Bellicum in Trials with Cancer Vaccine, Cell-Suicide Switches

essentially function like on/off switches. The system gives doctors a way to control cells even after they’ve been placed in a patient’s body by administering the trigger drug AP1903, an “on switch” of sorts that activates certain functions of the implanted cell at optimal times.

One such offering is the BPX-501 therapy, which uses Bellicum’s self-destruct switch technology. The treatment is being tested as a way to boost the safety and viability of what’s still considered a dangerous procedure, hematopoietic stem cell transplantation (HSCT). In HSCT, cancer patients are infused with donated T-cells to rebuild their weakened immune systems. But the treatment can go badly awry, even becoming fatal, when the donated cells attack the patient in what’s known as graft versus host disease.

Bellicum addresses this by programming a self-destruct switch into the donated T-cells before they are transplanted. If the patient develops graft versus host disease, he or she can be given AP1903, which triggers the preprogrammed cell—gone rogue and attacking the patient—to kill itself. Bellicum is now aiming to complete by the third quarter of 2014 another clinical trial of the therapy on cancer patients having blood stem cell transplants.

The second of Bellicum’s offerings is its BPX-201 prostate cancer vaccine, consisting of dendritic cells programmed to fight prostate cancer. The vaccine is made from the patient’s own white blood cells, which are embedded with an on/off switch. Doctors wait 24 hours for modified cells to collect in the patient’s lymph nodes before administering the AP1903 that switches on the vaccine. Waiting until the vaccine cells are in the right position “significantly increases” the vaccine’s effectiveness and potency, Bellicum says. The company’s treatment keeps the cancer-fighting effect turned on for longer, producing armies of T-cells able to recognize and attack prostate cancer cells.

Options for prostate cancer treatments have grown since Bellicum first began developing the treatment, which may mean that Bellicum’s treatments become a later—not first—option for patients. While the state of flux in prostate cancer therapies may mean it’s hard to know what competition BPX-201 is up against after it emerges from clinical trials, Farrell says that “in all likelihood,” patients will at some point want to weigh the treatment.

Bellicum has also developed a more powerful, easier-to-manufacture second generation version of the technology. Armed with a fresh round of cash, the company is now focused on follow-on rounds of clinical trials for the commercial versions of its products.

“We’re a small company and we have a fairly ambitious clinical program. The immediate challenge is to execute successfully,” Farrell says.