It’s the world’s most expensive drug, and one of only two available for spinal muscular atrophy, the top genetic killer of children under two years old. And now the drug’s maker, Novartis, wants to give it away using a procedure considered controversial by advocacy groups.

Starting Jan. 2, Novartis will give 100 patients free Zolgensma, a one-shot cure for SMA selling for $2.1 million in the U.S., via lottery. Zolgensma got approval from the FDA in May, but regulators in Europe and Japan haven’t yet given it the green light. 

Under the program, patients who submitted treatment applications by their doctors will enter a bi-weekly draw conducted by an independent commission. Novartis told Reuters that the giveaway program “is anchored in principles of fairness, clinical need and global accessibility.”

Novartis’s plan was criticized by patient advocacy groups, with TreatSMA calling the lottery-style program “too crude” and a member of SMA Europe telling the Wall Street Journal that the plan makes the drug “look like a prize.” 

Novartis told the WSJ that bioethics experts advised them and the plan addresses concerns about discrimination toward some patients. “Unfortunately, there is no perfect solution,” a spokesman said.

The program focuses on countries where the medicine is pending approval, and Novartis cited low manufacturing capacity as a the main reason for its approach. It currently has only one facility in the U.S., and expects to build two more plants next year. 

Spinal muscular atrophy is a rare genetic disease leading to muscle weakness and paralysis. It’s caused by a defective or missing SMN1 gene, affecting one in 10,000 newborn babies. If left untreated, 90% of patients of Type 1 SMA will die by age of 2 years old. 

U.S. pharma Biogen’s Spinraza is the only SMA treatment available on the market. Spinraza costs $750,000 the first year, and must continue for life at $375,000 each year.  

Increasing competition for the SMA cure is expected to drive down the price. Swiss drugmaker Roche is waiting for the FDA to approve its SMA treatment Risdiplam by May. If approved, patients will be able to administer the drinkable drug at home.