The FDA has approved Janssen's Sylvant as the first ever treatment for multicentric Castleman's disease (MCD).
MCD is a rare blood disorder with high morbidity in which lymphocytes are over produced, leading to enlarged lymph nodes. Infections, multiple organ failure and malignancies including malignant lymphoma are common causes of death in patients.
The condition is so rare that it is difficult to track the number of cases, though a recent US analysis estimates between 1,100 and 1,300 cases in the US.
Sylvant (siltuximab) works by binding to human IL-6, a protein which plays a key role in the immune system but which is overproduced in MCD.
The drug was evaluated in MCD2001, the first ever randomised study of the disease, which was also double-blind, placebo-controlled study of 79 patients with the condition.
more than one-third of patients in the Sylvant arm (53 patients) had a durable tumour and symptomatic response to treatment plus best supportive care (BSC), a durable response defined as tumour and symptomatic response (reduction in tumour size and disease symptoms) that persisted for a minimum of 18 weeks without treatment failure.
Roche's Actemra in Japan
Another drug, Roche's Actemra was launched for Castleman's Disease in Japan in 2005, its first ever launch, but has never been licensed in Europe or the US for the condition.
Actemra has a similar mechanism to the Janssen's new drug, but targets the IL-6 receptor rather than binding to IL-6 itself.
After its approval in Japan in 2005, Roche gained licences in more common – and more lucrative – disease areas, most notably rheumatoid arthritis.
Janssen has already investigated Sylvant in a number of other cancer types, and is currently pursuing phase II trials for high risk smoldering multiple myeloma, an early, slow-growing type of the cancer.