ZURICH/SAN FRANCISCO (Reuters) - Swiss drugmaker Roche plans to price its oral spinal muscular atrophy drug (SMA) risdiplam aggressively to challenge two of the world’s most expensive medicines, Biogen’s Spinraza and Novartis’s gene therapy Zolgensma.

FILE PHOTO: The logo of Swiss drugmaker Roche is seen at its headquarters in Basel, Switzerland February 1, 2018. REUTERS/Arnd Wiegmann/File Photo

Spinraza’s list price is $750,000 in the first year, and $375,000 thereafter, while Novartis’s gene therapy for the genetic muscle wasting disease lists at $2.1 million, making it the drug industry’s most expensive one-time treatment.

Third-to-market risdiplam is due for a U.S. Food and Drug Administration decision by May 24.

While Roche has not released risdiplam’s price, drug chief Bill Anderson said the Basel-based company will price the drug much as it did its hemophilia A medicine Hemlibra in 2017, when it undercut traditional therapies made by rivals NovoNordisk and Takeda to help win patients.

“With Hemlibra, we priced at about half of bypassing agent,” Anderson said in an interview on Monday at the JP Morgan Healthcare Conference in San Francisco. “We aim to underwhelm with our price” with risdiplam, he added.

Hemlibra costs around $500,000 a year. Treatment that includes bypassing agents given to stop bleeding in hemophilia patients with resistance to traditional clotting factor treatments can top $1 million.

Experts see Zolgensma becoming the treatment of choice for newborn patients who test positive for SMA, because gene therapy may offer infants yet to exhibit symptoms hope for normal development.

Risdiplam, seen by analysts as topping $1 billion in annual sales, and Spinraza, already a roughly $2 billion per year seller, are seen competing for older patients. Oral, daily risdiplam may be less complicated, given Spinraza is given every four months via an infusion in the spine.

Zolgensma is also being tested in older patients with a spinal infusion, though the trial has been halted due to safety concerns. Novartis is awaiting the FDA’s go-ahead to restart.

Novartis also is developing an oral drug, branaplam, though its chief researcher, Jay Bradner, in December indicated the company had cooled to the medicine, saying he did not “see a big opportunity for oral therapy there, or we would develop this molecule further”.

Novartis has since clarified its stance, saying its trial of branaplam would continue, with a decision to be made after the study produces data later this year.