TEPP-46 (ML265)

ML265 potently activates PKM2 in vitro with an AC50 = 92 nM and shows a high degree of selectivity over the other 3 pyruvate kinase isoforms. ML265 binds at the dimer-dimer interface of the PKM2 homotetramer. It is capable of activating PKM2 in cell lysate of pervanadate treated cells, which is a condition known to inhibit PKM2 activity through accumulation of phosphotyrosine peptides. ML265 significantly increased the doubling time of H1299 cells under hypoxic conditions, but interestingly showed no effect under normoxia^[1].

ML265 gave superior plasma concentrations that persisted at higher levels over the 24 hour study. ML265 also displayed good oral bioavailability, low clearance, a long half-life and good volume of distrubtion. The 7-week mouse xenograft model (H1299 mouse xenograft) showed that the activation of PKM2 with ML265 was able to significantly reduce tumor size and occurrence without showing signs of acute toxicity. ^[1].

• PKM2 activity assay

  Pyruvate kinase activity is measured by monitoring pyruvate-dependent conversion of NADH to NAD+ by lactate dehydrogenase (LDH). Briefly, for cell line experiments, the medium is replaced with fresh medium 1 hr prior to the start of treatment with DMSO or activator. Also, where indicated, 100 μM pervanadate is added 10 min prior to cell lysis. Cells are lysed on ice with RIPA buffer containing 2 mM DTT and protease inhibitors and clarified by centrifugation at 21,000 × g. 5 μL of the supernatant is used to assess pyruvate kinase activity. Pyruvate kinase activity was subsequently normalized for total protein content.

• Cell lines

  H1299 cells

• Concentrations

  50 μM

• Incubation Time

  1 h

• Method

  H1299 cells incubated with 50 μM ML265 for 1 hour, lysed followed by 2-D electrophoresis, Western blot and PGAM1 antibody staining.

• Animal Models

  Male Balb/c mice

• Dosages

  IV: 1 mg/kg, PO: 10 mg/kg; IP: 10 and 50 mg/kg

• Administration

  IV, IP and PO