A phase I and pharmacokinetic study of oral perifosine with different loading schedules in patients with refractory neoplasms.

PURPOSE: To determine the maximum tolerated dose (MTD) of perifosine (NSC 639966), an alkylphospholipid modulator of signal transduction, using different oral loading and maintenance regimens in an effort to avoid gastrointestinal toxicity while seeking maximal sustained plasma concentrations. METHODS: Thirty-one patients with advanced neoplasms were treated with monthly cycles of perifosine loading doses of 300, 600, 900, 1,200 and 1,500 mg (dose levels 1 through 5, respectively) on days 1-2 depending on the actual dose of the initial cycle. For subsequent cycles, perifosine loading doses were reduced to 100, 200, 300, 400 and 1,000 mg at the respective corresponding dose levels. Daily perifosine "maintenance" doses of 50, 100, 150, 200 and 250 mg for levels 1 through 5, respectively, commenced on days 2 or 3 and continued for a total of 21 days. No treatment was given for days 22-27. The pharmacokinetics of perifosine with these schedules was characterized. RESULTS: Dose-limiting diarrhea developed at or above dose level 4. The MTD and recommended phase II dose was dose level 3B, with a loading dose of 900 mg on day 1 divided into two doses of 450 mg administered 6 h apart and a maintenance dose of 150 mg on day 2 through 21. On subsequent cycles, the loading dose was reduced to 300 mg. Non-gastrointestinal toxicities included three episodes of gout or gout-like syndromes observed at doses above the MTD. The median peak plasma concentration of perifosine achieved at the MTD was approximately 8.3 µg/mL. Four patients had stable disease ranging from 167 to 735 days. CONCLUSIONS: Perifosine given according to a loading and maintenance schedule can safely sustain concentrations of drug, approaching concentrations achieved in preclinical models with evidence of anti-tumor effect.

Under-representation of racial minorities in prostate cancer studies submitted to the US Food and Drug Administration to support potential marketing approval, 1993-2013.

BACKGROUND: US Food and Drug Administration (FDA) approval of new drugs depends on results from clinical trials that must be generalized to the US population. However, racial minorities are frequently under-represented in clinical studies. The enrollment of racial minorities was compared in key clinical studies submitted to the FDA in the last 10 years in support of potential marketing approval for prostate cancer (PCa) prevention or treatment. METHODS: Patient demographic data were obtained from archival data sets of large registration trials submitted to the FDA to support proposed PCa indications. Six countries/regions were analyzed: the United States, Canada, Australia, Europe, the United Kingdom, and Eastern Europe. Background racial demographics were collected from national census data. RESULTS: Seventeen key PCa clinical trials were analyzed. These trials were conducted in the past 20 years, comprising 39,574 patients with known racial information. Most patients were enrolled in the United States, but there appeared to be a trend toward increased non-US enrollment over time. In all countries, racial minorities were generally under-represented. There was no significant improvement in racial minority enrollment over time. The United States enrolled the largest nonwhite population (7.1%). CONCLUSIONS: Over the past 20 years, racial minorities were consistently under-represented in key PCa trials. There is a need for effective measures that will improve enrollment of racial minorities. With increased global enrollment, drug developers should aim to recruit a patient population that resembles the racial demographics of the patient population to which drug use will be generalized upon approval.

U.S. Food and Drug Administration approval summary: Erlotinib for the first-line treatment of metastatic non-small cell lung cancer with epidermal growth factor receptor exon 19 deletions or exon 21 (L858R) substitution mutations.

On May 14, 2013, the U.S. Food and Drug Administration approved erlotinib (Tarceva, Astellas Pharma Inc., Northbrook, IL, http://www.us.astellas.com/) for the first-line treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors have epidermal growth factor receptor (EGFR) exon 19 deletions or exon 21 (L858R) substitution mutations. This indication for erlotinib was approved concurrently with the cobas EGFR Mutation Test (Roche Molecular Systems, Inc., Basel, Switzerland, http://www.molecular.roche.com), a companion diagnostic test for patient selection. The approval was based on clinically important improvements in progression-free survival (PFS) and objective response rate (ORR) and an acceptable toxicity profile demonstrated in a multicenter, open label trial enrolling 174 patients with metastatic NSCLC whose tumors had EGFR mutations as determined by a laboratory-developed test. Patients were randomized (1:1) to receive erlotinib (150 mg/day) or platinum-based doublet chemotherapy. The primary endpoint was investigator-assessed PFS. Secondary endpoints included overall survival (OS) and ORR. Superior PFS (hazard ratio [HR] 0.34; 95% confidence interval [CI]: 0.23, 0.49; p < .001) and ORR (65% vs. 16%) were observed in the erlotinib arm. Median PFS was 10.4 months and 5.2 months in the erlotinib and chemotherapy arms, respectively. There was no difference in OS (HR 0.93; 95% CI: 0.64, 1.35) with median OS of 22.9 months and 19.5 months in the erlotinib and chemotherapy arms, respectively. The most frequent (≥30%) adverse reactions in the erlotinib-treated patients were rash, diarrhea, asthenia, cough, dyspnea, and decreased appetite. The most frequent (≥5%) grade 3 and 4 adverse reactions were rash and diarrhea.

Pharmacogenetically driven patient selection for a first-in-human phase I trial of batracylin in patients with advanced solid tumors and lymphomas.

PURPOSE: Batracylin (daniquidone), an ATP-insensitive topoisomerase I/II inhibitor, demonstrated wide interspecies variation in preclinical models consistent with formation of a toxic metabolite, N-acetyl-batracylin, following metabolism by N-acetyl-transferase 2 (NAT2). To minimize exposure to this toxic metabolite, this first-in-human study was conducted in patients with advanced refractory solid tumors or lymphomas demonstrated to have a slow NAT2 acetylator genotype. The objectives were to determine the safety, maximum tolerated dose (MTD), and pharmacokinetics of batracylin and its metabolites. METHODS: Based on the MTD for rats, the most sensitive species, the starting dose was 5 mg/day for 7 days in 28-day cycles. Dose escalation followed accelerated titration design 4B, with restaging performed every 2 cycles. RESULTS: Thirty-one patients were enrolled. Treatment was well tolerated; one patient experienced grade 3 toxicity (lymphopenia). Dose escalation was stopped at 400 mg/day due to grade 1 and 2 hemorrhagic cystitis. No objective responses were observed, but prolonged disease stabilization was observed in 2 patients, one with peritoneal mesothelioma (8 cycles) and another with adrenocortical cancer (18 cycles). Across an 80-fold range of doses, the ratios of systemic exposures for batracylin and N-acetyl batracylin were near 1. CONCLUSIONS: Pharmacogenetically selected patients reached a dose that was 20-fold higher than the MTD in rats and 70 % of the MTD in mice. This genotype-guided strategy was successful in safely delivering batracylin to patients. However, due to unexpected cystitis, not preventable by hydration, and in the absence of a stronger signal for antitumor activity, further development of batracylin has been stopped.

Assessment of audit methodologies for bias evaluation of tumor progression in oncology clinical trials.

As progression-free survival (PFS) has become increasingly used as the primary endpoint in oncology phase III trials, the U.S. Food and Drug Administration (FDA) has generally required a complete-case blinded independent central review (BICR) of PFS to assess and reduce potential bias in the investigator or local site evaluation. However, recent publications and FDA analyses have shown a high correlation between local site evaluation and BICR assessments of the PFS treatment effect, which questions whether complete-case BICR is necessary. One potential alternative is to use BICR as an audit tool to detect evaluation bias in the local site evaluation. In this article, the performance characteristics of two audit methods proposed in the literature are evaluated on 26 prospective, randomized phase III registration trials in nonhematologic malignancies. The results support that a BICR audit to assess potential bias in the local site evaluation is a feasible approach. However, implementation and logistical challenges need further consideration and discussion.

FDA approval summary: sunitinib for the treatment of progressive well-differentiated locally advanced or metastatic pancreatic neuroendocrine tumors.

On May 20, 2011, the U.S. Food and Drug Administration (FDA) approved sunitinib malate capsules (Sutent®; Pfizer, Inc., New York) for the treatment of progressive, well-differentiated pancreatic neuroendocrine tumors (pNETs) in patients with unresectable locally advanced or metastatic disease. In a phase III randomized trial, 171 patients received either sunitinib (37.5 mg) or placebo once daily. The progression-free survival (PFS) interval was the primary efficacy endpoint. Secondary endpoints included the overall survival (OS) time, objective response rate (ORR), patient-reported outcomes, and safety. Based on early results favoring sunitinib, the independent data monitoring committee recommended trial termination prior to the prespecified interim analysis. This premature analysis may have led to an overestimate of the treatment effect. In the FDA analysis of investigator-assessed PFS times, the median values for the sunitinib and placebo arms were 10.2 months and 5.4 months, respectively. The ORRs were 9.3% and 0% in the sunitinib and placebo arms, respectively. The OS data were not mature at the time of approval and were confounded by 69% crossover. Common adverse reactions in patients receiving sunitinib included diarrhea, nausea, asthenia, fatigue, neutropenia, hypertension, and palmar-plantar erythrodysesthesia syndrome. Two patients on sunitinib died as a result of cardiac failure. The Oncologic Drugs Advisory Committee voted eight to two that, despite residual uncertainty about the magnitude of the PFS effect because of early trial termination, sunitinib demonstrated a favorable benefit-risk profile in pNET patients. The FDA concurred with the committee's assessment and granted sunitinib regular approval for this rare malignancy with few available therapies.

Vandetanib for the treatment of symptomatic or progressive medullary thyroid cancer in patients with unresectable locally advanced or metastatic disease: U.S. Food and Drug Administration drug approval summary.

On April 6, 2011, the U.S. Food and Drug Administration approved vandetanib (Caprelsa tablets; AstraZeneca Pharmaceuticals LP) for the treatment of symptomatic or progressive medullary thyroid cancer in patients with unresectable, locally advanced, or metastatic disease. Vandetanib is the first drug approved for this indication, and this article focuses on the basis of approval. Approval was based on the results of a double-blind trial conducted in patients with medullary thyroid carcinoma. Patients were randomized 2:1 to vandetanib, 300 mg/d orally (n = 231), or to placebo (n = 100). The primary objective was demonstration of improvement in progression-free survival (PFS) with vandetanib compared with placebo. Other endpoints included evaluation of overall survival and objective response rate. The PFS analysis showed a marked improvement for patients randomized to vandetanib (hazard ratio = 0.35; 95% confidence interval, 0.24-0.53; P < 0.0001). The objective response rate for the vandetanib arm was 44% compared with 1% for the placebo arm. The most common grade 3 and 4 toxicities (>5%) were diarrhea and/or colitis, hypertension and hypertensive crisis, fatigue, hypocalcemia, rash, and corrected QT interval (QTc) prolongation. This approval was based on a statistically significant and clinically meaningful improvement in PFS. Given the toxicity profile, which includes prolongation of the QT interval and sudden death, only prescribers and pharmacies certified through the vandetanib Risk Evaluation Mitigation Strategy Program are able to prescribe and dispense vandetanib. Treatment-related risks should be taken into account when considering the use of vandetanib in patients with indolent, asymptomatic, or slowly progressing disease.

Phase I study of the synthetic triterpenoid, 2-cyano-3, 12-dioxoolean-1, 9-dien-28-oic acid (CDDO), in advanced solid tumors.

BACKGROUND: The triterpenoid 2-cyano-3,12-dioxoolean-1,9-dien-28-oic Acid (CDDO, previously RTA 401) is a multifunctional molecule that controls cellular growth and differentiation. While CDDO is capable of activating the transcription factor peroxisome proliferator activator receptor-γ (PPARγ), its apoptotic effects in malignant cells have been shown to occur independently of PPARγ. A phase I dose-escalation study was conducted to determine the toxicity, the maximum tolerated dose, and the pharmacokinetics and pharmacodynamics of CDDO, administered as a 5-day continuous infusion every 28 days in patients with advanced cancers. METHODS: An accelerated titration design was followed, with one patient per cohort entered, and doses ranging from 0.6 to 38.4 mg/m(2)/h. Pharmacokinetics of CDDO was assessed and cleaved poly (ADP-ribose) polymerase (c-PARP), as a marker of apoptosis, was measured in peripheral blood mononuclear cells to assess drug effect. RESULTS: Seven patients, one patient per dose level up to dose level 7 (38.4 mg/m(2)/h), were enrolled and received a total of 11 courses of treatment. Cmax increased proportionally with dose. Preclinically determined efficacious blood level (1 µM) of drug was attained at the highest dose level. One patient, at dose level 6, experienced grade 2 mucositis, nausea, vomiting, and anorexia. Four patients developed thromboembolic events subsequently considered as dose-limiting toxicity. No antitumor activity was noted. CONCLUSION: A causal relationship of observed thromboembolic events to CDDO was considered possible but could not be established.

Phase I study of PARP inhibitor ABT-888 in combination with topotecan in adults with refractory solid tumors and lymphomas.

A phase I trial of ABT-888 (veliparib), a PARP inhibitor, in combination with topotecan, a topoisomerase I-targeted agent, was carried out to determine maximum tolerated dose (MTD), safety, pharmacokinetics, and pharmacodynamics of the combination in patients with refractory solid tumors and lymphomas. Varying schedules and doses of intravenous topotecan in combination with ABT-888 (10 mg) administered orally twice a day (BID) were evaluated. Plasma and urine pharmacokinetics were assessed and levels of poly(ADP-ribose) (PAR) and the DNA damage marker γH2AX were measured in tumor and peripheral blood mononuclear cells (PBMC). Twenty-four patients were enrolled. Significant myelosuppression limited the ability to coadminister ABT-888 with standard doses of topotecan, necessitating dose reductions. Preclinical studies using athymic mice carrying human tumor xenografts also informed schedule changes. The MTD was established as topotecan 0.6 mg/m²/d and ABT-888 10 mg BID on days one to five of 21-day cycles. Topotecan did not alter the pharmacokinetics of ABT-888. A more than 75% reduction in PAR levels was observed in 3 paired tumor biopsy samples; a greater than 50% reduction was observed in PBMCs from 19 of 23 patients with measurable levels. Increases in γH2AX response in circulating tumor cells (CTC) and PBMCs were observed in patients receiving ABT-888 with topotecan. We show a mechanistic interaction of a PARP inhibitor, ABT-888, with a topoisomerase I inhibitor, topotecan, in PBMCs, tumor, and CTCs. Results of this trial reveal that PARP inhibition can modulate the capacity to repair topoisomerase I-mediated DNA damage in the clinic.

Multihistology, target-driven pilot trial of oral topotecan as an inhibitor of hypoxia-inducible factor-1α in advanced solid tumors.

PURPOSE: Hypoxia-inducible factor 1 (HIF-1) α is frequently overexpressed in human tumors and is associated with angiogenesis and metastasis. Topotecan, a topoisomerase I inhibitor, has been shown to inhibit HIF-1α expression in preclinical models. We designed a pilot trial to measure HIF-1α inhibition in tumor biopsies from patients with advanced solid tumors overexpressing HIF-1α, after treatment with oral topotecan. EXPERIMENTAL DESIGN: Topotecan was administered orally at 1.6 mg/m(2) once daily for 5 days/week for 2 weeks, in 28-day cycles. Objectives were to determine inhibition of expression of HIF-1α and HIF-1 target genes in tumor; to assess tumor blood flow by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI); and to measure pharmacokinetics. Tumor biopsies were collected at baseline and during the second cycle of treatment. RESULTS: Sixteen patients were enrolled. The dose of topotecan was reduced to 1.2 mg/m(2)/day due to myelosuppression. Seven patients had paired tumor biopsies. In 4 patients, HIF-1α nuclear staining became undetectable after treatment (7.5%-50% staining at baseline). Decreased levels of VEGF and GLUT-1 mRNA were measured in 4 patients; the changes were concordant with reduction in HIF-1α in 3 patients. Decreased tumor blood flow and permeability were observed by DCE-MRI in 7 of 10 patients after 1 cycle. One patient had a partial response accompanied by inhibition of HIF-1α in tumor and reduction in tumor blood flow on DCE-MRI. CONCLUSIONS: This multihistology, target assessment trial of a small molecule inhibitor of HIF-1α showed that topotecan could decrease HIF-1α expression in advanced solid tumors.

Phase I trial of fenretinide lym-x-sorb oral powder in adults with solid tumors and lymphomas.

BACKGROUND: The synthetic retinoid fenretinide (N-(4-hydroxyphenyl)retinamide, 4-HPR) has shown promising anticancer activity in preclinical studies, but its limited oral bioavailability has hindered clinical assessment. A novel lipid matrix, Lym-X-Sorb (LXS), was evaluated to improve fenretinide bioavailability and attain higher plasma concentrations. PATIENTS AND METHODS: Adults with refractory malignancies were administered fenretinide/LXS oral powder in 2 divided doses over 24 h for 7 consecutive days every 21 days in a standard phase I dose-escalation study with pharmacokinetic analysis. RESULTS: The principal toxicities observed were diarrhea, reversible night blindness, and allergic reaction. The maximum tolerated dose regimens were 1,000 mg/m(2)/day divided into 2 daily doses for 7 days, every 21 days, and 800 mg/m(2)/day divided into 3 daily doses for 7 consecutive days, every 21 days. CONCLUSION: Better fenretinide formulations are needed to improve adult patient acceptability and compliance and to achieve the consistent systemic exposures associated with activity in preclinical models.

Phase I trial of vandetanib and bevacizumab evaluating the VEGF and EGF signal transduction pathways in adults with solid tumours and lymphomas.

PURPOSE: Inhibition of epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) pathways may result in synergistic antitumour activity. We designed a phase I study to evaluate the combination of vandetanib, an investigational agent with activity against EGF receptor and VEGF receptor 2, and bevacizumab, a monoclonal antibody against VEGF. EXPERIMENTAL DESIGN: Patients with advanced solid tumours and lymphomas were enrolled. Objectives were to determine the safety and maximum tolerated dose of the combination, characterise pharmacokinetics, measure angiogenic marker changes in blood, and assess tumour blood flow using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Vandetanib was given orally once daily and bevacizumab intravenously once in every 3 weeks in 21-day cycles utilising a standard dose-escalation design. RESULTS: Fifteen patients were enrolled, and a total of 94 cycles of therapy were administered. No protocol-defined dose-limiting toxicities were observed; due to toxicities associated with chronic dosing, hypertension, proteinuria, diarrhoea and anorexia, dose escalation was stopped at the second dose level. We observed one partial response and one minor response; 9 patients experienced stable disease. There were significant changes in plasma VEGF and placental-derived growth factor levels, and decreases in K(trans) and k(ep) were observed by DCE-MRI. CONCLUSION: In this trial, we safely combined two targeted agents that cause dual blockade of the VEGF pathway, demonstrated preliminary evidence of clinical activity, and conducted correlative studies demonstrating anti-angiogenic effect. The recommended phase II dose was established as vandetanib 200 mg daily and bevacizumab 7.5 mg/kg every 3 weeks.

Differentiation therapy in poor risk myeloid malignancies: Results of a dose finding study of the combination bryostatin-1 and GM-CSF.

PURPOSE: Pharmacologic differentiating agents have had relatively limited clinical success outside of the use of ATRA in acute promyelocytic leukemia and DNA methyltransferase inhibitors in myelodysplastic syndromes. The differentiating effects of such agents can be enhanced in combination with lineage-specific growth factors. We developed a dose finding trial to assess toxicity, differentiating activity, and clinical impact of the combination of bryostatin-1 and GM-CSF. EXPERIMENTAL DESIGN: Patients with poor risk myeloid malignancies were eligible to enroll in a dose finding study of continuous infusion bryostatin-1 combined with a fixed dose of daily GM-CSF. Toxicities were graded per NCI CTC version 2.0 and pharmacokinetic and correlative study samples were obtained to assess the combination's clinical and biologic differentiating effects. RESULTS: Thirty-two patients were treated with the combination therapy and the dose determined to be most suitable for study in a larger trial was continuous infusion broystatin-1 at 16µg/m(2) for 14 days and subcutaneous GM-CSF at 125µg/m(2) daily for 14 days every 28 days. Arthralgias and myalgias limited further dose escalation. Clinically, the combination impacted differentiation with improvement of absolute neutrophil counts (p=0.0001) in the majority of patients. Interestingly, there were two objective clinical responses, including a CR after a single cycle. Both the bryostatin-1 plasma concentrations and the correlative studies supported biologic activity of the combination at the doses where clinical responses were observed. CONCLUSIONS: Combining growth factors with pharmacologic differentiating agents may increase their clinical effectiveness and further studies should focus on such combinations.

The statistics of phase 0 trials.

The PD-driven phase 0 trial is a new form, designed to be a first-in-man study, often of a new agent, conducted to assess drug effect on a molecular target, by means of a pharmacodynamic (PD) assay, in a very small number (10-15) of patients. Such a study is meant to be a proof of principle trial to determine whether the agent yields the PD effect predicted by pre-clinical studies. The dosage is meant to be pharmacologically active, but is neither toxic nor likely to yield clinical benefit. Such a trial may be used to serve as a very early test of an agent's biologic effect, allowing for early weeding out of ineffective agents, or as an early means of determining the most promising of competing analogue agents. This manuscript will present designs for such PD-driven studies that are statistically efficient and rigorous, focusing on non-comparative trials. The phase 0 trial promises to become an increasingly important tool for facilitating and speeding the development of new therapeutic agents, particularly in oncology.

Phase I trial of non-cytotoxic suramin as a modulator of docetaxel and gemcitabine therapy in previously treated patients with non-small cell lung cancer.

PURPOSE: In preclinical models, non-cytotoxic suramin (concentrations <50 µM) potentiates the activity of multiple chemotherapeutic agents. The present study evaluated the safety and tolerability of suramin in combination with docetaxel or gemcitabine in previously chemotherapy-treated patients with advanced non-small cell lung cancer. METHODS: Patients received suramin intravenously in combination with either docetaxel on day 1 or gemcitabine on days 1 and 8, of each 21-day treatment cycle. After 3 cycles, patients with partial response (PR) or better continued on the same combination, whereas patients with stable disease (SD) or worse crossed-over to the other combination. Pharmacokinetic analyses were performed before and after each treatment. RESULTS: Eighteen patients received a total of 79 courses (37 suramin plus docetaxel, 42 suramin plus gemcitabine). The dose-limiting toxicity (DLT) was febrile neutropenia, observed in three of six patients treated with suramin and docetaxel 75 mg/m(2). No DLTs were observed with suramin plus docetaxel 56 mg/m(2) or suramin plus gemcitabine 1,250 mg/m(2). Common adverse events included neutropenia, thrombocytopenia, anemia, fatigue, nausea, vomiting, skin rash, hyperglycemia, and electrolyte abnormalities. The target plasma suramin concentration range of 10-50 µM was achieved in 90% of treatments. Discernable antitumor activity was noted in 11 patients (2 PR, 9 SD). CONCLUSIONS: Non-cytotoxic suramin, in combination with docetaxel 56 mg/m(2) or gemcitabine 1,250 mg/m(2), was reasonably well-tolerated with a manageable toxicity profile. Target plasma concentrations were correctly predicted by our previously described dosing nomogram. The observed preliminary evidence of antitumor activity encourages evaluation of this strategy in efficacy trials.

Monitoring drug-induced gammaH2AX as a pharmacodynamic biomarker in individual circulating tumor cells.

PURPOSE: Circulating tumor cells (CTC) in peripheral blood of patients potentially represent a fraction of solid tumor cells available for more frequent pharmacodynamic assessment of drug action than is possible using tumor biopsy. However, currently available CTC assays are limited to cell membrane antigens. Here, we describe an assay that directly examines changes in levels of the nuclear DNA damage marker gammaH2AX in individual CTCs of patients treated with chemotherapeutic agents. EXPERIMENTAL DESIGN: An Alexa Fluor 488-conjugated monoclonal gammaH2AX antibody and epithelial cancer cell lines treated with topotecan and spiked into whole blood were used to measure DNA damage-dependent nuclear gammaH2AX signals in individual CTCs. Time-course changes in both CTC number and gammaH2AX levels in CTCs were also evaluated in blood samples from patients undergoing treatment. RESULTS: The percentage of gammaH2AX-positive CTCs increased in a concentration-dependent manner in cells treated with therapeutically relevant concentrations of topotecan ex vivo. In samples from five patients, percent gammaH2AX-positive cells increased post-treatment from a mean of 2% at baseline (range, 0-6%) to a mean of 38% (range, 22-64%) after a single day of drug administration; this increase was irrespective of increases or decreases in the total CTC count. CONCLUSIONS: These data show promise for monitoring dynamic changes in nuclear biomarkers in CTCs (in addition to CTC count) for rapidly assessing drug activity in clinical trials of molecularly targeted anticancer therapeutics as well as for translational research.

A phase I trial of UCN-01 and prednisone in patients with refractory solid tumors and lymphomas.

PURPOSE: UCN-01 potently inhibits protein kinase C, phosphatidylinositide-dependent kinase-1, and checkpoint kinase 1, which are involved in regulating cell cycle progression. We designed a phase I study to determine the maximum tolerated dose (MTD) of UCN-01 with prednisone in patients with advanced malignancies. METHODS: UCN-01 was administered as a continuous intravenous infusion over 72 h in cycle 1 and 36 h in subsequent cycles. Prednisone was given orally at 60 mg/m(2) per day for five consecutive days within each 28-day cycle. Standard dose escalation was employed, and MTD was defined as the dose at which no more than one of six patients experienced a dose-limiting toxicity (DLT). Plasma pharmacokinetics of UCN-01 were assessed. RESULTS: Fifteen patients received a total of 55 courses of treatment. The MTD and the recommended phase II dose of UCN-01 in this combination is 72 mg/m(2) total dose over 72 h for cycle 1 followed by 36 mg/m(2) per cycle over 36 h. All patients experienced hyperglycemia but responded to insulin treatment. Hypophosphatemia was a DLT in two patients. There were no cumulative toxicities. No objective responses were observed, but five patients had stable disease, including two patients with lymphoid malignancies who had prolonged disease stabilizations. UCN-01 has a long terminal half-life and low clearance; there was wide inter-patient variability in peak concentrations. CONCLUSION: UCN-01 can be safely administered in combination with prednisone without unacceptable toxicity. The prolonged stable disease in two patients with lymphoid malignancies is a proof of principle for the evaluation of cyclin-dependent kinase inhibitors in oncology.

Phase I trial of 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), a heat shock protein inhibitor, administered twice weekly in patients with advanced malignancies.

PURPOSE: Phase I dose-escalation study to determine the toxicity and maximum tolerated dose (MTD) of 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), a heat shock protein 90 (Hsp90) inhibitor, administered on a twice weekly schedule in patients with advanced cancer. EXPERIMENTAL DESIGN: 17-DMAG was administered as a 1- to 2-h infusion twice weekly in 4-week cycles. An accelerated titration design was followed until toxicity was observed, at which point standard dose-escalation proceeded. MTD was defined as the dose at which no more than one of the six patients experienced a dose-limiting toxicity (DLT). Pharmacokinetics were assessed, and Hsp70 mRNA, whose gene product is a chaperone previously shown to be upregulated following the inhibition of Hsp90, was measured in peripheral blood mononuclear cells (PBMCs). RESULTS: A total of 31 patients received 92 courses of treatment. The MTD was 21mg/m(2)/d; 20 patients were enrolled at this dose level. Nine patients had stable disease for a median of 4 (range 2-22) months. Both C(max) and AUC increased proportionally with dose. The most common toxicities were grade 1 or 2 fatigue, anorexia, nausea, blurred vision and musculoskeletal pain. DLTs were peripheral neuropathy and renal dysfunction. Expression of Hsp70 mRNA in PBMCs was highly variable. CONCLUSION: Twice-weekly i.v. infusion of 17-DMAG is well tolerated, and combination phase I studies are warranted.

Immunohistochemical detection of poly(ADP-ribose) polymerase inhibition by ABT-888 in patients with refractory solid tumors and lymphomas.

PURPOSE: Targeting the poly (ADP-ribose) polymerase (PARP) pathway for cancer treatment has been an active area of pre-clinical and clinical research. We aimed to determine whether the PARP inhibitor ABT-888 hits its therapeutic target in tumors by immunohistochemistry during a Phase 0 trial conducted at the National Cancer Institute. EXPERIMENTAL DESIGN: The expression of poly (ADP-ribose) (PAR) and full size PARP-1 were quantitatively examined by immunohistochemistry in paraffin-embedded tumor biopsies at baseline and 3-24 h after a single oral dose (25 or 50 mg) of ABT-888. RESULTS: Baseline PAR levels were moderate to high in three patients with non-Hodgkin lymphomas, and one each with small cell lung cancer, squamous cell carcinoma of the tongue and melanoma; low in two patients with cutaneous T-cell lymphoma and one with adenocarcinoma of external ear canal. A significant decrease in PAR (median decrease 30.2, range -13.1 to -69.8) was achieved after drug administration (n = 6 pairs; p = 0.03), whereas an increase in PARP-1 expression was observed in five of the six tumors. This resulted in a decrease in the ratio of PAR to PARP-1 in tumor biopsies (median -6.76, range -0.41 to -22.59; p = 0.03). CONCLUSIONS: ABT-888 hits its therapeutic target by significantly reducing PAR levels and the ratio of PAR to PARP-1 in human tumor cells detected by immunohistochemistry. Baseline tumor PAR levels vary considerably among patients who entered this phase 0 study. This underscores a need to investigate baseline PAR levels in association with response in future preclinical and clinical studies.

Early epigenetic changes and DNA damage do not predict clinical response in an overlapping schedule of 5-azacytidine and entinostat in patients with myeloid malignancies.

Sequential administration of DNA methyltransferase (DNMT) inhibitors and histone deacetylase (HDAC) inhibitors has demonstrated clinical efficacy in patients with hematologic malignancies. However, the mechanism behind their clinical efficacy remains controversial. In this study, the methylation dynamics of 4 TSGs (p15(INK4B), CDH-1, DAPK-1, and SOCS-1) were studied in sequential bone marrow samples from 30 patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) who completed a minimum of 4 cycles of therapy with 5-azacytidine and entinostat. Reversal of promoter methylation after therapy was observed in both clinical responders and nonresponders across all genes. There was no association between clinical response and either baseline methylation or methylation reversal in the bone marrow or purified CD34(+) population, nor was there an association with change in gene expression. Transient global hypomethylation was observed in samples after treatment but was not associated with clinical response. Induction of histone H3/H4 acetylation and the DNA damage-associated variant histone gamma-H2AX was observed in peripheral blood samples across all dose cohorts. In conclusion, methylation reversal of candidate TSGs during cycle 1 of therapy was not predictive of clinical response to combination "epigenetic" therapy. This trial is registered with http://www.clinicaltrials.gov under NCT00101179.