A Phase I/IIA Study of PLX3397 plus Pembrolizumab in Patients with Advanced Melanoma and Other Solid Tumors

Full Title

Phase 1/2a Study of Double-Immune Suppression Blockade By Combining A CSF1R Inhibitor (PLX3397) With An Anti-PD-1 Antibody (Pembrolizumab) To Treat Advanced Melanoma and Other Solid Tumors (Protocol version 09-MAR-2016)


In this study, researchers are finding the highest dose of the investigational drug PLX3397 that can be given safely with the immunotherapy drug pembrolizumab in patients with advanced melanoma and other solid tumors that cannot be successfully treated with standard therapies. They are also examining the preliminary effectiveness of this treatment.

PLX3397 is an investigational anticancer drug that works by targeting an enzyme called colony stimulating factor 1 (CSF1) receptor kinase. This enzyme drives the development and growth of white blood cells called M2 macrophages, which cause cancer cells to grow. PLX3397 is taken orally (by mouth).

Pembrolizumab is a form of immunotherapy. It works by blocking a molecule called PD-1 that shuts down the immune response. Blocking PD-1 can allow the immune system to detect and attack cancer cells. Pembrolizumab is already approved to treat melanoma and non-small cell lung cancer; its use in this study is considered investigational. It is given intravenously (by vein).


To be eligible for this study, patients must meet several criteria, including but not limited to the following:

  • Patients must have advanced ovarian cancer, GIST, or leiomyosarcoma that cannot be treated successfully with standard therapies.
  • Patients must recover from the side effects of prior therapies before entering the study.
  • Patients must be physically well enough that they are fully ambulatory, capable of all self care, and are capable of all but physically strenuous activities. As an example, patients must be well enough that they would be able to carry out office work or light housework.
  • This study is for patients age 18 and older.

For more information about this study and to inquire about eligibility, please contact Dr. Dmitriy Zamarin at 646-888-4882.