Ramzi Dagher

Approval Summary: Sunitinib for the Treatment of Imatinib Refractory or Intolerant Gastrointestinal Stromal Tumors and Advanced Renal Cell Carcinoma

Purpose: To describe the Food and Drug Administration (FDA) review and approval of sunitinib malate (Sutent). Sunitinib received regular approval for the treatment of gastrointestinal stromal tumor (GIST) after disease progression or intolerance to imatinib mesylate (Gleevec). Additionally, sunitinib received accelerated approval for the treatment of advanced renal cell carcinoma. Experimental Design: For the GIST indication, FDA reviewed data from a randomized, placebo-controlled trial with supportive evidence from a single-arm study. For the advanced renal cell carcinoma indication, FDA reviewed data from two single-arm studies of patients with cytokine-refractory metastatic renal cell carcinoma. Results: In patients with imatinib refractory or intolerant GIST, time-to-tumor progression of sunitinib-treated patients was superior to that of placebo-treated patients. Median time-to-tumor progression of sunitinib-treated patients was 27.3 weeks, compared with 6.4 weeks for placebo-treated patients (P < 0.0001). Partial responses were observed in 6.8% of sunitinib-treated patients. In patients with metastatic renal cell carcinoma, partial responses were observed in 25.5% (95% confidence interval, 17.5, 34.9) and 36.5% (95% confidence interval, 24.7, 49.6) of patients treated with sunitinib. Median response durations were 27.1 and 54 weeks. The most common adverse events attributed to sunitinib included diarrhea, mucositis, skin abnormalities, and altered taste. Reductions in left ventricular ejection fraction and severe hypertension were also more common in sunitinib-treated patients. Conclusions: On January 26, 2006, the FDA approved sunitinib for the treatment of patients with imatinib refractory or intolerant GIST. Accelerated approval was granted for the treatment of advanced renal cell carcinoma.

Bortezomib for the Treatment of Mantle Cell Lymphoma

Purpose: To describe the Food and Drug Administration review and marketing approval considerations for bortezomib (Velcade) for the treatment of patients with mantle cell lymphoma. Experimental Design: Food and Drug Administration reviewed a multicenter study of bortezomib in 155 patients with progressive mantle cell lymphoma after at least one prior therapy. Results: Seventy-seven percent were stage IV, and 75% had one or more extranodal sites of disease. Prior therapy included an anthracycline or mitoxantrone, cyclophosphamide, and rituximab. Median age was 65 years. All received bortezomib 1.3 mg/m2 i.v. on days 1, 4, 8, and 11 of each 3-week cycle. The primary end point was response. Response and progression were determined by independent review of serial computed tomography scans using International Lymphoma Workshop Response Criteria. The overall response rate was 31%, including complete response (CR) plus CR unconfirmed (CRu) plus partial response; median response duration was 9.3 months. The CR plus CRu response rate was 8% with a median duration of 15.4 months. Adverse events were similar to those observed previously for bortezomib. The most commonly reported treatment-emergent adverse events were asthenia (72%), peripheral neuropathies (55%), constipation (50%), diarrhea (47%), nausea (44%), and anorexia (39%). The most common adverse event leading to discontinuation was neuropathy. Conclusions: Bortezomib received regular approval for the treatment of patients with mantle cell lymphoma in relapse after prior therapy.

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 pruritis 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 pruritis 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 pruritis relief.

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.

Molecular confirmation of Ewing sarcoma.

Objective To analyze retrospectively results of reverse transcription polymerase chain reaction (RT-PCR) testing and demographic information in ?patients with known or suspected Ewing sarcoma/primitive neuroectodermal tumor family of tumors referred to the National Cancer Institute and to describe factors influencing the determination of molecular marker status. Patients and Methods Tumor samples from 76 patients from February 1997 to December 1999 were analyzed. In all cases, the diagnosis of this family of tumors was confirmed by histopathologic review. Results In 58 patients, the presence of a translocation associated with this family of tumors was confirmed using RT-PCR. Specifically, there were 45 Ewing sarcoma (EWS)-FLI type 1 translocations, four EWS–FLI type 2 translocations, five EWS–ERG translocations, and four less common EWS–FLI variants. Of patients with a confirmed translocation, four were confirmed only after nested RT-PCR techniques were used. In five patients who initially underwent needle biopsy, the diagnosis was confirmed only after open biopsy or repeat needle biopsy was undertaken.Samples from 18 patients were translocation-negative. Of these, seven samples were deemed inadequate for RT-PCR testing as a result of inappropriate tissue handling or the presence of necrotic material. Five patients were found to have a different diagnosis after complete histopathologic and molecular characterization. Six samples remained, in which adequate tissue was obtained with no evidence of a characteristic translocation. Conclusions In apparently translocation-negative samples, close attention should be given to the possibility of an alternative diagnosis, the potential need for nested RT-PCR, and the possibility of an inadequate sample. Strong consideration should be given to the use of open biopsy as opposed to needle biopsy to avoid the need for repeat biopsies and the potential for inaccurate assessment of molecular marker status.

Approval Summary: Docetaxel in Combination with Prednisone for the Treatment of Androgen-Independent Hormone-Refractory Prostate Cancer

Purpose: Docetaxel, a taxane previously approved for the treatment of breast cancer and non–small cell lung cancer, was approved by the United States Food and Drug Administration on May 19, 2004 for use in combination with prednisone for the treatment of metastatic androgen-independent (hormone-refractory) prostate cancer. The purpose of this summary is to review the database supporting this approval. Experimental Design: In a randomized, global study enrolling 1,006 patients, two schedules of docetaxel were compared with mitoxantrone + prednisone as follows: MTZ q 3w, mitoxantrone 12 mg/m2 every 21 days + prednisone 5 mg twice a day for a total of 10 cycles; TXT q 3w, docetaxel 75 mg/m2 every 21 days + prednisone 5 mg twice a day for a total of 10 cycles; and TXT qw, docetaxel 30 mg/m2 days 1, 8, 15, 22, and 29 every 6 weeks + prednisone 5 mg twice a day for a total of 5 cycles. Results: There was a statistically significant overall survival advantage shown for the TXT q 3w arm over MTZ q 3w (median survival 18.9 months versus 16.5 months, P = 0.0094). No overall survival advantage was shown for TXT qw compared with MTZ q 3w. The most commonly occurring adverse events included anemia, neutropenia, infection, nausea, sensory neuropathy, fluid retention, alopecia, nail changes, diarrhea, and fatigue. Conclusions: This report describes the Food and Drug Administration review supporting this first approval of a combination therapy for hormone-refractory prostate cancer based on demonstration of a survival benefit.

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.

Dexrazoxane (Totect™): FDA Review and Approval for the Treatment of Accidental Extravasation Following Intravenous Anthracycline Chemotherapy

Management of anthracycline extravasation is problematic and most reports are anecdotal. On September 6, 2007, the U.S. Food and Drug Administration approved Totect 500 mg (dexrazoxane hydrochloride for injection) for the treatment of extravasation resulting from i.v. anthracycline chemotherapy. In two studies, a total of 57 evaluable patients experienced extravasation from peripheral vein or central venous access sites with local swelling, pain, or redness. The presence of anthracycline in skin biopsy tissue was confirmed by tissue fluorescence, and treatment with a 3-day schedule of dexrazoxane began within 6 hours of the event. The primary endpoint was a reduction in the need for surgical intervention. Only one patient required surgical repair of the injury site, and late sequelae in the remainder were absent or mild. Also, the sponsor, TopoTarget A/S, Copenhagen, Denmark, performed controlled nonclinical studies in support of dexrazoxane dose and timing for the reduction of tissue injury resulting from anthracycline extravasation. For this uncommon but serious complication of anthracycline therapy, the need for surgical intervention was 1.7% with this regimen.

Randomized Trial and Pharmacokinetic Study of Pegfilgrastim versus Filgrastim after Dose-Intensive Chemotherapy in Young Adults and Children with Sarcomas

Purpose: To compare the effectiveness, tolerance, and pharmacokinetics of a single dose of pegfilgrastim to daily filgrastim in children and young adults with sarcomas treated with dose-intensive combination chemotherapy. Experimental Design: Patients were randomized to receive a single dose of 100 mcg/kg of pegfilgrastim s.c. or 5 mcg/kg/day of filgrastim s.c., daily until neutrophil recovery after two treatment cycles with vincristine, doxorubicin, and cyclophosphamide (VDC) and two cycles of etoposide and ifosfamide (IE). The duration of severe neutropenia (absolute neutrophil count, ≤500/mcL) during cycles 1 to 4 and cycle duration for all cycles were compared. Pharmacokinetics of pegfilgrastim and filgrastim and CD34+ stem cell mobilization were studied on cycle 1. Growth factor–related toxicity, transfusions, and episodes of fever and neutropenia and infections were collected for cycles 1 to 4. Results: Thirty-four patients (median age, 20 years; range 3.8-25.8) were enrolled, and 32 completed cycles 1 to 4. The median (range) duration of absolute neutrophil count of <500/mcL was 5.5 (3-8) days for pegfilgrastim and 6 (0-9) days for filgrastim (P = 0.76) after VDC, and 1.5 (0-4) days for pegfilgrastim and 3.75 (0-6.5) days for filgrastim (P = 0.11) after IE. More episodes of febrile neutropenia and documented infections occurred on the filgrastim arm. Serum pegfilgrastim concentrations were highly variable. Pegfilgrastim apparent clearance (11 mL/h/kg) was similar to that reported in adults. Conclusion: A single dose per cycle of pegfilgrastim was well tolerated and may be as effective as daily filgrastim based on the duration of severe neutropenia and number of episodes of febrile neutropenia and documented infections after dose-intensive treatment with VDC and IE. (Clin Cancer Res 2009;15(23):7361–7)

Lenalidomide in Combination with Dexamethasone for the Treatment of Multiple Myeloma After One Prior Therapy

PURPOSE Lenalidomide (CC-5013, Revlimid; Celgene Corporation, Summit, NJ), a thalidomide analogue, was granted approval by the U.S. Food and Drug Administration (FDA) on June 29, 2006, for use in combination with dexamethasone in patients with multiple myeloma (MM) who have received at least one prior therapy. The FDA approved lenalidomide with a restricted distribution program, RevAssist. EXPERIMENTAL DESIGN In two randomized, double-blind, multicenter studies, the combination of lenalidomide and dexamethasone (LD) was compared with placebo and dexamethasone (PD) in patients with MM who had received at least one prior therapy. The primary endpoint was time to progression (TTP). RESULTS Following a prespecified interim analysis of TTP, an independent data-monitoring committee advised the sponsor to halt the two studies. For both studies, the interim analysis for efficacy revealed a statistically significant longer TTP with LD than with PD. The most clinically relevant grade 3 and 4 adverse events that occurred more frequently in the LD arm were neutropenia, thrombocytopenia, deep vein thrombosis, pulmonary embolism, and atrial fibrillation. Thrombotic or thromboembolic events, including deep vein thrombosis, pulmonary embolism, thrombosis, and intracranial venous sinus thrombosis were reported more frequently in patients treated with LD than with PD. CONCLUSIONS The FDA approved lenalidomide based on interim results from two multicenter, placebo-controlled, randomized trials comparing the combination of LD with PD that revealed a longer TTP with LD than with PD. The major toxicity observed during these trials was myelosuppression. The serious toxicities included thromboembolic events. Lenalidomide is only available under the RevAssist Program.