5 WARNINGS AND PRECAUTIONS
5.1 Myelosuppression and Increased Risk of Myelosuppression without Vitamin Supplementation
Pemetrexed can cause severe myelosuppression resulting in a requirement for transfusions and which may lead to neutropenic infection. The risk of myelosuppression is increased in patients who do not receive vitamin supplementation. In Study JMCH, incidences of Grade 3–4 neutropenia (38% versus 23%), thrombocytopenia (9% versus 5%), febrile neutropenia (9% versus 0.6%), and neutropenic infection (6% versus 0) were higher in patients who received pemetrexed plus cisplatin without vitamin supplementation as compared to patients who were fully supplemented with folic acid and vitamin B12 prior to and throughout pemetrexed plus cisplatin treatment.
Initiate supplementation with oral folic acid and intramuscular vitamin B12 prior to the first dose of Pemetrexed Injection; continue vitamin supplementation during treatment and for 21 days after the last dose of Pemetrexed Injection to reduce the severity of hematologic and gastrointestinal toxicity of Pemetrexed Injection [see Dosage and Administration (2.4)]. Obtain a complete blood count at the beginning of each cycle. Do not administer Pemetrexed Injection until the ANC is at least 1500 cells/mm3 and platelet count is at least 100,000 cells/mm3. Permanently reduce Pemetrexed Injection in patients with an ANC of less than 500 cells/mm3 or platelet count of less than 50,000 cells/mm3 in previous cycles [see Dosage and Administration (2.6)].
In Studies JMDB and JMCH, among patients who received vitamin supplementation, incidence of Grade 3–4 neutropenia was 15% and 23%, the incidence of Grade 3–4 anemia was 6% and 4%, and incidence of Grade 3–4 thrombocytopenia was 4% and 5%, respectively. In Study JMCH, 18% of patients in the pemetrexed arm required red blood cell transfusions compared to 7% of patients in the cisplatin arm [see Adverse Reactions (6.1)]. In Studies JMEN, PARAMOUNT, and JMEI, where all patients received vitamin supplementation, incidence of Grade 3–4 neutropenia ranged from 3% to 5%, and incidence of Grade 3–4 anemia ranged from 3% to 5%.
5.2 Renal Failure
Pemetrexed can cause severe, and sometimes fatal, renal toxicity. The incidences of renal failure in clinical studies in which patients received pemetrexed with cisplatin were: 2.1% in Study JMDB and 2.2% in Study JMCH. The incidence of renal failure in clinical studies in which patients received pemetrexed as a single agent ranged from 0.4% to 0.6% (Studies JMEN, PARAMOUNT, and JMEI [see Adverse Reactions (6.1)]). Determine creatinine clearance before each dose and periodically monitor renal function during treatment with Pemetrexed Injection. Withhold Pemetrexed Injection in patients with a creatinine clearance of less than 45 mL/minute [see Dosage and Administration (2.3)].
5.3 Bullous and Exfoliative Skin Toxicity
Serious and sometimes fatal, bullous, blistering and exfoliative skin toxicity, including cases suggestive of Stevens-Johnson Syndrome/Toxic epidermal necrolysis can occur with pemetrexed. Permanently discontinue Pemetrexed Injection for severe and life-threatening bullous, blistering or exfoliating skin toxicity.
5.4 Interstitial Pneumonitis
Serious interstitial pneumonitis, including fatal cases, can occur with pemetrexed treatment. Withhold Pemetrexed Injection for acute onset of new or progressive unexplained pulmonary symptoms such as dyspnea, cough, or fever pending diagnostic evaluation. If pneumonitis is confirmed, permanently discontinue Pemetrexed Injection.
5.5 Radiation Recall
Radiation recall can occur with pemetrexed in patients who have received radiation weeks to years previously. Monitor patients for inflammation or blistering in areas of previous radiation treatment. Permanently discontinue Pemetrexed Injection for signs of radiation recall.
5.6 Increased Risk of Toxicity with Ibuprofen in Patients with Renal Impairment
Exposure to pemetrexed is increased in patients with mild to moderate renal impairment who take concomitant ibuprofen, increasing the risks of adverse reactions of pemetrexed. In patients with creatinine clearances 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 Injection. If concomitant ibuprofen use cannot be avoided, monitor patients more frequently for Pemetrexed Injection adverse reactions, including myelosuppression, renal, and gastrointestinal toxicity [see Dosage and Administration (2.5), Drug Interactions (7), and Clinical Pharmacology (12.3)].
5.7 Embryo-Fetal Toxicity
Based on findings from animal studies and its mechanism of action, Pemetrexed Injection can cause fetal harm when administered to a pregnant woman. In animal reproduction studies, intravenous administration of pemetrexed to pregnant mice during the period of organogenesis was teratogenic, resulting in developmental delays and increased malformations at doses lower than the recommended human dose of 500 mg/m2. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with Pemetrexed Injection and for 6 months after the last dose. Advise males with female partners of reproductive potential to use effective contraception during treatment with Pemetrexed Injection and for 3 months after the last dose [see Use in Specific Populations (8.1, 8.3) and Clinical Pharmacology (12.1)].