Lilly Halts Phase 3 Trials For Lupus Drug Tabalumab

Eli Lilly & Co. announced that it is pulling the plug on the development of its candidate drug tabalumab under investigation as a potential treatment for systemic lupus erythematosus (SLE). The company said the decision to halt tabalumab’s development is due to a lack of efficacy and not because of safety concerns.

Tabalumab is a monoclonal antibody (MAb) under the class of human immunoglobulin G subclass 4 (IgG4). The drug works by inhibiting membrane-bound and soluble B cell activating factor (BAFF). Lilly announced that it is giving up on the drug following its consecutive failures in clinical trials.

The drug failed to meet the ILLUMINATE 1 trial’s primary endpoint of statistically meaningful improvement on SRI-5 (SLE Responder Index-5 which measures lupus disease activity and response) versus standard of care therapy. A higher dose of the drug met the primary endpoint in the Phase 3 trial ILLUMINATE 2, but the company said the collective data from the two studies fell short of expectations when examining the drug’s efficacy against that of standard of care treatments.

Last year, tabalumab also disappointed researchers in its Phase 3 trial where it was investigated as potential treatment for rheumatoid arthritis. Similar to the recent studies, the decision to discontinue the trial was due to lack of efficacy rather than safety concerns. Shortly before that, Lilly announced it has discontinued the Phase 3 registration study of the tabalumab for moderate to severe rheumatoid arthritis.

Based on the overall results of the drug’s efficacy from the two recent pivotal Phase 3 studies, the company declared it will not proceed with global regulatory applications. “Although we were pleased that tabalumab met the criteria for statistically significant improvement in the SRI-5 endpoint in one of our trials, we are nonetheless disappointed that the overall results did not meaningfully improve the condition of the patients in these studies,” said J. Anthony Ware, SVP of Product Development, Lilly Bio-Medicines. Ware added that the ILLUMINATE trials are the largest late-stage clinical trials for lupus and that the company hopes data gathered from the studies will help in improving understanding of the autoimmune disease.

PMLive notes that tabalumab has been considered as a second-priority candidate by analysts following its lackluster performance in the rheumatoid arthritis study, with expected peak sales pegged at $250 million per year from multiple indications.

Lilly said that its decision to stop tabalumab’s development will result in a $75 million R&D expense for the third quarter.