The Time Has Come for This Small Biotech Firm to Grow and Thrive

CytomX Therapeutics

CytomX (CTMX) is a clinical-stage oncology-focused biopharmaceutical company developing a novel class of investigational antibody therapeutics based on the firm’s Probody® technology platform for cancer treatments. CytomX’s Probody therapeutics remain inactive until they are activated by proteases in the tumor microenvironment.  

Why This is Important

By remaining inactive until activated by the cancers’ microenvironment’s proteases, the Probody therapeutics minimizes the active drug’s toxicity in healthy body tissues. The drug becomes safer and more effective which enables CytomX’s innovative technology to turn previously undruggable targets into druggable targets and enables more effective combination therapies.

CytomX Advantages

  • Overcoming toxicity challenges associated with many current treatments.
  • Enhancing the efficacy and safety of combination regimens used to treat cancers.
  • Working efficiently on targets that were inaccessible to traditional antibody-drug conjugates.
  • Offering new more powerful treatment options for patients under-served by current therapies.

CytomX Pipeline Products

CytomX and its partners, which include top-tier biotechnology and biopharmaceutical companies, have co-developed a rich and promising pipeline of potential therapeutic candidates against difficult to drug targets and potential immunotherapeutic candidates against clinically-validated targets.

CX-2009: This Probody drug conjugate targets CD166.  

The product is wholly owned by CytomX.

It is in Phase 1/2 clinical trial being evaluated as monotherapy in patients with 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.

Although CD166 is widely and highly expressed on solid tumor cells it has been previously found to be undruggable, hence the importance of CytomX’s Probody approach to enable the product to succeed drugging CD166.  

It is important to know that in preclinical studies Probody drug conjugates targeting CD166 demonstrated complete regressions in models of breast and lung cancer in non-human primates.

Also important to know is that CX-2009 has been conjugated with DM4, a highly potent cytotoxic drug. DM4 is licensed from ImmunoGen (IMGN).

CX-2029: This Probody drug is being developed by CytomX and AbbVie (ABBV). The product targets CD71 – a transferrin receptor, which is highly expressed on a number of solid and hematologic tumors, as well as many normal tissues. The product is being evaluated in a Phase 1/2 clinical trial as monotherapy.

The target CD71 is an “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.

CD166 and CD71 are both among cancer targets that are considered inaccessible to conventional antibody-drug conjugates due to their presence on many healthy tissues.

BMS-986288: (CTLA-4-directed Probody therapeutic) This product is being developed in partnership with Bristol-Myers Squibb (BMY). Bristol-Myers is enrolling patients in the dose-escalation phase of the Phase 1/2a clinical trial of a second anti-CTLA-4 Probody.

BMS-986249: a Probody version of the anti-CTLA-4 antibody ipilimumab, a clinically validated inhibitory immune checkpoint protein, is the most advanced target from the 12-target collaboration.

CytomX Collaborators Comprise:  

AbbVie (ABBV), Amgen (AMGN), Astellas (ALPMY) and Bristol-Myers Squibb (BMY).

In the NEWS at ASCO

CytomX Therapeutics Selects Seven Presentations to be Featured as part of the American Society of Clinical Oncology’s (ASCO) ASCO20 Virtual Scientific Program May 29 – May 31, 2020.

The titles of the abstracts are currently available on ASCO with full abstracts including the dates and times of presentations scheduled for publication on May 13, 2020.

ASCO 2020 Clinical Highlights from Across the CytomX Probody Portfolio 

  • Preliminary Data from Phase 1/2 Trial of CX-2029, a CD71 Targeting Probody Drug Conjugate, Partnered with AbbVie.
  • Preliminary Phase 1 Clinical Data Presented by Bristol Myers Squibb from the Ongoing First-in-Human Phase 1/2a trial of BMS-986249, a Probody Version of the anti-CTLA-4 Antibody ipilimumab.
  • Updated Data from the Phase 1/2 Trial of CX-2009, an Anti-CD166 Probody Drug Conjugate.
  • Updated Clinical Data from the Phase 1/2 Trial of CX-072, an Anti-PD-L1 Probody Therapeutic, as Monotherapy, in Selected Tumor Types and in Combination with ipilimumab.

Amy Peterson, M.D., chief development officer of CytomX Therapeutics said, “Our presence at ASCO this year highlights the strong clinical progress made by CytomX and our partners in exploring the broad potential of the novel Probody technology platform. We look forward to updating the oncology community on this progress and on the next steps towards our vision of transforming the lives of patients with cancer.”

CX-2029: an Anti-CD71 Probody Drug Conjugate

Presentation Title: CX-2029, a Probody Drug Conjugate Targeting CD71 (Transferrin Receptor): Results from a First-in-Human Study (PROCLAIM-CX-2029) in Patients (Pts) With Advanced

Cancer Session Title: Developmental Therapeutics—Immunotherapy

Abstract: 3502

Session Type: Oral Presentation

CX-072: an Anti-PD-L1 Probody Therapeutic 

Presentation Title: PROCLAIM-CX-072: Analysis of Patients with Advanced Solid Tumors Receiving Long-Term Treatment With CX-072, a PD-L1 Probody Therapeutic, as a Single Agent or in Combination with Ipilimumab. 
Session Title: Developmental Therapeutics—ImmunotherapyAbstract: 2005
Session Type: Oral Presentation

Presentation Title: Evidence of Intratumoral Localization, Activation, and Immunomodulatory Effect of CX-072, a PROBODY Therapeutic Targeting PD-L1, in a Phase 1/2 Trial

Session Title: Developmental Therapeutics—Immunotherapy

Abstract: 3108

Session Type: Poster Presentation (Poster #172)

Presentation Title: Preliminary Population Pharmacokinetics Supports Phase 2 Dose Selection for Masked Anti–PD-L1 Antibody CX-072

Session Title: Developmental Therapeutics—Immunotherapy

Abstract: 3602

Session Type: Poster Presentation (Poster #332)

CX-2009: an Anti-CD166 Probody Drug Conjugate 

Presentation Title: CX-2009, A CD166-Directed PROBODY Drug Conjugate (PDC): Results From the First-in-Human Study in Patients with Advanced Cancer Including Breast Cancer

Session Title: Developmental Therapeutics—Immunotherapy

Abstract: 526

Session Type: Poster Presentation (Poster #18)

Presentation Title: Preliminary Clinical Pharmacokinetics and Dose-Response to Support a Phase 2 Dose Selection for CX-2009: A Masked Probody Drug Conjugate to CD166

Session Title: Developmental Therapeutics—Immunotherapy

Abstract: 3599

Session Type: Poster Presentation (Poster #329)

BMS-986249: an Anti-CTLA-4 Probody Therapy

Presentation Title: Anti–CTLA-4 Probody BMS-986249 Alone or in Combination with Nivolumab in Patients with Advanced Cancers: Initial Phase 1 Results

Session Title: Developmental Therapeutics—Immunotherapy

Abstract: 3058

Session Type: Poster Presentation (Poster #122) 

Prohost Observations

Presenting these abstracts and promising products and combination products at the upcoming ASCO meeting is encouraging to oncologists from all over the world, to CytomX’s collaborators and to biotech investors. We like this firm’s science, scientists and management. On April 25, 2017, after a few months of follow up on the firm’s decisions and performances, we decided to add it to the Prohost Portfolio. It was too early to invest in this ambitious firm, which was developing several products to be used as monotherapy or in combination with immunotherapy drugs.  

The stock declined like all stocks that are bought too early in time. We took advantage of the stock’s decline to accumulate on weaknesses. 

The presentations at ASCO will open savvy investors’ eyes to what this firm has accomplished. More investors will dare to bet on CTMX as it will present more than proof of concept of its Probody® technology platform for the treatment of cancer.    

We will be listening and we will keep investing in this firm while it is on its way towards marketing its products and even after marketing them, as long as they have no competitors to outdate them.

To read more about this firm please use the search engine at our website.

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