Reviewing the role of healthy volunteer studies in drug development.

BACKGROUND: With the exception of genotoxic oncology drugs, first-in-human, Phase 1 clinical studies of investigational drugs have traditionally been conducted in healthy volunteers (HVs). The primary goal of these studies is to investigate the pharmacokinetics and pharmacodynamics of a novel drug candidate, determine appropriate dosing, and document safety and tolerability. MAIN BODY: When tailored to specific study objectives, HV studies are beneficial to manufacturers and patients alike and can be applied to both non-oncology and oncology drug development. Enrollment of HVs not only increases study accrual rates for dose-escalation studies but also alleviates the ethical concern of enrolling patients with disease in a short-term study at subtherapeutic doses when other studies (e.g. Phase 2 or Phase 3 studies) may be more appropriate for the patient. The use of HVs in non-oncology Phase 1 clinical trials is relatively safe but nonetheless poses ethical challenges because of the potential risks to which HVs are exposed. In general, most adverse events associated with non-oncology drugs are mild in severity, and serious adverse events are rare, but examples of severe toxicity have been reported. The use of HVs in the clinical development of oncology drugs is more limited but is nonetheless useful for evaluating clinical pharmacology and establishing an appropriate starting dose for studies in cancer patients. During the development of oncology drugs, clinical pharmacology studies in HVs have been used to assess pharmacokinetics, drug metabolism, food effects, potential drug-drug interactions, effects of hepatic and renal impairment, and other pharmacologic parameters vital for clinical decision-making in oncology. Studies in HVs are also being used to evaluate biosimilars versus established anticancer biologic agents. CONCLUSION: A thorough assessment of toxicity and pharmacology throughout the drug development process is critical to ensure the safety of HVs. With the appropriate safeguards, HVs will continue to play an important role in future drug development.

Monitoring the quality of conduct of clinical trials: a survey of current practices.

BACKGROUND: There is a little empirical evidence to determine which, if any, monitoring practices best achieve the goals of trial monitoring set forth in ICH E6 under the variable circumstances of different clinical trial settings. PURPOSE: The purpose of this project was to describe current methods of monitoring clinical trials and to explore the rationale for the use of those methods. METHODS: An electronic survey of known monitoring practices was developed and sent to over 200 organizations involved in conducting clinical research. The survey collected information on institutional demographics, methods of overall study oversight, use of risk-based monitoring and factors that influence assessments of risk, and details on quality assurance and monitoring practices. RESULTS: Seventy-nine organizations completed the survey; our analysis included the 65 organizations that indicated they perform clinical trials. Data from the survey indicate that a wide variety of monitoring practices are currently being employed. Eighty-three percent of respondents use centrally available data to evaluate site performance, but only 12% of respondents always or frequently used centralized monitoring to replace on-site visits. Eighty-seven percent of respondents indicated that they always performed on-site visits. This varied by type of organization, with 31% of academic coordinating centers/cooperative groups/government organizations always performing on-site monitoring visits versus 84% of other organizations. The rationale for using a specific monitoring approach does not appear to be based on empirical evidence. Fifty-four percent of respondents stated that 'usual practice' determined the frequency with which they conducted on-site monitoring visits. LIMITATIONS: The overall response rate to our survey was only 30%; thus, we may not have captured the full variance of current monitoring practices, and our responding sample may not be representative. CONCLUSION: These findings underscore the necessity of research to provide an evidence base for monitoring practice.

A Phase I trial of the farnesyltransferase inhibitor L-778,123 and radiotherapy for locally advanced lung and head and neck cancer.

PURPOSE: Preclinical data have demonstrated that farnesyltransferaseinhibitors (FTIs) are radiation sensitizers in selected cell lines. The objective of this Phase I trial was to determine the maximally tolerated dose of the FTI L-778,123 in combination with radiotherapy in non-small cell lung cancer (NSCLC) and head and neck cancer (HNC). EXPERIMENTAL DESIGN: L-778,123 was given by continuous i.v. infusion and dose escalated in conjunction with standard radiotherapy. The presence of a ras mutation was not required for study entry. RESULTS: Nine patients (six NSCLC patients and three HNC patients) were enrolled on two dose levels of FTI. No dose-limiting toxicities were observed at the first dose level of 280 mg/m2/day during weeks 1, 2, 4, and 5 of radiotherapy. One episode of dose-limiting toxicity, grade IV neutropenia, was observed in one of three patients treated at 560 mg/m2/day during weeks 1, 2, 4, 5, and 7. No episodes of dose-limiting mucositis, esophagitis, or pneumonitis were observed. Of the four patients with NSCLC with evaluable disease, three patients had a complete response to treatment and one patient had a partial response. A complete clinical response to treatment was observed in two patients with HNC. In vitro studies in tumor cells obtained from a NSCLC patient on this trial showed radiosensitization with FTI and that tumor cells accumulated in G2-M after L-778,123 treatment. CONCLUSIONS: The combination of L-778,123 and radiotherapy at dose level 1 is associated with acceptable toxicity. Local responses have been observed in four NSCLC patients without a clear increase in radiotherapy-associated toxicities.

A phase I trial of the dual farnesyltransferase and geranylgeranyltransferase inhibitor L-778,123 and radiotherapy for locally advanced pancreatic cancer.

PURPOSE: Preclinical and clinical studies have demonstrated that inhibition of prenylation can radiosensitize cell lines with activation of Ras and produce clinical response in patients with cancer. The aim of this study was to determine the maximally tolerated dose of the dual farnesyltransferase and geranylgeranyltransferase I inhibitor L-778,123 in combination with radiotherapy for patients with locally advanced pancreatic cancer. EXPERIMENTAL DESIGN: L-778,123 was given by continuous intravenous infusion with concomitant radiotherapy to 59.4 Gy in standard fractions. Two L-778,123 dose levels were tested: 280 mg/m2/day over weeks 1, 2, 4, and 5 for dose level 1; and 560 mg/m2/day over weeks 1, 2, 4, 5, and 7 for dose level 2. RESULTS: There were no dose-limiting toxicities observed in the eight patients treated on dose level 1. Two of the four patients on dose level 2 experienced dose-limiting toxicities consisting of grade 3 diarrhea in one case and grade 3 gastrointestinal hemorrhage associated with grade 3 thrombocytopenia and neutropenia in the other case. Other common toxicities were mild neutropenia, dehydration, hyperglycemia, and nausea/vomiting. One patient on dose level 1 showed a partial response of 6 months in duration. Both reversible inhibition of HDJ2 farnesylation and radiosensitization of a study patient-derived cell line were demonstrated in the presence of L-778,123. K-RAS mutations were found in three of the four patients evaluated. CONCLUSIONS: The combination of L-778,123 and radiotherapy at dose level 1 showed acceptable toxicity in patients with locally advanced pancreatic cancer. Radiosensitization of a patient-derived pancreatic cancer cell line was observed.

Preclinical and clinical pharmacodynamic assessment of L-778,123, a dual inhibitor of farnesyl:protein transferase and geranylgeranyl:protein transferase type-I.

Farnesyl:protein transferase (FPTase) inhibitors were developed as anti-Ras drugs, but they fail to inhibit Ki-Ras activity because Ki-Ras can be modified by geranylgeranyl:protein transferase type-I (GGPTase-I). L-778,123, an inhibitor of FPTase and GGPTase-I, was developed in part because it can completely inhibit Ki-Ras prenylation. To support the clinical development of L-778,123, we developed pharmacodynamic assays using peripheral blood mononuclear cells (PBMCs) to measure the inhibition of prenylation of HDJ2 and Rap1A, proteins that are FPTase- and GGPTase-I substrates, respectively. We validated these assays in animal models and show that inhibition of HDJ2 prenylation in mouse PBMCs correlates with the concentration of FPTase inhibitors in blood. In dogs, continuous infusion of L-778,123 inhibited both HDJ2 and Rap1A prenylation in PBMCs, but we did not detect inhibition of Ki-Ras prenylation. We reported previously results from the first L-778,123 Phase I trial that showed a dose-dependent inhibition of HDJ2 farnesylation in PBMCs. In this report, we present additional analysis of patient samples from this trial and a second Phase I trial of L-778,123, and demonstrate the inhibition of both HDJ2 and Rap1A prenylation in PBMC samples. This study represents the first demonstration of GGPTase-I inhibition in humans. However, no inhibition of Ki-Ras prenylation by L-778,123 was detected in patient samples. These results confirm the pharmacologic profile of L-778,123 in humans as a dual inhibitor of FPTase and GGPTase-I, but indicate that the intended target of the drug, Ki-Ras, was not inhibited.

A comparison of rofecoxib versus celecoxib in treating pain after dental surgery: a single-center, randomized, double-blind, placebo- and active-comparator-controlled, parallel-group, single-dose study using the dental impaction pain model.

BACKGROUND: Rofecoxib and celecoxib, selective cyclooxygenase-2 inhibitors, have analgesic efficacy similar to that of nonselective nonsteroidal anti-inflammatory drugs. OBJECTIVE: This study was designed to confirm earlier findings that the overall analgesic efficacy of rofecoxib 50 mg was superior to that of celecoxib 200 mg and to extend the comparison to include celecoxib 400 mg. METHODS: In this single-center, randomized, double-blind, placebo- and active-comparator-controlled, parallel-group, single-dose study, patients who experienced moderate or severe pain after surgical extraction of at least 2 third molars received a single oral dose of either rofecoxib 50 mg, celecoxib 400 mg, celecoxib 200 mg, ibuprofen 400 mg, or placebo. Patients recorded scores of pain intensity, pain relief, and global assessment at prespecified time intervals throughout the 24-hour period after dosing. The end points were total pain relief (TOPAR) score over 8 hours (TOPAR8; primary end point), TOPAR score over 12 hours (TOPAR12), sum of pain intensity difference (SPID) over 8 and 12 hours (SPID8 and SPID12), patient's global assessment of study drug at 8 hours, time to confirmed perceptible pain relief (ie, time to onset of analgesic effect), peak pain intensity difference (PID), peak pain relief, time to first dose of rescue medication (ie, duration of analgesic effect), and percentage of patients using rescue medication. RESULTS: A total of 482 patients (358 females, 124 males; mean age, 22.1 years) were enrolled. Rofecoxib 50 mg (n = 151 patients) demonstrated significantly greater overall analgesic efficacy compared with celecoxib 400 mg (n = 151), as measured by TOPAR8 (least squares mean [SE] 17.2 [0.8] vs 15.0 [0.8]; P < 0.05) and TOPAR12 (25.3 [1.2] vs 21.0 [1.2]; P < 0.05), as well as a significantly longer duration of analgesic effect (P < 0.05). Time to onset of analgesic effect and peak analgesic effect were similar for rofecoxib 50 mg and celecoxib 400 mg. Rofecoxib also showed significantly greater overall analgesic efficacy than did celecoxib 200 mg (n = 90), including greater TOPAR8 scores (17.2 [0.8] vs 11.5 [1.1]; P < 0.001), faster onset of analgesic effect (P < 0.001), greater peak analgesic effect (P < 0.001 for peak pain relief and peak PID), and longer duration of analgesic effect (P < 0.001). The overall analgesic efficacy of rofecoxib 50 mg was similar to that of ibuprofen 400 mg (n = 45), except that the duration of analgesic effect of rofecoxib 50 mg was significantly longer (P < 0.001). All active treatments produced significantly greater overall analgesic efficacy compared with that of placebo (P < 0.001 for all scores [TOPAR8, TOPAR12, SPID8, SPID12, and patient's global assessment] for all study drugs). The adverse-events (AE) profile was generally similar in all treatment groups. The 3 most common AEs were nausea, postextraction alveolitis, and vomiting. CONCLUSIONS: In this study, rofecoxib 50 mg provided generally superior overall analgesic efficacy compared with that of celecoxib 400 and 200 mg, including a significantly longer duration of analgesic effect. The overall analgesic efficacy of rofecoxib 50 mg was generally similar to that of ibuprofen 400 mg, except for a significantly longer duration of analgesic effect.

Cycle Time Metrics for Multisite Clinical Trials in the United States.

Conducting randomized controlled trials entails a prolonged, costly study start-up (SSU) process that may create significant delays. Optimizing the operational aspects of multisite trials requires identifying benchmarks in the SSU process and the potential delays associated with them. We engaged in a collaborative effort to identify and describe key SSU intervals that correspond with necessary procedures and processes for activating multisite clinical trials in the US. After developing definitions for SSU benchmarks and obtaining data from research coordinating entities, we identified factors that were significantly associated with reduced cycle times, including the use of central institutional review boards for study approval and status as a private practice or independent research site. However, small sample sizes and large proportions of missing data hamper the interpretability of our results. Future development of standard measures of SSU efficiency will be critical to analyzing and improving study initiation processes at US research sites.

Quality by Design in Clinical Trials: A Collaborative Pilot With FDA.

The quality of a clinical trial can be assessed by whether the trial meets the needs of its various customers, as well as by its freedom from critical deficiencies or errors. In order to ensure the quality of a clinical trial, it is therefore important to conduct quality planning in parallel with the process to design and prior to the conduct of the trial. Quality planning consists of prospectively establishing quality goals and developing the products and processes required to deliver a quality trial. This article describes the quality planning process conducted by a pharmaceutical sponsor for a clinical trial and the pilot review of the resulting integrated quality management plan by the FDA. This pilot demonstrates the usefulness of this process to enable alignment between sponsors and regulators concerning quality in clinical trials.

Meeting the obligation to communicate clinical trial results to study volunteers.

Although the overwhelming majority of study volunteers want to receive information on the results of their participation in clinical trials, research suggests that most study volunteers never do. CISCRP - an independent nonprofit organization - in collaboration with Pfizer, conducted a study evaluating the feasibility and impact of a new process to inform study volunteers of the results of their clinical trials. Two process components were evaluated via surveys, focus groups, and interviews with volunteers and investigative site staff: a series of ongoing post-trial communications to set expectations for when trial results would be received; and routine development and delivery of the lay language trial results summary. The results of this assessment show that study volunteers and investigative site staff are extremely receptive to receiving clinical trial results and that the process of preparing and disseminating clinical trial results is feasible and generally easy to execute. The results also indicate that study volunteer comprehension of basic facts about their clinical trial pre- and post-test increased by as much as 65.6 percentage points, and suggest that this communication initiative may positively impact volunteer recruitment, retention and long-term trust in the clinical research enterprise.