Immunotherapy for Malignant Mesothelioma
Posted 23rd March 2018 by Jane Williams
The current field of cancer research is seeing gains in almost every aspect of care, from the foundations of the disease to the development of successful treatment. With increased funding and attention to oncology care, immunotherapy and precision medicine are among the most promising patient-centred areas of current research and translational medicine.
While diagnostic advancements and surgical innovations are also providing advancements in care for patients, immunotherapy is arguably seeing the most returns for patients with the increase in clinical trials and available drug therapies. Difficulties present for those with rare diseases, particularly cancers discovered at late stages or in areas not easily accessed in the body. Treatment options can be limited and aggressive.
Introducing immunotherapy options can give doctors and patients viable options for treatment for those who might be too advanced in disease or have unrespectable tumours (malignant mesothelioma).
Asbestos and mesothelioma
With between 2,500 and 3,000 diagnosed each year in developed nations like the United States and Great Britain, mesothelioma is a rare cancer that is also a leading global occupational cancer. Caused by exposure to asbestos, mesothelioma develops in the lining of organs, called the mesothelium. While this can present in the abdomen or even heart lining, up to 80% of all cases affect the lungs, known as pleural mesothelioma.
After asbestos is inhaled or ingested, the microscopic fibres lodge in the body and cause scarring and irritation. Over a latency period of anywhere from 10-50 years, this irritation can develop into mesothelioma tumours or other serious conditions like asbestosis. Over the course of so many years, most patients have forgotten about any potential exposure or are completely unaware they were ever exposed in the first place. By the time their general symptoms begin to present, like a persistent cough or abdominal pains, the cancer may already be more advanced. Many patients face a late-stage diagnosis (most patients diagnosed at stage 3) and thus, a poor prognosis. The aggressive progression of the disease and a late stage diagnosis means many patients face limited treatment options, with many having only about 15 months to live. Overall, mesothelioma has a low survival rate, demonstrating an increasing need for advanced and experimental treatment options.
Current treatments of mesothelioma
The standard treatment of mesothelioma has been a multimodal approach of surgery, chemotherapy and radiation for the past decade or so. While it has seen small, progressive gains, this course of treatment has not experienced large or impactful innovations. Standard surgical options, which have primarily been the first step in pursuing treatment, can also be hindered by metastases or tumours that have become unresectable. Due to the low rates of incidence and short window of opportunity for treatment, patients have been desperate for more advanced options to extend survival. Recently through genomic and proteomic research and translational medicine, breakthroughs like immunotherapy and personalised cancer vaccines have paved the way for crucial advanced options and opportunities for treatment that would have been otherwise impossible years before.
Breakthroughs in treatments
Perhaps the most impactful breakthrough for cancer care in recent years is the introduction of immuno-oncology drug therapies. Focused on isolating and treating tumours and cancers on a genetic and protein-specific level, it has provided not only an additional course of treatment for those eligible, but this research has also made connections between all cancers, both common and rare. One example of this is the PDL-1 protein connection found between lung cancer and pleural mesothelioma. While they are distinct cancers, both impact the lungs and both can share this specific protein, making treatments like pembrolizumab (Keytruda) a viable option for eligible patients with either of these cancers.
The increased funding, research and support behind these advancements have also led to an increased number of clinical trials, particularly focused on immunotherapy options, that can be available to those with mesothelioma and other rare cancers.
Given all the research and data from the preliminary clinical trials and increased breakthroughs through off-label usage from the past several years, innovations are beginning in ways immuno-oncology options are being considered, administered and studied for further treatment options. Once it was recognised as a possible treatment for mesothelioma, drug therapies like pembrolizumab were typically studied as a final, last resort for patients. However, for mesothelioma, as a cancer that typically requires a multimodal approach, studies have begun going further and testing the order and efficacy of drug therapies, radiation and neoadjuvant treatments.
The push for translational medicine in the past few years has also spread into other areas of genomic analysis and options for neoadjuvant treatments, including personalised cancer vaccines. For example, researchers uncovered that a specific gene called BAP1 is shared by many cancers, including both melanoma and mesothelioma. Working off of these findings and data, specialists have been able to begin clinical trials bringing these personalized cancer vaccines to mesothelioma patients. Although they have been small in scale, results have been promising thus far and are fulfilling the needs of patients in need of advanced options and those who are candidates for experimental neoadjuvant care.
Through immunotherapy, whether it be adjuvant or neoadjuvant, patients are finding that more and more clinical trials and new drug therapies are now options that would not have existed even a decade ago. For those with rare cancers, this can mean that advanced options and experimental trials can give patients who would be facing months to live with no course of treatment, a final chance or hopefully, an impactful way of managing or potentially curing their cancer.
Time is so crucial in cancer treatment, from early diagnosis, proper staging and available courses of action and treatment for both doctor and patients. With new research in diagnostic techniques in addition to immunotherapy and translational medicine breakthroughs, the scope of oncology care is changing in a way that gives those facing cancer many more options than ever before.
The Mesothelioma Cancer Alliance is an organisation dedicated to raising awareness for mesothelioma, educating on the dangers of asbestos exposure and supporting those affected by this rare cancer.
The Precision Medicine & Biomarkers Leaders Summit is taking place in just two months. See the agenda for more information.
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