONCLUSION In heavily pretreated patients with locally advanced or metastatic breast cancer, 75 and 250 mg temsirolimus showed antitumor activity and 75 mg temsirolimus showed a generally tolerable safety profile.

Phase I Clinical Study of AZD2171, an Oral Vascular Endothelial Growth Factor Signaling Inhibitor, in Patients With Advanced Solid Tumors

PURPOSE AZD2171 is a highly potent oral selective inhibitor of vascular endothelial growth factor (VEGF) signaling. This phase I study was designed to evaluate the safety and tolerability of increasing doses of AZD2171, with additional assessments of pharmacokinetics, pharmacodynamics, and efficacy. PATIENTS AND METHODS In part A, 36 patients with solid tumors and liver metastases refractory to standard therapies received once-daily oral AZD2171 (0.5 to 60 mg). Doses were escalated in successive cohorts until the maximum-tolerated dose was identified. In part B, patients with (n = 36) or without (n = 11) liver metastases were randomly assigned to receive once-daily AZD2171 (20, 30, or 45 mg). In both parts, treatment continued until tumor progression or dose-limiting toxicity (DLT) was observed. RESULTS Eighty-three patients received AZD2171, which was generally well tolerated at doses of 45 mg/d or less; the most frequently reported dose-related adverse events were diarrhea, dysphonia, and hypertension. The most common DLT was hypertension (n = 7), which occurred at AZD2171 doses of 20 mg and higher. After a single dose, maximum plasma (peak) drug concentration after single-dose administration (Cmax) was achieved 1 to 8 hours postdosing with an arithmetic mean half-life associated with terminal slope of a semilogarithmic concentration-time curve (t1/2 lamda(z)) of 22 hours. Pharmacodynamic assessments demonstrated time-, dose-, and exposure-related decreases in initial area under the curve, defined over 60 seconds post-contrast arrival in the tissue (iAUC60) using dynamic contrast-enhanced magnetic resonance imaging, as well as dose- and time-dependent reductions in soluble VEGF receptor 2 levels. Preliminary evidence of efficacy included two confirmed partial responses and 22 patients with stable disease; effects on tumor size appeared to be dose related. CONCLUSION Once-daily oral AZD2171 at doses of 45 mg or less was generally well tolerated and was associated with encouraging antitumor activity in patients with a broad range of advanced solid tumors.

A Phase I Dose–Escalation Study of Regorafenib (BAY 73–4506), an Inhibitor of Oncogenic, Angiogenic, and Stromal Kinases, in Patients with Advanced Solid Tumors

Purpose: Regorafenib is a novel oral multikinase inhibitor of angiogenic (VEGFR1-3, TIE2), stromal (PDGFR-β, FGFR), and oncogenic kinases (KIT, RET, and RAF). This first-in-man, phase I dose–escalation study assessed the safety, pharmacokinetic, pharmacodynamic, and efficacy profiles of regorafenib in patients with advanced solid tumors. Patients and Methods: Patients aged 18 years or older with advanced solid tumors refractory to standard treatment were recruited. Regorafenib was administered orally for 21 days on/seven days off in repeating cycles, until discontinuation due to toxicity or tumor progression. Adverse events (AE) were assessed using National Cancer Institute Common Terminology Criteria for Adverse Events v3.0. Pharmacokinetic profiles were measured after a single dose and on day 21. Pharmacodynamic and efficacy evaluations included tumor perfusion assessment using dynamic contrast-enhanced MRI, plasma cytokines, and tumor response using RECIST (v1.0). Results: Fifty-three patients were enrolled into eight cohorts at dose levels from 10 to 220 mg daily. The recommended dose for future studies was determined to be 160 mg daily, with a treatment schedule of 21 days on/seven days off in repeating 28-day cycles. The most common drug-related grade 3 or 4 AEs were dermatologic AEs (hand–foot skin reaction, rash), hypertension, and diarrhea. Pharmacokinetic analysis revealed a similar exposure at steady state for the parent compound and two pharmacologically active metabolites. Tumor perfusion and plasma cytokine analysis showed biologic activity of regorafenib. Three of 47 evaluable patients achieved a partial response (renal cell carcinoma, colorectal carcinoma, and osteosarcoma). Conclusion: Regorafenib showed an acceptable safety profile and preliminary evidence of antitumor activity in patients with solid tumors. Clin Cancer Res; 18(9); 2658–67. ©2012 AACR.

Phase II Clinical Trial of Titanocene Dichloride in Patients with Metastatic Breast Cancer

Background: Titanocene dichloride (MKT4) is a recently developed cytostatic agent that shows preclinical activity against human breast cancer xenograft models in nude mice. A phase II trial was conducted to evaluate the clinical activity of this inorganic early-transition metal complex in patients with metastatic breast cancer. Patients and Methods: Fifteen patients were enrolled into this multicenter phase II trial. Twelve patients with a median age of 58 years were eligible for toxicity and response. All 12 patients had prior surgery and metastatic disease at study entry. Seven patients had prior radiotherapy, 9 patients had prior hormone therapy, and 8 patients had prior adjuvant chemotherapy. No previous chemotherapy for metastatic disease was allowed. Titanocene dichloride was intravenously administered at a dose of 270 mg/m2 every 3 weeks. Results: Among the 12 eligible patients evaluable for response, no objective remission was observed. Two patients (17%) showed a ‘minor remission’, and 5 patients (42%) experienced a ‘no change’ situation of their disease. Moderate to severe drug-related toxicities (CTC grade II–III) affecting the gastrointestinal, neurological, hepatic and renal system occurred in the majority of patients. Therefore, in 5 patients the dose had to be reduced to 240 mg/m2. Conclusion: MKT4, given at a dose of 240–270 mg/m2 in this schedule, was not effective in patients with metastatic breast cancer. The tolerability of the 3-weekly dosing regimen was acceptable when the MKT4 dose was reduced to 240 mg/m2.

Association of CYP2C8, CYP3A4, CYP3A5, and ABCB1 Polymorphisms with the Pharmacokinetics of Paclitaxel

Purpose: To retrospectively evaluate the effects of six known allelic variants in the CYP2C8, CYP3A4, CYP3A5, and ABCB1 genes on the pharmacokinetics of the anticancer agent paclitaxel (Taxol). Experimental Design: A cohort of 97 Caucasian patients with cancer (median age, 57 years) received paclitaxel as an i.v. infusion (dose range, 80-225 mg/m2). Genomic DNA was analyzed using PCR RFLP or using Pyrosequencing. Pharmacokinetic variables for unbound paclitaxel were estimated using nonlinear mixed effect modeling. The effects of genotypes on typical value of clearance were evaluated with the likelihood ratio test within NONMEM. In addition, relations between genotype and individual pharmacokinetic variable estimates were evaluated with one-way ANOVA. Results: The allele frequencies for the CYP2C8*2, CYP2C8*3, CYP2C8*4, CYP3A4*3, CYP3A5*3C, and ABCB1 3435C>T variants were 0.7%, 9.2%, 2.1%, 0.5%, 93.2%, and 47.1%, respectively, and all were in Hardy-Weinberg equilibrium. The population typical value of clearance of unbound paclitaxel was 301 L/h (individual clearance range, 83.7-1055 L/h). The CYP2C8 or CYP3A4/5 genotypes were not statistically significantly associated with unbound clearance of paclitaxel. Likewise, no statistically significant association was observed between the ABCB1 3435C>T variant and any of the studied pharmacokinetic variables. Conclusions: This study indicates that the presently evaluated variant alleles in the CYP2C8, CYP3A4, CYP3A5, and ABCB1 genes do not explain the substantial interindividual variability in paclitaxel pharmacokinetics.

Phase I Dose Escalation and Pharmacokinetic Study of BI 2536, a Novel Polo-Like Kinase 1 Inhibitor, in Patients With Advanced Solid Tumors

PURPOSE BI 2536 is a novel, potent, and highly specific inhibitor of polo-like kinase 1 (Plk1), which has an essential role in the regulation of mitotic progression. The aim of this trial was to identify the maximum tolerated dose (MTD) of BI 2536 and to determine the safety, pharmacokinetics, and antitumor activity in patients who had advanced solid tumors. PATIENTS AND METHODS This phase I trial followed an open label, toxicity-guided, dose-titration design. Single doses of BI 2536 (25 to 250 mg) were administered as a 1-hour intravenous infusion; patients who experienced clinical benefit were eligible for additional treatment courses. Safety and pharmacokinetics were investigated. Tumor response was evaluated according to Response Evaluation Criteria in Solid Tumors Group guidelines. RESULTS The MTD was defined at 200 mg in a total of 40 patients entered; reversible neutropenia constituted the dose-limiting toxicity (DLT) and the most frequent adverse event at the MTD (grade 3 to 4; 56%). Nausea (52%), fatigue (52%), and anorexia (44%) also were common and were mostly of mild to moderate intensity (Common Terminology Criteria of Adverse Events <or= grade 2). One patient experienced a transient partial response. At doses equal to or greater than the MTD, 23% of patients experienced disease stabilization for 3 or more months. Dose-proportional increases in the maximum plasma concentration and total exposure were observed. BI 2536 showed a high total clearance and high distribution into tissue. CONCLUSION The MTD of BI 2536 when administered as a single-dose, 1-hour infusion was 200 mg; BI 2536 was well tolerated and showed a favorable pharmacokinetic profile. Antitumor activity of BI 2536 was observed.

Phase I study of the angiogenesis inhibitor BIBF 1120 in patients with advanced solid tumors.

Purpose: BIBF 1120 is an oral, potent angiokinase inhibitor targeting receptors of the vascular endothelial growth factors, platelet-derived growth factors, and fibroblast growth factors. This phase I, accelerated titration study assessed the maximum tolerated dose, safety, pharmacokinetics, and pharmacodynamic effects of BIBF 1120. Patients and Methods: Sixty-one patients with advanced cancers received BIBF 1120 in successive cohorts. Twenty-five received 50 to 450 mg once daily and 36 received 150 to 300 mg twice daily in 4-week treatment courses interspersed by 1 week of washout. Dynamic contrast-enhanced magnetic resonance imaging assessed antiangiogenic effect in 42 patients. Results: Most frequent BIBF 1120–related adverse events were mostly mild to moderate (Common Toxicity Criteria grade 1-2) nausea (68.9%), vomiting (45.9%), and diarrhea (44.3%). The majority of dose-limiting adverse events of Common Toxicity Criteria grade 3 or 4 were reversible liver enzyme elevations. The maximum tolerated dose was 250 mg of BIBF 1120 for once and twice daily dosing. BIBF 1120 was absorbed moderately fast (tmax = 1-3 hours at steady state), with no deviation from dose linearity and no decrease of exposure over time. The gMean terminal half-life was from 13 to 19 hours. One complete and two partial responses occurred in patients with renal cell cancer (n = 2) and colorectal cancer (n = 1). Dynamic contrast-enhanced magnetic resonance imaging showed a significant reduction in tumor blood flow in 55% of evaluable patients. Conclusions: BIBF 1120 dosed continuously displayed a favorable safety and pharmacokinetics profile, and first efficacy signals were observed. Twice daily dosing permitted increased drug exposure without additional toxicity. Two hundred milligrams BIBF 1120 twice daily is the recommended dose for phase II monotherapy studies. Clin Cancer Res; 16(1); 311–9

Variants in the SLCO1B3 gene: Interethnic distribution and association with paclitaxel pharmacokinetics

To explore retrospectively the relationships between paclitaxel pharmacokinetics and three known, non‐synonymous single‐nucleotide polymorphisms (SNPs) in SLCO1B3, the gene encoding organic anion transporting polypeptide (OATP)1B3. Accumulation of [3H]paclitaxel was studied in Xenopus laevis oocytes injected with cRNA of Oatp1b2, OATP1A2, OATP1B1, OATP1B3, OAT1, OAT3, OCT1, and NTCP. The 334T>G (Ser112Ala), 699G>A (Met233Ile), and 1564G>T (Gly522Cys) loci of SLCO1B3 were screened in 475 individuals from five ethnic groups and 90 European Caucasian cancer patients treated with paclitaxel. Only OATP1B3 was capable of transporting paclitaxel to a significant extent (P=0.003). The 334T>G and 699G>A SNPs were less common in the African‐American and Ghanaian populations (P<0.000001). Paclitaxel pharmacokinetics were not associated with the studied SNPs or haplotypes (P>0.3). The studied SNPs in SLCO1B3 appear to play a limited role in the disposition of paclitaxel, although their clinical significance in other ethnic populations remains to be investigated.

Association of Paclitaxel pharmacokinetics with the development of peripheral neuropathy in patients with advanced cancer.

Purpose: The shortening of infusion time from 3 to 1 hour decreases the systemic exposure (area under the curve, AUC) of total and unbound paclitaxel but increases the AUC of its vehicle Cremophor EL, whereas the time above total paclitaxel concentrations of 0.05 μmol/L (T>0.05) remains almost constant. As both Cremophor EL and paclitaxel are neurotoxic, we evaluated their pharmacodynamic effects on the development of peripheral neuropathy as the most important nonhematologic toxicity. Experimental Design: Patients with advanced cancer of different origin were randomized to receive a maximum of 12 weekly-given 1- or 3-hour infusions of 100 mg/m2 paclitaxel (Taxol). Twenty-four patients were assessable for both pharmacokinetics and peripheral neuropathy development evaluated by a clinical scoring system including sensory symptoms, strength, tendon reflexes, and vibratory sense. Results: Patients with peripheral neuropathy development (n = 14) received more weeks of therapy (P = 0.056) and showed significantly higher T>0.05 (P = 0.022) and overall systemic drug exposures (weeks of therapy × AUC) for total paclitaxel (P = 0.002) and unbound paclitaxel (P = 0.003) than those without peripheral neuropathy. In Kaplan-Meier analyses, T>0.05 ≥ 10.6 hours (P = 0.023), AUC of total paclitaxel ≥ 4.7 μg/mL × hour (P = 0.047), and AUC of unbound paclitaxel ≥ 0.375 μg/mL × hour (P = 0.095) were identified as being potential factors for peripheral neuropathy development. In a Cox regression analysis, only T>0.05 ≥ 10.6 hours remained as an independent risk factor (relative risk, 18.43; P = 0.036) after adjusting for prior vincamycin (relative risk, 11.28; P = 0.038). Conclusions: From the results obtained in this study, it is concluded that exposure to paclitaxel but not Cremophor EL is associated with peripheral neuropathy development.

Regression of cutaneous tumor lesions in patients intratumorally injected with a recombinant single-chain antibody-toxin targeted to ErbB2/HER2

ScFv(FRP5)-ETA is a recombinant single-chain antibody-toxin with binding specificity for ErbB2/HER2. Previously potent antitumoral activity of the molecule against ErbB2 overexpressing tumor cells was demonstrated in vitro and in animal models. Here we report on the first application of scFv(FRP5)-ETA in human cancer patients summarizing case reports collected in four different clinical centers. Eleven patients suffering from metastatic breast and colorectal cancers and from malignant melanoma were treated on a compassionate-use basis by intratumoral injection of scFv(FRP5)-ETA into cutaneous lesions once daily for 7–10 days. Total daily doses ranged from 60 to 900 µg, and total doses per treatment cycle ranged from 0.6 to 6.0 mg. Treatment caused injected tumors to shrink in six of the 10 cases evaluated (60%). Complete regression of injected tumor nodules was accomplished in four patients (40%) and partial reduction in tumor size in another two patients (20%). Adverse reactions were restricted to local symptoms such as pain and inflammation at injection sites which were fully reversible. Only in one patient treated at the highest daily doses systemic liver toxicity of grade 2 was observed and treatment was discontinued on day 7. No hematologic, renal, and/or cardiovascular toxicities were noted. Our results demonstrate that local therapy with scFv(FRP5)-ETA can be effective against ErbB2 expressing tumors justifying further clinical development of this reagent.