California-based Xoma, focused on the discovery and development of therapeutic antibodies, said its phase IIb trial of Xoma 052 in type II diabetes patients did not achieve the primary endpoint of reduction in glycosylated hemoglobin, or HbA1c, after six monthly treatments with XOMA 052 compared to placebo. There were no serious drug-related adverse events.

The randomized, placebo-controlled, dose-ranging phase IIb trial enrolled 421 patients at multiple sites in the U.S. in 2010. Eligible patients had type II diabetes and were receiving metformin monotherapy, the standard of care for initial treatment of diabetes. Patients were randomized to receive one of four Xoma 052 doses or placebo monthly over six months via subcutaneous administration. The primary endpoint of the study was the change in HbA1c levels from baseline compared to placebo at six months.

Baseline characteristics were similar between the Xoma 052 and placebo groups. At study entry, the mean CRP was 4.8 mg/L and 4.2 mg/L in the XOMA 052 and placebo groups, respectively. Mean HbA1c was 7.8% for the Xoma 052-treated patients and 7.7% for placebo-treated patients. Mean duration of type II diabetes was approximately six years in both groups.

At six months, all Xoma 052 doses had reductions in CRP, with adjusted mean percent changes from baseline that were highly significant compared to placebo with p-values (adjusted for multiple comparisons) at 0.0005 or less.  The median reductions in this trial were 33% to 54% in the four dose groups, compared with zero reduction for placebo.