In a recent paper
in Expert Opinion on Orphan Drugs
, personnel from the FDA’s Center for Devices and Radiological Health and the Office of Orphan Products Development describe the current opportunities and challenges in developing new medical devices for rare diseases. The wide variety of these FDA approved devices
includes a retinal prosthesis for retinitis pigmentosa, a specially designed artificial valve for Tetralogy of Fallot, a device to help repair skin in epidermolysis bullosa, and a prosthetic titanium rib for patients with hypoplastic thorax syndrome.
The challenge of device development for rare diseases
A number of factors make it challenging to develop drug treatments and devices for people with rare diseases. These include the small number of people affected, lack of knowledge about the disease natural history, and lack of well-defined study endpoints.
Developing new devices has had its own additional challenges. The FDA’s Office of Orphan Products Development
has provided incentives to develop new products for rare diseases, but these have not always been helpful facilitating new devices for rare diseases
. For example, marketing exclusivity may not be as much of an incentive for medical device companies as it is for pharmaceutical companies. The vast majority of rare diseases do not have any FDA approved medical devices.
The Humanitarian Device Exemption
In 1990, Congress passed the Safe Medical Devices Act. Since that time, the FDA has allowed certain medical devices to go through an alternate approval process, the Humanitarian Device Exemption (HDE) pathway. Because demonstrating effectiveness can be challenging in small patient populations, these humanitarian use devices (HUDs) only have to show that they are safe and are a “probable benefit to health.” This contrasts with devices in the standard premarket approval process that must show rigorous proofs of efficacy. As of 2015, 69 HDEs have been approved.
Not all devices for rare diseases are eligible for the HDE pathway, however. Only conditions that affect fewer than 4,000 new individuals in the US per year can qualify. Some diseases otherwise defined as “rare” by the US affect a larger number of people. However, on Oct 21, Republican senator Cory Gardner of Colorado and Democrat senator Joe Donnelly of Indiana introduced the Rare Disease Innovation Act
, which would expand the threshold to diseases that affect 8,000 or fewer individuals annually. The bill
is currently in the Health, Education, Labor, and Pensions Committee.
In the meantime, rare conditions affecting more than 4,000 people may benefit from another FDA voluntary program, the Expedited Access Pathway
. This program is designed to help accelerate the approval process for devices for life-threatening or irreversibly debilitating diseases.
Other FDA initiatives to promote device approval for rare diseases
The FDA’s Center for Devices and Radiological Health has taken other steps to increase approvals of new effective devices for rare diseases. These have included the following: a program to smooth the implementation of clinical trials, new guidance documents on investigational device exemptions, and industry education on performing successful early feasibility studies.
The FDA also funds 2 grant programs to provide financial assistance for developers of some rare disease devices. One of these programs, the Orphan Grants Program, has helped bring more than 55 products to marketing approval. Yet with over 30 million Americans suffering from rare diseases, there must remain large unmet needs for new devices. Further initiatives will be needed to increase the availability of these potentially life-saving products.