The U.S. Food and Drug Administration (FDA) recently approved levoleucovorin (Khapzory) injection, a folate analog, for three indications: rescue after high-dose methotrexate therapy in patients with osteosarcoma; diminishing the toxicity associated with overdosing on folic acid antagonists or impaired methotrexate elimination; and the treatment of patients with metastatic colorectal cancer in combination with fluorouracil.
Levoleucovorin is contraindicated in patients who have had severe hypersensitivity to leucovorin products, folic acid, or folinic acid.
The most common adverse reactions (≥ 20%) in patients receiving high-dose methotrexate therapy with levoleucovorin rescue were stomatitis (38%) and vomiting (38%). The most common adverse reactions (> 50%) in patients receiving levoleucovorin in combination with fluorouracil for metastatic colorectal cancer were stomatitis (72%), diarrhea (70%), and nausea (62%). Gastrointestinal toxicities, including stomatitis and diarrhea, occur more commonly and may be of greater severity and of prolonged duration. Deaths from severe enterocolitis, diarrhea, and dehydration have occurred in elderly patients receiving weekly d,l-leucovorin and fluorouracil. Concomitant use of d,l-leucovorin with trimethoprim/sulfamethoxazole for the acute treatment of Pneumocystis jirovecii pneumonia in patients with human immunodeficiency virus infection increased treatment failure and morbidity. ■