Syntrix doses first metastatic melanoma patient testing dual inhibotor of CXCR1/2 with Merck’s Keytruda

Syntrix Pharmaceuticals has started its Phase 1/2 clinical trial that will combine SX-682 with Keytruda, Merck’s anti-PD-1 therapy, as it dosed the first patient, it said Thursday.

SX-682 is an oral dual inhibitor of  CXCR1 and CXCR2 (CXCR1/2) being developed for the treatment of cancer.

This open-label clinical trial test SX-682 in combination with Keytruda (pembrolizumab) in up to 77 patients with metastatic melanoma.  The patients will receive SX-682 and pembrolizumab together as combination therapy, and be evaluated in the study for approximately 2 years.

Syntrix expects to report initial clinical data from the trial in the first half of 2020.

Stuart Kahn, chief medical officer at Syntrix said this clinical trial will allow exploring the potential synergies between SX-682 and Keytruda. He said it offers the potential to treat metastatic melanoma that is otherwise poorly responsive to checkpoint inhibitors.

In preclinical studies, Syntrix noted, SX-682 enhances both PD-1 immune checkpoint blockade and T cell receptor engineered T cell immunotherapies (JCI Insight, Nature and Cancer Cell). Effects include a reduction of myelosuppressive cells in the tumor microenvironment and augmentation of NK and T cell infiltration into the tumor site. Clinical studies show an inverse correlation between CXCR1/2 ligands in the blood and survival of patients treated with anti-PD1 therapy.