More than 20 years after approving the first ever drug for the neurological disorder amyotrophic lateral sclerosis (ALS), the US Food and Drug Administration (FDA) has given its approval to the second drug for ALS treatment.

The new drug, known as edaravone, will be manufactured in the U.S. by MT Pharma America, a subsidiary of the Japan-based Mitsubishi Tanabe Pharma Corporation. Edaravone has been sold in Japan and South Korea since 2015.

"After learning about the use of edaravone to treat ALS in Japan, we rapidly engaged with the drug developer about filing a marketing application in the United States," said Eric Bastings, the deputy director of the FDA's neurology products division, as per KSL. "This is the first new treatment approved by the FDA for ALS in many years, and we are pleased that people with ALS will now have an additional option."

To be marketed as Radicava in the U.S., the new drug will cost $1,086 per infusion. Following the dosing and administration as per the label, patients using the drugs for 12 months or 13 cycles will need to spend $145,524 annually.

According to New York Times, MT Pharma America plans to provide some co-pay assistance to ASL patients with commercial insurance. The company also wishes to help other ASL patients who are not insured or may face delays in paying for their treatments. Qualified ALS patients may even be treated with Radicava free of charge.

Radicava is said to slow down the decline of physical function due to ALS by 33 percent. Patients that wish to receive the new ALS treatment must have an intravenous line inserted and left in place indefinitely. The first round of Radicava treatment will be an hour-long infusion daily for 14 days, followed by 14 days off. After the rest, the patients' Radicava infusion will be given daily for 10 out of 14 days, with 14 days off.

ALS patients using the Radicava may experience bruising and gait disturbance. People who are allergic to sulfite may experience life-threatening allergic reactions. Other adverse effects of the drug include hives, swelling and shortness of breath.