Complex sentence: Alemtuzumab, daclizumab and CD20 monoclonal antibodies such as rituximab, ocrelizumab and ofatumumab have all shown some benefit and are under study as potential treatments for MS. Nevertheless their use has also been accompanied by the appearance of potentially dangerous adverse effects, most importantly opportunistic infections.
Split into simpler sentences: Alemtuzumab, daclizumab and CD20 monoclonal antibodies such as rituximab, ocrelizumab and ofatumumab have all shown some benefit and are under study as potential treatments. Their use has also been accompanied by the appearance of potentially dangerous adverse effects, most importantly opportunistic infections.