Right now, no cure exists for people living with systemic sclerosis (also known as systemic scleroderma). There are treatment options available to manage systems. However, these also come with issues. Available treatments focus on symptom management and reducing associated complications. People with systemic sclerosis deserve a therapy that will address the underlying cause of their disease, reduce damage, and provide a better quality of life.
Could CABA-201 be that therapy? Right now, we don’t know the answer to that question. But CABA-201 is being explored for systemic sclerosis treatment. In fact, on March 20, 2024, clinical-stage biotechnology company Cabaletta Bio Inc. (“Cabaletta”) shared that CABA-201, its lead candidate developed using the proprietary CABA™ platform, received Orphan Drug designation from the US FDA.
What is Systemic Sclerosis?
Systemic sclerosis is a rare, chronic autoimmune connective tissue disorder. The exact cause is unknown. However, we know that people with scleroderma have excess levels of collagen, a protein that normally strengthens connective tissue. This causes fibrosis (scar tissue buildup), which leads to thickening in the skin and organs. Systemic scleroderma is 4x more common in females than males. Symptoms, which often appear in middle age, may include:
- Hardened and thickened patches of skin
- Joint pain and stiffness
- Swollen hands and feet
- Kidney dysfunction
- Fatigue
- Shortness of breath
- Diarrhea
- Dysphagia (difficulty swallowing)
- Painful bumps under the skin and/or open sores on the fingers
- Heartburn
- High blood pressure
- Raynaud’s phenomen, which causes the fingers to turn blue/white in response to cold temperatures
- Impaired esophageal, lung, kidney, and heart function
- Lack of esophageal and colon motility
- Renal failure
- Pulmonary disease
CABA-201 and the Orphan Drug Designation
As I mentioned earlier, there are available therapies for systemic sclerosis, from drugs like cholchicine and D-penicillamine to surgery and antibiotics. However, this community still faces a number of unmet needs that would benefit from a novel therapy.
Enter CABA-201, which Cabaletta describes as:
a fully human CD19 chimeric antigen receptor (CAR) T cell therapy containing a 4-1BB co-stimulatory domain.
This investigational therapy is being explored in the Phase 1/2 RESET-SSc study. The study encompasses two cohorts, one with severe skin involvement and the other with lung, heart, or kidney involvement. During the study, researchers will evaluate CABA-201 as a potential systemic sclerosis intervention. In particular, researchers hope to understand how well CABA-201 can “reset” the immune system and lead to remission.
The FDA seems to think that CABA-201 shows promise in this sphere. As a result, the regulatory agency granted Orphan Drug Designation to CABA-201 for systemic sclerosis. Throughout history, it has been difficult to stimulate drug development and review in the rare disease space. The FDA catalyzed drug development through the Orphan Drug Act in the 1980s, which created the Orphan Drug designation. This designation is given to drugs or biologics intending to treat rare conditions in the United States, or conditions affecting fewer than 200,000 people nationwide. Cabaletta also receives tax credits, fee waivers, increased FDA communication, and 7 years of market exclusivity if the drug is approved.
Outside of systemic sclerosis, Cabaletta is exploring CABA-201 as a potential treatment for generalized myasthenia gravis, lupus, and myositis.
