Heat Biologics Inc. has been given a 180-day extension from NASDAQ to raise its stock price above $1 or face delisting, according to a filing with the Securities and Exchange Commission.

The Durham-based biopharmaceutical company, which is developing drugs to activate a patient’s immune system against cancer, received a notice from NASDAQ on March 15, telling the company that it had 180 days to regain compliance.

The initial 180-day period ended on Sept. 11, and NASDAQ granted Heat Biologics an additional 180-day extension. If the company’s stock rises above $1 for any 10 consecutive business days, the company will be considered compliant with listing requirements.

On March 21, Heat Biologics reported positive interim results for its non-small cell lung cancer trial indicating low toxicities, a positive safety profile and strong immune responses. Fifteen patients thus far had been treated with the company’s HS-110/Nivolumab combination.

On April 28, Heat Biologics acquired 80 percent of Pelican’s common stock. Pelican is a biotechnology company that develops therapies designed to activate the immune system.

Pelican was awarded a $15.2 million Cancer Prevention Institute of Texas grant on June 28 to develop PTX-25 and fund a Phase 1 clinical trial to test the drug’s potential benefits to patients with several types of cancer.

Heat Biologics’ stock is trading at 64 cents, up 6 percent from market close on Wednesday. The stock price is up 14 percent from the average trading price of 56 cents over the past week.