Carcinoid syndrome is a rare disease affecting thousands of patients with neuroendocrine tumors that originate in the gastrointestinal tract and metastasize or spread to the liver or other organs. Overproduction of serotonin within these metastatic neuroendocrine tumor (mNET) cells is a driver of carcinoid syndrome, which is characterized by debilitating diarrhea, facial flushing, abdominal pain, heart valve damage and other serious consequences. The severe and unpredictable diarrhea associated with carcinoid syndrome has a profound impact on cancer patients’ lives, often preventing them from participating in daily activities.

The current standard of care for carcinoid syndrome is somatostatin analog depot injection (SSA), first approved in 1998. SSA therapy fails to maintain adequate control of carcinoid syndrome for most patients, with many becoming not adequately controlled within the first two years after the therapy is initiated. Patients with carcinoid syndrome can live for many years with metastatic cancer, requiring the need for long-term treatment options to effectively manage their disease.

Carcinoid syndrome occurs in approximately 5% of carcinoid tumors.

Carcinoid syndrome is a combination of symptoms caused by the release of excessive serotonin and other substances into the blood stream from metastatic carcinoid tumors.