M3258 (M 3258) is a potent, reversible, highly selective and orally acitve LMP7 inhibitor with ceullar IC50 of 4.1 nM.M3258 does not inhibit other constitutive proteasome and immunoproteasome subunits (IC50>2.5 uM).M3258 demonstrated strong antitumor efficacy in multiple myeloma xenograft models.M3258 treatment led to a significant and prolonged suppression of tumor LMP7 activity and ubiquitinated protein turnover and the induction of apoptosis in multiple myeloma cells both in vitro and in vivo.M3258 showed superior antitumor efficacy in selected multiple myeloma and mantle cell lymphoma xenograft models compared with the approved nonselective proteasome inhibitors bortezomib and ixazomib.

Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months.
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.