FDA Puts Heat Biologics Bladder Cancer Trial on Partial Hold

Xconomy Raleigh-Durham — 

The FDA has stopped Heat Biologics from enrolling patients in a clinical trial evaluating a treatment for bladder cancer while the company works through an issue regarding the cells used as the source for its cancer immunotherapy.

Chapel Hill, NC-based Heat (NASDAQ: HTBX) said Wednesday that it does not believe that there are any safety issues associated with its cancer treatment, HS-410, and the FDA is permitting patients who are currently enrolled in the Phase 2 trial to continue in the study. But the partial clinical hold means that no new patients will join the trial until the FDA finishes reviewing the matter. The markets frowned on the development, sending Heat’s stock price down 20 percent, to $1.96 per share, in trading this morning.

Like other drug companies developing cancer immunotherapies, Heat aims to harness the body’s immune system to fight cancer. Heat says its cancer treatments work by introducing an antigen that shares the characteristics of cancer cells, which in turn triggers an immune system response to fight the cancer cells. This platform technology, which Heat calls Immune Pan-Antigen Cytotoxic Therapy, or “ImPACT,” is developed from a master cell line, which offers the potential advantage of providing a cancer vaccine that could apply to all patients, in contrast to immunotherapies developed from a patient’s own cells. Heat has said that its “off the shelf” approach to immunotherapy would be easier to manufacture and less expensive than personalized approaches to cancer treatment.

Heat said the FDA placed the bladder cancer study on a partial clinical hold after the company notified the regulator that the cell line used to make the immunotherapy had been previously misidentified. The company said it has since updated the information, which the FDA is now reviewing.

Heat completed enrollment in the 75-patient Phase 2 bladder cancer study in October. The trial is evaluating the Heat immunotherapy in combination with bacillus Calmette-Guerin vaccine, a decades-old tuberculosis treatment that is also the standard of care for early-stage bladder cancer. The main goal of this trial is one year of disease-free survival. But Heat also wants to see how HS-410 works on its own. The company was enrolling an additional 25 bladder cancer patients in a group treated with only the Heat immunotherapy. Until the FDA’s partial clinical hold, seven patients had been treated in this second patient group, according to the company.

The partial clinical hold puts a crimp in Heat’s aim to raise much-needed cash to finance its clinical trial work. Last month, Heat disclosed plans to raise $12.5 million through a stock offering. The company has not yet said how many shares it would sell, nor has it set a price or date for the sale. In addition to financing the Phase 2 trial of its bladder cancer immunotherapy, the company explained in securities filings that the capital would also fund an early-stage clinical trial of another Heat immunotherapy, HS-110, in non-small cell lung cancer.

Heat maintains that its bladder cancer immunotherapy has been consistent throughout all of the company’s clinical trials, and it expects to proceed with the existing cell line if the FDA removes the partial clinical hold. For now, Heat said that its timelines for enrolling the clinical trial remain “materially unchanged.” The company expects initial results from the study will be available in the fourth quarter of 2016.

Photo courtesy of Flickr user second_mouse under a Creative Commons license.