Madison Vaccines Expands Series A To Advance Prostate Cancer Drugs

Xconomy Wisconsin — 

Madison Vaccines’ backers have injected around $2 million more into the startup to help advance three clinical trials of its experimental DNA vaccines that aim to treat prostate cancer.

The expansion of the Series A funding round ups the total to $11 million, Madison Vaccines co-founder, president, and CEO Rick Lesniewski told Xconomy today.

The additional money comes from previous investors, including Venture Investors, the Wisconsin Alumni Research Foundation, the State of Wisconsin Investment Board, and Venture Management, all based in Madison.

Madison Vaccines (MVI) is creating vaccines from tiny circular bits of DNA called plasmids. The company’s lead DNA vaccine, MVI-816, contains instructions for a protein named prostatic acid phosphatase (PAP), which is made by prostate cells. When injected into the skin, the DNA is taken up by the body’s cells, which use the DNA to make copies of the PAP protein. That protein, in turn, acts as an antigen to stimulate an immune response against PAP.

MVI’s lead vaccine, which is currently in a Phase 2 trial, has been primarily tested in men after their prostates have been removed, but before the cancer has spread to the bones or other organs. The idea is to prevent, or at least delay, the onset of metastases and the need for castration by priming the immune system to recognize cancerous cells and kill them.

Lesniewski said the new cash will primarily be used for a clinical trial to test the safety and effectiveness of MVI’s lead vaccine combined with a PD-1 pathway inhibitor drug, which is designed to keep cancer cells from camouflaging themselves. In theory, the inhibitor would help unmask the cancer cells, and the vaccine would train the body’s immune system to knock them out. Lesniewski declined to specify which PD-1 inhibitor will be used, or how many patients will be recruited for the trial.

Two PD-1 inhibitors have been approved for commercial use in the U.S.: pembrolizumab (Keytruda) from Merck and nivolumab (Opdivo) from Bristol-Myers Squibb. They are part of a wave of drug industry research that aims to harness the immune system to fight cancer. But most of the excitement has centered on the re-engineering of immune system cells or on protein-based drugs, like the PD-1 inhibitors above.

One key piece of the puzzle could be combining DNA vaccines like the one MVI has developed with other therapies, like checkpoint inhibitors.

“We think we’re well-positioned to help answer the question whether a vaccine plus a checkpoint inhibitor can be beneficial to these patients,” Lesniewski said.

Unlike the company’s Phase 2 trial testing the effects of MVI-816 fighting solo against early-stage prostate cancer, the combination treatment study will target men with late-stage prostate cancer—after the disease has spread and shows no response to castration therapy, Lesniewski said.

The drug combination trial, which could begin this summer, will be led by MVI co-founder Doug McNeel, an oncologist and professor of medicine at the University of Wisconsin-Madison. The Prostate Cancer Foundation and the Movember Foundation awarded McNeel and a team of university researchers a $1.5 million grant last year to conduct the study.

MVI will provide matching funds that will pay for the supply of drugs used in the study, and other operational expenses, Lesniewski said.

Meanwhile, MVI is moving ahead with two company-sponsored clinical trials. The Phase 2 trial to treat more than 100 patients with its lead drug candidate has expanded beyond UW-Madison to enroll patients at Johns Hopkins University and the University of California, San Francisco.

In addition, the FDA has approved MVI’s application to launch a Phase 1 trial of its second vaccine candidate, MVI-118, targeting the human androgen receptor, which fuels the advancement of prostate cancer and can cause resistance to current treatments. That 40-patient trial is slated to begin at UW-Madison in the next few months, Lesniewski said. It will target men whose prostate cancer has just metastasized and who have recently started androgen deprivation therapy, Lesniewski said.

“MVI is now uniquely positioned with our product candidates in three distinct stages of prostate cancer, from pre-metastatic, to the start of metastases, to late-stage, castrate-resistant disease,” Lesniewski said. “We believe our products can make a meaningful difference in treating this disease.”