Continuing reassessment of the risks of erythropoiesis-stimulating agents in patients with cancer

PURPOSE

Erythropoiesis-stimulating agents (ESA) are approved for the treatment of anemia in patients with nonmyeloid malignancies whose anemia is due to the effect of concomitantly administered chemotherapy. Since the 1993 approval of epoetin alfa in patients with cancer, the risk of thrombovascular events, decreased survival, and poorer tumor control have been increasingly recognized. The risks of ESAs in patients with cancer and the design of trials to assess these risks have been the topic of discussion at two Oncologic Drugs Advisory Committees in 2004 and 2007.

EXPERIMENTAL DESIGN

Evaluation of randomized clinical trials comparing use of ESAs to transfusion support alone in patients with active cancer.

RESULTS

Six studies (Breast Cancer Erythropoeitin Survival Trial, Evaluation of NeoRecormon on outcome in Head And Neck Cancer in Europe, Danish Head and Neck Cancer, Lymphoid Malignancy, CAN-20, and Anemia of Cancer) investigating ESAs in oncology patients showed decreased survival, decreased duration of locoregional tumor control, and/or increased risk of thrombovascular events. In these six studies, ESA dosing was targeted to achieve and maintain hemoglobin values in excess of current recommendations, and in three of the six studies, ESAs were administered to patients not receiving chemotherapy.

CONCLUSIONS

ESAs increase the risk of thrombovascular events and result in decreased survival and poorer tumor control when administered to achieve hemoglobin levels of > or =12 g/dL in patients with nonmyeloid malignancies. No completed or ongoing randomized, controlled trial has addressed safety issues of ESAs in patients with chemotherapy-associated anemia using currently approved dosing regimens in an epidermal tumor type. Additional studies are needed to better characterize these risks.

U.S. Food and Drug Administration approval: panitumumab for epidermal growth factor receptor-expressing metastatic colorectal carcinoma with progression following fluoropyrimidine-, oxaliplatin-, and irinotecan-containing chemotherapy regimens

PURPOSE

To describe the Food and Drug Administration review and marketing approval considerations for panitumumab (Vectibix) for the third-line treatment of patients with epidermal growth factor receptor-expressing metastatic colorectal carcinoma.

EXPERIMENTAL DESIGN

Food and Drug Administration reviewed a single, open-label, multicenter trial in which 463 patients with epidermal growth factor receptor-expressing metastatic colorectal cancer who had progressed on or following treatment with a regimen containing a fluoropyrimidine, oxaliplatin, and irinotecan were randomized (1:1) to receive best supportive care (BSC) with or without panitumumab (6 mg/kg every other week) administered until disease progression or intolerable toxicity. Progression and response were confirmed by an independent review committee masked to treatment assignment. At progression, patients in the BSC-alone arm were eligible to receive panitumumab.

RESULTS

Although median progression-free survival (PFS) was similar in both treatment arms ( approximately 8 weeks), the mean PFS was approximately 50% longer among patients receiving panitumumab than among those receiving BSC alone (96 versus 60 days, respectively) and the objective response rate in patients receiving panitumumab was 8%. However, no difference in overall survival was shown between the two study arms.

CONCLUSIONS

Panitumumab received accelerated approval based on improvement in PFS and an independently confirmed response rate of 8%, similar to that observed with other active agents at this advanced stage of disease. Confirmation of clinical benefit will be required for full approval.

Good clinical practice and the conduct of clinical studies in pediatric oncology

This article discusses the principles that guide good clinical practice standards, with particular emphasis on how they to relate to pediatric oncology research and recent efforts at harmonization. The authors review the clinical trials process and the roles of the participants, highlighting the pivotal role of the clinical investigator and the research team, and briefly review the historical aspects of drug development regulations in the United States and the current regulatory paths for pediatric oncology drug development. Where relevant, historical events that underlie many of the regulations and their current applications are described, and practical examples are provided.

Testing of Adenoviral Vector Gene Transfer Products

This chapter describes the agency requirements and guidelines for drug development of adenoviral-containing products. The Food and Drug Administration (FDA) assessment of safety and ultimately effectiveness of adenovirus containing products involves thorough evaluation of the information contained in the Investigational New Drug Application (IND), and any supporting information cross-referenced to another IND or drug master file. Many factors contribute to development of FDA recommendations and requirements for characterization of adenovirus vectors. The FDA receives input and feedback from a variety of sources in formulating recommendations regarding adenovirus manufacturing and characterization. The recommendations may change with advances in technology and through accumulating experience. FDA considers the potential risks and benefits of each vector product and each proposed clinical trial when making its recommendations. The FDA is cognizant of the need for flexibility in its recommendations and will consider many factors, including the intended target population, the seriousness of the disease under study, the potential benefits and risks from the investigational product, when advising sponsors about their adenovirus development program.

Innovations in patient care: changing clinical practice and improving quality

BACKGROUND

In the traditional hospital organization, administrators supply the resources while physicians determine their use. Given this dichotomy, a partnership between clinicians and hospital management is essential for efforts to enhance the quality of care while controlling costs. To foster this partnership, in 1986 the University of Rochester's Strong Memorial Hospital developed its Innovations in Patient Care (IPC) program, which several other medical centers have duplicated. CURRENT STATUS AND LOGISTICS: Hospital operating revenues of approximately $175,000 per year are provided to both fund proposals and support core IPC staff. Clinical staff submit proposals to study innovations to promote higher quality care and/or the efficient and appropriate use of diagnostic and therapeutic services. Many of the 77 projects funded to date have led to important changes in clinical practice.

CASE STUDIES

One study, whose principal investigator was assistant director of emergency medicine, showed that structured, condition-specific (for example, asthma, pharyngitis, lacerations, and isolated closed-head injury) quicksheets improved documentation of clinical findings, resource use, and clinical practice. A study organized by the leadership of surgical nursing revealed that a nursing case management model led to reductions in patient length of stay and increases in nurse satisfaction. Another study, designed by a fellow in neonatalogy, developed and tested guidelines for the use of head ultrasounds in screening very-low-birthweight infants for intraventricular hemorrhage.

CONCLUSIONS

IPC programs, which integrate well with initiatives in total quality management, can be effectively used to change clinical practice and improve the quality and efficiency of patient care.

Regulatory issues in clinical applications of cytokines and growth factors

This article describes the drug approval process at the Center for Biologics Evaluation and Research (CBER), FDA, for cytokines and growth factors that would be licensed for clinical use in the U.S.A. CBER is responsible for setting policy, providing guidance to industry and to academic investigators as they develop and evaluate these new products, and for recommendations about the approvability of license applications. Product development generally parallels clinical development, and the expectations at each stage of the IND (Investigational New Drug) process are discussed. FDA involvement continues beyond licensure to the post marketing phase. The goal is to assure that new cytokines and growth factors are safe and effective and available in a timely manner.

Relationship between 5-fluoro-2'-deoxyuridylate, 2'-deoxyuridylate, and thymidylate synthase activity subsequent to 5-fluorouracil administration, in xenografts of human colon adenocarcinomas

5-Fluorouracil (FUra) has been administered to mice bearing xenografts of human colon adenocarcinomas. In two tumor lines, HxGC3 and HxVRC5, intrinsically resistant to FUra, 2'-deoxyuridylate (dUMP) accumulated 13.4- and 23.9-fold above basal levels. In HxELC2 xenografts, which demonstrated some sensitivity to FUra, there was a decrease in dUMP concentration after drug administration. Maximal intratumor levels of 5-fluoro-2'-deoxyuridylate (FdUMP) were found at 1 hr, but decreased in all tumor lines by 4 hr after administration of FUra. Data derived in tumor cytosols suggested that FdUMP levels in situ were not rate-limiting for formation of covalent ternary complex, but that accumulation of dUMP would retard the rate of complex formation. Subsequent to administration of FUra, thymidylate synthase activity was reduced greater than 75% in all tumors, but it recovered rapidly in tumors resistant to FUra. In addition, the pretreatment level of activity of thymidylate synthase was 12.7-fold greater in HxVRC5 tumors than in HxELC2 tumors. This elevated activity in HxVRC5 tumors appears not to be a consequence of gene amplification. Formation of FdUMP or the accumulation of dUMP did not correlate with the activity of phosphatases measured at pH 5.8 or pH 9.2 in each tumor line. Further, inhibition of phosphatase activity did not alter, significantly, the net rate of dissociation of the FdUMP-thymidylate synthase-[6R]-CH2-H4PteGlu complex.

Increased lung compliance in mice exposed to sulfur dioxide

Mice exposed 6-9 days to 40 ppm. SO2 lost 21% of body weight, but static lung compliance increased 37% (P less than or equal to 0.01). Slopes of saline volume-pressure curves increased 8% (non-sig) pointing to a decrease in surface tension rather than tissue elasticity. Alveolar stability, lung weight and lung wet/dry ratio decreased 2 to 6%, whereas trapped gas in-increased 17%, but none were statistically significant.