Targeting DCIS, Triple-negative Breast, and Ovarian Cancers

Dr Knutson is conducting 2 phase 2 clinical trials using vaccines from TapImmune Inc., an immuno-oncology company based in Jacksonville, Florida, which licensed the technology from the Mayo Clinic in 2012. The vaccines — TPIV 110 and TPIV 200 — comprise proprietary peptide antigens that elicit both CD8+ and CD4+ immune responses.

In March, TapImmune received a $3.7 million grant from the US Department of Defense (DOD) for a phase 2 clinical study of women with DCIS using the company’s peptide HER2/neu-targeted T cell vaccine, TPIV 110. The trial, set to begin in the fall, will enroll 40 to 50 women with DCIS, which accounts for approximately 20% of US breast cancer cases. The vaccine will be administered 6 weeks prior to standard surgical resection.

“There are several vaccine approaches that are being tested in companies and academia that may be competitive for DCIS,” Dr Knutson said. “This, however, is a new indication for which there are few candidates.”

Glynn Wilson, PhD, chairman, president, and CEO of TapImmune, said in an interview with Cancer Therapy Advisor that results of a phase 1 study were presented at the 2015 San Antonio Breast Cancer Symposium and are expected to be published by the end of the year.2

The second phase 2 study, of which Dr Knutson is principal investigator, will use TapImmune’s TPIV 200 vaccine targeting folate receptor alpha to determine whether triple-negative breast cancer recurrence can be prevented.

The trial is expected to enroll 280 women and begin later this year. The study is fully funded by a $13.3 million, 5-year DOD Breakthrough Award grant. TapImmune is also conducting a phase 2 study of TPIV 200 as a standalone therapy in triple-negative breast cancer.

Dr Wilson said phase 1 results for the TPIV 200 vaccine, to be reported shortly, will show that some patients have immune responses going out to a year. “That’s a very long time in the vaccine field and we think that’s because broad stimulation of T cells that we’re seeing involves T memory cells.”

TapImmunue is also conducting 2 clinical trials of its TPIV 200 vaccine in ovarian cancer. The first, in collaboration with Memorial Sloan Kettering Cancer Center, is a phase 2 trial (ClinicalTrials.gov Identifier: NCT02764333) in combination with the PD-L1 checkpoint inhibitor, durvalumab, in women with platinum-resistant ovarian cancer.

The US Food and Drug Administration (FDA) granted Orphan Drug and Fast Track Designation for TPIV 200 in ovarian cancer. To date, the trial has more than 50% recruited, Dr Wilson said.

The company is also recruiting women with platinum-sensitive ovarian cancer for a phase 2 study (ClinicalTrials.gov Identifier: NCT02978222) of the TPIV 200 vaccine plus adjuvant GM-CSF vs GM-CSF alone.

“There is an added feature here which is very important,” Dr Wilson said. “If you look at the cancers we’re trying to treat — ovarian and breast cancer, whether it’s triple-negative or HER2 breast cancers…patients, after they have been treated, are at high risk of recurrence. So, one of the things we can do with a vaccine — it’s almost a perfect point to come in with a vaccine — is to stimulate the immune system to prevent recurrence. And, of course, that includes metastatic disease, too.”