Second generation proteasome inhibitors: carfilzomib and immunoproteasome-specific inhibitors (IPSIs)

Curr Cancer Drug Targets. 2011 Mar;11(3):285-95. doi: 10.2174/156800911794519725.


The ubiquitin-proteasome pathway (UPP) is an attractive chemotherapeutic target due to its intrinsically stringent regulation of cell cycle, pro-survival, and anti-apoptotic regulators that disproportionately favor survival and proliferation in malignant cells. A reversible first-in-class proteasome inhibitor, bortezomib, is Food and Drug Administration approved for multiple myeloma and relapsed/refractory mantle cell lymphoma and has proven to be extremely effective, both as a single agent and in combination. An irreversible second generation proteasome inhibitor, carfilzomib, has shown preclinical effectiveness against hematological and solid malignancies both in vitro and in vivo. Carfilzomib, a peptidyl-epoxyketone functions similarly to bortezomib through primary inhibition of chymotrypsin-like (ChT-L) activity at the b5 subunits of the core 20S proteasome. Carfilzomib is also currently achieving successful response rates within the clinical setting. In addition to conventional proteasome inhibitors, a novel approach may be to specifically target the hematological-specific immunoproteasome, thereby increasing overall effectiveness and reducing negative off-target effects. The immunoproteasome-specific inhibitor, IPSI-001, was shown to have inhibitory preference over the constitutive proteasome, and display enhanced efficiency of apoptotic induction of tumor cells from a hematologic origin. Herein, we discuss the preclinical and clinical development of carfilzomib and explore the potential of immunoproteasome-specific inhibitors, like IPSI-001, as a rational approach to exclusively target hematological malignancies.

Publication types

  • Review

MeSH terms

  • Animals
  • Antineoplastic Agents / therapeutic use*
  • Humans
  • Neoplasms / drug therapy*
  • Neoplasms / immunology
  • Neoplasms / metabolism
  • Oligopeptides / therapeutic use*
  • Protease Inhibitors / therapeutic use*
  • Proteasome Endopeptidase Complex / metabolism
  • Proteasome Inhibitors*


  • Antineoplastic Agents
  • Oligopeptides
  • Protease Inhibitors
  • Proteasome Inhibitors
  • carfilzomib
  • Proteasome Endopeptidase Complex