Advancing a Pipeline

Our expanding pipeline of ProbodyTM therapeutics is built on a robust portfolio of proprietary and patented technology. Rooted in innovation and differentiation, and driven by our vision and mission, we are advancing a deep oncology pipeline of Probody therapeutics by blazing our own trail and in partnership with some of the world’s leading biopharmaceutical companies.

Research & development

Product Candidate
LEAD Optimization
Phase 1/2
Commercial Rights
PD-L1 Probody immunotherapy
CytomX Therapeutics
CD166 Probody drug conjugate
CytomX Therapeutics
CTLA-4 Probody immunotherapy
BMS-986249 - Partner Logo
CD71 Probody drug conjugate
CX-2029 - Partner Logo CytomX Therapeutics
Probody Drug Conjugate
Probody Drug Conjugate - Partner Logo
T Cell Bispecific
T Cell Bispecific - Partner Logo CytomX Therapeutics
Additional PDCs, IO, TCBs
CytomX Therapeutics
  • Immunotherapies
  • Probody drug conjugates
  • T cell engaging bispecifics
  • Multiple programs

Lead candidates

We are utilizing our Probody platform to develop potential best-in-class immunotherapies against clinically validated targets and potential first-in-class therapeutics against novel, difficult-to-treat drug targets. We expect our Probody therapeutics have the potential to:

  • Overcome toxicity challenges associated with many current treatments
  • Enhance the efficacy and safety of combination regimens used to treat cancer
  • Expand the universe of possible drug targets previously considered inaccessible to traditional antibody drug conjugates
  • Offer new more powerful treatment options, especially for patients underserved by current therapies

CX-072 (PD-L1-targeting Probody therapeutic)

CX-072 is a wholly owned PD-L1-targeting Probody therapeutic for the treatment of cancer, currently being evaluated in a Phase 1/2 clinical trial. To support initiation of the study, CytomX launched PROCLAIM (Probody Clinical Assessment In Man), a clinical trial program that enables clinical study sites and physicians to access our Probody therapeutics under one international umbrella. The first module within the PROCLAIM program is an open-label, dose-finding Phase 1/2 study evaluating CX-072 as monotherapy and in combination with Yervoy® (ipilimumab) or Zelboraf® (vemurafenib) in patients with certain cancers. Initial clinical data was presented at the ASCO and ESMO 2018 Annual Meetings showed that CX-072 demonstrated tolerability and anti-tumor activity, while reducing activation of the immune system outside the tumor. Initial clinical translation data presented at SITC confirmed that CX-072 is unmasked, activated and has biological activity in patient tumors while remaining predominantly masked and intact in circulation.


CytomX has achieved the initial three goals of the PROCLAIM-CX-072 clinical trial:

CX-2009 (CD166-directed Probody drug conjugate)

The company is current enrolling patients in the PROCLAIM-CX-2009 study, a Phase 1/2 clinical trial evaluating CX-2009 as monotherapy in patients with select advanced solid tumors, including breast cancer, castration-resistant prostate cancer, cholangiocarcinoma (bile duct cancer), endometrial cancer, head and neck cancer, non-small-cell lung cancer and ovarian cancer.

While CD166 is widely and highly expressed on solid tumor cells, it has been previously considered “undruggable” given its expression on normal tissues. In preclinical studies, Probody drug conjugates targeting CD166 have led to complete regressions in models of breast and lung cancer at therapeutically relevant doses, and are well tolerated in non-human primates. CX-2009 has been conjugated with DM4, a highly potent cytotoxic drug. DM4 is developed by and licensed from ImmunoGen.

BMS-986249 (CTLA-4-directed Probody therapeutic)

Bristol-Myers Squibb is enrolling patients in a Phase 1/2 clinical trial to evaluate a CTLA-4-directed Probody therapeutic alone or in combination with Opdivo® (nivolumab) in solid cancers that are advanced or have spread.

CTLA-4, a clinically validated inhibitory immune checkpoint protein, is the most advanced target from the 12-target collaboration.

CX-2029 (CD71-directed Probody drug conjugate)

CytomX and AbbVie are co-developing a PDC directed against CD71, the transferrin receptor that is highly expressed on a number of solid and hematologic tumors, as well as many normal tissues. CytomX is enrolling subjects in a Phase 1/2 clinical trial to evaluate a CX-2029, a CD71-directed Probody drug conjugate, as monotherapy in patients with metastatic or locally advanced unresectable solid tumors or diffuse large B-cell lymphoma.

CD71 is an excellent “internalizer,” which has the potential to efficiently deliver toxin to tumor cells. Historically, CD71 has not been widely pursued as a target given its expression on normal tissues and potential for causing toxicities. CytomX presented proof-of-concept data at AACR in 2016 demonstrating the creation of a therapeutic window for a CD71-targeting PDC.

CX-188 (PD-1-targeting Probody therapeutic)

Our third wholly owned program that is advancing towards the clinic is CX-188, a PD-1-targeting Probody therapeutic. As with anti-PD-L1 therapies, PD-1 monotherapy and combinations have been associated with significant toxicities.

Our preclinical studies have shown that CX-188 has the potential for an improved therapeutic index relative to PD-1 antibodies. The IND for CX-188 was cleared by the FDA. Due to a recent program and portfolio prioritization, CytomX has decided to indefinitely postpone the clinical trials of CX-188, a PD-1 Probody. CytomX may elect to initiate clinical trials of CX-188 in the future.

Clinical trials

Our most promising drug candidates are currently in clinical trials, investigating their potential utility in a number of advanced or recurrent solid tumors or lymphomas.

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Access information for healthcare providers & patients

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