By Enrique Blanco, MD.

Many biotech and pharmaceutical companies have prioritised drug development for rare congenital and genetic diseases in past years, given the high unmet need and favourable clinical development paths. Unfortunately, these diseases often have severe or even fatal manifestations with few treatments available.

Emerging genetic data and new approaches like gene therapy are rendering monogenic diseases more tractable together with regulatory and legislative initiatives that have encouraged research and development. Consequently, pipeline activity has increased considerably, and there are now many more products in development.

In a report by Pharmaprojects® of July 2020, there are 27 rare congenital and genetic diseases with at least ten products in active development. A further 153 conditions have at least one product in active development.

However, how do we define a rare disease?

That depends on where we live. The European Union classifies a disease as rare if it affects less than one person in 2,000. In the United States, a condition is classified as rare if it affects less than 200,000 individuals; in Japan, the criterion is one person in 2,500. Despite these differences in definition, there is a crucial aspect of rare diseases that everyone can agree on: researching and developing treatments for them is uniquely challenging.

The situation continues to be a matter of concern.

There are around 7,000 distinct types of rare and genetic diseases that affect more than 400 million people worldwide (Global Genes. Rare Facts.) and about one in ten people in the United States, but 95% of rare diseases lack an FDA-approved product for treatment.

Furthermore, a study of clinical trials in the US, EU, and Japan found that only 16% of rare diseases have any related clinical trial activity (Sakate, R. et al. 2018).
These numbers are not surprising, as many daunting barriers stand between researchers and results:
1- The natural history of rare diseases is often poorly understood.
2- Knowledge and clinical manifestations over time are incomplete.
3- Appropriate efficacy endpoints are not available.
4- Under-representation in health care coding systems due to
individual rarity, which contributes to poor recognition and resource allocation (prevents clinical research from being performed).

Where is pharma investing in the rare disease sector?

Based on data obtained from the National Centre for Advancing Translational Sciences (US, NIH), the Genetic and Rare Diseases Centre (GARD) emphasises the vast unmet need that exists.

Diseases with the greatest of approved therapies (US) include Dwarfism, Lennox-Gastaut Syndrome (a particular type of epilepsy), and Cystic Fibrosis. Still, even for these diseases, the number of approved therapies is minimal compared to more prevalent conditions.

Large pharma companies dominate the commercial landscape; Takeda, Pfizer, Sanofi, GlaxoSmithKline, and Novartis each have at least eight approved therapies. However, increasingly the smaller, more specialised players such as Sarepta Therapeutics, Vertex Pharmaceuticals, and Ionis Pharmaceuticals are developing new products. Their prominence in the pipeline makes these companies perennial acquisition targets.

In conclusion, the industry is becoming increasingly focused on narrowly defined diseases, scientific advancements, and incentives for developing/finding new therapies that can potentially transform the lives of many patients with rare congenital and genetic disorders. Modern tools are urgently required to aid rare disease research. This research will enable natural history studies, mapping the patient journey, quantifying existing treatment patterns, serving as a control arm for new drugs in development, and demonstrating the effectiveness of off-label drug use to treat rare diseases.

Global Genes. Rare Facts.

Sakate R. Trends of clinical trials for drug development in rare diseases. Current Clinical Pharmacology. August 2018; 13 (3):199-208.
GARD. 2020.
Prevalence of Rare Diseases: Bibliographic Data. Orphanet Report Series. Rare Diseases Collection, January 2020. Number 1.
The National Economic Burden of Rare Disease Study (US). February 25, 2021.
Pharmaprojects® July, 2020.

Exhibit 1: Total Economic Burden of Rare Disease in the U.S. in 2019: $966 Billion

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