Ixabepilone in combination with capecitabine and as monotherapy for treatment of advanced breast cancer refractory to previous chemotherapies.

PURPOSE: To describe the considerations leading to marketing approval of ixabepilone in combination with capecitabine and as monotherapy for the treatment of advanced breast cancer that is refractory to other chemotherapies. EXPERIMENTAL DESIGN: Data from one randomized multicenter trial comparing combination therapy with ixabepilone and capecitabine to capecitabine alone were analyzed for support of the combination therapy indication. For monotherapy, a single-arm trial of ixabepilone was analyzed. Supporting data came from an additional single-arm combination therapy study and two single-arm monotherapy studies. RESULTS: In patients with metastatic or locally advanced breast cancer who had disease progression on or following an anthracycline and a taxane, ixabepilone plus capecitabine showed an improvement in progression-free survival compared with capecitabine alone {median progression-free survival, 5.7 [95% confidence interval (95% CI), 4.8-6.7] versus 4.1 (95% CI, 3.1-4.3) months, stratified log-rank P < 0.0001; hazard ratio, 0.69 (95% CI, 0.58-0.83)}. As monotherapy for patients who had disease progression on or following an anthracycline, a taxane, and capecitabine, ixabepilone as monotherapy showed a 12% objective response rate by independent blinded review and 18% by investigator assessment. The major toxicities from ixabepilone therapy were peripheral neuropathy and myelosuppression, particularly neutropenia. CONCLUSIONS: On October 16, 2007, the Food and Drug Administration approved ixabepilone for injection in combination with capecitabine or as monotherapy for the treatment of patients with advanced breast cancer who have experienced disease progression on previous chemotherapies.

Sprycel for chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia resistant to or intolerant of imatinib mesylate.

PURPOSE: On June 28, 2006, the U.S. Food and Drug Administration approved dasatinib (Sprycel; Bristol-Myers Squibb), a new small-molecule inhibitor of multiple tyrosine kinases, for the treatment of adults with chronic phase, accelerated phase, or myeloid or lymphoid blast phase chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) with resistance or intolerance to prior therapy including imatinib. This summary reviews the database supporting this approval. EXPERIMENTAL DESIGN: Four single-arm multicenter studies supported the efficacy and safety of dasatinib. The primary efficacy end point in chronic phase CML was major cytogenetic response. The primary end point in accelerated phase, myeloid phase, and lymphoid blast phase CML, and Ph(+) ALL was major hematologic response. RESULTS: The four studies combined enrolled 445 patients. In patients with chronic phase CML, the major cytogenetic response rate was 45% with a complete cytogenetic response rate of 33%. Major hematologic response rates in patients with accelerated phase CML, myeloid CML, lymphoid blast CML, and Ph(+) ALL were 59%, 32%, 31%, and 42%, respectively. Median response durations in chronic phase, accelerated phase, and myeloid phase CML had not been reached. The median durations of major hematologic response were 3.7 months in lymphoid blast CML and 4.8 months in Ph(+) ALL. Common toxicities with dasatinib included myelosuppression, bleeding, and fluid retention. CONCLUSIONS: This report describes the Food and Drug Administration review supporting the approval of dasatinib for CML and Ph(+) ALL based on the rates and durability of cytogenetic and hematologic responses.

Tasigna for chronic and accelerated phase Philadelphia chromosome--positive chronic myelogenous leukemia resistant to or intolerant of imatinib.

PURPOSE: This Food and Drug Administration (FDA) approval report describes the data and analyses leading to the approval by the FDA of nilotinib (Tasigna, AMN-107; Novartis Pharmaceuticals Corporation), an inhibitor of Bcr-Abl tyrosine kinase, for the treatment of chronic-phase (CP) and accelerated-phase (AP) chronic myelogenous leukemia (CML) resistant to or intolerant of imatinib. EXPERIMENTAL DESIGN: The FDA approval of the efficacy and safety of nilotinib was based on the results of an ongoing single-arm, open-label, phase 2 clinical trial. The primary end point for CML-CP was unconfirmed major cytogenetic response. The efficacy end point for CML-AP was confirmed hematologic response. RESULTS: The major cytogenetic response rate in 232 evaluable CP patients was 40% (95% confidence interval, 33%, 46%). The hematologic response rate in 105 evaluable AP patients was 26% (95% confidence interval, 18%, 35%). The median duration of response has not been reached for both CML-CP and CML-AP responding patients. In CML-CP patients, the common serious drug-related adverse reactions were thrombocytopenia and neutropenia. In CML-AP patients, the common serious drug-related adverse reactions were thrombocytopenia, neutropenia, pneumonia, febrile neutropenia, leukopenia, intracranial hemorrhage, elevated lipase, and pyrexia. Nilotinib prolongs the QT interval and sudden deaths have been reported; these risks and appropriate risk minimization strategies are described in a boxed warning on the labeling. CONCLUSIONS: On October 29, 2007, the U.S. FDA granted accelerated approval to nilotinib (Tasigna) for use in the treatment of CP and AP Philadelphia chromosome positive CML in adult patients resistant to or intolerant of prior therapy that included imatinib.

Vorinostat for treatment of cutaneous manifestations of advanced primary cutaneous T-cell lymphoma.

PURPOSE: To discuss vorinostat approval for treatment of cutaneous manifestations of advanced cutaneous T-cell lymphoma (CTCL). EXPERIMENTAL DESIGN: Data from 1 single-arm, open-label, multicenter pivotal trial and 11 other trials submitted to support the new drug application for vorinostat in the treatment of advanced primary CTCL were reviewed. The pivotal trial assessed responses by changes in overall skin disease score using a severity-weighted assessment tool (SWAT). Vorinostat could be considered active in CTCL if observed response rate was at least 20% and the lower bound of the corresponding 95% confidence interval (95% CI) excluded 5%. Patients reported pruritus relief using a questionnaire and a visual analogue scale. RESULTS: The pivotal trial enrolled 74 patients with stage IB or higher CTCL. Median number of prior treatments was 3, and 61 patients (82%) had stage IIB or higher disease. The objective response rate in the skin disease assessed by change in the overall SWAT score from the baseline was 30% (95% CI, 18.5 to 42.6) in patients with stage IIB or higher disease. Median response duration (end of response defined by 50% increase in SWAT score from the nadir) was 168 days. Median time to tumor progression was 148 days for overall population and 169 days for patients with stage IIB or higher disease. Assessment of pruritus relief was considered unreliable. CONCLUSIONS: Vorinostat showed activity in CTCL, and skin responses were a clinical benefit. Vorinostat was approved for treatment of cutaneous manifestations of CTCL. A nonblinded, single-arm trial did not allow a reliable assessment of pruritus relief.

Food and Drug Administration requirements for testing and approval of new radiopharmaceuticals.

In March 2004, the Food and Drug Administration (FDA) published a report entitled Challenge and Opportunity on the Critical Path to New Medical Products in which it explained the critical path to medical product development and called for a nationwide effort to modernize the critical-path sciences with the aim of moving medical product development and patient care into the 21st century. The report identified medical imaging and imaging biomarkers as potential clinical development tools to facilitate medical product development and to help minimize drug attritions and development timelines. Also, in recent years, basic research on receptor-based imaging has led to an increase in the new investigational radiopharmaceuticals, many of which are in basic research stages in academic institutions. It is therefore an opportune time to review the FDA requirements for testing and approval of new radiopharmaceuticals to further the cause of development and approval of newer medical imaging and therapeutic agents. Although the radiopharmaceutical-development process aligns well with the drug-development process for conventional pharmaceuticals, it has its own challenges and unique considerations. For example, unique issues surrounding short-lived positron emission tomography drugs have necessitated revisions and refinements to the existing regulations. The FDA Modernization Act mandate has finally resulted in the publication of new cGMPs (current good manufacturing practice) for positron emission tomography drugs. Often, the radiopharmaceutical community is not well-informed about the regulatory pathways and scientific basis for the regulations they are subjected to. Questions, such as (1) "Do I need an investigational new drug (IND) or can I do my investigation under an RDRC (radioactive drugs research committee) oversight?" (2) "What type of information on radiopharmaceutical product quality is needed for an IND?" (3) "What level of cGMPs I am expected to operate under?" (4) "Do I need a traditional IND or can I perform studies under an exploratory IND?" (5) "What are the IND-enabling pharmacology and toxicology studies?" (6) "Is my practice consistent with pharmacy compounding or do I need to file an application with the FDA?", for example, are a source of confusion to the radiopharmaceutical community. This review provides an overview of FDA's drug development and approval process with special emphasis on radiopharmaceuticals and attempts to clarify many regulatory issues and questions by providing appropriate discussion and FDA references.

Synthesis and biologic evaluation of a radioiodinated quinazolinone derivative for enzyme-mediated insolubilization therapy.

We have developed a new strategy that aims to concentrate therapeutic radionuclides within solid tumors. This approach, which we have named EMIT (enzyme-mediated insolubilization therapy), is a method for enzyme-dependent, site-specific, in vivo precipitation of a radioactive molecule (from a water-soluble precursor) within the extracellular space of solid tumors. The prodrug, ammonium 2-(2'-phosphoryloxyphenyl)-6-iodo-4-(3H)-quinazolinone, labeled with iodine-125 ((125)IPD) and its authentic compound labeled with iodine-127 (IPD) have been synthesized, purified, and characterized. The alkaline phosphatase (ALP)-mediated conversion of these water-soluble nonfluorescent prodrugs to the water-insoluble fluorescent species, iodine-125-labeled 2-(2'-hydroxyphenyl)-6-iodo-4-(3H)-quinazolinone ((125)ID) and its iodine-127-labeled derivative (ID), has been demonstrated in vitro. Biodistribution studies in mice indicate that both (125)IPD and (125)ID are minimally retained by most tissues and organs. In addition, following its intravenous injection in mice, (125)IPD is localized in ALP-rich regions and converted to (125)ID, which remains indefinitely within the tissues where it is produced. We believe that EMIT is a strategy that will lead to the active and specific concentration and entrapment of therapeutic radionuclides within solid tumors, the consequent protracted irradiation of tumor cells within the range of the emitted particles, and the effective therapy of solid tumors.