
SAN FRANCISCO — Not many investors had pegged the long-stagnant immunotherapy developer NantKwest as one of the big stock winners of this week.
But on Monday, the first day of the J.P. Morgan Healthcare Conference, the stock soared 91% after the company’s founder and CEO, Dr. Patrick Soon-Shiong, gave an unusual television interview. With characteristic showmanship, the biotech billionaire announced that one patient with pancreatic cancer saw a complete disease response after receiving five infusions of a treatment his companies are developing.
In a presentation to investors on Tuesday, Soon-Shiong said that the patient’s complete response has held up for two months so far. That’s an encouraging result in a devastating disease, but it falls far short of the evidence that researchers and oncologists look for before getting their hopes up about early-stage data. And it may not be enough to keep NantKwest’s stock buoyed. NantKwest’s stock was down 31% as the market close approached on Tuesday.