Medical breakthroughs related to vaccines have been nothing but revolutionary since the beginning of the pandemic. The road leading to the latest ones was both long and complex, but nonetheless astounding. And many of the lessons learned along the way are now contributing to other areas of medical research. Despite this, however, cancer continues to be one disease process that continues to challenge researchers. It is the second leading cause of death in the U.S., right behind heart disease. And many cancers have limited prognosis once identified. But that might be changing soon as targeted cancer therapy appears to offer tremendous hope. Based on recent reports, these innovative cancer treatments might usher in a completely new era of cancer care.
Two studies recently published highlight just how quickly these changes might occur. Though they involve different types of cancers, both utilized targeted cancer therapy to achieve some impressive results. These two methods of innovative cancer treatments also approached precision medicine care slightly differently. One of them leveraged sparsely-made cancer proteins as a treatment target while the other attacked cancer cell defenses. But in both instances, dramatic improvements in treated patients occurred. Without question, these findings will set many additional research studies in motion in the near future. And if similar results are found in larger trials, the way we manage cancer could change forever.
“No patients have required chemotherapy, radiation, or surgery [and] there has been no disease recurrence observed during the follow-up period…This highlights the clinical impact of biomarker-driven therapy, in other words of moving precision medicine into early-stage disease.” – Andrea Cercek, MD, Oncology Professor and Specialist, Memorial Sloan Kettering Cancer Center in New York
Targeted Cancer Therapy for Rectal Cancer
When it comes to specific cancer types, colorectal cancer is a common one. The most effective intervention to date involves early detection via endoscopy and a healthy lifestyle. However, these efforts often fall short and roughly 4% of men and women suffer from this cancer. It is in fact the third most common cancer around. And for those with bulky tumors, a combination of surgery, chemotherapy and radiation is often required. If confined to the colorectal area, prognosis now exceeds 90% at five years. But for those that have spread, the five-year survival rates drops quickly. This highlights the need for innovative cancer treatments.
Understanding this, researchers at Memorial Sloan Kettering in New York recently enrolled 14 patients with rectal cancer in a study. All had large rectal tumors that had remained localized, and none had received treatment yet. Likewise, all these patients’ rectal cancers lacked a protein that could repair cellular damage, labelled as +dMMR cancers. The lack of this protein is what makes these types of rectal cancers resistant to treatment. These patients were then given an IV targeted cancer therapy that contained a drug called dostarlimab (GlaxoSmithKline). Interestingly, dostarlimab is a monoclonal antibody and specific checkpoint inhibitor, which are classes of the latest innovative cancer treatments. In essence, dostarlimab removes a protective shield that these cancer cells have, allowing the body’s immune system to eliminate them. After six months of treatment, all 14 patients were found to be in complete remission based on extensive workups.
“This strategy is the real breakthrough. This is about more than just this drug or even breast cancer. Its real advantage is that [this approach] enables us to take potent therapies directly to cancer cells.” – Eric Winer, MD, Director of the Yale Cancer Center
Targeted Cancer Therapy for Metastatic Breast Cancer
When it comes to breast cancer, some 13% of women will develop this condition in their lifetime. As the second most common cause of cancer, it carries significant morbidity and mortality. If detected early, through mammograms and other screening methods, treatment is often favorable and sometimes curative. But that’s not the case for metastatic breast cancer, where innovative cancer treatments are desperately needed. The average survival rate is less than 17 months for those undergoing treatment. This is especially true if certain biomarkers are absent on the tumor. As a result, targeted cancer therapy is now being tried in this patient population, and the results look quite promising.
In a recent study also at Memorial Sloan Kettering, researchers enrolled 557 patients with known metastatic breast cancer. These patients had low counts of a tumor biomarker protein called HER2. In breast cancer patients with high HER2 levels, existing targeted cancer therapy has been effective. But that’s not previously been the case for HER2 low patients. However, a new treatment, called trastuzumab deruxtecan, increased longevity by nearly 7 months and halted tumor growth for 5 months. The drug is a combination of a monoclonal antibody and chemotherapy. Once the monoclonal antibody attached to a surface HER2 protein, it allows the chemotherapy to enter the cancer cell. It then kills the cell and transfuses into adjacent cancer cells even without the HER2 protein. Though not curative, the extended longevity and quality of life for any cancer therapy is rare. This is why cancer specialists are excited about this leading to other innovative cancer treatments.
A Burgeoning Field of Investigation
While these innovative cancer treatments are intriguing and offer hope, there are some limitations. Rectal cancers that are +dMMR represent a minority of cases, usually around 5-10% of patients. Likewise, the targeted cancer therapy described for metastatic breast cancer only extends life rather than being curative. However, the positive results of these studies demonstrate the promise of targeted cancer therapy for the future. Other similar research programs are in the midst of testing similar innovative cancer treatments for pancreatic and prostate cancers. Many are also leveraging big data to develop innovative cancer treatments. Thus far, these are also showing promising results. Based on this, it is probable that the cancer treatment landscape is rapidly moving toward a precision medicine one.