Carmustine

Carmustine for Injection, USP is a nitrosourea indicated as palliative therapy as a single agent or in established combination therapy with other approved chemotherapeutic agents in the following: Brain tumors glioblastoma, brainstem glioma, medulloblastoma, astrocytoma, ependymoma, and metastatic brain tumors ( 1 ) Multiple myeloma-in combination with prednisone ( 1 ) Relapsed or refractory Hodgkin's lymphoma in combination with other approved drugs ( 1 ) Relapsed or refractory Non-Hodgkin's lymphomas in combination with other approved drugs ( 1 ) Carmustine for Injection, USP is indicated as palliative therapy as a single agent or in established combination therapy in the following: Brain tumors glioblastoma, brainstem glioma, medulloblastoma, astrocytoma, ependymoma, and metastatic brain tumors. Multiple myeloma in combination with prednisone. Relapsed or refractory Hodgkin's lymphoma in combination with other approved drugs. Relapsed or refractory Non-Hodgkin's lymphomas in combination with other approved drugs.

For injection: 100 mg of carmustine lyophilized powder in a single-dose vial for reconstitution and a vial containing 3mL sterile diluent (Dehydrated Alcohol Injection, USP) For injection: 100 mg of carmustine as a lyophilized powder in a single-dose vial for reconstitution and a vial containing 3 mL sterile diluent (Dehydrated Alcohol Injection, USP).

Hypersensitivity (4) Carmustine for Injection is contraindicated in patients with previous hypersensitivity to Carmustine for Injection or its components.

Administration Reactions: Extravasation may occur; monitor infusion site closely during administration (5.3) Carcinogenicity: Potentially carcinogenic to humans. Monitor patient periodically for such signs and apprise the patient of the symptoms for which they need to seek medical help. (5.4) Ocular Toxicity: Has occurred when administered via unapproved intraarterial intracarotid route. (5.5) Embryo-Fetal toxicity: Can cause fetal harm. Advise females of reproductive potential of the potential risk to a fetus and to avoid pregnancy. (5.6)

5.1 Myelosuppression Bone marrow toxicity is a dose-limiting, common and severe toxic effect of Carmustine for Injection occurring 4-6 weeks after drug administration (thrombocytopenia occurs at about 4 weeks post-administration persisting for 1 to 2 weeks; leukopenia occurs at 5 to 6 weeks after a dose of Carmustine for Injection persisting for 1 to 2 weeks; thrombocytopenia is generally more severe than leukopenia; anemia is less frequent and less severe compared to thrombocytopenia and/or leukopenia) Complete blood count should therefore be monitored weekly for at least six weeks after a dose. Repeat doses of Carmustine for Injection should not be given more frequently than every six weeks. The bone marrow toxicity of Carmustine for Injection is cumulative and therefore the dosage adjustment must be considered on the basis of nadir blood counts from prior dose [see Adverse Reactions (6) ] . Greater myelotoxicity (e.g., leukopenia and neutropenia) has been reported when carmustine was combined with cimetidine [see Drug Interactions (7) ] .

5.2 Pulmonary toxicity Cases of fatal pulmonary toxicity with Carmustine for Injection have been reported. Pulmonary toxicity characterized by pulmonary infiltrates and/or fibrosis has been reported to occur from 9 days to 43 months after treatment with Carmustine for Injection and related nitrosoureas. Pulmonary toxicity from Carmustine for Injection is dose-related. Patients receiving greater than 1400 mg/m 2 cumulative dose are at significantly higher risk than those receiving less. However, there have been reports of pulmonary fibrosis in patients receiving lower total doses. Interstitial fibrosis (with lower doses) occurred rarely. Additionally, delayed onset pulmonary fibrosis occurring up to 17 years after treatment has been reported in patients who received Carmustine for Injection (in cumulative doses ranging from 770 to 1800 mg/m 2 combined with cranial radiotherapy for intracranial tumors) in childhood and early adolescence. Other risk factors include past history of lung disease and duration of treatment. Baseline pulmonary function studies should be conducted along with frequent pulmonary function tests during treatment. Patients with a baseline below 70% of the predicted forced vital capacity (FVC) or carbon monoxide diffusing capacity (DLCO) are particularly at risk.

5.3 Administration Reactions Injection site reactions may occur during the administration of Carmustine for Injection. Rapid intravenous infusion of Carmustine for Injection may produce intensive flushing of the skin and suffusion of the conjunctiva within 2 hours, lasting about 4 hours. It is also associated with burning at the site of injection although true thrombosis is rare. Given the possibility of extravasation, close monitoring of the infusion site for possible infiltration during drug administration is recommended. A specific treatment for extravasation reactions is unknown at this time.

5.4 Carcinogenicity Long-term use of nitrosoureas, such as Carmustine for Injection, has been reported to be associated with the development of secondary malignancies. Carmustine was carcinogenic when administered to laboratory animals [see Nonclinical Toxicity (13.1) ] . Nitrosourea therapy, such as Carmustine for Injection, has carcinogenic potential in humans. Patients treated with Carmustine for Injection should be monitored long-term for development of second malignancies.

5.5 Ocular Toxicity Carmustine for Injection has been administered through an intraarterial intracarotid route; this procedure is investigational and has been associated with ocular toxicity. Safety and effectiveness of the intra-arterial route have not been established.

5.6 Embryo-Fetal Toxicity Carmustine was embryotoxic in rats and rabbits and teratogenic in rats when given in doses lower than the maximum cumulative human dose based on body surface area. There are no adequate and well- controlled studies in pregnant women. Advise pregnant women of the potential risk to the fetus [ see Use in Specific Populations ( 8.1 , 8.3 ) ]. Advise females of reproductive potential to use highly effective contraception during and after treatment with Carmustine for Injection for at least 6 months after therapy. Advise males of reproductive potential to use effective contraception during and after treatment with Carmustine for Injection for at least 3 months after therapy [see Use in Specific Populations ( 8.1 , 8.3 )].

The following serious adverse reactions are described elsewhere in the labeling: Myelosuppression [see Warnings and Precautions (5.1) ] Pulmonary toxicity [see Warnings and Precautions (5.2) ] Administration Reactions [see Warnings and Precautions (5.3) ] Carcinogenicity [see Warnings and Precautions (5.4) ] Ocular Toxicity [see Warnings and Precautions (5.5) ] The following adverse reactions associated with the use of Carmustine for Injection were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Cardiac Disorders Tachycardia and chest pain. Eye Disorders Conjunctival edema, conjunctival hemorrhage, blurred vision and loss of depth perception Gastrointestinal Toxicity Nausea, vomiting, anorexia, and diarrhea Hepatotoxicity Increased transaminase, increased alkaline phosphatase, increased bilirubin levels Infections and Infestations Opportunistic infection (including with fatal outcome). Neoplasms Benign, Malignant and Unspecified (including cysts and polyps) Acute leukemia, bone marrow dysplasias. Nephrotoxicity Progressive azotemia, decrease in kidney size, renal failure Nervous System Disorders Headaches, encephalopathy, and seizures Pulmonary Toxicity Pneumonitis, interstitial lung disease Reproductive System and Breast Disorders Gynecomastia Skin and Subcutaneous Tissue Disorders Burning sensation, hyperpigmentation, swelling, pain, erythema, skin necrosis, alopecia, allergic reaction Vascular Disorders Veno-occlusive disease. Most common adverse reactions (>1%) are nausea, vomiting, renal toxicity, pneumonitis, pulmonary toxicity, myelosuppression ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Avet Pharmaceuticals Inc. at 1-866-901-DRUG (3784) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Cimetidine: Increased myelosuppression with concomitant use. (7.1) Phenobarbital: Induces carmustine metabolism, reducing exposure. May lead to reduced efficacy. (7.1) Phenytoin: Carmustine for Injection may reduce the efficacy of phenytoin. (7.2)

7.1 Effect of other drugs on Carmustine for Injection Cimetidine: Greater myelosuppression (e.g., leukopenia and neutropenia) has been reported when oral cimetidine has been coadministered with carmustine. Consider alternative drugs to cimetidine. Phenobarbital: Phenobarbital induces the metabolism of carmustine and may compromise antitumor activity of Carmustine for Injection. Consider alternative drugs to phenobarbital.

7.2 Effect of Carmustine for Injection on other drugs Phenytoin: Carmustine for Injection when coadministered with phenytoin may reduce phenytoin serum concentrations. Consider alternative drugs to phenytoin.

Lactation: Advise lactating females not to breastfeed (8.2)

8.1 Pregnancy Risk Summary Carmustine for Injection can cause fetal harm when administered to a pregnant woman based on the mechanism of action [ see Clinical Pharmacology (12.1) ] and findings in animals [see Data] . Limited available data with Carmustine for Injection use in pregnant women are insufficient to inform a drug-associated risk of major birth defects and miscarriage. Carmustine was embryotoxic in rats and rabbits and teratogenic in rats (thoracoabdominal closure, neural tube, and eye defects and malformations of the skeletal system of the fetus) when given in doses lower than the maximum cumulative human dose based on body surface area. Consider the benefits and risks of Carmustine for Injection for the mother and possible risks to the fetus when prescribing Carmustine for Injection to a pregnant woman. Adverse outcomes in pregnancy occur regardless of the health of the mother or the use of medications. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Data Animal Data Intraperitoneal (IP) administration of carmustine to pregnant rats 14 days prior to mating and during the period of organogenesis at cumulative doses ≥ 26 mg/kg (158 mg/ m 2 ), approximately 0.1 times the maximum cumulative human dose of 1400 mg/m 2 , resulted in pre-implantation loss, increased resorptions (including completely resorbed litters), and reduced the number of live births in the presence of maternal toxicity. Carmustine administered IP to pregnant rats during the period of organogenesis at cumulative doses ≥ 4 mg/kg (24 mg/m 2 ), approximately 0.02 times the maximum cumulative human dose based on a mg/m 2 basis, resulted in reduced fetal weight and various malformations, which included thoracoabdominal closure defects, neural tube defects, and eye defects, including microphthalmia/anophthalmia, and skeletal anomalies in the skull, sternebra, vertebrae and ribs, and reduced skeletal ossification) in the presence of maternal toxicity. Embryo-fetal death was observed at cumulative doses ≥ 8 mg/kg (48 mg/m 2 ), approximately 0.03 times the maximum cumulative human dose on a mg/ m 2 basis. Intravenous (IV) administration of carmustine to rats at a cumulative dose of 50 mg/kg (300 mg/m 2 ), approximately 0.2 times the maximum cumulative human dose on a mg/m 2 basis, during the last quarter of pregnancy resulted in the death of offspring within 4 months. Carmustine administered IV to rabbits during the period of organogenesis resulted in spontaneous abortions in mothers and growth defects in the fetus, mainly at cumulative doses ≥ 13 mg/kg (156 mg/ m 2 ), approximately 0.1 times the maximum cumulative human dose on a mg/ m 2 basis.

8.2 Lactation Risk Summary There is no information regarding the presence of carmustine in human milk, the effects on the breastfed infant, or the effects on milk production. Because many drugs are excreted in human milk and because of the potential for serious adverse events (e.g., carcinogenicity and myelosuppression) in nursing infants, nursing should be discontinued while taking Carmustine for Injection.

8.3 Females and Males of Reproductive Potential Contraception Advise female patients to avoid pregnancy during treatment with Carmustine for Injection because of the risk of fetal harm [see Use in Specific Populations (8.1) ] . Advise female patients of reproductive potential to use highly effective contraception during and for up to six months after completion of treatment. Advise males with female sexual partners of reproductive potential to use effective contraception during Carmustine for Injection treatment and for at least three months after the final dose of Carmustine for Injection [ see Nonclinical Toxicology (13.1) ]. Infertility Based on nonclinical findings, male fertility may be compromised by treatment with Carmustine for Injection [see Nonclinical Toxicology (13.1) ].

8.4 Pediatric Use Safety and effectiveness in children have not been established. Delayed onset pulmonary fibrosis occurring up to 17 years after treatment has been reported in a long-term study of patients who received Carmustine for Injection in childhood and early adolescence (1-16 years). Eight out of the 17 patients (47%) who survived childhood brain tumors, including all the 5 patients initially treated at less than 5 years of age, died of pulmonary fibrosis, [see Adverse Reactions (6.1) ].

8.5 Geriatric Use Clinical studies of Carmustine for Injection did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dose range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Carmustine for Injection and its metabolites are known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and renal function should be monitored.

The mechanism of action of carmustine is not fully understood. While carmustine alkylates DNA and RNA, it is not cross-resistant with other alkylators. As with other nitrosoureas, it may also inhibit several key enzymatic processes by carbamoylation of amino acids in proteins. The metabolites may contribute to antitumor activity and toxicities of carmustine.