In an unexpected move, Marathon Pharmaceuticals announced Monday that it is pausing the roll-out of its now FDA-approved Duchenne muscular dystrophy drug—which has an $89,000-per-year list price.

The announcement comes in the wake of intense outcry from patients, the public, and lawmakers over the drug’s eye-popping price, which Marathon announced last week.

The drug, deflazacort, is a steroid treatment that slows the progression of Duchenne, a rare, devastating neuromuscular disorder that leaves mostly boys unable to walk by their teens (it's X-linked recessive). The disorder also shortens their lifespan to 25-30 years.

Deflazacort is an old drug that’s available as a generic overseas. Previously, US patients could import a year’s worth for around $1,200. But on Thursday, Marathon announced it had received FDA approval to sell its version in the US under the brand name Emflaza. Because the company had it approved through the FDA’s ‘orphan drug’ program—that is, a priority review for drugs that treat rare disorders—the company now has the seven years of market exclusivity that come with that program. And also part of that deal, the company has received an FDA voucher to expedite a future review, which is intended to act as an incentive for pharmaceutical companies to develop orphan drugs. The vouchers are transferrable, though, and often sell for hundreds of millions of dollars.

Anticipating blowback from the drug’s steep list price, Marathon quickly explained that rebates, discounts, financial programs, and insurance coverage will make sure patients can get the drug at an affordable price. The company said it expects patients will pay $20 out-of-pocket, or less.

Still, none of Marathon’s actions or assurances have sat well with patients, advocates, and lawmakers.

As Ars reported last week, health experts worry that some patients will slip through the cracks and be stuck with a crushing bill.

Dana Edwards, a New Jersey mother whose 12-year-old has taken deflazacort since he was five years old, told Kaiser Health News Monday that the company was “robbing my insurance company.”

Also Monday, Sen. Bernie Sanders (I-Vt.) and Rep. Elijah Cummings (D-Md.) wrote a strongly worded letter to Marathon. In it, the two legislators chastised and questioned the company over its pricing and use of the “orphan drug” program.

“Marathon’s apparent abuse of government-granted exclusivity periods and incentives to sell what should be a widely available drug for $89,000 a year is unconscionable,” Sanders and Cummings wrote in their letter. “Exorbitantly pricing potentially life-saving medications that should be widely available for a fraction of the price hinders patient access and drives up costs for the entire health care sector.”

In their letter, the two lawmakers requested information about how Marathon priced the drug and how much money it stood to earn.

In response to the general outcry, the company said it would put a hold on its plans to roll out the brand-name drug until it could hear and review concerns.

In a statement, Marathon Chairman and CEO Jeff Aronin said:

“Since last week’s approval, we have heard both support from the community and concerns about how the pricing and reimbursement details will affect individual patients and caregivers, such as how it affects coverage of other components of Duchenne treatment. Based on these questions, today we are announcing: 1. We are pausing our commercialization efforts in order to meet with Duchenne community leaders and explain our commercialization plans, review their concerns, discuss all options, and move forward with commercialization based on the resulting plan of action 2. We will continue to maintain our Expanded Access Program for patients receiving EMFLAZA 3. Patients currently receiving deflazacort from other sources may continue to have that option

The statement went on to explain the drug’s pricing: