Introduction

Rare disease drug developers face specific challenges not encountered by developers of drugs for common diseases, such as geographically dispersed and small patient populations, prolonged trial recruitment periods, and a lack of approved biomarkers, among others. Several programs at the Food and Drug Administration (FDA) incentivize the development of drugs for rare diseases and help fill the treatment gap for patients with these conditions. Herein, we discuss regulatory pathways and designations that manufacturers in the rare disease space can utilize.

Overview of Established and Novel FDA Programs

While the FDA has several long-established pathways, designations, and voucher programs to accelerate drug development and approval timelines, only one is specific to rare disease drug development: the Orphan Drug Designation (ODD). Irrespective of rare disease focus, many drugs in development for rare diseases will also meet the eligibility requirements for Accelerated Approval and/or Fast Track or Breakthrough designations. Table 1 details eligibility requirements and benefits associated with the various FDA programs.

Recently, the FDA has demonstrated its growing support of the rare disease community and associated challenges with drug development in this space. In July 2024, the FDA introduced the Rare Disease Innovation Hub, which leads several new initiatives and programs that specifically address rare disease drug development hurdles and provide certain benefits or incentives for manufacturers to leverage (i.e., the Rare Disease Endpoint Advancement Pilot and the Rare Disease Evidence Principles).

The Hub also coordinates rare disease efforts across the Center for Drug Evaluation and Research and Center for Biologics Evaluation and Research, and engages with the rare disease community through its Rare Disease Innovation, Science, and Exploration workshop series.

Table 1. Overview of Rare Disease-Specific FDA Programs

The FDA’s newest initiative related to rare diseases is the proposed Plausible Mechanism Pathway for personalized therapies with known specific biological causes. While program details are still in development, this pathway may be useful for antisense oligonucleotides and gene-editing treatments for ultra-rare diseases, as it may lead to market approval following successful clinical “n of 1” studies.

Additionally, the Commissioner’s National Priority Voucher Program—which is not limited to rare diseases—has been awarded to 18 drug products across various diseases with unmet needs and stages of development since the pilot program launched in June 2025. Recipients in the rare disease space include drugs in development for multiple myeloma, sickle cell disease, drug-resistant tuberculosis, and porphyria.

Future Policy Changes

Rare disease drug manufacturers should monitor Congress for the potential reauthorization of the Rare Pediatric Disease Designation and Priority Review Voucher (RPD Designation and PRV) program. Created in 2012, this program incentivized the development of treatments for rare pediatric diseases by reducing marketing application review timelines to six months. Despite advocacy from manufacturers and patient groups for the program’s reauthorization, the program expired and ceased designating drugs for RPD in December 2024.

The Give Kids a Chance Act included in the Consolidated Appropriations Act of 2026 has passed the House and is currently in the Senate. The bill would reauthorize the RPD Designation and PRV program and modify the ODD exclusivity criteria to apply to the same drug for same indication, rather than for the same disease, potentially allowing more approvals for rare disease indications.

Dive Deeper

There are several regulatory assistance programs available to help manufacturers in the rare disease space which reduce development burdens and may enhance the market viability of their products. Importantly, a single product may qualify for and participate in multiple programs simultaneously. By strategically leveraging these regulatory pathways, manufacturers can accelerate innovation and improve access to much-needed therapies for patients with rare and ultra-rare conditions.

Avalere Health applies expertise in FDA regulatory strategy and evidence generation planning to access strategies for rare disease treatments, helping rare disease drug developers and patient advocacy groups meet their objectives. To learn more about how Avalere Health can help you with clinical development planning, value, and access strategies for rare and ultra-rare disease assets, connect with us.