According to biotechnology Gilead Sciences, the FDA rejected a new drug application (NDA) for filgotinib. The drug, designed to treat patients with moderate to severe rheumatoid arthritis (RA), is known as a disease-modifying anti rheumatic drug (DMARD). Filgotinib inhibits janus kinase (JAK). In fact, it was only the fourth potential JAK inhibitor available for RA. JAK inhibitors work by preventing the immune system from going into overdrive, thus reducing inflammation.
Filgotinib
One of the main reasons why the FDA rejected the NDA for filgotinib was concerns over testicular toxicity. According to Gilead’s Sonia Choi, animal studies of filgotinib saw potentially harmful semen-related changes. While the FINCH Phase 3 clinical trial showed that Filgotinib improved RA symptoms in previously treated patients, the toxicity is a huge concern. This is especially true in doses of 200mg or higher.
Currently, Gilead Sciences is holding the MANTA and MANTA-RAy studies. These will help determine whether filgotinib presents the same safety and toxicity issues in human males as it did in animals. During the studies, Gilead Sciences will test the intersection of filgotinib and male reproductive safety in patients with rheumatoid arthritis, psoriatic arthritis (PsA), ankylosing spondylitis (AS), axial spondyloarthritis, and inflammatory bowel disease.
Following data from these studies, the FDA will reconsider the NDA. Outside of the United States, filgotinib was approved for rheumatoid arthritis by the European Medicines Agency (EMA).
Rheumatoid Arthritis (RA)
Rheumatoid arthritis is a chronic inflammatory disorder which impacts joints. In many cases, RA is difficult to deal with and diagnose. For some patients, the disorder progresses slowly. Others may never experience worsening symptoms. In rare cases, symptoms occur rapidly. Many patients with rheumatoid arthritis experience periods of remission followed by symptomatic periods. Each year, there are over 200,000 new RA diagnoses in the United States. However, worldwide, RA prevalence for women over 55 years old is 5%. RA is much more commonly found in females than males.
Symptoms of rheumatoid arthritis include:
- Joint pain, stiffness, weakness, tenderness, and inflammation
- Muscle and back pain
- Severe fatigue
- Dry mouth
- Bone erosion
- Joint deformity
- Difficulty with climbing stairs and other daily activities
- Poor grip strength
- Anemia
- Skin swelling, lumps, and redness
Learn more about RA.