Celldex Announces First Patient Dosed in Phase 1 Study of CDX-585 in Patients with Advanced Malignancies

HAMPTON, N.J., May 31, 2023 (GLOBE NEWSWIRE) -- Celldex Therapeutics, Inc. (NASDAQ:CLDX) today announced that the first patient has been dosed in a Phase 1 study of CDX-585. CDX-585 combines highly active PD-1 blockade with anti-ILT4 blockade to overcome immunosuppressive signals in T cells and myeloid cells. Celldex plans to develop CDX-585 for the treatment of solid tumors either as monotherapy or in combination with other oncologic treatments. CDX-585 is the first compound from Celldex’s research and collaboration agreement with Biosion, Inc. and combines Celldex’s ILT4 mAb with Biosion’s PD-1 mAb.

"We are excited to advance CDX-585 into clinical development as we continue to build our experience with our bispecific platform," said Diane C. Young, M.D, Senior Vice President and Chief Medical Officer of Celldex Therapeutics. "Targeting both myeloid and T cell checkpoints with a bispecific is a novel approach that we believe could provide benefit for patients that are either refractory to or not likely to benefit from PD-1 blockade alone.”

This open-label, multi-center, intravenous study of CDX-585 is being evaluated in patients with advanced or metastatic solid tumors that have progressed during or after standard of care therapy. The dose-escalation phase of the study (n=~30 patients) is designed to determine a maximum tolerated dose (MTD) and to select CDX-585 dose(s) for future evaluation in tumor specific expansion cohorts. In the first phase, increasing doses of CDX-585 will be administered intravenously (0.03 mg/kg up to 10.0 mg/kg) every 2 weeks until confirmed disease progression, intolerance, or for a maximum of 2 years. In the second phase, potential expansion cohorts will evaluate the safety, tolerability and biologic effects, including anti-tumor activity, of selected dose level(s) of CDX-585 in specific tumor types.

Preclinical data recently presented at the American Association of Cancer Research (AACR) Annual Meeting 2023 demonstrated that CDX-585 is a potent antagonist of both PD-1 and ILT4, and CDX-585 is more potent than the combination of PD-1 and ILT-4 mAbs in several model systems. CDX-585 also demonstrated a good pharmacokinetic profile and no evidence of toxicity supporting initiation of clinical development.

For additional information on this trial (NCT05788484), please visit www.clinicaltrials.gov.

About CDX-585
CDX-585 is a dual targeting PD-1/ILT4 bispecific antibody from Celldex’s bispecific antibody platform. Expression of ILT4 in several tumor types is associated with poor outcome and in preclinical models, antagonist antibodies to ILT4 have demonstrated immune enhancing and antitumor effects. Preclinical studies have shown that CDX-585 is a potent antagonist of both PD-1 and ILT4, and CDX-585 is more potent than the combination of PD-1 and ILT-4 mAbs in several model systems. CDX-585 is being developed as part of a research and collaboration agreement with Biosion, Inc. and combines Celldex’s ILT4 mAb with Biosion’s PD-1 mAb.