First Melanoma Patient Dosed with Syntrix’ SX-682 in Combo with Keytruda in Phase 1/2 Trial

Syntrix Pharmaceuticals has dosed the first patient in an ongoing Phase 1/2 clinical trial testing its experimental therapy SX-682 in combination with Keytruda (pembrolizumab) as a treatment for advanced melanoma, the company announced.

The open-label trial (NCT03161431) is being conducted at the Massachusetts General Hospital Cancer Center and Dana-Farber Cancer Institute, and is  expected to include 77 participants with stage 3 or 4 melanoma.

SX-682 is a potent small-molecule inhibitor that blocks the activity of CXCR1 and CXCR2, two receptors essential for cancer cells to evade the immune system, spread throughout the body, and resist cancer treatments.

By inhibiting CXCR1/2 signals, this investigational agent prevents immunosuppressive cells from entering the tumor site, making cancer cells more susceptible to the effects of other immunotherapies, like Merck’s anti-PD-1 antibody Keytruda.  (Outside of the U.S. and Canada Merck is known as MSD.)

In the ongoing clinical trial, participants first will receive increasing doses of SX-682 — ranging from 25 mg to 400 mg — twice-daily for three weeks. This will be followed by three months of Keytruda treatment.

After selecting the optimal dose for further tests, additional participants will receive the selected dose in combination with Keytruda. In addition to safety, which is the primary goal, researchers will evaluate patients’ response to therapy, time to disease progression or death, and overall survival as secondary measures.

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

“CXCR1/2 is involved in virtually all human tumor types, where it suppresses anti-tumor immunity,” Stuart Kahn, MD, chief medical officer at Syntrix, said in a press release. “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.”

Syntrix in collaborations with academic researchers have demonstrated that SX-682 has the potential to fight several types of tumors, including melanoma, breast cancer, and lung cancer, when used alone and with other cancer treatments.

Thus, the company is planning to expand SX-682’s clinical program to include Phase 1/2 trials in myelodysplastic syndrome, as well as prostate, lung, and breast cancers.

For more information about the melanoma trial, such as contact and locations, is available here.