Hot on the heels of the first ever sale of a pediatric review voucher for a whopping $67 million, Canadian pharmaceutical manufacturer Knight Therapeutics announced Tuesday (12 August) that it plans to auction off a similar voucher of its own.
FDA currently maintains two priority review voucher systems: one known for tropical diseases, and the other for pediatric rare diseases.
Background: Tropical Disease Vouchers
The tropical disease priority review voucher system was established under the FDA Amendment Act of 2007 (FDAAA). Under the system, companies that receive approval for a tropical disease treatment are eligible to receive a transferrable voucher that allows the bearer to receive six-month priority review status for any future product. Products undergoing priority review are generally given an approval decision—positive or negative—within six months after the applicant's filing date.
The legislation was enacted to spur development of treatment options for tropical diseases, which FDA notes have been remarkably stagnant over the last half century. "Because these diseases are found primarily in poor and developing countries, existing incentives have been insufficient to encourage development of new and innovative drug therapies," explained FDA in a 2008 guidance document on the subject. FDA said it was taking an interest in the topic given the needs of other countries and the ability of those diseases to affect Americans in an increasingly globalized economy.
Under normal circumstances, FDA only grants priority review status to products which fill a treatment void or would otherwise represent a significant advancement compared to existing treatments. Because these reviews cost more than traditional drug reviews, the cost per application is more. However, under the voucher program, any company willing to pay the additional cost of the review may have its product reviewed by FDA, the agency explained.
FDA typically reviews priority review applications within six months, instead of the standard 10 months.
Limits on Tropical Vouchers: Time and Cost
But despite high expectations for the program, the tropical disease voucher system hasn't been used much, in part because it's somewhat restrictive. As FDA explains in its guidance document on the voucher, "The sponsor redeeming the voucher must notify FDA of their intent to submit a human drug application with a priority review voucher at least 365 days prior to submission of the human drug application for which a priority review voucher will be used to obtain a priority review." That advance review time makes it impractical for many companies, which may not be willing to purchase a voucher until they know their product will be able to be submitted to FDA.
And just as important, some drugs simply won't benefit from a faster review from FDA. For example, if a drug has outstanding questions that must be answered, the voucher might simply facilitate a quicker complete response letter (CRL).
And in addition to the purchase price of the voucher from another company, users of the vouchers must also pay FDA to use them—$2,325,000 per voucher as of FY 2014.
A New Voucher System: Key Differences
FDA has also recently established a second priority review voucher system: the rare pediatric disease priority review voucher program.
The first rare pediatric disease voucher was given to the pharmaceutical company BioMarin in February 2014 after its rare disease drug Vimizim was granted FDA approval. While FDA is still in the process of writing a guidance on the pediatric voucher program, the program, which was established under the 2012 FDA Safety and Innovation Act (FDASIA), contains a notable improvement over the tropical disease voucher program.
Unlike the 365-day waiting period to use a tropical disease voucher, a pediatric rare disease voucher can be used just 90 days after notifying FDA of a company's intent to use it (Section 529).
It's a small change, but one that was apparently worthwhile to Sanofi and Regeneron, which in July 2014 purchased BioMarin's rare pediatric disease voucher for a whopping $67.5 million.
What's a Tropical Disease Voucher Worth?
But to date, no company has yet sold its tropical disease priority review voucher. Novartis, which obtained a voucher after one of its tropical disease products (Coartem) was approved, used the voucher (unsuccessfully) on Ilaris (canakinumab).
But thanks to Knight Therapeutics, we may soon know what a tropical disease voucher is worth to members of industry—if it's worth anything at all.
In an announcement on 12 August 2014, the company said it has hired an advisor to help it sell its voucher, obtained after the March 2014 approval of Impavido (miltefosine) for patients with visceral, mucosal and cutaneous leishmaniasis.
"A big pharma may want our voucher if they are behind in a race to market and want to catch up or if they are ahead in a race and don't want their competitor to hop on a faster bus," the company's CEO, Jonathan Ross Goodman, said in a statement. "We hope to be the next to sell a Priority Review Voucher and would like to set the bar high to encourage others to invest in R&D for neglected tropical diseases."
However, while the company makes mention of the high sale price of BioMarin's priority review voucher, it's worth noting (again) that tropical disease priority review vouchers have more restrictions on their use than do pediatric rare disease vouchers. The former has a 365-day waiting period, while the latter has just a 90-day waiting period before it can be used.
The takeaway: While there's still likely to be interest in purchasing Knight's voucher, its relative restrictions means there may be fewer suitors and a smaller eventual sale price than BioMarin's voucher.