A U.S. shortage of the new generic version of Vyvanse, an ADHD medication, is due in part to federal limits on production, according to an industry group representing generic drug makers.
Manufacturers haven’t been able to secure enough raw material “to launch their products at full commercial scale,” according to a letter from the Association for Accessible Medicines addressed to the Drug Enforcement Administration, which sets the limits on production that the industry must follow.
These restrictions on obtaining the drug’s active ingredients have curbed generic manufacturing, and people and insurers are paying more for the branded drug as a result, the letter says.
The DEA didn’t immediately provide a comment in response to inquiries from Bloomberg News.
The agency is generally reevaluating aspects of the quota process for controlled substances, according to a notice published earlier this month.
Production of many drugs used to treat attention-deficit/hyperactivity disorder, including Adderall and Vyvanse, is limited by the government since the medications are designated as controlled substances and they’re seen as prone to addiction and abuse.
Caps on production set by the DEA are meant to ensure legitimate demand is met while also preventing an excess of supply that could leak into the black market.
Vyvanse was only available as a branded drug sold by Takeda Pharmaceutical Co. until late August, when the market opened up to generic competition.
Drugmakers haven’t received permission to manufacture enough generic Vyvanse because of two chicken-and-egg situations, according to the letter, which is dated Nov. 14.
The DEA sets limits in part based on past production and future sales commitments, the AAM says, but companies making a new generic drug haven’t sold any amounts at all in the past.
At the same time, the companies are reluctant to sign new sales contracts without knowing whether they’ll get government permission to make enough of the drug.
If they fail to get the green light, they’ll have to pay customers’ fees for not fulfilling the contracts.
The role of these limits in the ongoing shortage of ADHD medicines has been contested, with some manufacturers saying they have been a challenge to increasing availability, while the DEA has said that they aren’t the cause.
The AAM hasn’t received a response from the DEA, according to David Gaugh, the group’s interim president and CEO.
Medications used to treat ADHD have been in tight supply since August 2022, when a labor crunch at Teva Pharmaceutical Industries Ltd. curtailed availability of generic versions of Adderall, which is also used to treat the condition.
This has set off a cascade of shortages as patients switch to alternatives such as Vyvanse or scramble to find the medicine from other companies.
At least seven drugmakers are reporting shortages of generic Vyvanse, according to the Food and Drug Administration. Two drugmakers said that they would produce more generic Vyvanse if granted permission.
“We could make a significant impact on solving the shortage if we were granted adequate amounts” of raw materials, according to Hikma Pharmaceuticals Plc.
Francesco Tallarico, chief legal officer at Apotex Inc., said his company “would look to assist with the supply shortages if there is any shift in quota provided by the DEA.”
Despite constraints, generics made up 60% of prescriptions filled for Vyvanse last month, according to data from Symphony Health.