Pemetrexed
Also sold as: Alimta, Pemfexy, Pemrydi Rtu, Axtle
Related Medications
These drugs share a pharmacologic classification but are NOT interchangeable. Listing here does not imply clinical equivalence. A physician must evaluate each drug individually for the patient's specific condition.
Classification: Folic Acid Metabolism Inhibitors (source: RxClass/NLM)
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Drug Information
Mechanism of Action
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.
Indications & Uses
1 INDICATIONS AND USAGE Pemetrexed for Injection is a folate analog metabolic inhibitor indicated: in combination with pembrolizumab and platinum chemotherapy, for the initial treatment of patients with metastatic non-squamous non-small cell lung cancer (NSCLC), with no EGFR or ALK genomic tumor aberrations. ( 1.1 ) in combination with cisplatin for the initial treatment of patients with locally advanced or metastatic, non-squamous NSCLC. ( 1.1 ) as a single agent for the maintenance treatment of patients with locally advanced or metastatic, non-squamous NSCLC whose disease has not progressed after four cycles of platinum-based first-line chemotherapy. ( 1.1 ) as a single agent for the treatment of patients with recurrent, metastatic non-squamous, NSCLC after prior chemotherapy. ( 1.1 ) Limitations of Use: Pemetrexed for Injection is not indicated for the treatment of patients with squamous cell, non-small cell lung cancer. ( 1.1 ) initial treatment, in combination with cisplatin, of patients with malignant pleural mesothelioma whose disease is unresectable or who are otherwise not candidates for curative surgery. ( 1.2 ) 1.1 Non-Squamous Non-Small Cell Lung Cancer (NSCLC) Pemetrexed for Injection is indicated: in combination with pembrolizumab and platinum chemotherapy, for the initial treatment of patients with metastatic non-squamous non-small cell lung cancer (NSCLC), with no EGFR or ALK genomic tumor aberrations. in combination with cisplatin for the initial treatment of patients with locally advanced or metastatic, non-squamous NSCLC. as a single agent for the maintenance treatment of patients with locally advanced or metastatic, non-squamous NSCLC whose disease has not progressed after four cycles of platinum-based first-line chemotherapy. as a single agent for the treatment of patients with recurrent, metastatic non-squamous, NSCLC after prior chemotherapy. Limitations of Use: Pemetrexed for Injection is not indicated for the treatment of patients with squam
Dosage & Administration
2 DOSAGE AND ADMINISTRATION The recommended dose of pemetrexed for injection administered with pembrolizumab and platinum chemotherapy in patients with a creatinine clearance (calculated by Cockcroft-Gault equation) of 45 mL/min or greater is 500 mg/m 2 as an intravenous infusion over 10 minutes, administered after pembrolizumab and prior to platinum chemotherapy, on Day 1 of each 21-day cycle. ( 2.1 ) The recommended dose of pemetrexed for injection, administered as a single agent or with cisplatin, in patients with creatinine clearance of 45 mL/minute or greater is 500 mg/m 2 as an intravenous infusion over 10 minutes on Day 1 of each 21-day cycle. ( 2.1 , 2.2 ) Initiate folic acid 400 mcg to 1000 mcg orally, once daily, beginning 7 days prior to the first dose of pemetrexed for injection and continue until 21 days after the last dose of pemetrexed for injection. ( 2.4 ) Administer vitamin B 12 , 1 mg intramuscularly, 1 week prior to the first dose of pemetrexed for injection and every 3 cycles. ( 2.4 ) Administer dexamethasone 4 mg orally, twice daily the day before, the day of, and the day after pemetrexed for injection administration. ( 2.4 ) 2.1 Recommended Dosage for Non-Squamous NSCLC The recommended dose of pemetrexed for injection when administered with pembrolizumab and platinum chemotherapy for the initial treatment of metastatic non-squamous NSCLC in patients with a creatinine clearance (calculated by Cockcroft-Gault equation) of 45 mL/min or greater is 500 mg/m 2 as an intravenous infusion over 10 minutes administered after pembrolizumab and prior to carboplatin or cisplatin on Day 1 of each 21-day cycle for 4 cycles. Following completion of platinum-based therapy, treatment with pemetrexed for injection with or without pembrolizumab is administered until disease progression or unacceptable toxicity. Please refer to the full prescribing information for pembrolizumab and for carboplatin or cisplatin. The recommended dose of pemetrexed for injection when administered with cisplatin for initial treatment of locally advanced or metastatic non-squamous NSCLC in patients with a creatinine clearance (calculated by Cockcroft-Gault equation) of 45 mL/min or greater is 500 mg/m 2 as an intravenous infusion over 10 minutes administered prior to cisplatin on Day 1 of each 21-day cycle for up to six cycles in the absence of disease progression or unacceptable toxicity. The recommended dose of pemetrexed for injection for maintenance treatment of non-squamous NSCLC in patients with a creatinine clearance (calculated by Cockcroft-Gault equation) of 45 mL/min or greater is 500 mg/m 2 as an intravenous infusion over 10 minutes on Day 1 of each 21-day cycle until disease progression or unacceptable toxicity after four cycles of platinum-based first-line chemotherapy. The recommended dose of pemetrexed for injection for treatment of recurrent non-squamous NSCLC in patients with a creatinine clearance (calculated by Cockcroft-Gault equation) of 45 mL/min or greater is 500 mg/m 2 as an intravenous infusion over 10 minutes on Day 1 of each 21-day cycle until disease progression or unacceptable toxicity. 2.2 Recommended Dosage for Mesothelioma The recommended dose of pemetrexed for injection when administered with cisplatin in patients with a creatinine clearance (calculated by Cockcroft-Gault equation) of 45 mL/min or greater is 500 mg/m 2 as an intravenous infusion over 10 minutes on Day 1 of each 21-day cycle until disease progression or unacceptable toxicity. 2.3 Renal Impairment Pemetrexed for Injection dosing recommendations are provided for patients with a creatinine clearance (calculated by Cockcroft-Gault equation) of 45 mL/min or greater [see Dosage and Administration ( 2.1 , 2.2 )] . There is no recommended dose for patients whose creatinine clearance is less than 45 mL/min [see Use in Specific Populations ( 8.6 )] . 2.4 Premedication and Concomitant Medications to Mitigate Toxicity Vitamin Supplementation Initiate folic acid 400 mcg to 1000 mcg orally once daily, beginning 7 days before the first dose of pemetrexed for injection and continuing until 21 days after the last dose of pemetrexed for injection [see Warnings and Precautions ( 5.1 )] . Administer vitamin B 12 , 1 mg intramuscularly, 1 week prior to the first dose of pemetrexed for injection and every 3 cycles thereafter. Subsequent vitamin B 12 injections may be given the same day as treatment with pemetrexed for injection [see Warnings and Precautions ( 5.1 )] . Do not substitute oral vitamin B 12 for intramuscular vitamin B 12 . Corticosteroids Administer dexamethasone 4 mg orally twice daily for three consecutive days, beginning the day before each pemetrexed for injection administration. 2.5 Dosage Modification of Ibuprofen in Patients with Mild to Moderate Renal Impairment Receiving Pemetrexed for Injection In patients with creatinine clearances between 45 mL/min and 79 mL/min, modify administration of ibuprofen as follows [see Warnings and
Side Effects (Adverse Reactions)
6 ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in other sections of the labeling: Myelosuppression [see Warnings and Precautions ( 5.1 )] Renal failure [see Warnings and Precautions ( 5.2 )] Bullous and exfoliative skin toxicity [see Warning and Precautions ( 5.3 )] Interstitial pneumonitis [see Warnings and Precautions ( 5.4 )] Radiation recall [see Warnings and Precautions ( 5.5 )] The most common adverse reactions (incidence ≥20%) of pemetrexed for injection, when administered as a single agent are fatigue, nausea, and anorexia. ( 6.1 ) The most common adverse reactions (incidence ≥20%) of pemetrexed for injection when administered with cisplatin are vomiting, neutropenia, anemia, stomatitis/pharyngitis, thrombocytopenia, and constipation. ( 6.1 ) The most common adverse reactions (incidence ≥20%) of pemetrexed for injection when administered in combination with pembrolizumab and platinum chemotherapy are fatigue/asthenia, nausea, constipation, diarrhea, decreased appetite, rash, vomiting, cough, dyspnea, and pyrexia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Ingenus Pharmaceuticals, LLC at 1-877-748-1970 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 cannot be directly compared to rates in other clinical trials and may not reflect the rates observed in clinical practice. In clinical trials, the most common adverse reactions (incidence ≥20%) of pemetrexed for injection, when administered as a single agent, are fatigue, nausea, and anorexia. The most common adverse reactions (incidence ≥20%) of pemetrexed for injection, when administered in combination with cisplatin are vomiting, neutropenia, anemia, stomatitis/pharyngitis, thrombocytopenia, and constipation. The most common adverse reactions (incidence ≥20%) of pemetrexed for injection, when administered in combination with pembrolizumab and platinum chemotherapy, are fatigue/asthenia, nausea, constipation, diarrhea, decreased appetite, rash, vomiting, cough, dyspnea, and pyrexia. Non-Squamous NSCLC First-line Treatment of Metastatic Non-squamous NSCLC with Pembrolizumab and Platinum Chemotherapy The safety of pemetrexed for injection, in combination with pembrolizumab and investigator's choice of platinum (either carboplatin or cisplatin), was investigated in Study KEYNOTE-189, a multicenter, double-blind, randomized (2:1), active-controlled trial in patients with previously untreated, metastatic non-squamous NSCLC with no EGFR or ALK genomic tumor aberrations. A total of 607 patients received pemetrexed for injection, pembrolizumab, and platinum every 3 weeks for 4 cycles followed by pemetrexed for injection and pembrolizumab (n=405), or placebo, pemetrexed for injection, and platinum every 3 weeks for 4 cycles followed by placebo and pemetrexed for injection (n=202). Patients with autoimmune disease that required systemic therapy within 2 years of treatment; a medical condition that required immunosuppression; or who had received more than 30 Gy of thoracic radiation within the prior 26 weeks were ineligible [see Clinical Studies ( 14.1 )] . The median duration of exposure to pemetrexed for injection was 7.2 months (range: 1 day to 1.7 years). Seventy-two percent of patients received carboplatin. The study population characteristics were: median age of 64 years (range: 34 to 84), 49% age 65 years or older, 59% male, 94% White and 3% Asian, and 18% with history of brain metastases at baseline. Pemetrexed for Injection was discontinued for adverse reactions in 23% of patients in the pemetrexed for injection, pembrolizumab, and platinum arm. The most common adverse reactions resulting in discontinuation of pemetrexed for injection in this arm were acute kidney injury (3%) and pneumonitis (2%). Adverse reactions leading to interruption of pemetrexed for injection occurred in 49% of patients in the pemetrexed for injection, pembrolizumab, and platinum arm. The most common adverse reactions or laboratory abnormalities leading to interruption of pemetrexed for injection in this arm (≥2%) were neutropenia (12%), anemia (7%), asthenia (4%), pneumonia (4%), thrombocytopenia (4%), increased blood creatinine (3%), diarrhea (3%), and fatigue (3%). Table 2 summarizes the adverse reactions that occurred in ≥20% of patients treated with pemetrexed for injection, pembrolizumab, and platinum. Table 2: Adverse Reactions Occurring in ≥20% of Patients in KEYNOTE-189 a Graded per NCI CTCAE version 4.03. b Includes asthenia and fatigue. c Includes genital rash, rash, rash generalized, rash macular, rash maculo-papular, rash papular, rash pruritic, and rash pustular. Pemetrexed for Injection Pembrolizumab Platinum Chemotherapy n=405 Placebo Pemetrexed for Injection Platinum Chemotherapy n=202 Adverse Reaction All Grades a (%) Grade 3-4 (%) All Grades (%) Grade 3-4 (%) Gastrointestinal Disorders Nau
Drug Interactions
7 DRUG INTERACTIONS Ibuprofen increased risk of pemetrexed for injection toxicity in patients with mild to moderate renal impairment. Modify the ibuprofen dosage as recommended for patients with a creatinine clearance between 45 mL/min and 79 mL/min. ( 2.5 , 5.6 , 7 ) 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 for injection [see Dosage and Administration ( 2.5 )] . Monitor patients more frequently for myelosuppression, renal, and gastrointestinal toxicity, if concomitant administration of ibuprofen cannot be avoided.
Contraindications
4 CONTRAINDICATIONS Pemetrexed for Injection is contraindicated in patients with a history of severe hypersensitivity reaction to pemetrexed [see Adverse Reactions ( 6.1 )]. History of severe hypersensitivity reaction to pemetrexed. ( 4 )
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Data sourced from RxNorm (NLM/NIH), FDA Orange Book, OpenFDA, DailyMed. Last updated: 2026-03-02.