Immunotherapy and pancreatic cancer
There’s an urgent need for improved treatment options for pancreatic cancer. It’s a particularly difficult cancer to treat, even in the early stages. In the United States, it’s also the fourth of the leading causes of death by cancer.
The most effective treatment is complete surgical resection (removal). Unfortunately, fewer than 20 percent of people with pancreatic cancer are eligible for the surgery.
The disease is also more resistant to chemotherapy than some other types of cancer. Currently, there is no effective long-term treatment.
What is immunotherapy?
Immunotherapy (also called biologic therapy) is being used to treat some types of cancer. It’s a way to use your body’s own internal defense system to fight disease. It works by:
- stimulating the immune system to fight cancer cells
- making tumors more vulnerable to attack by the immune system
- using immune system proteins created by biotechnicians and designed to attack cancer cells
To date, the U.S. Food and Drug Administration (FDA) has not approved an immunotherapy for pancreatic cancer. However, it’s the subject of a lot of research.
Read on to learn what the research says and what you need to know about clinical trials.
How does immunotherapy work?
There are different types of immunotherapy, and they work in different ways.
Monoclonal antibodies are lab-generated molecules that target specific tumor antigens.
Immune checkpoint inhibitors
Your immune system works by attacking foreign cells. It must not harm healthy cells during that process.
To produce an immune response, molecules on particular immune cells need to be activated or inactivated. This is called a checkpoint, and it’s when your immune system needs to be able to tell cancer cells from healthy cells.
Unfortunately, cancer is pretty good at avoiding detection at checkpoints, so drugs called immune checkpoint inhibitors target these checkpoints. They help the immune system to recognize cancer cells as foreign and to come out fighting.
These vaccines are designed to boost your immune response against cancer cells.
Adoptive T-cell transfer
In this treatment, T cells (a type of white blood cell) are removed from your body. They’re genetically modified or treated to boost their activity. When they’re returned to your body, they’re better able to do their job of killing cancer cells.
Oncolytic virus therapy
In this therapy, a virus carries modified genes to tumor cells. Those genes cause the tumor cells to self-destruct. This, in turn, triggers your immune system to go on the attack. It also improves your overall immune response to cancer.
What does the research say?
Researchers are currently working to:
- identify more antigens linked to pancreatic cancer
- develop vaccines to prevent recurrence following surgery
- develop vaccines to slow or halt cancer growth in people who can’t have the surgery
Progress is being made.
Immune checkpoint inhibitors, vaccines, and combination immunotherapies are all showing promising results as pancreatic cancer treatments. Here are just a few examples:
- A 2017 research paper found that the MUC4 nanovaccine blocked tumor progression. Study authors say there’s a strong case for evaluating the vaccine in combination with immune checkpoint inhibitors.
- A 2015 study reported extended survival with heterologous prime/boost with Cy/GVAX and CRS-207.
- A 2013 study used mice to test a drug called AMD3100 (plerixafor). The drug was designed to break down a barrier around pancreatic cancer tumors that would allow T cells to get through. T-cell activity was boosted with an antibody to block a second target, leading to a reduction in cancer cells.
- A 2012 phase II trial combined algenpantucel-L to standard adjuvant therapy (which aims to kill cancer cells that remain after primary treatment, to reduce the risk of a cancer coming back). The 12-month disease-free survival rate was 62 percent. The 12-month overall survival rate was 86 percent.
What about clinical trials?
There are many steps necessary to gain FDA approval of new therapies. One of these is a clinical trial. It’s the best way for researchers to evaluate safety and effectiveness of treatments in humans. Even when treatments don’t work out quite as expected, trials still help advance the science.
Joining a clinical trial may be the only way to access groundbreaking therapies. And by participating, you may be helping to pave the way for others.
Not everyone is eligible for every trial, though. Eligibility may be based on many factors, such as age, specific type of pancreatic cancer, and stage at diagnosis. Any previous treatments may also be taken into account.
If you’re interested in joining a clinical trial, talk to your oncologist. You can also explore your options on the searchable database at ClinicalTrials.gov.
Right now, there are many trials of immunotherapies for pancreatic cancer. Some are actively seeking participants. This is just a small sample:
- NCT03193190: Phase Ib/II, open-label, multicenter, randomized study designed to assess immunotherapy-based treatment combinations in participants with metastatic pancreatic cancer.
- NCT03136406: Phase Ib/II study to evaluate metronomic combination therapy in people with pancreatic cancer who have had previous therapy and chemotherapy.
- NCT02305186: Randomized multicenter phase Ib/II study of chemoradiation therapy (CRT) in combination with pembrolizumab (MK-3475) compared to CRT alone. The trial is for people with resectable (or borderline resectable) pancreatic cancer.
- NCT03086642: Phase I study of talimogene laherparepvec for the treatment of locally advanced or metastatic pancreas cancer resistant to at least one chemotherapy regimen.
What’s the outlook?
Your prognosis depends on a number of things. Tumor type, grade, and stage at diagnosis all play a role. Here’s how staging works.
Of course, some people respond better to treatments than others. People who have surgery tend to do better than people who don’t.
These are survival rates for exocrine pancreatic cancer. It’s important to note that these are figures from 1992 to 1998:
Five-year survival rates for exocrine pancreatic cancer by stage:
These are survival rates for neuroendocrine pancreatic tumors (NET) treated with surgery. These figures are based on people diagnosed between 1985 and 2004.
Five-year survival rates for NET treated with surgery:
Survival rates for pancreatic cancer may have changed since these statistics were compiled.
Talk to your oncologist about your personal outlook. They’ll be able to assess your personal health profile and give you some idea of what to expect.
Research is advancing quickly, and it’s likely that immunotherapies for pancreatic cancer will continue to improve. As it does, we may move closer to an effective, long-term treatment for pancreatic cancer.