CTT develops small molecule scaffolds with a unique mode of binding to enzyme biomarkers important in cancer.

Targeting the enzyme biomarker Prostate Specific Membrane Antigen (PSMA) on cancer is leading to exciting new imaging and therapeutic agents for prostate and other cancers. PSMA is expressed on greater than 90% of all prostate cancers. The expression increases as the cancer spreads and metastasizes and expression is strong  in late-stage androgen-independent prostate tumors.

PSMA is also an attractive target given its broader expression on the neovasculature of various solid tumors, including kidney, bladder, lung, prostate, colorectal, pancreatic and melanoma cancers.


  • Imaging PET Diagnostic for Prostate Cancer and other solid vascularized tumors
  • Companion Therapeutic for Prostate Cancer and other solid vascularized tumors

The Target: Prostate Specific Membrane Antigen

  • Well validated target
  • Expressed on >95% of prostate tumors
  • Expression increases as the prostate cancer progresses
  • Minimal expression on normal tissue
  • Expressed on blood vessels in most solid tumors

Various chemical scaffolds have been developed as inhibitors of PSMA’s enzymatic activity. It is well recognized that significant advances in prostate cancer could be achieved if the simplicity and affinity of small molecule PSMA inhibitors could be harnessed as an effective platform to deliver chemo and/or radio-therapeutic payloads.

PSMA image

The Targeting Scaffold: Phosphoramidate-based peptidomimetic

  • Binds extracellularly
  • Nanomolar affinity to PSMA
  • Binds “irreversibly” and is rapidly and extensively internalized
  • Can carry a wide variety of payloads

CTT has developed both imaging and therapeutic drugs based on a peptidomimetic core that targets PSMA with high affinity. This specific PSMA targeting molecule was selected from a class of irreversible PSMA inhibitors that can deliver a number of different payloads to PSMA positive tumors. Although comparable to other PSMA inhibitors in terms of affinity for PSMA, CTT’s unique technology represents the only known irreversible PSMA inhibitors. In addition, CTT’s PSMA inhibitors possess nanomolar or better affinity for PSMA and can selectively deliver payloads to the surface and intracellular space of prostate tumor cells through the rapid internalization of the enzyme inhibitor complex.

PSMA linker image