Epirubicin

12.1 Mechanism of Action Epirubicin is an anthracycline cytotoxic agent. Although it is known that anthracyclines can interfere with a number of biochemical and biological functions within eukaryotic cells, the precise mechanisms of epirubicin's cytotoxic and/or antiproliferative properties have not been completely elucidated. Epirubicin forms a complex with DNA by intercalation of its planar rings between nucleotide base pairs, with consequent inhibition of nucleic acid (DNA and RNA) and protein synthesis. Such intercalation triggers DNA cleavage by topoisomerase II, resulting in cytocidal activity. Epirubicin also inhibits DNA helicase activity, preventing the enzymatic separation of double-stranded DNA and interfering with replication and transcription. Epirubicin is also involved in oxidation/reduction reactions by generating cytotoxic free radicals. The antiproliferative and cytotoxic activity of epirubicin is thought to result from these or other possible mechanisms. Epirubicin is cytotoxic in vitro to a variety of established murine and human cell lines and primary cultures of human tumors. It is also active in vivo against a variety of murine tumors and human xenografts in athymic mice, including breast tumors.

1 INDICATIONS AND USAGE ELLENCE is indicated as a component of adjuvant therapy in patients with evidence of axillary node tumor involvement following resection of primary breast cancer [see Clinical Studies (14.1) ] . ELLENCE is an anthracycline topoisomerase inhibitor indicated as a component of adjuvant therapy in patients with evidence of axillary node tumor involvement following resection of primary breast cancer ( 1 ).

2 DOSAGE AND ADMINISTRATION • The recommended starting dose of ELLENCE is 100 to 120 mg/m 2 . Dosage reductions are possible when given in certain combinations ( 2.2 ). • Administer intravenously in repeated 3- to 4-week cycles, either total dose on Day 1 of each cycle or divided equally and given on Days 1 and 8 of each cycle ( 2.2 ). • Consider use of antiemetics when given in conjunction with other emetigenic drugs ( 2.1 ). • Patients administered the 120 mg/m 2 regimen of ELLENCE should receive prophylactic antibiotic therapy ( 2.1 ). • Adjust dosage after the first treatment cycle based on hematologic and nonhematologic toxicities ( 2.3 ). • Reduce dose in patients with hepatic impairment ( 2.3 , 8.6 ). • Consider lower doses in patients with severe renal impairment ( 2.3 , 8.7 ). 2.1 Important Administration Instructions When possible, to reduce the risk of developing cardiotoxicity in patients receiving ELLENCE after stopping treatment with other cardiotoxic agents, especially those with long half-lives such as trastuzumab, delay ELLENCE-based therapy until the other agents have cleared from the circulation [see Warnings and Precautions (5.1) ]. Antiemetics may reduce nausea and vomiting; consider use of antiemetics before administration of ELLENCE or when clinically indicated, particularly when given in conjunction with other emetigenic drugs [see Adverse Reactions (6.1) ]. Patients administered the 120 mg/m 2 regimen of ELLENCE should receive prophylactic antibiotic therapy. 2.2 Recommended Dose The recommended dose of ELLENCE is 100 to 120 mg/m 2 administered as an intravenous bolus [see Dosage and Administration (2.4) ] . The following regimens are recommended: CEF-120: Cyclophosphamide 75 mg/m 2 oral on Days 1 to 14 ELLENCE 60 mg/m 2 intravenously on Days 1 and 8 5-Fluorouracil 500 mg/m 2 intravenously on Days 1 and 8 Repeat every 28 days for 6 cycles FEC-100: 5-Fluorouracil 500 mg/m 2 intravenously on Day 1 ELLENCE 100 mg/m 2 intravenously on Day 1 Cyclophosphamide 500 mg/m 2 intravenously on Day 1 Repeat every 21 days for 6 cycles Administer ELLENCE in repeated 3- to 4-week cycles. The total dose of ELLENCE may be given on Day 1 of each cycle or divided equally and given on Days 1 and 8 of each cycle. 2.3 Dose Modifications ELLENCE dosage adjustments for hematologic and non-hematologic toxicities within a cycle of treatment, is based on nadir platelet counts <50,000/mm 3 , absolute neutrophil counts (ANC) <250/mm 3 , neutropenic fever, or Grades 3/4 nonhematologic toxicity. Reduce ELLENCE Day 1 dose in subsequent cycles to 75% of the Day 1 dose given in the current cycle. Delay Day 1 chemotherapy in subsequent courses of treatment until platelet counts are ≥100,000/mm 3 , ANC ≥1500/mm 3 , and nonhematologic toxicities have recovered to ≤ Grade 1. Cardiac Toxicity Discontinue ELLENCE in patients who develop signs or symptoms of cardiomyopathy [see Warnings and Precautions (5.1) ]. Bone Marrow Dysfunction Consider administering a lower starting dose (75–90 mg/m 2 ) for heavily pretreated patients, patients with pre-existing bone marrow depression, or in the presence of neoplastic bone marrow infiltration [see Warnings and Precautions (5.4) ]. For patients receiving a divided dose of ELLENCE (Day 1 and Day 8), the Day 8 dose should be 75% of Day 1 if platelet counts are 75,000–100,000/mm 3 and ANC is 1000 to 1499/mm 3 . If Day 8 platelet counts are <75,000/mm 3 , ANC <1000/mm 3 , or Grades 3/4 nonhematologic toxicity has occurred, omit the Day 8 dose. Hepatic Impairment In patients with elevated serum AST or serum total bilirubin concentrations [see Warnings and Precautions (5.5) and Clinical Pharmacology (12.3) ] , reduce dosage as follows: • Bilirubin 1.2 to 3 mg/dL or AST 2 to 4 times upper limit of normal 1/2 of recommended starting dose • Bilirubin > 3 mg/dL or AST > 4 times upper limit of normal 1/4 of recommended starting dose Renal Impairment Consider lower doses in patients with severe renal impairment (serum creatinine > 5 mg/dL) [see Warnings and Precautions (5.6) and Clinical Pharmacology (12.3) ] . 2.4 Preparation and Administration Precautions Preparation Storage of the solution for injection at refrigerated conditions can result in the formation of a gelled product. This gelled product will return to a slightly viscous to mobile solution after 2 to a maximum of 4 hours equilibration at controlled room temperature (15–25°C). Inspect parenteral drug products visually for particulate matter and discoloration prior to administration, whenever solution and container permit. ELLENCE is a cytotoxic drug. Follow applicable special handling and disposable procedures 1 [see References (15) ]. Incompatibilities Avoid prolonged contact with any solution of an alkaline pH as it will result in hydrolysis of the drug. Do not mix ELLENCE with heparin or fluorouracil due to chemical incompatibility that may lead to precipitation. ELLENCE can be used in combination with other antitumor agents, but d

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: • Cardiac Toxicity [see Warnings and Precautions (5.1) ] • Secondary Malignancies [see Warnings and Precautions (5.2) ] • Extravasation and Tissue Necrosis [see Warnings and Precautions (5.3) ] • Severe Myelosuppression [see Warnings and Precautions (5.4) ] • Tumor-Lysis Syndrome [see Warnings and Precautions (5.7) ] • Thrombophlebitis and Thromboembolic Events [see Warnings and Precautions (5.9) ] • Potentiation of Radiation Toxicity and Radiation Recall [see Warnings and Precautions (5.10) ] The most common adverse reactions (≥10%) are leukopenia, neutropenia, anemia, thrombocytopenia, amenorrhea, lethargy, nausea/vomiting, mucositis, diarrhea, infection, conjunctivitis/keratitis, alopecia, local skin toxicity, and rash/itch ( 6 ). To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc at 1-800-438-1985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reactions rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The safety of ELLENCE was evaluated in two studies (Studies MA-5 and GFEA-05) evaluating combination regimens in patients with early breast cancer [see Clinical Studies (14.1) ] . Of the 1260 patients treated in these studies, 620 patients received the higher-dose ELLENCE regimen (FEC-100/CEF-120), 280 patients received the lower-dose ELLENCE regimen (FEC-50), and 360 patients received CMF. Serotonin-specific antiemetic therapy and colony-stimulating factors were not used in these trials. Clinically relevant adverse reactions are summarized in Table 1. Table 1. Adverse Reactions in Patients with Early Breast Cancer Event % of Patients FEC-100/CEF-120 (N=620) FEC-50 (N=280) CMF (N=360) Grades 1–4 Grades 3/4 Grades 1–4 Grades 3/4 Grades 1–4 Grades 3/4 FEC & CEF = cyclophosphamide + ELLENCE + fluorouracil; CMF = cyclophosphamide + methotrexate + fluorouracil; NA = not available Grade 1 or 2 changes in transaminase levels were observed but were more frequently seen with CMF than with CEF. Hematologic Leukopenia 80 59 50 1.5 98 60 Neutropenia 80 67 54 11 96 78 Anemia 72 6 13 0 71 0.9 Thrombocytopenia 49 5 4.6 0 51 3.6 Endocrine Amenorrhea 72 0 69 0 68 0 Hot flashes 39 4 5 0 69 6 Body as a Whole Lethargy 46 1.9 1.1 0 73 0.3 Fever 5 0 1.4 0 4.5 0 Gastrointestinal Nausea/vomiting 92 25 83 22 85 6 Mucositis 59 9 9 0 53 1.9 Diarrhea 25 0.8 7 0 51 2.8 Anorexia 2.9 0 1.8 0 6 0.3 Infection Infection 22 1.6 15 0 26 0.6 Febrile neutropenia NA 6 0 0 NA 1.1 Ocular Conjunctivitis/keratitis 15 0 1.1 0 38 0 Skin Alopecia 96 57 70 19 84 7 Local toxicity 20 0.3 2.5 0.4 8 0 Rash/itch 9 0.3 1.4 0 14 0 Skin changes 4.7 0 0.7 0 7 0 Delayed Events Table 2 describes the incidence of delayed adverse reactions in patients participating in the MA-5 and GFEA-05 trials. Table 2. Long-Term Adverse Reactions in Patients with Early Breast Cancer Event % of Patients FEC-100/CEF-120 (N=620) FEC-50 (N=280) CMF (N=360) Two cases of acute lymphoid leukemia (ALL) were also observed in patients receiving ELLENCE. However, an association between anthracyclines such as ELLENCE and ALL has not been clearly established. Cardiac events Asymptomatic drops in LVEF 2.1 In study MA-5, cardiac function was not monitored after 5 years. 1.4 0.8 CHF 1.5 0.4 0.3 Leukemia AML 0.8 0 0.3 Hematologic Dose-dependent, reversible leukopenia and/or neutropenia is the predominant manifestation of hematologic toxicity associated with ELLENCE and represents the most common acute dose-limiting toxicity of this drug. In most cases, the white blood cell (WBC) nadir is reached 10 to 14 days from drug administration. Leukopenia/neutropenia is usually transient, with WBC and neutrophil counts generally returning to normal values by Day 21 after drug administration. As with other cytotoxic agents, ELLENCE at the recommended dose in combination with cyclophosphamide and fluorouracil can produce severe leukopenia and neutropenia. Severe thrombocytopenia and anemia may also occur. Clinical consequences of severe myelosuppression include fever, infection, septicemia, septic shock, hemorrhage, tissue hypoxia, symptomatic anemia, or death. If myelosuppressive complications occur, use appropriate supportive measures (e.g., intravenous antibiotics, colony-stimulating factors, transfusions). Myelosuppression requires careful monitoring. Assess total and differential WBC, red blood cell (RBC), and platelet counts before and during each cycle of therapy with ELLENCE [see Warnings and Precautions (5.4) ]. Gastrointestinal A dose-dependent mucositis (mainly oral stomatitis, less often esophagitis) may occur in patients treated with ELLENCE. Clinical manifestations of mucositis may include a pain or burning sensation, erythema, erosions

7 DRUG INTERACTIONS • Avoid using cardiotoxic agents in combination with ELLENCE ( 7.1 ). • Discontinue cimetidine during treatment with ELLENCE ( 7.2 ). 7.1 Cardiotoxic Agents Closely monitor cardiac function when ELLENCE is used in combination with other cardiotoxic agents. Patients receiving ELLENCE after stopping treatment with other cardiotoxic agents, especially those with long half-lives such as trastuzumab, may be at an increased risk of developing cardiotoxicity [see Dosage and Administration (2) and Warnings and Precautions (5.1) ] . Trastuzumab may persist in the circulation for up to 7 months. Therefore, avoid anthracycline-based therapy for up to 7 months after stopping trastuzumab when possible. Monitor the patient's cardiac function closely if anthracyclines are used before this time. Concomitant use of ELLENCE with other cardioactive compounds that could cause heart failure (e.g., calcium channel blockers), requires close monitoring of cardiac function throughout treatment. 7.2 Cimetidine Cimetidine increases the exposure to epirubicin [see Clinical Pharmacology (12.3) ]. Discontinue cimetidine during treatment with ELLENCE. 7.3 Other Cytotoxic Drugs ELLENCE used in combination with other cytotoxic drugs may show on-treatment additive toxicity, especially hematologic and gastrointestinal effects. Paclitaxel: The administration of epirubicin immediately prior to or after paclitaxel increased the systemic exposure of epirubicin, epirubicinol and 7-deoxydoxorubicin aglycone [see Clinical Pharmacology (12.3) ]. Docetaxel: The administration of epirubicin immediately prior to or after docetaxel did not have an effect on the systemic exposure of epirubicin, but increased the systemic exposure of epirubicinol and 7-deoxydoxorubicin aglycone [see Clinical Pharmacology (12.3) ]. 7.4 Radiation Therapy There are few data regarding the coadministration of radiation therapy and ELLENCE. In adjuvant trials of ELLENCE-containing CEF-120 or FEC-100 chemotherapies, breast irradiation was delayed until after chemotherapy was completed. This practice resulted in no apparent increase in local breast cancer recurrence relative to published accounts in the literature. A small number of patients received ELLENCE-based chemotherapy concomitantly with radiation therapy but had chemotherapy interrupted in order to avoid potential overlapping toxicities. It is likely that use of ELLENCE with radiotherapy may sensitize tissues to the cytotoxic actions of irradiation. Administration of ELLENCE after previous radiation therapy may induce an inflammatory recall reaction at the site of the irradiation.