Cancer is a frightening disease, and according to the World Health Organization its prevalence is on the rise. The WHO predicts that global cancer incidence rates will grow by nearly 60% to 22 million cases per year over the next two decades.
The concern with cancer is that it's not only a deadly disease -- it's currently the second-leading cause of death in the U.S., trailing only heart disease -- but it's also extremely costly to treat and acts as a serious drain on global health care networks. Based on an American Cancer Society report issued in 2010, the global economic impact caused by premature death and disability associated with cancer was $895 billion in 2008. This represented 1.5% of the world's GDP, and it doesn't even include the direct medical costs to treat cancer, such as drugs and hospitalization expenses.
The solution is simple: we need highly efficient and innovative new methods to treat cancer in order to improve patient quality of life and extend survival. That sounds easy, but it's a lot tougher than it looks. A study conducted in 2006 by Nature Reviews Drug Discovery suggests that approximately 95% of cancer therapies that enter clinical development will fail, compared to around 90% for all other compounds.
While there is no magic bullet that can make cancer disappear (at least not yet anyway), recent innovations suggest that tackling cancer could be just an injection away.
3D vaccines: the next cutting-edge cancer therapy?
According to a study published in Nature Biotechnology in December, a novel 3D vaccine developed by researchers could be the next-generation solution to delaying tumor growth or perhaps even curing cancer.
The seven-author research team at the National Institute of Biomedical Imaging and Bioengineering sought to create a vaccine that could effectively instruct the immune system to seek out and destroy cancer cells.
Cancer cells often go undetected by the immune system, which is what makes fighting them so difficult. Current vaccine technology works by harvesting white blood cells and manipulating them to recognize foreign antigens found on the surface of cancer cells. By retraining these white blood cells, drug developers hope to enact an immune response that will delay or stop tumor growth.
However, these seven researchers wanted to take a slightly different approach and instead decided to see if they could reprogram these dendritic cells from inside the body with the use of implantable biomaterials. In their first attempt, which was published in 2009, researchers introduced a biodegradable and porous "scaffolding" under the skin of mice (about the size of a dime) that housed tumor antigens as well as other biological and chemical components meant to attract dendritic cells. The scaffolding delivered a 90% survival rate in mice after 25 days. Under normal circumstances most mice would have died from the tested cancer in that time span.
But NIBIB's researchers weren't done there. They came back years later with the new idea of a true 3D cancer vaccine. Instead of putting a patient (or in this case mice) through surgery where biodegradable scaffolding would be implanted under their skin, researchers used porous silica rods in a liquid solution and injected that solution into the patient. The idea here is that once the liquid solution dispersed, the silica rods would form a random scaffolding that could house dendritic and immune cells as well as antigens and even drugs.
Researchers compared this second-generation 3D vaccine to a bolus injection in mice which had received an injection of lymphoma cells. Not surprisingly, the 3D vaccine was more effective at preventing tumor growth, leading to a 90% survival rate at 30 days compared to just a 60% survival rate for the bolus injection at the 30-day mark.
Furthermore, researchers believe it could have applications against more than just cancer (e.g., against infectious diseases).
Of course, we should keep in mind this is a very early stage study and more evidence will be needed that biomaterial scaffolding created via 3D vaccines is a plausible solution to combating cancer. Additionally, there are no guarantees that mouse models will translate well into human clinical trials. As noted above, the failure rate of oncology-based clinical trials is unfortunately high.
Some cancer vaccines are a reality right now
Though we could be waiting a while before NIBIB's science finds its way into a large clinical trial, there are a handful of cancer vaccines which are a reality now, either as an approved drug from the Food and Drug Administration or in clinical trials.
Keep in mind that not all vaccines are first-line in nature or prevent disease. Some vaccines are designed to attack later-stage disease or merely enhance your immune systems' ability to recognize and destroy foreign cells, such as cancer cells.
Perhaps few of these vaccines have turned more heads in recent months than Bristol-Myers Squibb's (NYSE:BMY) Opdivo and Merck's (NYSE:MRK) Keytruda. Both are part of a new class of drugs known as anti-PD-1 inhibitors, and both are currently approved as a late-stage defense against certain types of metastatic melanoma. In clinical trials that led to its approval, Opdivo demonstrated tumor shrinkage in 32% of patients, with a third of those patients exhibiting a durable response of at least six months. For Keytruda, 24% of patients had their tumors shrink, with a duration of response ranging from 1.4 months to 8.5 months.
Neither of these response rates may sound particularly intriguing, but you have to keep in mind that Opdivo and Keytruda are approved as essentially a last resort for advanced melanoma patients. Most patients in these trials had tried two or more different types of medications and progressed, so to see these anti-PD-1 therapies work as well as they did was actually remarkable. Both hold significant promise in treating other solid tumor cancers as well.
Another interesting player in this space is NewLink Genetics (NASDAQ:NLNK), which is utilizing its HyperAcute immunotherapy platform to hopefully develop life-saving cancer vaccines. Its two most developed vaccines are algenpantucel-L, which is being studied in both resectable and non-resectable pancreatic cancer, and tergenpumatucel-L for advanced non-small cell lung cancer, or NSCLC. Last year NewLink noted that tergenpumatucel-L led to a median overall survival of 11.3 months in patients with advanced NSCLC, while 62% of patients receiving algenpantucel-L for resectable pancreatic cancer exhibited disease-free survival after one year. Currently, NewLink has finished enrollment for phase 3 studies of algenpantucel-L, while tergenpumatucel-L is still enrolling for phase 3 trials.
Clearly, there's still a lot of work left to be done, including finding a way to make these therapies last longer. However, we're seeing more and more drug developers examine pathways that involve enhancing the body's immune system to fight off cancer, and the results have largely favored improved survival with cancer immunotherapies. I look forward to ongoing innovation in this space, and to the improvement of cancer patients' quality of life.