Vaccine technology company Heat Biologics has secured a line of credit from Square 1 Bank as a continuing effort to raise financing to help pay for clinical trials for its novel cancer-fighting immunotherapy.

The amount of the financing was not disclosed.

“Proceeds of the credit facility will be used to support ongoing clinical trials and company growth,” Square 1, which is based in Durham, said in announcing the deal Wednesday. 

Heat has been in the midst of a $4.14 million fundraising effort for more than a year.

As of December 2011, the company had raised $2.8 million in equity financing from three investors were were not identified in an SEC filing.

Earlier this year, the North Carolina Biotechnology Center awarded the biotechnology company a $250,000 loan to cover some of the company’s trial expenses. Chapel Hil-based Heat is in the midst of a fundraising round expected to raise $4.1 million to finance clinical trials.

“We were immediately impressed with the company’s management team and their cutting edge technology which has the potential to disrupt the way cancer and other diseases are treated,” said Mara Huntington, senior vice president for Square 1’s Life Sciences division, said. . We are pleased to be Heat Biologics’ financial partner.”

Heat is in clinical trials studying its vaccine candidate HS-110 to treat nonsmall cell lung cancer. The company plans to start additional clinical studies in bladder and ovarian cancer this year. Heat’s proprietary Immune Pan-Antigen Cytotoxic Therapy, or ImPACT, reprograms live tumor cells to continually produce antigens that prompt the body’s immune system to fight disease. ImPACT is used to make off-the-shelf vaccines that can be used by a general population of patients, unlike some of the personalized medicine therapies that are patient specific.

Heat Biologics was spun out of the University of Miami in 2008. The company last year relocated to North Carolina. Its technology has applications beyond cancers.

Heat is also conducting preclinical research of its technology as a possible HIV treatment. The company has received National Institutes of Health funding to support the HIV research.