The landscape of cancer therapy in the country will undergo a dramatic change as the Philippine Food and Drug Administration (FDA) finally approved a new non-chemotherapy drug that is already considered as new treatment option in many countries around the world.
Pembrolizumab is a targeted immunotherapy medication that is now indicated in the Philippines for first-line treatment of deadly lung malignancy, specifically non-small cell lung cancer (NSCLC).
Close to a hundred Filipino oncologists, pulmonologists and pathologists learned more about this new treatment option in a medical symposium recently organized by MSD in the Philippines.
Oncology expert and key opinion leader Prof. Byoung-Chul Cho, MD, PhD, from Yonsei University College of Medicine, South Korea, delivered a talk describing the results of more than 20 clinical trials or human participant studies that assessed the safety and efficacy of pembrolizumab in treating cancer patients of various ethnicities.
A novel treatment option
According to the results of clinical trials, including MSD’s landmark Keynote-024 study, pembrolizumab has been found to better than chemotherapy as treatment for stage 4 NSCLC in patients that pass certain laboratory test criteria. First, these patients’ cells exhibit a high level of protein called PD-L1 (programmed death ligand).
Second, they do not have mutations in EGFR (epidermal growth factor receptor) or ALK (anaplastic lymphoma kinase) genes.
“If EGFR mutation is present, EGFR targeted therapy should definitely be your first line of treatment. However, if first-line treatment fails in these patients with EGFR or ALK, then they become good candidates for pembrolizumab treatment as well,” explained Cho.
For NSCLC patients with high PD-L1 expression, the clinical trials show that they have a significantly better
chance for progression-free survival and overall survival if their first treatment utilizes pembrolizumab rather than chemotherapy. They also experience fewer treatment-related adverse events.
For these reasons, Cho emphasized the advantage of taking pembrolizumab as new option for first-line treatment of NSCLC, and this requires that PD-L1 testing should be one of the very first steps performed at the time of patient diagnosis.
The importance of testing
A panel of local medical experts discussed the practical use of pembrolizumab in the Philippine setting during the medical symposium. The panelists included some of the most highly esteemed doctors in their respective fields—Antonio Villalon, MD, past president of the Philippine College of Physicians and the Philippine Society of Medical Oncology ; Camilo Roa, MD, past president of the Philippine College of Chest Physicians; and Nelia Tan-Liu, MD, chairman of Cardinal Santos Medical Center’s Department of Pathology.
Villalon opened the panel discussion highlighting the challenges of PD-L1 testing in the Philippine setting.
Outlining the usual battery of tests checking histopathology, EGFR and many others, PD-L1 is usually last on the list and more often than not, pathologists are left with scarce tissue specimen.
“It usually takes a month before the patient completes tests and can receive first treatment,” said Villalon.
For her part, Tan-Liu, who is widely considered as the pathologist with the most extensive experience in PD-L1 testing, expressed commitment toward continued reliability and efficiency of PD-L1 testing.
Testing protocols can also be changed to prioritize PD-L1 testing in patients suspected of having NSCLC. However, moving forward, all experts agree on the need for improvements in procedures and overall accessibility of PD-L1 testing.
Roa, a pulmonologist, noted that while clinical trials of chemotherapy often ended with zero surviving patients, the same results have not been seen in the trials of targeted immunotherapy such as pembrolizumab. Because of this, he expressed optimism that more patients may feel encouraged to seek treatment.
“With chemotherapy, lung cancer treatment often ends at the point of diagnosis. Patients don’t want to spend so much, become miserable and even lose their hair for a benefit of extending life for four months on average,” he explained. “What we are seeing may be a potential cure.”
For his part, MSD Country Manager for the Philippines Beaver Tamesis affirmed that “maybe our grandchildren will think very differently about cancer compared to how we think about it today,” optimistic that in the future, a cure will finally be found.
At present, pembrolizumab is already being used to treat both melanoma and NSCLC in the following Asia Pacific countries: Korea, Japan, Taiwan, Hong Kong, Thailand, Malaysia, Singapore, Australia, New Zealand, and now also the Philippines.
In the United States, it was first approved in 2014 for treatment of stage 4 melanoma. Just recently as well, its indication has been extended to NSCLC, among others.
MSD currently has the largest immuno-oncology clinical development program across the industry. As the clinical trials continue, new indications for pembrolizumab are being found and are being submitted for regulatory approval.
In the near future, the hope for a cure for cancers of all kinds may indeed become a reality.