A decade ago, developers thought drugs that work like zandelisib might be one of the next big classes of cancer medicines. Drugs of this type block certain enzymes from a family called PI3K, which are involved in cell growth and differentiation. They are also oral treatments, offering convenience versus chemotherapy or the biologic drugs that serve as the backbone of many cancer regimens.
However, many have failed in clinical testing, in part due to side effects, while the ones that won approval have struggled commercially. The first to reach the U.S. market was Gilead’s Zydelig in 2014, which seven years later earned the company just $62 million in sales, a drop of $10 million versus 2020.
