Posted 11 March 2015 | By Alexander Gaffney, RAC,

Drugmaker United Therapeutics has become just the second company in US history to obtain a new type of voucher which allows a company to potentially get its drug approved by the US Food and Drug Administration (FDA) in 40% less time than it normally takes.

Background

The voucher in question is known as a rare pediatric disease priority review voucher (PRV), and is modeled off a similar program intended to help spur the development of new drugs for so-called "neglected" tropical diseases.

The essence of the PRV program is this: There are some drugs for which few, if any, economic incentives exist to encourage development. Given a choice of where to spend their development dollars, most drug companies (especially those beholden to stockholders) will seek to develop products for diseases which can allow for economic returns. As a result, few companies have historically targeted new treatments for diseases which exclusively affect small populations of patients or populations in economically poor regions like Africa.

Since the 1984 passage of the Orphan Drug Act, the US has begun to recognize that incentives can help spur development for these areas. Under the Orphan Drug Act, companies are eligible for several extra years of marketing exclusivity, during which time FDA is not permitted to approve a generic, for getting a drug for a "rare" disease approved.

Then, in 2007, legislators adopted a new tactic. Under the FDA Amendments Act, FDA was authorized to give special vouchers to companies which obtained approval for drugs intended to treat a designated list of neglected tropical diseases. The voucher is special in two notable ways. First, the voucher makes its holder eligible to have one of its subsequent drug products reviewed under FDA's priority review pathway. Instead of the normal 10 months it takes FDA to review most new drugs, FDA is directed to review the drug in just 6 months.

Second, the owner of the voucher may sell that voucher to another company (and, as of 2014, that company may then re-sell it as well).

Together, both aspects of the voucher are meant to give companies a powerful incentive to develop drugs for neglected treatments. Vouchers have sold for between $67 million and $125 million, giving sponsors a quick infusion of cash they can use to develop other drugs. And for companies with a potential blockbuster in their pipeline, the voucher can be used to get their product to market more quickly, extending the amount of usable patent protection they have left (if any).

The Pediatric Voucher

Then, in 2012, legislators passed into law a new PRV program as part of a sweeping piece of legislation known as the FDA Safety and Innovation Act (FDASIA).

The PRV program, known as the rare pediatric disease priority review voucher, is closely modeled after the tropical voucher system, but with one key difference: It aims to aid in the development of new drugs for "certain rare pediatric diseases," not tropical ones.

Those diseases are defined as those which primarily (50%+ cases) affect children aged 0-18, and affect fewer than 200,000 persons in the US. Alternatively, FDA may award a voucher if a company has "no reasonable expectation that the costs of developing and making available the drug in the US can be recovered from sales of the drug in the US."

Prior to this week, FDA had only awarded one rare pediatric disease voucher—in February 2014 to the pharmaceutical company BioMarin for the approval of its rare disease drug Vimizim. BioMarin later sold the voucher for a then-record-setting price of $67.5 million.

New Voucher Awarded, but There's a Problem…

Now FDA has awarded its second rare pediatric disease voucher, bringing good news to the drug's sponsor and potentially bad news to other companies hoping to obtain a voucher of their own.

First, the good news: On 10 March 2015 FDA announced the approval of United Therapeutics' new rare pediatric disease drug Unituxin, a drug intended for use as part of first-line therapy for children with high-risk neuroblastoma, a type of cancer which forms from immature nerve cells. In its approval notice, FDA said the disease is only estimated to affect one in 100,000 children, and is only diagnosed 650 times per year. It is currently fatal in about half of all cases.

In return for its efforts in bringing the drug to market for a 650-person-per-year market, United Therapeutics was awarded FDA's second-ever rare pediatric disease voucher, giving it the opportunity to either use the voucher on one of its own future drug submissions, or to sell the voucher to an interested company. The company didn't divulge its plan for the voucher in a statement to the press.

Here's the bad news: FDA's rare pediatric disease voucher contains a little-known provision which is actually meant to limit its use. Under FDASIA, FDA "may not award any priority review vouchers … after the last day of the 1-year period that begins on the date that the Secretary awards the third rare pediatric disease priority voucher."

In other words, FDA has just one more rare pediatric disease priority voucher it can award before a one-year timer begins. Thereafter, Congress will have to reauthorize the program.

To be sure, most signs point to Congress doing so. In December 2014, President Barack Obama signed into law legislation overwhelmingly passed by Congress that reformed the PRV system for neglected tropical diseases. Now that Congress is actively considering ways to accelerate the development of new drugs, this could be one area which attracts congressional attention in the coming months.

FDA Announcement