Breakthrough in Endometrial Cancer Treatment

CBP-1019, a bi-specific ligand drug conjugate developed using Coherent's proprietary Bi-XDC technology platform, targets Folate Receptor (FRα) and Transient Receptor Potential Vanilloid Subfamily Member 6 receptor (TRPV6). Both receptors are broadly and often highly expressed in many cancers, including gynecological and gastrointestinal malignancies.

The drug carries a DX-8951 derivative, a topoisomerase I inhibitor (TOPOi), as its payload. Early Phase I/II results have demonstrated CBP-1019's therapeutic potential in addressing advanced solid malignancies, including recurrent endometrial, colorectal, and pancreatic cancers.

Dr. Robert Huang, Founder and CEO of Coherent, commented on the FDA's decision: "This represents the second FTD granted to Coherent Biopharma, following the designation of CBP-1008, another drug derived from Coherent's proprietary Bi-XDC technology platform, in October 2024 for the treatment of platinum-resistant ovarian clear cell carcinoma. This further underscores the platform's therapeutic potential and highlights the company's robust innovation capabilities in drug development and offering new therapeutic options for patients with advanced/metastatic EC worldwide."

Promising Clinical Trial Results

The CBP-1019-101 study, a global, multicenter, open-label Phase I/II clinical trial conducted in the U.S. and China, has shown encouraging results. As of October 31, 2024, 61 patients with advanced solid tumors were enrolled and treated with CBP-1019 at various dose levels, administered intravenously every two weeks in 4-week cycles.

CBP-1019 demonstrated a favorable safety and tolerability profile, with no observed cases of interstitial lung disease, stomatitis, or ocular toxicity—typical adverse events associated with TOPOi-based antibody-drug conjugates.

Among the 10 advanced/metastatic EC patients enrolled, all of whom had received at least one prior line of platinum-based systemic chemotherapy and presented with visceral metastases, CBP-1019 exhibited superior efficacy regardless of FRα/TRPV6 expression status. At the 3.0 mg/kg dose level (potential recommended Phase II dose), 7 out of 9 evaluable advanced/metastatic EC patients achieved an objective response rate of 42.9% and a disease control rate of 100%. Median duration of response and progression-free survival were not yet reached, and all patients remained on treatment as of the data cutoff date.

Addressing a Significant Unmet Medical Need

Endometrial cancer is a serious gynecological malignancy threatening women's health, with approximately 15% of patients in the advanced stage of the disease. Limited treatment options and poor prognosis result in a 5-year survival rate of only 17%, highlighting a significant unmet medical need.

The FDA's Fast Track Designation for CBP-1019 is expected to facilitate the development and expedite the review of this promising drug, potentially enabling it to reach patients earlier. Clinical programs with Fast Track designation can benefit from early and frequent communication with the FDA throughout the regulatory review process and may be eligible for Accelerated Approval and Priority Review if relevant criteria are met.