Ablynx’ vobarilizumab has failed to hit targets in a mid-stage trial assessing its safety and effectiveness as a treatment for systemic lupus erythematosus (SLE).

The Phase II STEADY trial did not meet the primary endpoint of dose response based on the modified BILAG (British Isles Lupus Assessment Group) based combined lupus assessment (mBICLA) at Week 24, the firm said.

mBICLA is a composite measure of SLE disease activity across all body systems, driven by an improvement in the BILAG, no worsening of the modified SLEDAI-2K (SLE disease activity index excluding the low complement scoring) and no significant worsening of the physician global assessment (PGA), compared to baseline.

On the plus side, safety findings from the trial were positive, with treatment-related serious adverse events reported in 2 percent of all vobarilizumab treated patients compared to 6.5 percent in the placebo group.

Ablynx’ chief medical officer Dr Robert K Zeldin said the firm is disappointed that the data did not show a dose response in the analysis of the study's primary endpoint, and noted that the full data set would be further analysed.

In September 2013 the group signed a global exclusive option licensing deal with AbbVie for the development and commercialisation of the drug in rheumatoid arthritis (RA) and SLE.

AbbVie will review the complete data set when available from the Phase II STEADY SLE study to determine whether to exercise its option to license vobarilizumab, Ablynx noted.

If AbbVie does exercise its option this would trigger a payment to Ablynx, but if not, the agreement would terminate.

The drug seems to be faring better as a treatment for RA, with mid-stage data looking promising. In one Phase II trial, vobarilizumab reduced signs and symptoms of RA and resulted in ACR20, ACR50 and ACR70 scores of up to 81 percent, 49 percent and 24 percent, respectively, at week 12, as compared to 78 percent, 45 percent and 23 percent, respectively, at week 12 in the tocilizumab arm.

Also, the drug induced clinical remission in up to 41 percent of patients, as compared to 27 percent of patients treated with tocilizumab, Ablynx noted.