Keytruda’s New FDA Approval for Mesothelioma: A Breakthrough in Treatment
The U.S. Food and Drug Administration (FDA) has recently expanded the use of Keytruda (pembrolizumab), an immunotherapy drug, marking a significant advancement in the treatment of unresectable advanced or metastatic malignant pleural mesothelioma (MPM). Approved on September 17, 2024, the combination of Keytruda with pemetrexed and platinum-based chemotherapy offers new hope to mesothelioma patients, who previously had limited first-line treatment options. This approval, based on the KEYNOTE-483 clinical trial, represents a critical breakthrough for patients fighting this rare and aggressive form of cancer.
The Rise of Immunotherapy
Keytruda is an immune checkpoint inhibitor that helps the immune system recognize and attack cancer cells. First approved for lung cancer treatment in 2015, it has since shown remarkable efficacy across several cancers, including melanoma, head and neck cancers, bladder cancer, and now mesothelioma. Immunotherapy has fundamentally transformed cancer treatment by targeting the body’s immune response rather than directly attacking cancer cells, which sets it apart from traditional treatments like chemotherapy and radiation.
For patients with mesothelioma, Keytruda’s approval marks an essential milestone. Mesothelioma is notoriously difficult to treat, primarily because it is usually diagnosed at an advanced stage. Mesothelioma often affects the lining of the lungs and is caused by asbestos exposure, with the pleural form being the most common. It is also a cancer with a high mortality rate, partly because traditional treatments, such as surgery, chemotherapy, and radiation, have limited success in extending patient survival.
KEYNOTE-483: The Study Behind the Approval
The FDA’s approval was driven by findings from the KEYNOTE-483 study (NCT02784171), a phase 2/3 randomized, open-label clinical trial. The study enrolled 440 patients with unresectable advanced or metastatic malignant pleural mesothelioma who had not previously received systemic therapy for their advanced disease. Patients were randomly assigned into two groups: one receiving Keytruda combined with pemetrexed and platinum-based chemotherapy, and the other receiving only the chemotherapy combination.
The key measure of effectiveness was overall survival (OS), and the findings were remarkable. Patients who received Keytruda along with chemotherapy had a median survival of 17.3 months, compared to 16.1 months for those undergoing chemotherapy alone. While this difference may seem slight, in the realm of mesothelioma, each additional month of survival can be vital.
Additionally, the combination therapy led to a significant improvement in progression-free survival (PFS), a measure of how long patients live without their disease worsening. The median PFS was 7.1 months in both groups, but the hazard ratio for the risk of progression or death favored the Keytruda group, indicating a 20 percent reduction in the likelihood of disease progression or death compared to chemotherapy alone. Importantly, the objective response rate, which measures the percentage of patients whose cancer shrinks or disappears after treatment, was 52 percent in the Keytruda group versus 29 percent in the chemotherapy-alone group. This higher response rate indicates that more patients benefited from the immunotherapy combination.
The Promise of Combination Therapy
The success of combining Keytruda with pemetrexed and platinum-based chemotherapy is particularly encouraging for mesothelioma patients, as this combination takes advantage of two different cancer-fighting mechanisms. Chemotherapy directly targets and kills rapidly dividing cancer cells, while immunotherapy unleashes the body’s immune system to attack cancer. The dual approach can lead to a more effective and sustained response.
This treatment is now available to patients for up to two years or until disease progression or unacceptable toxicity occurs, with Keytruda dosed at either 200 mg every three weeks or 400 mg every six weeks. This flexibility in dosing allows for more patient-centered care, accommodating those who may have difficulty adhering to more frequent treatment schedules.
Expanding Options for Mesothelioma Patients
Keytruda’s approval as a first-line treatment for advanced mesothelioma offers patients and healthcare providers an important new option. Until now, pemetrexed and platinum-based chemotherapy were the mainstays of treatment, with many patients left with few options after the disease progressed. The availability of immunotherapy introduces a promising alternative that could significantly extend patient survival and improve quality of life.
While the survival benefit in the KEYNOTE-483 trial was modest, it is crucial to remember that mesothelioma is an aggressive disease. Even incremental improvements in OS can have a meaningful impact on patients and their families. Furthermore, as researchers continue to explore the use of immunotherapies in mesothelioma and other cancers, we can expect even more effective treatment combinations to emerge in the future.
Project Orbis: Global Collaboration for Faster Approvals
The FDA’s review of Keytruda for mesothelioma was conducted under Project Orbis, a global initiative aimed at expediting cancer treatment approvals. Through Project Orbis, the FDA collaborated with regulatory agencies in Australia and Canada, ensuring that patients in multiple countries have faster access to new treatments. This collaborative approach highlights the importance of international cooperation in the fight against cancer, particularly for rare diseases like mesothelioma.
The approval of Keytruda for mesothelioma also benefited from Priority Review, a designation given to drugs that offer significant improvements in treatment or provide treatment where no adequate therapies exist. This expedited review process ensures that promising new therapies reach patients as quickly as possible.
Looking Ahead
The FDA’s approval of Keytruda for mesothelioma is a major step forward in the ongoing effort to improve treatment options for this challenging disease. For the thousands of people diagnosed with mesothelioma each year, this new immunotherapy combination provides a new ray of hope, offering the potential for longer survival and better quality of life.
As research into immunotherapies continues to grow, so too does the promise of more effective treatments for even the most difficult-to-treat cancers. For now, Keytruda, in combination with chemotherapy, stands as a beacon of progress for mesothelioma patients, giving them renewed optimism in their fight against this devastating disease.
If you or someone you know may have been suffering from lung cancer or mesothelioma, contact Goldberg, Persky & White P.C. at 412-471-3980 to discuss your case and protect your rights. Our team is committed to advocating for justice and holding those responsible for asbestos exposure accountable.
