Leucovorin, also known as folinic acid, is a medication used primarily to reduce the toxic effects of methotrexate and to enhance the effectiveness of certain chemotherapy drugs. It is available as a generic drug and is manufactured by multiple companies. Regarding ownership, GlaxoSmithKline (GSK) previously marketed leucovorin under the brand name Wellcovorin from 1983 to 1997 and currently holds the New Drug Application (NDA) for Wellcovorin. However, GSK no longer manufactures or markets leucovorin, which is now widely available as a generic drug from various manufacturers including Hikma Pharmaceuticals, Fresenius Kabi, Sagent Pharmaceuticals, and others. In summary:

• GSK holds the NDA for Wellcovorin but does not currently manufacture or market leucovorin.
• Leucovorin is produced and sold in generic forms by multiple pharmaceutical companies such as Hikma, Fresenius Kabi, and Sagent.