Thieno[2,3-d]pyrimidin-4-amine, 5,6-dimethyl-N-[1-(phenylmethyl)-3-pyrrolidinyl]-, compd. with benzenesulfonate (1:1)

Fasnall is an inhibitor of fatty acid synthase (FASN) with an IC₅₀ value of 3.71 μM for the human recombinant enzyme.¹ It inhibits tritiated acetate incorporation into lipids (IC₅₀ = 5.84 μM), increases ceramide accumulation, and induces the formation of lipid droplets in BT474 HER2⁺ breast cancer cells. Fasnall has antiproliferative activity against non-tumorigenic MCF-10A and tumorigenic MCF-7, MDA-MB-468, BT474, and SK-BR-3 breast cancer cells that directly correlates to the level of FASN expression in vitro. It reduces tumor volume and increases survival in the murine MMTV-Neu model of HER2⁺ breast cancer. Fasnall also potentiates carboplatin response in vivo, increasing the objective response rate of stable disease from 25% for carboplatin alone to 88% for carboplatin with fasnall.

1. Alwarawrah, Y., Hughes, P., Loiselle, D., et al. Fasnall, a selective FASN inhibitor, shows potent anti-tumor activity in the MMTV-Neu model of HER2+ breast cancer Cell Chem. Bio. 23(6),678-688(2016).