Receptor binding assays in HEK 293 cells transfected with the rat Y2 receptor cDNA demonstrate that BIIE-0246 competes with high affinity (IC ₅₀ =15±3 nM) against specific [ ¹²⁵ I]PYY _3-36 binding sites. In contrast, BIIE-0246, at concentrations up to 10 μM, fails to compete for significant amounts of specific [ ¹²⁵ I]GR231118, [ ¹²⁵ I]hPP and [ ¹²⁵ I][Leu ³¹ , Pro ³⁴ ]PYY binding sites in HEK 293 cells transfected with the rat Y ₁ , Y ₄ or Y ₅ receptor cDNA, respectively.

On chow diet, genetically obese NPY mice show increased gain in body weight and adiposity. Treatment with BIIE-0246 promotes body weight gain in both genotypes after 4.5 weeks, and already at 2 weeks. BIIE-0246 has no significant effect on fat mass gain. In DIO, BIIE-0246 has different effects on body weight and composition depending on the genotype (treatment×genotype interaction in body weight P<0.05, in fat mass P<0.001 and in lean mass P<0.05). In DIO-WT group, post hoc analysis reveals increased body weight and fat mass gain, and a tendency to decrease lean mass gain. In DIO-NPY, BIIE-0246 inhibits fat mass gain (P=0.05). Interestingly, increased cholesterol levels are detected also in WT mice treated with BIIE-0246 for 2 weeks, but not in the 4.5-week cohort. In DIO-NPY mice in both treatment groups, cholesterol levels correlate positively with body fat mass (DIO-NPY vehicle P<0.01; DIO-NPY BIIE-0246 P<0.001), but not in any other group, and the slope of the regression curve of cholesterol and fat mass is significantly decreased in BIIE-0246-treated DIO-NPY group when compared with vehicle-treated group.