ChemoCentryx Inc said on Friday the US health agency approved its lead drug for treating a rare, fatal autoimmune disease, sending the biopharmaceutical company’s shares up by more than 70%.

The drug, avacopan, which will be available under brand name Tavneos in the next few weeks, will have a wholesale price of between $150,000 and $200,000 per patient per year, Chief Executive Thomas Schall told Reuters.

Avacopan is administered orally to treat antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) – a group of conditions characterized by destruction and inflammation of small blood vessels and affecting different organs, particularly the kidney.

The drug works by blocking the activity of a protein called C5a receptor, which is responsible for causing numerous inflammatory diseases.

Current treatments include immunosuppressants such as Biogen Inc and partner Roche Holding AG’s cancer drug Rituxan, combined with daily administration of steroids, which can cause severe side effects.

The disease affects about 40,000 people in the United States, with about 4,000 new cases each year, according to the company.

Stifel analyst Dae Gon Ha estimates Avacopan to generate sales of $1.3 billion by 2035.

The drug had received mixed reviews from an expert panel to the US Food and Drug Administration in May, with the committee’s vote split equally on whether the efficacy data supported the drug’s approval.

Following this meeting, the company submitted additional data in July for its marketing application for avacopan.

The company has an exclusive license agreement with Swiss-based Vifor Pharma, giving it the commercialization rights in the United States, while Vifor has rights for the rest of the world.

The drug was approved in Japan last month and the European regulatory body could give its nod by the end of this year.

The company is also testing avacopan for other conditions, including a type of skin disease.