In this podcast, we’ll discuss several studies about targeted therapy highlighted at ASCO’s 2014 Annual Meeting, specifically for ovarian cancer, lung cancer, leukemia, and thyroid cancer.
ASCO: You're listening to a podcast from Cancer.Net. This cancer information website is produced by the American Society of Clinical Oncology known as ASCO, the world's leading professional organization for doctors that care for people with cancer.
In today's podcast, we'll discuss several studies about targeted therapy highlighted at ASCO's 2014 Annual Meeting, specifically for ovarian cancer, lung cancer, leukemia, and thyroid cancer. This podcast will be led by Dr. Gregory Masters, who is a medical oncologist at the Helen F. Graham Cancer Center, Christiana Care Health System in Delaware. Dr. Masters is also a member of ASCO's Cancer Communications Committee.
The ASCO Annual Meeting is the premiere educational and scientific event where physicians, researchers, and other healthcare professionals gather to discuss the latest in cancer care and treatment. This Cancer.Net podcast helps put new research findings into context and explains what this news means for patients. ASCO would like to thank Dr. Masters for summarizing these studies.
Dr. Masters: Hello, I'm Dr. Gregory Masters and I'm going to talk a little bit about some targeted agent therapies that will be presented at this year's American Society of Clinical Oncology's annual meeting. I'm pleased to talk to you about some recent developments in the research to be presented at this meeting. On this 50th anniversary of ASCO, the American Society of Clinical Oncology, we can look to some of these trials of targeted therapy as evidence of the progress being made in cancer care. I'm going to talk about 4 specific studies that are being presented in abstract form at this year's annual meeting. They have to do with using targeted therapy to treat cancer.
What is targeted therapy, and how is it effective in cancer? Well, to treat cancer, we have three main standard treatments available. We have surgery, radiation, and chemotherapy. Those are pretty self-explanatory. Targeted therapy is a different kind of treatment that tries to identify specific biologic and molecular differences in the cancer cells compared to normal cells, so that we can treat cancers more effectively and hopefully with less toxicity of treatment. Targeted therapy is oncology's magic bullet. This is precision medicine in oncology. Targeted therapies can work in different ways. They try to prevent cells from giving signals to continue growing. They try to interfere with the development of new blood vessels that are necessary for supplying oxygen and nutrients for tumor cell growth. Targeted therapies can help promote cancer cell death, or what we call apoptosis, when the cells die off and can no longer survive. Targeted therapies can stimulate the immune system to destroy cancer cells. And finally, sometimes targeted therapies can help deliver specific toxic treatments, such as chemotherapy drugs. Finally, targeted agents can sometimes deliver specific toxic chemotherapy drugs directly to cancer cells by having a delivery device that goes directly to the tumor. In this way, targeted agents can interfere with the growth and survival of cancer cells and may affect the ability of cancers to metastasize, or spread through the system.
Targeted cancer drugs come in different forms. Some are small molecule enzyme inhibitors. These drugs are often available in pill form and can be used to target enzymes that are necessary in cancer cells for growth. Those might be different than normal cells used for growth, and so we can target the unique characteristics of cancer cells with these agents. Also, targeted drugs sometimes come in the form of immune therapies called monoclonal antibodies, which are a type of immune therapy that targets the specific proteins on a cancer cell that are unique to that cell and may be different from normal cells, allowing a more effective treatment for the cancer and less toxicity to the rest of the body. Targeted therapies are good for patients because we're delivering the right medicine for a specific patient for a specific disease. This may allow us to achieve better results, less toxicity, and treatment that can be more cost-effective because we're giving the right drug and the right treatment to the right patient.
I'd like to talk about several specific abstracts or research studies that are presented at this year's American Society of Clinical Oncology meeting. These all have to do with new targeted therapies that are being used in a variety of different cancers. The first study I'd like to talk about is the use of a drug called ibrutinib in the treatment of chronic lymphocytic leukemia. Ibrutinib is an oral chemotherapy drug or targeted agent that works by inhibiting a specific enzyme called the Bruton's tyrosine kinase. This study was performed in over 300 patients with relapsed, chronic lymphocytic leukemia whose cancer had worsened following initial therapy of at least two or more treatments. The study randomized patients to one of two different treatments: ibrutinib, the oral targeted drug, or another drug called ofatumumab, that's given intravenously. In this study, the Ibrutinib was found to be more effective with 42% of patients having improvement in disease with Ibrutinib compared to 4% of patients improved with Ofatumumab. That led to an improvement in the overall survival with a 57% lowering in the risk of dying from lymphoma or leukemia and a 80% decrease in the risk of cancer progression. This new drug, ibrutinib, may offer a superior new option using a targeted therapy for patients with chronic lymphocytic leukemia.
A second study I'd like to discuss is the use of a drug, lenvatinib, in the treatment of radioactive iodine refractory differentiated thyroid cancer. Thyroid cancer is an uncommon disease. Generally, it can be treated effectively and for cure with surgery and radiation. Sometimes however, the cancer becomes refractory or resistant to those treatments. Last year, there was information on a new drug called Sorafenib that was effective in treating differentiated thyroid cancer. This year, there's another new drug that may also be quite effective in treating this disease. Lenvatinib is a tyrosine kinase inhibitor that is able to target multiple different enzymes within the thyroid cancer tumor cells. By using this treatment in a study that compared lenvatinib to placebo, there was an improvement in the ability to control the cancer and also a prolongation in the time until cancer progressed. This treatment suggests that we are able to provide more effective treatments with good toxicity profiles, meaning less side effects for patients, and adds another second option for treating differentiated thyroid cancer that's refractory to standard radioactive iodine therapy.
A third study I'd like to talk about is a study in which patients with ovarian cancer were treated with a combination of two targeted drugs, and that was compared to a single drug alone. This study looked at patients with ovarian cancer that had progressed after first therapy, generally chemotherapy, and 90 patients were enrolled in this study. Patients received either a single drug, olaparib, which works by inhibiting an enzyme poly ADP ribose polymerase or PARP and compared that to a treatment using the same drug, olaparib, in combination with a second drug, Cediranib. Cediranib is a drug that's given orally and works as a VEGFR inhibitor. It inhibits the vascular endothelial growth factor receptor. By giving these two drugs in combination, the study showed that 80% of women who received the combination therapy had decreases in their tumor size compared to only 48% who received olaparib alone. Also in patients who received the combination of two targeted drugs, it took about 18 months for the cancer to progress, compared to only 9 months if they received single agent therapy with olaparib alone. Because of this improvement in the response rate and the time to progression, this study suggests that using combined treatment with two targeted drugs, olaparib and Cediranib, may be able to replace our standard treatments with chemotherapy.
Finally, I'd like to talk about a drug in advanced non-small cell lung cancer. This cancer is a very difficult cancer to treat. If the cancer progresses after the first treatment with chemotherapy, it becomes even more difficult, and on average, patients live less than one year. Chemotherapy has a role in helping to control the cancer in these patients, but it's not curative. This research study used a combination of a standard chemotherapy drug dose of Taxol and compared that to the same chemotherapy dose of Taxol with the addition of a targeted drug, ramucirumab. Ramucirumab is an antibody that targets the anti-VEGF2 antigen on cancer cells. It's given intravenously and may help prevent new blood vessel formation that allows cancer cells to grow. This study looked at over 1,200 patients who had recurrent non-small cell lung cancer, both squamous and non-squamous histologies, and the study showed that the patients who received a combination of both the chemotherapy drug dose of Taxol and the targeted drug, ramucirumab, had an improvement in response rate, or tumor shrinkage, of 23% compared to 14% of patients who received chemotherapy alone. That also translated into an improvement in overall survival of 10 and a half months for patients receiving combination therapy compared to 9 months for patients who received chemotherapy alone. While the improvement in survival is small, this is a positive step in the right direction in trying to help treat these patients with more effective and more targeted drugs. It adds a new drug to our arsenal for treating this difficult disease.
So what does this research mean for patients? When we're able to target drugs specifically to the cancer, we're able to better identify unique characteristics of the tumor cells in ways that we can actually deliver chemotherapy or other targeted drugs directly to those cancers to provide better responses and better control of their disease. By improving our ability to understand the cancer, we provide therapies that are more likely to help an individual patient. We're adding more options to treat these difficult and incurable diseases, and by giving these drugs, we're able to improve the quality of life through disease control and symptom control. Our hope is that as we improve our ability to target drugs specifically to the cancer, that we can then move these agents into earlier stages of disease that will improve the ability to cure more cancers at an early stage and prevent patients from developing advanced cancers that are so difficult to treat. Thank you for listening to this podcast.
ASCO: Thank you, Dr. Masters. More information from ASCO's 2014 Annual Meeting can be found at www.cancer.net including additional podcasts covering other highlighted research from this event.
Cancer.Net is supported by the Conquer Cancer Foundation, which is working to create a world free from the fear of cancer by funding breakthrough research, sharing knowledge with physicians and patients worldwide, and supporting initiatives to ensure that all people have access to high-quality cancer care. Thank you for listening to this Cancer.Net podcast. [music]