Siltuximab, a drug that has been tested as a potential new treatment for multiple myeloma, was approved last week by the U.S. Food and Drug Administration (FDA).

Its approval, however, was as a new treatment for a form of Castleman's dis­ease, a rare disorder similar to lymphoma.

Siltuximab ^[1] will be marketed in the United States by the Janssen Biotech division of Johnson & Johnson (NYSE:JNJ).  The drug's brand name will be Sylvant.

Johnson & Johnson also has submitted an application with the European Medi­cines Agency to market siltuximab in Europe as a treatment for Castleman's disease. A decision on the Euro­pe­an application, however, has not yet been announced.

Siltuximab has been investigated in several clinical trials as a potential treatment for myeloma.  Initial results for one trial were presented at the American Society of Hematology annual meeting in 2011.  The results showed that siltuximab was active against multiple myeloma, but patients treated with the drug also ex­peri­enced significant side effects (see related Beacon ^[2] news article).   Updated results from that trial were pub­lished last year ^[3], and another study was published recently ^[4] examining the impact of siltuximab on the heart function of myeloma patients treated with the drug.

Only one clinical trial of siltuximab in myeloma patients is still ongoing and recruiting patients.  The inter­na­tion­al multicenter trial ^[5] is testing siltuximab as a potential treatment for high-risk smoldering myeloma.

It's not known whether the location of Janssen Biotech's headquarters – which is in Pennsylvania – influ­enced the company's decision to select Sylvant as the brand name for sil­tuximab.

For more information about siltuximab's FDA approval, see the related press releases from the FDA ^[6] and Johnson & Johnson ^[7].