Array BioPharma Reports Initial Results From Novel Immunotherapy Combination At The Society For Immunotherapy Of Cancer (SITC) 32nd Annual Meeting

- ARRY-382 (CSF1R inhibitor) demonstrated initial signs of clinical activity when combined with KEYTRUDA® (anti-PD1 antibody) immunotherapy in patients with solid tumors -

- Array plans to expand ongoing Phase 2 CSF1R + PD1 combination study into other tumor types including pancreatic cancer -

BOULDER, CO, USA I November 13, 2017 I Array BioPharma Inc. (Nasdaq: ARRY), a biopharmaceutical company focused on the discovery, development and commercialization of targeted small molecule cancer therapies, today announced data from the Phase 1b clinical trial evaluating the immunotherapy combination of ARRY-382, with Merck's KEYTRUDA® (pembrolizumab), an anti-PD-1 antibody, in patients with certain advanced solid tumors, at the Society for Immunotherapy of Cancer (SITC) 32nd Annual Meeting, being held Nov. 8-12, 2017 in National Harbor, Maryland.  ARRY-382 is a highly selective oral inhibitor of the CSF1R kinase and would be among the first investigational compounds targeting this pathway.

"We are pleased to announce completion of the Phase 1b clinical study of ARRY-382 in combination with KEYTRUDA.  In addition to establishing an appropriate Phase 2 dose for the combination, we are encouraged by the early signs of activity in patients with tumor types that have been historically unresponsive to anti-PD1 therapies," said Ron Squarer, Chief Executive Officer, Array BioPharma.

In the Phase 1b dose escalation trial, the recommended Phase 2 dose of ARRY-382 was determined to be 300 mg daily in combination with KEYTRUDA 2 mg/kg given intravenously every 3 weeks.

Nineteen patients, with a median of two prior lines of therapy and 42% with ≥3 prior regimens, were treated in the study.  Patients with pancreatic (n=6), colorectal (n=5), ovarian (n=3), gastric and melanoma (n=2, each), and triple negative breast cancer (n=1) were enrolled.  Investigators noted that ARRY-382 had a manageable safety profile when administered with KEYTRUDA in this study, and the most common grade 3/4 adverse events (AEs) (>10%), regardless of causality, included increased AST, increased blood creatine kinase (CK), rash, increased lipase, increased alkaline phosphatase (ALP), increased alanine aminotransferase (ALT) and anemia. 

The combination of ARRY-382 and KEYTRUDA demonstrated early signs of activity, with 11% (n=2) of patients achieving a confirmed partial response, based on RECIST version 1.1 guidelines  The first responder, who was treated with ARRY-382 at 200 mg, had Stage III pancreatic ductal adenocarcinoma.  As of the data cut-off, this patient was on study treatment in cycle 14 (42 weeks).  The second responder, who was treated with ARRY-382 at 300 mg, had stage IV ovarian cancer with liver metastasis.  As of the data cut-off, this patient was on study treatment in cycle 8 (24 weeks).

The current trial was designed to enroll Phase 2 cohorts in both melanoma and non-small cell lung cancer patients, and now Array plans to expand the study to include other patient populations, including a cohort of pancreatic cancer patients. The Phase 2 portion of the study is currently active and enrolling patients.

About CSF1R and ARRY-382

Colony-stimulating factor 1 receptor (CSF1R) is a cell-surface receptor for its ligands, colony-stimulating factor 1 (CSF1) and IL-34.[1, 2] CSF1R is thought to play an important role as regulator of the development, morphology, survival, and functions of tissue macrophages as well as tumor-associated macrophages (TAMs). TAMs play a role in modulating anti-tumor adaptive immunity and CSF1 is believed to be a driver of TAM differentiation towards an immunosuppressive tumor promoting phenotype. Increased CSF1 expression is implicated in tumor progression and metastasis, and is associated with poor prognosis in some cancers.[3] Combining a PD-1 inhibitor with a CSF1R inhibitor in preclinical models shows enhanced antitumor activity.  ARRY-382 is a highly selective, oral inhibitor of CSF1R. 

About Array BioPharma

Array BioPharma Inc. is a biopharmaceutical company focused on the discovery, development and commercialization of targeted small molecule drugs to treat patients afflicted with cancer.  Nine registration studies are currently advancing related to seven Array-owned or partnered drugs: binimetinib (MEK162), encorafenib (LGX818), selumetinib (partnered with AstraZeneca), danoprevir (partnered with Roche), ipatasertib (partnered with Genentech), larotrectinib (partnered with Loxo Oncology) and tucatinib (partnered with Cascadian Therapeutics).


1. Pixley FJ, Stanley ER. Trends Cell Biol. 2004;14(11):628-638.
2. Lin H, et al. Science. 2008;320(5877):807-811.
3. Aharinejad S, et al. Cancer Res. 2004;64(15):5378-5384.

SOURCE: Array BioPharma

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