CytomX Therapeutics 2019 Research and Development Day Highlights Clinical Data from Lead Programs and the Broad Potential of Probody™ Therapeutic Platform
- CX-2009, a First-in-Class Probody Drug Conjugate Targeting CD166, Demonstrates Encouraging Anti-Cancer Activity in Multiple Tumor Types and Safety in Phase 1 Dose Escalation -
- CX-072, A Potentially Differentiated Anti-PD-L1 Agent, Shows Favorable Anti-Cancer Activity in Multiple Tumor Types as Monotherapy and in Combination with Yervoy®, with Encouraging Safety Profile that Compares Favorably to Historical Controls for other PD-Pathway Inhibitors -
- Probody Platform Breadth and Versatility Emphasized as Company’s Oncology Pipeline Deepens -
- Research and Development Day Hosted Today in
SOUTH SAN FRANCISCO,,
Members of the CytomX management team including
“Our inaugural R&D Day will showcase the tremendous progress CytomX has made in building a pipeline of novel anti-cancer agents with our highly innovative Probody technology platform,” said
2019 Research and Development Day Program Highlights
CX-072 Anti-PD-L1 Probody Therapeutic Monotherapy: Continues to Demonstrate Favorable Safety and Durable Anti-Cancer Activity with Encouraging Early Snapshot of Data from Expansion Cohorts in Select Tumor Types at 10 mg/kg:
CX-072 is a wholly owned Probody therapeutic targeting programmed cell death ligand 1 (PD-L1). The Company’s PROCLAIM-CX-072 Monotherapy dose escalation (Parts A and A2) trial is complete without a maximum tolerated dose (MTD) having been reached. Of 24 efficacy evaluable patients with generally weakly immunogenic tumors and treated with doses greater than or equal to 3 mg/kg of CX-072, 12 (50%) demonstrated tumor shrinkage including four partial responses; one confirmed partial response (ongoing), 2 unconfirmed partial responses who are off study and one unconfirmed partial response (ongoing with confirmation scan pending). CX-072 as monotherapy was generally well tolerated in the study.
CytomX selected 10 mg/kg as the dose for its expansion cohorts (Part D). This dose was chosen because it was estimated to achieve a greater than 98% receptor occupancy of PD-L1 expressed on the tumor, demonstrated a favorable safety profile, and demonstrated evidence of biological activity. Pharmacokinetic exposure at the 10 mg/kg dose was sustained above the target level regardless of anti-drug antibody (ADA) status (8 of 13 evaluated patients were positive, 4 were negative, and one had unknown status as of
Today, the company will present preliminary data from the Company’s PROCLAIM-CX-072 Part Devaluating CX-072 at 10 mg/kg in patients with triple negative breast cancer (TNBC), undifferentiated pleomorphic sarcoma (UPS), cutaneous squamous cell carcinoma (cSCC) and anal squamous cell carcinoma (SCC) as of a
CX-072 anti-PD-L1 Probody Therapeutic in Combination with YERVOY® (ipilimumab) Continues to Demonstrate Durable Anti-Cancer Activity and a Favorable Safety Profile:
The Company’s PROCLAIM-CX-072 combination dose escalation of CX-072 with ipilimumab (Part B1) is complete with the MTD defined as the combination of 3 mg/kg of ipilimumab and 10 mg/kg of CX-072. Of 19 patients evaluable for efficacy, four (21%) patients experienced confirmed responses as of the
CX-2009, a First-In-Class CD166 Targeting Probody Drug Conjugate, Demonstrates Anti-Cancer Activity Across a Range of Doses and Tumor Types and an Encouraging Safety Profile
CX-2009 is a wholly owned Probody drug conjugate (PDC) that targets CD166, an antigen that is broadly and highly expressed in many types of cancer. CX-2009 is conjugated with the DM4 payload, a clinically-validated toxin licensed from
The Company’s PROCLAIM-CX-2009 dose escalation trial is complete. Patients with breast, castration-resistant prostate, cholangiocarcinoma, endometrial, head and neck, non-small cell lung and ovarian cancers were enrolled with the study comprised of two parts (Part A - unselected patients; Part A2 – patients selected for high CD166 levels). During dose escalation, 76 patients were treated at doses ranging from 0.25 to 10 mg/kg of CX-2009 every 3 weeks. The MTD was not reached. As of the
CX-2009 was generally well tolerated in the trial with 23 (30.3%) patients experiencing a Grade 3/4 TRAE. The most common adverse event observed was ocular toxicity, an anticipated toxicity associated with the DM4 payload. Other Grade 3/4 TRAEs included liver function test abnormalities, gastrointestinal disorders and nervous system disorders. Currently, dose optimization is underway to further to inform dose selection. Ocular toxicity prophylaxis has been introduced to this dose optimization phase. Dr. Spira, will also review a case study of a patient from PROCLAIM-CX-2009.
“These preliminary data from our ongoing PROCLAIM program provide additional proof of concept for both CX-072 and CX-2009, as well as the Probody platform itself,” said
Continued Dr. Humphrey, “Our CX-2009 data shows the ability of our technology to potentially address an entirely new class of highly expressed tumor antigens, with the opportunity to make otherwise undruggable targets available to patients with a wide variety of cancers.”
The Next Wave of Innovation
Anticipated 2019 Milestones
PROCLAIM-CX-072 (PD-L1 Probody Therapeutic)
- Additional data from monotherapy expansions in selected tumor types at 10 mg/kg arm (Part D).
- Initiation of expansion studies of combination with ipilimumab in selected tumor types.
- Preliminary data from the combination arm with Zelboraf® (vemurafenib) in patients with V600E BRAF-positive melanoma (Part C).
PROCLAIM-CX-2009 (CD166 Probody Drug Conjugate)
- Additional safety and efficacy data from the monotherapy dose escalation arm (Parts A and A2).
- Initiation of an expansion cohort(s) in selected tumor types at a selected dose.
CytomX today announced that due to a recent program and portfolio prioritization, the company has decided to indefinitely postpone the clinical trials of CX-188, a PD-1 Probody. The Company may elect to initiate clinical trials of CX-188 in the future.
- As part of our strategic oncology collaboration, BMS has advanced BMS-986249, a CTLA-4 Probody therapeutic, into an ongoing Phase 1/2 clinical trial. BMS has stated that they anticipate preliminary data from this trial in 2019.
January 2019, BMS provided CytomX notification of termination for three collaboration discovery targets due to portfolio reprioritization. The termination of these targets does not affect other ongoing collaboration discovery and development activities that include BMS-986249.
CytomX 2019 Research and Development Day Webcast
CytomX will host its 2019 Research and Development Day this morning from
FY 2018 Financial Results Conference Call and Webcast
CytomX will report full-year 2018 financial results tomorrow,
CytomX Therapeutics Forward-Looking Statements
This press release includes forward-looking statements. Such forward-looking statements involve known and unknown risks, uncertainties and other important factors that are difficult to predict, may be beyond our control, and may cause the actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied in such statements. In particular, data summarized above for CX-072 and CX-2009, including data on efficacy and safety, including treatment related adverse events, immune related adverse events and anti-drug antibodies, is based on a limited number of patients and at specific doses and, in some cases, specific cancer types. Accordingly, you should not rely on any of these forward-looking statements, including those relating to the potential benefits, safety and efficacy of CytomX’s Probody Platform technology or any of it or its collaborative partners’ product candidates, CytomX’s expectations regarding the potential applications of its Probody Platform technology, CytomX’s expectations regarding the timing and initiation of clinical trials, CytomX’s expectations regarding the timing and availability of clinical data from its ongoing clinical trials, and CytomX’s ability and the ability of its collaborative partners to develop and advance product candidates into and successfully complete clinical trials, including CytomX’s Phase 1/2 clinical trials of CX-072, CX-2009 and CX-2029. Risks and uncertainties that contribute to the uncertain nature of the forward-looking statements include: the unproven nature of CytomX’s novel Probody Platform technology; three of CytomX’s product candidates under its Probody platform are in the initial stages of clinical development and its other product candidates are currently in preclinical development, and the process by which preclinical and clinical development could potentially lead to an approved product is long and subject to significant risks and uncertainties; the possibility that the results of early clinical trials may not be predictive of future results and that additional side effects may be uncovered; the possibility that CytomX’s clinical trials will not be successful; CytomX’s dependence on the success of CX-072, CX-2009 and CX-2029; CytomX’s reliance on third parties for the manufacture of the company’s product candidates; and possible regulatory developments in
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VP, Investor Relations and Corporate Communications
1 Larkin J et al. N Engl J Med 2015; 373:23-34 DOI: 10.1056
Source: CytomX Therapeutics Inc.