Endocrine Abstracts

Since our first report on successful treatment of one patient with moderate-severe GO in 2006, several non-controlled studies have suggested that RTX can be more effective in active GO than intravenous methylprednisolone (ivMP). One randomised controlled trial comparing RTX to placebo and one comparing RTX to steroids in moderate-severe GO were recently published.

We have randomised 32 patients with active moderate-severe GO to be treated with RTX or ivMP and studied the decrease of the CAS as a primary end point. At 24 weeks, the CAS decreased more significantly after RTX and 100% of patients improved compared to 69% after ivMP (P<0.001). Dose finding analysis has shown that a single dose of 500 mg RTX is as effective as two doses of 1000 mg, two weeks apart. Disease reactivation was never observed in patients treated with RTX, but in 5 (31%) after ivMP. Either treatment was not effective on proptosis, palpebral aperture, and the total eye score, but RTX proved to be more effective than ivMP on motility and quality of life, thus suggesting that, compared to steroids, it may act as a disease modifying therapy. Stan et al. did not find RTX effective in treating active GO, when compared to placebo. The study was conducted on 21 patients, of whom two, after RTX, developed optic neuropathy. Major differences that may have influenced the outcome of their study are a much longer disease duration (11.2 months vs 4.5 months), a greater number of patients previously treated with steroids (40% vs 19%) and a lesser degree of motility involvement (mean diplopia score 2 vs 3.5). RTX may be a good alternative to steroids in non-responders, but its administration should be limited only to experienced centres, until the results of multicentre RCT trials on a greater number of patients will be available.