Roche's ($RHHBY) too-hot-to-handle PD-L1 drug MPDL3280A jumped back in the spotlight over the weekend. Researchers posted early-stage data demonstrating that the treatment--which takes the blinders off the immune system to spur an attack on cancer--scored a hopeful 26% response rate among a small group of non-small cell lung cancer patients who smoked.
For lead investigator Jean-Charles Soria, the one-in-four response rate, where patients saw their tumors shrink, flags the potential of this treatment in helping patients fight back against a particularly lethal kind of cancer. Tumor shrinkage is a widely used indication that a drug is active and spurring a response which has promise in promoting patients' survival rate. A total of 53 patients were recruited for this early study, most of whom were smokers.
"There is no discussion, this is really working," Soria told reporters at the European Cancer Congress in Amsterdam, according to a Bloomberg report. "This is the first targeted agent showing more activity in smoking patients than in never smokers." And he speculated that the larger number of genetic mutations present in the lung cancer that afflicts smokers helped explain the higher rate of success for a drug that can unleash an immune system assault.
MPDL3280A is one of three immunotherapy drugs that have transfixed the oncology field. At ASCO last summer investigators zeroed in on very promising early data highlighting the extraordinary promise of these treatments in fighting cancer. Bristol-Myers Squibb ($BMY) took the initial lead in the field with a strong 40% response rate found in a melanoma study of a Yervoy/nivolumab combo, offering a look at the potential of a PD-1 treatment. Then Merck ($MRK), which has been struggling to find something positive to say about its hapless research efforts, stepped up with stellar data for MK-3475, now the star program in its pipeline.
PD-1 and PD-L1 are the two partners--a kind of lock-and-key mechanism--that play an important role in the immune system, camouflaging cancer cells while fighting invaders like viruses and bacteria. By targeting either end of the lock and key, a drug can reveal the cancer in such a way that the immune system fields an army of T cells to fight it off. Combining these immunotherapies with other targeted therapies is seen as a major new step in oncology with the potential for remarkable improvements for many cancer patients.
The market potential for these drugs is enormous--Citigroup analysts estimated the field could be worth $35 billion--which no one is ignoring. Merck, Bristol-Myers and Roche are all hustling these programs along, devoting significant resources to fast-paced development programs and leaping into late-stage trials.
Editor's Corner: ASCO confab highlights immunotherapies, 'breakthrough' drugs and small victories