Pfizer says its CAR T cancer therapy could outshine rivals

"CAR T cells can probably be more powerful," Dolsten said in an interview.

Novartis and smaller biotechs Kite Pharma and Juno Therapeutics are farthest along in developing CART T cells, which in some small early-stage trials have eliminated all trace of blood cancers in as many as 90 percent of patients who had run out of other options. If approved, some analysts expect the treatments to cost as much as $450,000 for a single treatment.

Their drugs are made by removing T-cells from the patient, genetically altering them to seek out a specific protein found on cancer cells and infusing the cells back into the patient, a process that can take weeks.

Pfizer, with Cellectis' technology, aims to make off-the-shelf CAR T cells that can be used immediately. Instead of using the patient's own T-cells, its so-called allogeneic approach involves a single healthy donor who can potentially supply T-cells that can treat thousands of patients.

But to succeed and be safe, those engineered cells would have to be further altered to ensure a patient's body does not reject the foreign cells, triggering a potentially deadly immune system response.

The Pfizer/Cellectis method would allow the T-cells to be manufactured at lower cost and be shipped to hospitals.

Pfizer believes it is uniquely placed to produce high quality off-the-shelf cells in quantities needed to treat thousands of patients.

"None of the other companies have that capability," Pfizer CEO Ian Read said at the JP Morgan Healthcare Conference in San Francisco. "Therefore they could not go that route."