Legislators Urge Added Incentives for Ebola Drug Development

Leading US senators are proposing legislation to add Ebola to the list of diseases eligible for priority review vouchers from FDA as an incentive for biopharmaceutical companies to invest in treatments for this deadly disease. The priority review voucher (PRV) program for neglected tropical diseases (NTDs) currently applies to 16 deadly conditions that afflict millions of people in developing countries, but are rare or “neglected” in the US and Europe. Ebola is not on FDA’s list, as it was not considered a serious threat when the program was established in 2007, but that obviously has changed.

Consequently, Sen. Tom Harkin (D-Iowa), chairman of the Senate Health, Education, Labor, and Pensions (HELP) Committee and of the Senate Appropriations Committee that oversees the Health and Human Services (HHS) budget, and Sen. Lamar Alexander (R-TN), ranking Republican on the HELP Committee, seek to correct that omission. They are readying legislation to extend the voucher program to encourage private sector development of new Ebola treatments.

FDA has been criticized for omitting Ebola from its NTD list, but the virus also is not on the World Health Organization’s (WHO) list of 17 neglected tropical diseases seeking treatments. WHO added scabies to its list in July 2014, but the only viruses cited are Dengue and rabies.

The FDA PRV program was authorized by the FDA Amendments Act (FDAAA) of 2007 to promote the development of new drugs and vaccines for neglected tropical diseases. The policy allows the sponsor of a qualifying treatment that is approved by FDA to also receive a voucher that provides a speedy priority review of another drug applying for market approval. The sponsor can use the voucher to speed the review of another new drug, or the firm can sell it to other biopharma companies developing their own therapies.

Despite considerable enthusiasm for the PRV program, only four vouchers have been awarded over the past seven years. The first voucher was controversial, as it went to Novartis following FDA approval of its antimalarial treatment Coartem, which already was widely used throughout the developing world. Johnson & Johnson’s Janssen unit gained a voucher in 2012 with approval of a new treatment for drug-resistant tuberculosis. And in March 2014, FDA approved a new treatment for Leishmaniasis, Impavido (miltefosine), developed by Paladin Therapeutics of Canada, with the benefit of fast track designation, priority review and orphan product designation.

The voucher program was extended to pediatric rare diseases in 2012, and the first voucher in this category was awarded to BioMarin in February 2014 for the drug Vimizim. BioMarin announced in July the sale of its voucher to Sanofi and Regeneron for $67.5 million, an amount that could boost the PRV market. Meanwhile, FDA has been responding to pressure from Congress to do more to support the voucher program. The agency issued draft guidance on implementing the voucher program in 2008, but took several more years to hold a planned public meeting on expanding the neglected disease list and on further refining the program. In July 2014, FDA issued more detailed guidance on developing treatments for neglected tropical diseases, which offers advice on preclinical testing and conduct of clinical trials for such therapies and describes agency programs for orphan drugs and expedited approvals that can be beneficial.

While some critics regard the voucher program as a giveaway to Big Pharma, most policy makers consider this approach a valid way to use market incentives to encourage beneficial investments by industry. Voucher advocates would like any legislation to include changes to make PRVs more viable, such as reducing the period for a sponsor to notify FDA of its intent to use a voucher and permitting multiple sales of PRVs for tropical diseases.

While there’s a sense that special incentives may not be needed now to spur development of Ebola treatments, as both government agencies and private entities are pouring money into new antivirals and vaccines, most observers feel that renewed focus on the voucher program can only be a plus, and that it will help maintain interest in developing new NTD therapies over the long run.