and Platforms


Our proprietary antibody-drug conjugate (ADC) platform centers on using a novel linker to increase the likelihood of clinical success by delivering a potent, active drug while minimizing off-target activity.

Antibody-Drug Conjugate (ADC) Platform

Our ADCs combine three components to deliver an active drug, or payload, inside the tumor cell, as well as produce a bystander effect in the surrounding tumor microenvironment.

Antibodies used in ADCs seeking out targets, or antigens, on tumor cells. They direct delivery of the cancer-killing therapy to the tumor. Our platform uses the antibody hRS7 to target the following antigens:
  • Trop-2, which is found in many types of solid tumors (TRODELVY)
  • CEACAM5, (IMMU-130)
  • HLA-DR, (IMMU-140)
The linker is a molecule that joins, or conjugates, the payload to the antibody. It helps to keep the ADC stable until it reaches its target so the active drug does not damage healthy cells while in circulation. It then releases the active drug to kill the cancer cells. Most ADCs use a linker that require an enzyme to the release the active drug.
Our linker, called CL2A, is unique in 3 ways:
  • It does not require an enzyme
  • It can produce a bystander effect by delivering active drug both inside the tumor, as well as in the surrounding area
  • It can support a high drug-to-antibody ratio. Our linker facilitates delivery of up to eight molecules of SN-38, the active drug, per antibody molecule inside the tumor cell and the tumor microenvironment. This ability to deliver so much active drug may explain why, in an animal model, our ADCs deliver more than 120 times the amount of SN-38 than when irinotecan, the parent drug, is administered intravenously.
SN-38 is our payload of choice. It is the active metabolite of irinotecan, an approved chemotherapeutic agent. The safety profile of SN-38 is well characterized.