Syntrix Pharmaceuticals Announces Dosing of First Patient in Phase 1/2 Clinical Trial of SX-682 in Combination with KEYTRUDA® (pembrolizumab) in Metastatic Melanoma

AUBURN, Wash., June 20, 2019 /PRNewswire/ -- Syntrix Pharmaceuticals today announced that it has dosed the first patient in its Phase 1/2 clinical trial that will combine SX-682 with KEYTRUDA® (pembrolizumab), Merck's anti-PD-1 therapy.  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 will evaluate the safety, tolerability, immune response markers, and overall response rates achieved with SX-682 in combination with KEYTRUDA® in up to 77 patients with metastatic melanoma.  The study is being conducted at the Massachusetts General Hospital and Dana-Farber Cancer Institute.

Patients will receive daily SX-682 monotherapy for three weeks followed by treatment with daily SX-682 in combination with KEYTRUDA®.  The study will evaluate biomarkers identified from paired biopsies taken before and after the three-weeks of monotherapy and combination treatments, as well as clinical outcomes observed over the course of the trial. Syntrix expects to report initial clinical data from the trial in the first half of 2020.

"CXCR1/2 is involved in virtually all human tumor types, where it suppresses anti-tumor immunity," said Stuart Kahn, MD, chief medical officer at Syntrix.  "This clinical trial will allow us to explore the potential synergies between SX-682 and KEYTRUDA® and offers the potential to treat metastatic melanoma that is otherwise poorly responsive to checkpoint inhibitors."

In preclinical studies, 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.

KEYTRUDA® is a registered trademark of Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA.

ABOUT SX-682: SX-682 is a clinical-stage oral allosteric small-molecule inhibitor of CXCR1 and CXCR2 (CXCR1/2).  CXCR1/2 are a combined "master switch" of the immunosuppressive tumor microenvironment. Clinical studies have shown an inverse correlation between blood CXCR1/2 ligands and anti-PD1 response and survival. SX-682 has been validated in major solid tumor models, where it exhibits mono-agent activity, blocks metastasis, depletes MDSCs, activates infiltration and killing by immune effector cells, reverses chemo-resistance, and enhances anti-PD1.

ABOUT SYNTRIX: Syntrix is a pharmaceutical company committed to discovering and delivering innovative therapies to solve the most difficult clinical problems. Convergent Science & Strategy. Breakthrough Medicines.

DISCLOSURE NOTICE: This release contains forward-looking information that is based on company management's current beliefs and expectations and are subject to currently unknown information, risks and circumstances. Actual results may vary from what is projected.  Syntrix does not undertake any obligation to publicly update these forward-looking statements, whether as a result of new information, future events or otherwise.

Media Contact: Aaron Schuler, PhD, 253-833-8009, x21

SOURCE Syntrix Pharmaceuticals