In a news release, the drug company Centocor, which makes ustekinumab and sponsored the study, calls the new drug "superior" to Enbrel.
But Amgen, the drug company that makes Enbrel, notes that the study only lasted for 12 weeks and didn't address long-term safety.
Both ustekinumab and Enbrel are biologic drugs. Ustekinumab targets two inflammatory chemicals, interleukin 12 and interleukin 23. Enbrel is a TNF blocker; that is, it inhibits tumor necrosis factor (TNF).
In the new study, 903 patients with moderate to severe plaque psoriasis either got ustekinumab (in a higher or lower dose) or Enbrel for 12 weeks.
Patients in the ustekinumab groups got one shot of the experimental drug in their assigned dose when the study started and another shot four weeks later. Patients in the Enbrel group got two shots of Enbrel every week for 12 weeks.
By the end of the study, 65% of patients in the lower-dose ustekinumab group and almost 71% of those in the higher-dose ustekinumab group had, at most, minimal signs of their psoriasis, according to their doctors, compared to 49% of patients treated with Enbrel.
Both drugs were generally well tolerated and had similar safety profiles during the study, according to data presented in Paris at the European Academy of Dermatology and Venereology Congress.
"This study is significant for the dermatology community, as it is the first comparator trial of biologic therapies for psoriasis," researcher Christopher Griffiths, MD, FRCP, of England's University of Manchester, says in a Centocor news release.
"Treatment with ustekinumab ... has demonstrated significant clinical efficacy with infrequent self-administered injections. Both are important considerations when evaluating the burden of disease for many adult patients living with moderate to severe psoriasis and who are candidates for a biologic treatment," Griffiths notes.
In an email, Sonia Fiorenza, Amgen's director of corporate communications, tells WebMD that "the big question with any new therapy, especially one targeting a new pathway, is not short-term efficacy; it's long-term safety. This 12-week study doesn't address that question."
Fiorenza says Enbrel "continues to have a consistent safety profile," has been used for 16 years, is "the number one prescribed biologic in psoriasis, and 80% of patients are highly satisfied with Enbrel."
Centocor has submitted ustekinumab for FDA approval. In June, an advisory panel recommended that the FDA approve ustekinumab. The FDA often follows the recommendations of its advisory panels, but it's not obligated to do so.