According to an August 25 Reuters report, the U.S. Food and Drug Administration is likely to approve Merck & Co.'s highly anticipated immuno-oncology drug, pembrolizumab, as a treatment for melanoma well ahead of a late October deadline. If approved, the drug would be the first in a promising new class designed to help the body's own immune system fend off cancer by blocking a protein called PD-1, used by tumors to evade disease-fighting cells.
One researcher with a keen interest in this area is Robert H. Pierce, M.D., Chief Medical Officer at OncoSec Medical Inc., a company developing a DNA-based intratumoral cancer immunotherapy called ImmunoPulse. Prior to OncoSec, Dr. Pierce worked at Merck Research Labs, where he was the Executive Director/Member of the Global Anti-PD-1 Development Team. He is well-regarded for his career-long research into mechanisms of immune tolerance.
According to Dr. Pierce, it is believed that 60 to 70 percent of patients with metastatic melanoma exhibit no response to the form of anti-PD-1 immunotherapy that Merck is developing. This has led some experts to suggest that anti-PD-1 therapy should be combined with other forms of immunotherapy to improve outcomes further.
One potentially fruitful form of antitumor immunotherapy involves a phenomenon known as electroporation, involving the application of a brief electric field to a living cell. This causes a temporary opening of pores in a cell's membrane, increasing its permeability so that a drug or other agent injected into the area can flow into the cell by an increased factor of 1,000 or more. Using an apparatus consisting of a generator that creates a pulsed electric field and a handheld applicator with electrode needles, the cancer cells affected by this electric field can undergo electroporation. Such technology has been conceived for use in so-called electroimmunotherapy. This therapy can involve the use of a specific cytokine, a substance known to boost the human immune system against cancer cells, to stimulate an immune response producing both a local and a systemic effect against cancerous cells.
This is, in fact, the approach that Dr. Pierce and his team at OncoSec are pursuing. OncoSec's proprietary technology platform, ImmunoPulse, prompts the body's own immune system to target and destroy both local and metastasized cancer cells. Using a electroporation, ImmunoPulse delivers brief electrical pulses of DNA IL-12, which has shown in early studies to date to stimulate the patient's own immune system to destroy cancer cells. OncoSec's most intense focus is on three main cancers: metastatic melanoma, Merkel cell carcinoma and cutaneous T-cell lymphoma. Early clinical studies of ImmunoPulse thus far have demonstrated positive efficacy and a favorable safety profile in the treatment of various skin cancers, as well as the potential to initiate a systemic immune response without the toxicities associated with some other systemic treatments.
Further studies might clarify the potential role that ImmunoPulse can play as a companion therapy to anti-PD-1 drugs such as pembrolizumab and others.