[Effectiveness and safety of radium chloride in the treatment of ankylosing spondylitis. Results of an observational study].

After radium chloride was approved for the therapy of ankylosing spondylitis (AS) in Germany on October 23, 2000, an open, non-comparative prospective observational study was planed. The assessment involved 308 patients with the diagnosis of AS and radiological evidence of spinal involvement who were treated with at least one injection of radium chloride. 278 of these patients received the full cycle of 10 injections (a total of 10 MBq radium-224) one injection one per week for a period of 10 successive weeks. Validated outcomes were measured before therapy and six months after therapy according to the recommendations of the "assessment in ankylosing spondylitis working group"(ASAS). The primary endpoint was disease activity assessed using the BASDAI ("Bath Ankylosing Spondylitis Disease Activity Index"). Secondary endpoints included the BASFI ("Bath Ankylosing Spondylitis Functional Index"), as well as self-reported pain and global patient ratings. Patients showed significant improvement in all of the parameters assessed (BASDAI, BASFI, pain, global patient rating) at 6-months post-treatment. At this time, the mean BASDAI and BASFI scores improved from 5.5 to 3.5 and from 5.6 to 3.7, respectively. Pain decreased from a mean of 7.3 to 4.1, and disease activity (as rated by patients) also decreased from 7.2 to 4.1 (p < 0.001 for all of them). Drug tolerance was good. Six adverse events were documented, none of which was serious and none led to discontinuation of treatment. According to the data provided here medical treatment with radium chloride seems to be effective and safe during an observation period of 6 months. Nevertheless, a randomized placebo-controlled study should be performed in the near future in order to safeguard the level of evidence.