Clinical data
Other namesHT-0712, IPL 455,903
ATC code
  • None
  • (3S,5S)-5-(3-(Cyclopentyloxy)-4-methoxyphenyl)-3-(3-methylbenzyl)piperidin-2-one
CAS Number
PubChem CID
CompTox Dashboard (EPA)
Chemical and physical data
Molar mass393.527 g·mol−1
3D model (JSmol)
  • O=C3NC[C@H](c2cc(OC1CCCC1)c(OC)cc2)C[C@H]3Cc4cccc(c4)C
  • InChI=1S/C25H31NO3/c1-17-6-5-7-18(12-17)13-20-14-21(16-26-25(20)27)19-10-11-23(28-2)24(15-19)29-22-8-3-4-9-22/h5-7,10-12,15,20-22H,3-4,8-9,13-14,16H2,1-2H3,(H,26,27)/t20-,21-/m1/s1 checkY

HT-0712, also known as IPL-455903,[1] is an experimental cognitive enhancing drug (nootropic) which is currently undergoing clinical trials. It is currently being licensed by Helicon Therapeutics in San Diego, California. It was originally discovered and tested as part of a preclinical anti-inflammatory program by Inflazyme Pharmaceuticals.[2]

Mechanism of action

HT-0712 appears to act as a PDE4 inhibitor, thereby increasing cAMP levels. When cAMP levels are increased in neurons, this may trigger activation of cAMP response element-binding proteins (CREB). CREBs are transcription factors involved in the formation of long-term memory.[2]

The side effects of the drug are not yet fully known.


A 2014 study found that HT-0712 significantly boosted memory formation in mice. Data also indicated that HT-0712 may be effective to treat age-associated memory impairment in humans. [3]


  1. ^ Giembycz MA (October 2008). "Can the anti-inflammatory potential of PDE4 inhibitors be realized: guarded optimism or wishful thinking?". Br. J. Pharmacol. 155 (3): 288–90. doi:10.1038/bjp.2008.297. PMC 2567889. PMID 18660832.
  2. ^ a b MacDonald E, Van der Lee H, Pocock D, et al. (2007). "A novel phosphodiesterase type 4 inhibitor, HT-0712, enhances rehabilitation-dependent motor recovery and cortical reorganization after focal cortical ischemia". Neurorehabil Neural Repair. 21 (6): 486–96. doi:10.1177/1545968307305521. PMID 17823313.
  3. ^ Peters, M; Bletsch, M; Stanley, J; Wheeler, D; Scott, R; Tully, T (2014). "The PDE4 inhibitor HT-0712 improves hippocampus-dependent memory in aged mice". Neuropsychopharmacology. 39 (13): 2938–48. doi:10.1038/npp.2014.154. PMC 4229572. PMID 24964813.