Peregrine Pharmaceuticals (NASDAQ:PPHM) announced the presentation of data from preclinical studies demonstrating the combination of phosphatidylserine (PS) blockade with anti-PD-1 or anti-CTLA-4 immune checkpoint inhibitors promoted strong, localized and enhanced efficacy in models of melanoma and breast cancer. These data were presented at the 106th Annual Meeting of the American Association for Cancer Research (AACR) being held inPhiladelphia, Pennsylvania from April 18-22, 2015. Peregrine’s lead PS-blocking antibody, bavituximab, is currently being evaluated in second-line non-small cell lung cancer (NSCLC) in a Phase III clinical trial named Sunrise.

“The data presented this week at AACR showed in much greater detail the collective ability of PS and PD-1 blockade to change the immune response in melanoma and breast cancer models,” said Jeff T. Hutchins, Ph.D., vice president of preclinical research at Peregrine. “These data showed that blocking PS resulted in a decrease in immune-blocking cell types such as myeloid-derived suppressor cells and M2 macrophages while increasing the number of activated T-cells that are able to specifically recognize and kill tumor cells which set the stage for anti-PD-1 therapy that keeps the immune response going. The result were synergistic anti-tumor effects in established melanoma and breast cancers. The consistency of the data generated from pre-clinical experiments, and, more recently, in clinical translational studies is impressive. When taken together with the additional lung cancer translational data presented Sunday, we are obtaining a clearer picture as to the potential of bavituximab in different immuno-oncology combinations. We look forward to presenting additional supporting data over the coming months.”

In a poster titled: “Antibody-mediated phosphatidylserine blockade significantly enhances the efficacy of immune checkpoint blockades in K1735 and B16 mouse melanoma models,” researchers from Peregrine, UT Southwestern Medical Center and the University of Californiaat Irvine presented data assessing the antitumor effect of the combination of PS blockade and anti-CTLA-4 or anti-PD-1 antibodies in preclinical models of melanoma. Both combinations showed significantly superior tumor growth inhibition over single treatment, with many subjects achieving complete tumor regressions. The combination treatment showed significantly greater total and functional tumor-infiltrating CD8+ T, more IL-2- and interferon gamma (IFNγ)-producing splenic T cells, and lower number of splenic myeloid derived suppressor cells myeloid-derived suppressor cells (MDSCs) than did single treatment. In addition, the ratio of M2 to M1 macrophages in the tumor was significantly lower in the combination treatment than that in single treatment. Finally, no toxicity was observed in any of the treatment groups following multiple treatment doses.

In a poster titled: “Targeting of phosphatidylserine by monoclonal antibodies enhances the activity of immune checkpoint inhibitors in breast tumors,” Peregrine researchers presented data demonstrating that PS blockade enhances the anti-tumor activity of combination therapies including anti-PD-1 antibodies in an immune competent model of breast cancer. Tumor growth inhibition correlates with statistically significant increases in the infiltration of CD8+ T cells and a reduction of myeloid-derived suppressor cells (MDSCs). The combination of these mechanisms promotes strong and localized anti-tumor responses without the side-effects of systemic immune activation. (Original Source)

Shares of Peregrine closed yesterday at $1.41 . PPHM has a 1-year high of $2 and a 1-year low of $1.19. The stock’s 50-day moving average is $1.43 and its 200-day moving average is $1.41.

On the ratings front, Peregrine has been the subject of a number of recent research reports. In a report released yesterday, Roth Capital analyst Joseph Pantginis maintained a Buy rating on PPHM, with a price target of $5, which implies an upside of 254.6% from current levels. Separately, on March 13, MLV & Co.’s Thomas Yip reiterated a Buy rating on the stock and has a price target of $3.50.

According to, which ranks over 7,500 financial analysts and bloggers to gauge the performance of their past recommendations, Joseph Pantginis and Thomas Yip have a total average return of 13.5% and 5.0% respectively. Pantginis has a success rate of 56.4% and is ranked #87 out of 3575 analysts, while Yip has a success rate of 50.0% and is ranked #2095.

Peregrine Pharmaceuticals Inc is a biopharmaceutical company with a portfolio of monoclonal antibodies in clinical trials for treatment & diagnosis of cancer. With its phosphatidylserine-targeting platform, it is pursuing two clinical programs in cancer.