Pfizer said Tuesday that dendritic cells – stem cells grown from two types of lymphocytes harvested from patients’ blood – were found to be highly protective against hepatitis C viruses when administered as “boosters” of its vaccine, Glivec. (In Japanese, Glivec is called Valcyte.) The results of the testing support the company’s plans to significantly expand sales of Glivec in the United States and overseas. Pfizer has more than tripled Glivec sales through expanded use of the drug in combination with other oral hepatitis C treatments, and held $9 billion in its Glivec franchise at the end of 2018. Pfizer has been testing the use of Glivec with dendritic cells – extracted from blood donated by people with hepatitis C – because the injection is much more convenient for patients than other vaccines such as Merck’s falvetex, that are given through injections through the skin. That product is still the most prescribed hepatitis C therapy in the US. The Glivec booster group was given in an infirmary setting, and the dendritic cells arrived through a process that looked like a catheter. The second arm of the study tested the exact opposite regimen – patients with hepatitis C were given extra Glivec.
Of the nearly 1,200 patients studied, 19 patients suffered a serious complication called enteritis, which is caused by infection with HEP. Pfizer said its findings were consistent with other drugs containing dendritic cells. Glivec is the world’s best-selling cancer drug, even though it lost market exclusivity in 2014. Since then, it has lost some of its popularity, however, due to competition from Gilead Sciences’s Sovaldi and Harvoni. Some analysts think the Glivec franchise may reach its peak of about $8 billion to $9 billion in 2020, compared with about $6 billion in 2018. Analysing this new data, RBC Capital Markets analyst Randall Stanicky said Pfizer could easily do $2 billion in extra Glivec sales by 2020. Investors boosted Pfizer’s stock 4.7 percent in mid-morning trading, and the FDA is expected to weigh whether to approve Glivec as a booster next month.
Reza Mahammad, senior vice president of global medical affairs at Pfizer, said the company expected its initial dendritic cell booster for Glivec would hit the market by March 2020. The drug requires either a spleen biopsy, or intestinal surgery to extract the plasma from the bone marrow to make the cells. Mohammadi said the dendritic cells extract was less painful than previous iterations, because of simpler surgery and, presumably, less bleeding.