By Nickky Faustine P. de Guzman
A NEW DRUG is now available in the Philippines that can treat advanced skin and lung cancers, better than chemotherapy.
“But of course I don’t want to keep everyone’s hopes high. It’s not a wonder drug,” said St. Luke’s Medical Center Global City Cancer Institute head Dr. Gerardo Cornelio in a press conference on March 17 at Diamond Hotel.
Pembrolizumab has been approved by the Food and Drug Administration (FDA) for the treatment of advanced or metastatic lung cancer and skin cancer (melanoma) for which the first-line treatment, chemotherapy, has failed.
“It has the potential to become an integral part of cancer treatment. It has and will be treated across a broad spectrum of cancers,” said Dr. Cornelio.
The drug is given intravenously every three weeks with dosage at 2mg/kg. The price starts at P100,000 and varies based on the dosage level and condition of the patient.
Used by people whose cancers are not responsive to chemotherapy, Pembrolizumab is currently available at the Philippine General Hospital, Asian Hospital, National Kidney and Transplant Institute, and two other centers in Cebu.
“The patients are outpatients, but they should stay inside the room for 30 minutes before they leave,” said Mr. Cornelio. He added: “I give them pre-medication for my peace of mind.”
Pre-medication includes preparing the patient for liver and thyroid tests, because one of the side effects of the treatment is hypothyroidism. Unlike chemotherapy, Pembrolizumab doesn’t cause hair loss.
“Chemotherapy has improved over the years. It still works, but the side effects include the targetting of normal cells,” said Dr. Cornelio. “The limitations of chemotherapy responses are partial, brief, and with unpredictable side effects.”
The world is in continuous search for other cancer treatments besides classical chemotherapy. A recent breakthrough innovation in the United States, immunotherapy was recently approved by the FDA and is now available in the Philippines with pharmaceutical company Merck Sharp and Dohme (MSD), which is involved in oncology research and development, as the pioneer provider. MSD Philippines is a wholly owned subsidiary of Merck and Co. Inc.
Immunotherapy uses a patient’s own immune system to fight diseases such as cancer. One type of immunotherapy is immune checkpoint inhibitors, which is a form of cancer treatment that prevents the interaction between a tumor and the immune system’s T-cells, which recognize and destroy cancer cells. When the two interact, a protein in the tumor called programmed death-ligand 1 (PD-L1) deactivates T-cells. Pembrolizumab is an anti PD-LI immunotherapy drug, which prevents the tumor from deactivating T-cells.
Dr. Cornelio highlighted said in his presentation that PD-L1 is “not an absolutely predictive biomarker.” Biomarkers are proteins found in tissue, blood, or other fluids that can determine the outcome of a patient’s disease or response to medication.
According to the World Health Organization, there were 8.2 million cancer-related deaths in 2012, and lung cancer is the significant contributor to that number. The number of cases is expected to rise to 22 million in the next 20 years. In the Philippines, oncologist Ena R. Ang said lung cancer is the second most common in incidence and mortality in both men and women. The most common type of lung cancer is non-small cell lung cancer, which is the focus of the immunotherapy.
Meanwhile, melanoma accounts for less than 5% of all skin cancer cases in the Philippines, “but it is the most difficult to treat,” said Dr. Ang.
Among Asian patients with melanoma, the affected parts are most often the mouth, eyes, soles of the feet, and palms. “We don’t actively look for it so the treatment [for melanoma] is late,” she said.
Since neither chemotherapy nor immunotherapy assure a patient’s survival, especially if the cancers are advanced, the doctors could not overemphasize the importance of early diagnosis and treatment, both for lung and skin cancers. Prevention and detection, after all, are better than cure.
“Majority [of the skin and lung cancers] are diagnosed at the late stage,” said Ms. Ang. “The survival rate [in these cases] is low: 7%… The higher the stage the lower the survival rate.”