Peregrine Pharmaceuticals (PPHM) Announces Publication of Proof-of-Concept Data Supporting the Diagnostic Potential of Phosphatidylserine-Positive Exosomes in Ovarian Cancer


Peregrine Pharmaceuticals (NASDAQ:PPHM) announced the publication of positive proof-of-concept data for a novel exosome-based cancer detection platform.  Results of the study, conducted at University of Texas (UT) Southwestern Medical Center, showed researchers were able to distinguish between healthy subjects and patients with ovarian tumors based on the levels of exosomes containing phosphatidylserine (PS) found in their plasma.   Furthermore, analysis of the PS-positive exosome levels allowed researchers to distinguish between malignant and benign tumors.  These data were recently published online by the peer-reviewed journal, Oncotarget, in a paper titled, “Detection of phosphatidylserine-positive exosomes as a diagnostic marker for ovarian malignancies: a proof-of-concept study.”

Peregrine is currently advancing the proprietary exosome-based cancer diagnostic technology, licensed from UT Southwestern Medical Center in July 2016, with the goal of developing an optimized test for further clinical testing.  As part of these efforts, the company is in the process of seeking a strategic partner for collaboration on developing and commercializing the technology.  The platform is based on the diagnostic potential of tumor exosomes, which are small vesicles from tumor cells that are released into the blood as tumors grow. Tumor derived exosomes have PS on their surface as a detectable marker.  It is believed that even small tumors begin to release PS-positive exosomes and thus the ability to detect these exosomes in the blood may be an indicator of the presence of a tumor.

In the study published by Oncotarget, plasma samples from 34 patients with ovarian tumors and 10 healthy subjects were analyzed for the presence of PS-expressing exosomes in a blinded test. Results demonstrated that those patients with malignant ovarian cancer displayed significantly higher blood PS exosome levels than those with benign tumors (median 0.237 vs. -0.027, p=0.0001) and the malignant and benign groups displayed significantly higher blood PS exosome levels than the healthy subjects (median 0.237 vs -0.158, p < 0.0001 and -0.027 vs -0.158, p=0.0002, respectively).

“These initial proof-of-concept results are encouraging as they appear to support the underlying concept that the measurement of PS-positive exosome levels in blood could be a simple way to detect and monitor cancer.  While the work is still early, we think these data serve as an important first step in highlighting the diagnostic potential of this platform,” said Steven W. King, president and chief executive officer of Peregrine.  “This type of diagnostic technology is particularly important in an area such as ovarian cancer, in which screening options are limited and the ability to detect the disease at an early stage is inadequate.  We look forward to continuing to explore the potential of the technology platform in ovarian as well as other types of cancer.”

“There is a significant and growing interest in the healthcare industry around the ability to detect cancer and monitor its progression with more readily accessible blood tests.   With this area being one of the fastest growing segments of the oncology diagnostics market, we believe that our exosome-based technology represents a significant product development and licensing opportunity,” stated Stephen Worsley, vice president of business development at Peregrine.  “Based on the fact that PS is a marker associated with a broad range of cancer types, we believe our platform has potential applications in several solid tumors beyond ovarian cancer.  With that in mind, we look forward to aligning with a partner to help explore the potential of this promising technology.”

Shares of Peregrine Pharma closed yesterday at $0.323. PPHM has a 1-year high of $1.12 and a 1-year low of $0.28. The stock’s 50-day moving average is $0.31 and its 200-day moving average is $0.34.

Peregrine Pharmaceuticals, Inc. is a biopharmaceutical company that engages in the provision of monoclonal antibody therapeutics. It operates through Peregrine and Avid segments. The Peregrine segment refers to research and development of monoclonal antibodies for the treatment and diagnosis of cancer. The Avid segment provides contract management services for peregrine and third-party customers on a fee-for-services basis.