Paclitaxel

INDICATIONS AND USAGE Paclitaxel Injection, USP is indicated as subsequent therapy for the treatment of advanced carcinoma of the ovary. As first-line therapy, Paclitaxel Injection, USP is indicated in combination with cisplatin. Paclitaxel Injection, USP is indicated for the adjuvant treatment of node-positive breast cancer administered sequentially to standard doxorubicin-containing combination chemotherapy. In the clinical trial, there was an overall favorable effect on disease-free and overall survival in the total population of patients with receptor-positive and receptor-negative tumors, but the benefit has been specifically demonstrated by available data (median follow-up 30 months) only in the patients with estrogen and progesterone receptor-negative tumors ( see CLINICAL STUDIES: Breast Carcinoma ). Paclitaxel Injection, USP is indicated for the treatment of breast cancer after failure of combination chemotherapy for metastatic disease or relapse within 6 months of adjuvant chemotherapy. Prior therapy should have included an anthracycline unless clinically contraindicated. Paclitaxel Injection, USP, in combination with cisplatin, is indicated for the first-line treatment of non-small cell lung cancer in patients who are not candidates for potentially curative surgery and/or radiation therapy. Paclitaxel Injection, USP is indicated for the second-line treatment of AIDS-related Kaposi's sarcoma.

DOSAGE AND ADMINISTRATION Note: Contact of the undiluted concentrate with plasticized PVC equipment or devices used to prepare solutions for infusion is not recommended. In order to minimize patient exposure to the plasticizer DEHP [di-(2-ethylhexyl)phthalate], which may be leached from PVC infusion bags or sets, diluted paclitaxel solutions should be stored in bottles (glass, polypropylene) or plastic bags (polypropylene, polyolefin) and administered through polyethylene-lined administration sets. All patients should be premedicated prior to paclitaxel administration in order to prevent severe hypersensitivity reactions. Such premedication may consist of dexamethasone 20 mg PO administered approximately 12 and 6 hours before paclitaxel, diphenhydramine (or its equivalent) 50 mg I.V. 30 to 60 minutes prior to paclitaxel, and cimetidine (300 mg) or ranitidine (50 mg) I.V. 30 to 60 minutes before paclitaxel. For patients with carcinoma of the ovary , the following regimens are recommended (see CLINICAL STUDIES, Ovarian Carcinoma ): 1) For previously untreated patients with carcinoma of the ovary, one of the following recommended regimens may be given every 3 weeks. In selecting the appropriate regimen, differences in toxicities should be considered (see TABLE 11 in ADVERSE REACTIONS, Disease-Specific Adverse Event Experiences ). a. Paclitaxel administered intravenously over 3 hours at a dose of 175 mg/m 2 followed by cisplatin at a dose of 75 mg/m 2 ; or b. Paclitaxel administered intravenously over 24 hours at a dose of 135 mg/m 2 followed by cisplatin at a dose of 75 mg/m 2 . 2) In patients previously treated with chemotherapy for carcinoma of the ovary, paclitaxel has been used at several doses and schedules; however, the optimal regimen is not yet clear (see CLINICAL STUDIES, Ovarian Carcinoma ). The recommended regimen is paclitaxel 135 mg/m 2 or 175 mg/m 2 administered intravenously over 3 hours every 3 weeks. For patients with carcinoma of the breast , the following regimens are recommended (see CLINICAL STUDIES, Breast Carcinoma): 1) For the adjuvant treatment of node-positive breast cancer, the recommended regimen is paclitaxel, at a dose of 175 mg/m 2 intravenously over 3 hours every 3 weeks for 4 courses administered sequentially to doxorubicin-containing combination chemotherapy. The clinical trial used 4 courses of doxorubicin and cyclophosphamide (see CLINICAL STUDIES, Breast Carcinoma ). 2) After failure of initial chemotherapy for metastatic disease or relapse within 6 months of adjuvant chemotherapy, paclitaxel at a dose of 175 mg/m 2 administered intravenously over 3 hours every 3 weeks has been shown to be effective. For patients with non-small cell lung carcinoma , the recommended regimen, given every 3 weeks, is paclitaxel administered intravenously over 24 hours at a dose of 135 mg/m 2 followed by cisplatin, 75 mg/m 2 . For patients with AIDS-related Kaposi's sarcoma , paclitaxel administered at a dose of 135 mg/m 2 given intravenously over 3 hours every 3 weeks or at a dose of 100 mg/m 2 given intravenously over 3 hours every 2 weeks is recommended (dose intensity 45 to 50 mg/m 2 /week). In the 2 clinical trials evaluating these schedules (see CLINICAL STUDIES, AIDS-Related Kaposi's Sarcoma ), the former schedule (135 mg/m 2 every 3 weeks) was more toxic than the latter. In addition, all patients with low performance status were treated with the latter schedule (100 mg/m 2 every 2 weeks). Based upon the immunosuppression in patients with advanced HIV disease, the following modifications are recommended in these patients: 1) Reduce the dose of dexamethasone as 1 of the 3 premedication drugs to 10 mg PO (instead of 20 mg PO); 2) Initiate or repeat treatment with paclitaxel only if the neutrophil count is at least 1,000 cells/mm 3 ; 3) Reduce the dose of subsequent courses of paclitaxel by 20% for patients who experience severe neutropenia (neutrophil <500 cells/mm 3 for a week or longer); and 4) Initiate con…

WARNINGS Anaphylaxis and severe hypersensitivity reactions characterized by dyspnea and hypotension requiring treatment, angioedema, and generalized urticaria have occurred in 2 to 4% of patients receiving paclitaxel in clinical trials. Fatal reactions have occurred in patients despite premedication. All patients should be pretreated with corticosteroids, diphenhydramine, and H 2 antagonists. (see DOSAGE AND ADMINISTRATION ). Patients who experience severe hypersensitivity reactions to Paclitaxel should not be rechallenged with the drug. Bone marrow suppression (primarily neutropenia) is dose-dependent and is the dose-limiting toxicity. Neutrophil nadirs occurred at a median of 11 days. Paclitaxel should not be administered to patients with baseline neutrophil counts of less than 1,500 cells/mm 3 (<1,000 cells/mm 3 for patients with KS). Frequent monitoring of blood counts should be instituted during paclitaxel treatment. Patients should not be re-treated with subsequent cycles of paclitaxel until neutrophils recover to a level >1,500 cells/mm3 (>1,000 cells/mm 3 for patients with KS) and platelets recover to a level >100,000 cells/mm 3 . Severe conduction abnormalities have been documented in <1% of patients during paclitaxel therapy and in some cases requiring pacemaker placement. If patients develop significant conduction abnormalities during paclitaxel infusion, appropriate therapy should be administered and continuous cardiac monitoring should be performed during subsequent therapy with paclitaxel. Pregnancy Paclitaxel can cause fetal harm when administered to a pregnant woman. Administration of paclitaxel during the period of organogenesis to rabbits at doses of 3 mg/kg/day (about 0.2 the daily maximum recommended human dose on a mg/m 2 basis) caused embryo- and fetotoxicity, as indicated by intrauterine mortality, increased resorptions, and increased fetal deaths. Maternal toxicity was also observed at this dose. No teratogenic effects were observed at 1 mg/kg/day (about 1/15 the daily maximum recommended human dose on a mg/m 2 basis); teratogenic potential could not be assessed at higher doses due to extensive fetal mortality. There are no adequate and well-controlled studies in pregnant women. If paclitaxel is used during pregnancy, or if the patient becomes pregnant while receiving this drug, the patient should be apprised of the potential hazard to the fetus. Women of child-bearing potential should be advised to avoid becoming pregnant.

CONTRAINDICATIONS Paclitaxel is contraindicated in patients who have a history of hypersensitivity reactions to Paclitaxel or other drugs formulated in polyoxyl 35 castor oil. Paclitaxel should not be used in patients with solid tumors who have baseline neutrophil counts of <1,500 cells/mm 3 or in patients with AIDS-related Kaposi's sarcoma with baseline neutrophil counts of <1,000 cells/mm 3 .

DRUG INTERACTIONS In a Phase 1 trial using escalating doses of paclitaxel (110 to 200 mg/m 2 ) and cisplatin (50 or 75 mg/m 2 ) given as sequential infusions, myelosuppression was more profound when paclitaxel was given after cisplatin than with the alternate sequence (i.e., paclitaxel before cisplatin). Pharmacokinetic data from these patients demonstrated a decrease in paclitaxel clearance of approximately 33% when paclitaxel was administered following cisplatin. The metabolism of paclitaxel is catalyzed by cytochrome P450 isoenzymes CYP2C8 and CYP3A4. Caution should be exercised when administering paclitaxel concomitantly with known substrates or inhibitors of the cytochrome P450 isoenzymes CTP2C8 and CYP3A4. Caution should be exercised when paclitaxel is concomitantly administered with known substrates (e.g, midazolam, buspirone, felodipine, lovastatin, eletriptan, sildenafil, simvastatin, and triazolam), inhibitors (e.g., atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, ritonavir, saquinavir, and telithromycin), and inducers (e.g., rifampin and carbamazepine) of CYP3A4. (see CLINICAL PHARMACOLOGY ). Caution should also be exercised when paclitaxel is concomitantly administered with known substrates (e.g., repaglinide and rosiglitazone), inhibitors (e.g., gemfibrozil), and inducers (e.g., rifampin) of CYP2C8. (see CLINICAL PHARMACOLOGY ). Potential interactions between paclitaxel, a substrate of CYP3A4, and protease inhibitors (ritonavir, saquinavir, indinavir, and nelfinavir), which are substrates and/or inhibitors of CYP3A4, have not been evaluated in clinical trials. Reports in the literature suggest that plasma levels of doxorubicin (and its active metabolite doxorubicinol) may be increased when paclitaxel and doxorubicin are used in combination. Hematology Paclitaxel therapy should not be administered to patients with baseline neutrophil counts of less than 1,500 cells/mm 3 . In order to monitor the occurrence of myelotoxicity, it is recommended that frequent peripheral blood cell counts be performed on all patients receiving paclitaxel. Patients should not be re-treated with subsequent cycles of paclitaxel until neutrophils recover to a level >1,500 cells/mm 3 and platelets recover to a level >100,000 cells/mm 3 . In the case of severe neutropenia (<500 cells/mm 3 for 7 days or more)during a course of paclitaxel therapy, a 20% reduction in dose for subsequent courses of therapy is recommended. For patients with advanced HIV disease and poor-risk AIDS-related Kaposi's sarcoma, paclitaxel, at the recommended dose for this disease, can be initiated and repeated if the neutrophil count is at least 1,000 cells/mm 3 . Hypersensitivity Reactions : Patients with a history of severe hypersensitivity reactions to products containing polyoxyl 35 castor oil (e.g., cyclosporin for injection concentrate and teniposide for injection concentrate) should not be treated with paclitaxel. In order to avoid the occurrence of severe hypersensitivity reactions, all patients treated with paclitaxel should be premedicated with corticosteroids (such as dexamethasone), diphenhydramine and H 2 antagonists (such as cimetidine or ranitidine). Minor symptoms such as flushing, skin reactions, dyspnea, hypotension, or tachycardia do not require interruption of therapy. However, severe reactions, such as hypotension requiring treatment, dyspnea requiring bronchodilators, angioedema, or generalized urticaria require immediate discontinuation of paclitaxel and aggressive symptomatic therapy. Patients who have developed severe hypersensitivity reactions should not be rechallenged with paclitaxel. Cardiovascular Hypotension, bradycardia, and hypertension have been observed during administration of paclitaxel, but generally do not require treatment. Occasionally paclitaxel infusions must be interrupted or discontinued because of initial or recurrent hypertension. Frequent vital sign monitoring, particularly during…

Nursing Mothers It is not known whether the drug is excreted in human milk. Following intravenous administration of carbon 14-labeled paclitaxel to rats on days 9 to 10 postpartum, concentrations of radioactivity in milk were higher than in plasma and declined in parallel with the plasma concentrations. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants, it is recommended that nursing be discontinued when receiving paclitaxel therapy.

ADVERSE REACTIONS Pooled Analysis of Adverse Event Experiences from Single-Agent Studies Data in the following table are based on the experience of 812 patients (493 with ovarian carcinoma and 319 with breast carcinoma) enrolled in 10 studies who received single-agent paclitaxel injection. Two hundred and seventy-five patients were treated in 8, Phase 2 studies with paclitaxel doses ranging from 135 to 300 mg/m 2 administered over 24 hours (in 4 of these studies, G-CSF was administered as hematopoietic support). Three hundred and one patients were treated in the randomized Phase 3 ovarian carcinoma study which compared 2 doses (135 or 175 mg/m 2 ) and 2 schedules (3 or 24 hours) of paclitaxel. Two hundred and thirty-six patients with breast carcinoma received paclitaxel (135 or 175 mg/m 2 ) administered over 3 hours in a controlled study. TABLE 10. SUMMARY a OF ADVERSE EVENTS IN PATIENTS WITH SOLID TUMORS RECEIVING SINGLE-AGENT PACLITAXEL Percent of Patients (n=812) · B one Marrow —Neutropenia <2,000/mm 3 90 <500/mm 3 52 —Leukopenia <4,000/mm 3 90 <1,000/mm 3 17 —Thrombocytopenia <100,000/mm 3 20 <50,000/mm 3 7 —Anemia <11 g/dL 78 <8 g/dL 16 —Infections 30 —Bleeding 14 —Red Cell Transfusions 25 —Platelet Transfusions · Hy persensitivity Reaction b 2 —All 41 —Severe † 2 · Card i ovascular —Vital Sign Changes c —Bradycardia (n=537) 3 —Hypotension (n=532) 12 —Significant Cardiovascular Events 1 · A bnormal ECG —All Pts 23 —Pts with normal baseline (n=559) 14 · Peripheral Neuropathy —Any symptoms 60 —Severe symptoms † 3 · My algia/Arthralgia —Any symptoms 60 —Severe symptoms † 8 · G astrointestinal —Nausea and vomiting 52 —Diarrhea 38 —Mucositis 31 · Alopecia 87 · Hep atic (Pts with normal baseline and on study data) —Bilirubin elevations (n=765) 7 —Alkaline phosphatase elevations (n=575) 22 —AST (SGOT) elevations (n=591) 19 · Injecti on Site Reaction 13 a Based on worst course analysis. b All patients received premedication. c During the first 3 hours of infusion. † Severe events are defined as at least Grade III toxicity. None of the observed toxicities were clearly influenced by age. Disease-Specific Adverse Event Experiences First-Line Ovary in Combination For the 1084 patients who were evaluable for safety in the Phase 3 first-line ovary combination therapy studies, TABLE 11 shows the incidence of important adverse events. For both studies, the analysis of safety was based on all courses of therapy (6 courses for the GOG-111 study and up to 9 courses for the Intergroup study). TABLE 11. FREQUENCY a OF IMPORTANT ADVERSE EVENTS IN THE PHASE 3 FIRST-LINE OVARIAN CARCINOMA STUDIES Percent of Patients Intergroup GOG-111 T175/3 b c75 c (n = 339) C750 c c75 c (n = 336) T135/24 b c75 c (n = 196) C750 c c75 c (n = 213) · B one Marrow —Neutropenia <2,000/mm 3 91 d 95 d 96 92 <500/mm 3 33 d 43 d 81 d 58 d —Thrombocytopenia <100,000/mm 3e 21 d 33 d 26 30 <50,000/mm 3 3 d 7 d 10 9 —Anemia <11 g/dL f 96 97 88 86 <8 g/dL 3 d 8 d 13 9 —Infections 25 27 21 15 —Febrile Neutropenia 4 7 15 d 4 d · Hypersensitivity Reaction —All 11 d 6 d 8 d.g 1 d.g —Severe † 1 1 3 d.g — d.g · Neurotoxicity h —Any symptoms 87 d 52 d 25 20 —Severe symptoms † 21 d 2 d 3 d — d · Nausea and Vomiting —Any symptoms 88 93 65 69 —Severe symptoms † 18 24 10 11 · Myalgia/Arthralgia —Any symptoms 60 d 27 d 9 d 2 d —Severe symptoms † 6 d 1 d 1 — · Diarrhea —Any symptoms 37 d 29 d 16 d 8 d —Severe symptoms † 2 3 4 1 · Asthenia —Any symptoms NC NC 17 d 10 d —Severe symptoms † NC NC 1 1 · Alopecia —Any symptoms 96 d 89 d 55 d 37 d —Severe symptoms † 51 d 21 d 6 8 a Based on worst course analysis. b Paclitaxel (T) dose in mg/m 2 /infusion duration in hours. c Cyclophosphamide (C) or cisplatin (c) dose in mg/m 2 . d P<0.05 by Fisher exact test. e <130,000/mm 3 in the Intergroup study. f <12 g/dL in the Intergroup study. g All patients received premedication. h In the GOG-111 study, neurotoxicity was collected as peripheral neuropathy and in the Intergroup study, neurotoxicity was…