Understanding MCAS

What is Mast Cell Activation Syndrome (MCAS)?

Mast cell activation syndrome (MCAS) refers to a group of disorders characterized by multisystem symptoms resulting from the accumulation of altered mast cells and/or abnormal mast cell mediator release. Due to the ubiquitous nature of mast cells throughout human body tissue, MCAS has the potential to affect every organ system, frequently without showing abnormalities in routine testing.

There have been some advances in MCAS in recent years, but the indication remains in need of additional research to better diagnose and treat.

Mast cells are “first responders” of the innate and adaptive immune systems.

Mast Cells Explained

Types of MCAS

MCAS is characterized by the body releasing inappropriate amounts of chemicals, causing repeated anaphylactic symptoms/episodes. MCAS is typically determined to be primary, secondary, or idiopathic.

Primary

MCAS resulting from a clonal population of mast cells where a genetic alteration in the cells exists; includes the rare disorders systemic and cutaneous mastocytosis.

Secondary

Mast cell activation is known to occur as a result of underlying allergic, autoimmune, or neoplastic processes, such as an IgE-dependent allergy.

Idiopathic

All other cases of MCAS, determined as a final diagnosis after other MCAS criteria have been fulfilled and no underlying cause for mast cell activation can be consistently identified.

The Challenge of Diagnosis

The pathway to presentation can be complicated to identify, as the mast cell may not be the central pathogenic component. Instead, there could be another factor stimulating mast cells to act abnormally.

Did you know? MCAS is relatively new – first hypothesized in the late 20th  Century with the first case reports not documented until 2007.

Frequency

Its idiopathic nature and broad spectrum make pinpointing the number of MCAS sufferers challenging. On the common side (i.e., allergic rhinitis, allergic asthma), up to 30% of the general population can be affected.

Mastocytosis and Monoclonal Mast Cell Activation Syndrome (MMAS) are considered rare diseases, affecting approximately 1 in 10,000 – 20,000 people.

Signs & Symptoms

Heart

Skin

Lung

Gastrointestinal

Other

TRIGGERS

IgE-Mediated

I.e., a food, drug, Hymenoptera venom (e.g. from bees and wasps), or inhalant that often can be identified via allergy testing.

Non-IgE-Mediated

I.e., physical stimuli (exercise, stress, infections), drugs, inflammatory of neoplastic disease

Unfortunately, there is no cure for MCAS. Patients need to avoid triggers and use doctor-prescribed medications to manage symptoms.

FSD Pharma’s Role in MCAS

FSD Pharma has received clearance for from the U.S.Food and Drug Administration and Health Canada to conducta Phase 2 trial of FSD201. The corresponding study protocol is titled “A Randomized, Double-Blind Placebo Controlled Parallel Group Study of Safety and Efficacy of FSD201 in Patients with Chronic Widespread Musculoskeletal Nociplastic Pain Associated with Idiopathic Mast Cell Activation Syndrome (Disorder)”.