Pemetrexed (Page 4 of 9)

6.2 Postmarketing Experience

The following adverse reactions have been identified during post-approval use of pemetrexed. Because these reactions are 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.

Blood and Lymphatic System — immune-mediated hemolytic anemia

Gastrointestinal — colitis, pancreatitis

General Disorders and Administration Site Conditions — edema

Injury, poisoning, and procedural complications — radiation recall

Respiratory — interstitial pneumonitis

Skin — Serious and fatal bullous skin conditions, Stevens-Johnson syndrome, and toxic epidermal necrolysis

7 DRUG INTERACTIONS

Effects of Ibuprofen on Pemetrexed

Ibuprofen increases exposure (AUC) of pemetrexed [see Clinical Pharmacology (12.3)]. In patients with creatinine clearance between 45 mL/min and 79 mL/min:

• Avoid administration of ibuprofen for 2 days before, the day of, and 2 days following administration of pemetrexed [see Dosage and Administration (2.5)].
• Monitor patients more frequently for myelosuppression, renal, and gastrointestinal toxicity, if concomitant administration of ibuprofen cannot be avoided.

8 USE IN SPECIFIC POPULATIONS

8.1 Pregnancy

Risk Summary

Based on findings from animal studies and its mechanism of action, pemetrexed can cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1)]. There are no available data on pemetrexed use in pregnant women. In animal reproduction studies, intravenous administration of pemetrexed to pregnant mice during the period of organogenesis was teratogenic, resulting in developmental delays and malformations at doses lower than the recommended human dose of 500 mg/m² [see Data]. Advise pregnant women of the potential risk to a fetus [see Use in Special Populations (8.3)].

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

Data

Animal Data

Pemetrexed was teratogenic in mice. Daily dosing of pemetrexed by intravenous injection to pregnant mice during the period of organogenesis increased the incidence of fetal malformations (cleft palate; protruding tongue; enlarged or misshaped kidney; and fused lumbar vertebra) at doses (based on BSA) 0.03 times the human dose of 500 mg/m². At doses, based on BSA, greater than or equal to 0.0012 times the 500 mg/m² human dose, pemetrexed administration resulted in dose-dependent increases in developmental delays (incomplete ossification of talus and skull bone; and decreased fetal weight).

8.2 Lactation

Risk Summary

There is no information regarding the presence of pemetrexed or its metabolites in human milk, the effects on the breastfed infant, or the effects on milk production. Because of the potential for serious adverse reactions in breastfed infants from pemetrexed, advise women not to breastfeed during treatment with pemetrexed and for one week after the last dose.

8.3 Females and Males of Reproductive Potential

Based in animal data pemetrexed can cause malformations and developmental delays when administered to a pregnant woman [see Use in Specific Populations (8.1)].

Pregnancy Testing

Verify pregnancy status of females of reproductive potential prior to initiating Pemetrexed Injection [see Use in Specific Populations (8.1)].

Contraception

Females

Because of the potential for genotoxicity, advise females of reproductive potential to use effective contraception during treatment with pemetrexed and for 6 months after the last dose.

Males

Because of the potential for genotoxicity, advise males with female partners of reproductive potential to use effective contraception during treatment with pemetrexed and for 3 months after the last dose [see Nonclinical Toxicology (13.1)].

Infertility

Males

Pemetrexed may impair fertility in males of reproductive potential. It is not known whether these effects on fertility are reversible [see Nonclinical Toxicology (13.1)].

8.4 Pediatric Use

The safety and effectiveness of pemetrexed in pediatric patients have not been established.

The safety and pharmacokinetics of pemetrexed were evaluated in two clinical studies conducted in pediatric patients with recurrent solid tumors (NCT00070473 N=32 and NCT00520936 N=72). Patients in both studies received concomitant vitamin B₁₂ and folic acid supplementation and dexamethasone.

No tumor responses were observed. Adverse reactions observed in pediatric patients were similar to those observed in adults.

Single-dose pharmacokinetics of pemetrexed were evaluated in 22 patients age 4 to 18 years enrolled in NCT00070473 were within range of values in adults.

8.5 Geriatric Use

Of the 3,946 patients enrolled in clinical studies of pemetrexed, 34% were 65 and over and 4% were 75 and over. No overall differences in effectiveness were observed between these patients and younger patients. The incidences of Grade 3-4 anemia, fatigue, thrombocytopenia, hypertension, and neutropenia were higher in patients 65 years of age and older as compared to younger patients: in at least one of five randomized clinical trials. [see Adverse Reactions (6.1) and Clinical Studies (14.1, 14.2)].

8.6 Patients with Renal Impairment

Pemetrexed is primarily excreted by the kidneys. Decreased renal function results in reduced clearance and greater exposure (AUC) to pemetrexed compared with patients with normal renal function [Warnings and Precautions (5.2, 5.6) and Clinical Pharmacology (12.3)]. No dose is recommended for patients with creatinine clearance less than 45 mL/min [see Dosage and Administration (2.3)].

10 OVERDOSAGE

No drugs are approved for the treatment of pemetrexed overdose. Based on animal studies, administration of leucovorin may mitigate the toxicities of pemetrexed overdosage. It is not known whether pemetrexed is dialyzable.

11 DESCRIPTION

Pemetrexed for Injection, USP is a folate analog metabolic inhibitor. The drug substance, pemetrexed disodium 2.5 hydrate has the chemical name L-Glutamic acid, N-[4-[2-(2-Amino-4,7-Dihydro-4-oxo-1H- pyrrolo[2,3-d]Pyrimidin-5-yl)Ethyl] Benzoyl]-L-Glutamic acid disodium 2.5 hydrate. It is a white to off-white crystalline powder with a molecular formula of C₂₀ H₁₉ N₅ Na₂ O₆ .2.5H₂ O and a molecular weight of 516.45 g/mol. The structural formula is as follows:

Pemetrexed for Injection, USP is supplied as a sterile lyophilized powder for intravenous infusion available in single-dose vials. The product is a white to either light yellow or green-yellow lyophilized powder or cake. Each 750 mg vial of pemetrexed for injection, USP contains pemetrexed disodium equivalent to 750 mg pemetrexed and 750 mg of mannitol. Hydrochloric acid and/or sodium hydroxide may have been added to adjust pH.

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

Pemetrexed is a folate analog metabolic inhibitor that disrupts folate-dependent metabolic processes essential for cell replication. In vitro studies show that pemetrexed inhibits thymidylate synthase (TS), dihydrofolate reductase, and glycinamide ribonucleotide formyltransferase (GARFT), which are folate-dependent enzymes involved in the de novo biosynthesis of thymidine and purine nucleotides. Pemetrexed is taken into cells by membrane carriers such as the reduced folate carrier and membrane folate binding protein transport systems. Once in the cell, pemetrexed is converted to polyglutamate forms by the enzyme folylpolyglutamate synthetase. The polyglutamate forms are retained in cells and are inhibitors of TS and GARFT.