CHICAGO — Tremelimumab treatment stabilized patients with advanced hepatocellular carcinoma due to chronic hepatitis C infection for more than 12 months, according to data presented at the AACR Annual Meeting 2012, held here March 31 - April 4.
Researchers evaluated 21 patients treated with tremelimumab intravenously at a dose of 15 mg/kg every 90 days for about two cycles. Tumor burden was reduced for two patients, and disease stabilized for more than a year in 11 patients.
“The unique conditions [of heptaocellular carcinoma and hepatitis C infection] permitted us to monitor the antitumor effects and immune response to well-defined viral antigens, killing two birds with one stone,” said lead researcher Ignacio Melero, M.D., Ph.D., a consultant in the department of oncology and a professor and senior investigator in El Centro de Investigación Médica Aplicada at Universidad de Navarra in Pamplona, Spain.
In an intention-to-treat analysis, researchers observed a median overall survival of 7.5 months and time to progression of 6.4 months. They reported treatment-related adverse events among 80 percent of patients; grade 3 or higher adverse events included one case of pruritus, one case of purpura and five cases of elevated transaminases.
Melero and colleagues also observed a reduction of hepatitis C virus in the patients’ blood, which was also accompanied with objective enhancements of antiviral immunity.
“The short series of patients already showing clinical activity offers clear signs for the need to extend these trials,” Melero said. “It is unusual to spot clear signs of clinical activity with such a small number of patients, and the information on antiviral activity is also very promising.”
The study was supported by Pfizer, and tremelimumab has been licensed by MedImmune. Melero is a consultant for Bristol-Myers Squibb.