For the second year in a row, the American Society of Clinical Oncology (ASCO) has named immunotherapy as the Society’s Advance of the Year. Immunotherapy refers to a category of drugs that harness the body’s own immune system to fight cancer. Immune checkpoint inhibitors are one type of immunotherapy that has been astonishingly successful, given the slow pace of cancer treatment breakthroughs in the past. According to the recently released 12th annual progress report from ASCO, “2017 Clinical Cancer Advances,”
“Since 2011, the Food and Drug Administration (FDA) has approved 15 uses for such drugs in cancer care—five in the past year alone.”
This expanded armamentarium of new cancer drugs has greatly improved the treatment options for patients with a variety of cancers, including head and neck, lung, kidney, bladder, and Hodgkin lymphoma. The report goes on to point out that “the approval of atezolizumab, in fact, marked the first new bladder cancer treatment in over three decades.”
ASC0 President Daniel F. Hayes sums it up nicely when he says
“In less than a decade, immunotherapy has gone from being considered a promising theoretical treatment to one that has become a standard of care that is helping extend or improve the lives of thousands of patients.”
Immunotherapy 2.0 is taking cancer immunotherapy to the next level by refining knowledge in some key areas such as,
- identifying patients in whom these treatments work best
- discovering mechanisms of resistance that can be overcome, and
- developing better means of reducing toxicities
Why some tumors respond and others don’t
The new checkpoint inhibitor therapies work by preventing tumor cells with PD-L1 proteins on their surface from deactivating cancer-fighting T-cells. Recent research has shown that checkpoint inhibitors are more effective against tumors that have high levels of the PD-L1 protein on their surface. This may explain why some patients do exceedingly well when treated with this type of drug, but other patients do not respond well at all. But it is not the whole story because the relationship between PD-L1 levels and response is less clear in some cancers. For example, studies demonstrated that some lung cancers responded to PD-L1 inhibitors even though they had low levels of PD-LI. More work research needs to be done to determine if this is a problem with how the PD-L1 levels are measured in the lab, or if there is something else going on.
Further, researchers have found that hypermutated cancers that have a large number of mutations appear to be more susceptible to treatment with checkpoint inhibitors—perhaps, because those mutations cause the tumor to produce more abnormal proteins (antigens) that are recognized as foreign by the immune system.
Observations of this sort will one day allow clinicians to determine which type of patient with what type of tumor markers will respond best to what type of treatment. This is the goal of truly personalized medicine. To reach this goal, we need adequately funded research and a steady flow of committed, well-trained researchers.
Progress costs money
According to this year’s ASCO report, almost one in three top advances featured in the 2017 Clinical Cancer Advances report was made possible by federal grants. However, “the NIH still has less purchasing power than it did a decade ago.”
As ASCO President, Daniel Hayes sums up,
“Much work still lies ahead. After a decade of flat funding, we are encouraged by the recent increase in NIH support. Sustained federal investment is needed to continue our momentum and build on the progress we’ve achieved. We need to catch up and keep up,”
ASCO is calling on Congress and the Trump Administration to “build on its recent investments in cancer research, and provide at least $34.1 billion for the NIH in Fiscal Year 2017.”