Recently, some therapies for a small number of patients, including Ibrance made by Pfizer, have passed the screening of the Pharmaceutical Benefits Committee of Health Insurance Review & Assessment Service (HIRA)_{건강보험심사평가원}, getting a green light for insurance benefits. Not a few patients are watching these cases with envy, however. Among them are patients with multicentric Castleman's disease, a rare blood cancer, whose number in Korea has yet to be confirmed.

The disease features untypical lymphadenosis in all lymphatic glands of a body.

Because the prognosis of the multicentric Castleman's disease is the worst and the median survival rate for patients no alternative treatments remains only 5.5 months.

Because the diagnosis itself is difficult, the average diagnosis period is 27.5 months after the occurrence, and some people knew about their disease as late as 10 years after being hit by the disease. In the U.S., less than one person per population of 100,000 reportedly gets the disease.

Patients with multicentric Castleman's disease have received steroid and chemo therapy, but these were only allopathic treatments amid no alternative therapies. The median survival rate of these treatments was only 18.5 to 19 months.

The release of Sylvant (compound: siltuximab) in 2015 changed the situation.

Sylvant, approved as the first therapy to cure the disease, was an interleukin-6 inhibitor, and 34 percent of patients experienced the decrease of the cancer size and improved symptoms (compared with 0 percent for the placebo group) in clinical trials. The occurrence rates of abnormal reactions with three grades or higher and severe side effects were similar between the Sylvant group and the placebo group.

Based on the results, National Comprehensive Cancer Network (NCCN) added the disease to the guideline in 2015. In other words, the NCCN made its treatment guideline thanks to the appearance of Sylvant. The Korean government also approved Sylvant in December 2015.

It has been two years since Korea approved it, but the therapy has not received insurance benefit even though it is the only treatment to cure the disease. Accordingly, patients have to pay about 5 million won ($4,350) a month to treat with Sylvant.

All this explains why patients with the Castleman’s disease – for whom the only recognized therapy comes with a prohibitive price -- cannot help but envy the news about other rare disease treatments receiving insurance benefits.