AACR: Apexigen, BMS steal the show with promising I-O combo in pancreatic cancer

Last August, tiny California biotech Apexigen revved up its pipeline with a $73 million venture round that allowed it to move its lead immuno-oncology candidate into clinical trials. Now, it’s rolling out early data from that research that are turning heads at the annual American Association for Cancer Research (AACR) meeting in Atlanta.

Apexigen is testing a combination of its CD40-activating antibody with Bristol-Myers Squibb’s PD-1 inhibitor Opdivo and chemotherapy in patients with advanced pancreatic cancer. At AACR, they announced that the combination shrunk tumors in 20 out of 24 patients that could be analyzed in an interim review of a phase 1b study. The results were so encouraging that the trial has moved to phase 2, the presenters said.

Apexigen’s immuno-oncology drug candidate, APX005M, was designed to stimulate several elements of the immune system so that it’s better equipped to recognize and fight cancer. The company’s strategy is to combine it with other I-O treatments in cancer. Toward that end, it is collaborating with several drug developers in addition to BMS including Boehringer Ingelheim and Johnson & Johnson’s Janssen.

RELATED: Apexigen, BMS to combine CD40 and anti-CSF-1 drugs with Opdivo in new study

In the trial described at AACR, half the participants are receiving chemotherapy plus APX005M and half are getting that combo plus Opdivo. Most of the patients experienced side effects, but several were able to stay on the regimen for about a year, said investigators from the University of Pennsylvania, one of the clinical trial sites, during the AACR presentation.

“We are very excited about the encouraging data so far, especially because metastatic pancreatic cancer has a five-year survival rate of less than 9 percent, making it an area of high unmet medical need,” said the Parker Institute’s Chief Medical Officer Ramy Ibrahim, M.D., in a statement.

The AACR announcement marked the first clinical data out of a study funded by the Parker Institute for Cancer Immunotherapy, which was founded in 2016 by Facebook billionaire Sean Parker. The institute developed the trial in collaboration with the I-O focused nonprofit Cancer Research Institute.

Apexigen is one of many biotechs focused on expanding the potential market for immune checkpoint inhibitors—and BMS has been more than happy to oblige with Opdivo. Its flagship I-O drug has struggled to compete in the market against Merck’s blockbuster Keytruda, which has proven effective in several cancer types, including most recently kidney cancer.

BMS did celebrate one other success at AACR this past weekend, announcing data from a phase 2 study showing that a combination of Opdivo and its other checkpoint inhibitor Yervoy performed well in patients with high-grade neuroendocrine tumors.

Apexigen, meanwhile, is eager to test combinations of Opdivo and APX005M in other cancers. Last summer, it said it was enrolling a phase 1 trial that will combine the two drugs along with cabiralizumab, an anti-CSF-1 antibody that BMS is developing with Five Prime Therapeutics. That trial is enrolling patients with lung cancer, melanoma and kidney cancer.

The Parker Institute’s Ibrahim believes the pancreatic cancer trial presented at AACR will benefit not only Apexigen’s other trials, but multiple other I-O combinations being tested around the world. “What we learn in this trial can inform the work being done on other solid tumor types, so that we can make immunotherapy beneficial for more patients,” Ibrahim said.