What Is It, and Why Does It Matter?
Wellcovorin (leucovorin calcium) is a type of folate your body can use. In case reports of people with folate receptor 1‑related cerebral folate transport deficiency (FOLR1‑CFTD), it was seen to raise levels of 5‑MTHF, an active form of folate in the body. Cerebral folate deficiency limits how folate gets into the brain. This can lead to severe developmental delay, movement problems, seizures, and other serious nerve issues. You may hear this condition called FOLR1‑CFTD when linked to a change in the FOLR1 gene.
The FDA cleared expanded use of this medicine to treat FOLR1‑CFTD in adults and children who have a confirmed change in the FOLR1 gene. This is the first FDA‑recognized treatment option for this rare genetic condition. This medicine supplies a usable folate source and may help address the low brain folate described with this disorder.
Why Was It Approved?
The FDA's decision relied on a review of published reports with patient‑level details and supportive biology, instead of traditional clinical trials. No clinical trials have tested leucovorin in people with FOLR1 changes. The FDA noted that real‑world or observational evidence may support approval when the benefit is clear, compared with the usual course of the disease.
In studies described in the medical literature, most people who took oral Wellcovorin had improvement in neurological symptoms. Reported gains included fewer or less severe seizures, and better movement, communication, or behavior. Among a smaller group who had spinal fluid testing before and after starting treatment, levels of folate around the brain went up, and many reached normal levels.
Safety information on its use in FOLR1‑CFTD is limited because the evidence comes from case reports. A severe allergic reaction called anaphylaxis can occur and needs urgent medical care.
What Do I Need to Know?
Wellcovorin is an oral medicine that you can take with or without food. Your health care provider will base the dose on body weight and may adjust it over time. You can take the total daily dose once a day or split it into smaller doses. Very large single doses are not advised. If needed, you may dissolve a tablet in a small amount of liquid or crush and mix it with soft food. Give it right after you mix it.
Do not use this medicine for FOLR1‑CFTD if you have ever had an allergic reaction to leucovorin, levoleucovorin, folic acid, or any tablet ingredient. Get medical help right away if you have signs of a severe reaction, such as trouble breathing, hives, or swelling. Your health care provider may stop the medicine, depending on how severe the reaction is.
Tell your health care provider about all medicines you take. Leucovorin can affect seizure control if you use certain anti‑seizure drugs, so extra monitoring may be needed. Do not take this medicine with trimethoprim‑sulfamethoxazole because this mix has been linked with treatment failure of that antibiotic in some settings.
Data on use during pregnancy or while breastfeeding in people with FOLR1‑CFTD is not available. If you are pregnant, planning to get pregnant, or breastfeeding, discuss potential risks and benefits with your health care provider. This medicine is not recommended if you have a specific enzyme deficiency that affects folate processing. It is also not used to treat anemia caused by low vitamin B12.