DENVER – Only one-third of a group of patients with hepatitis C achieved a sustained virologic response when a protease inhibitor was added to standard ribavirin and interferon dual therapy, a real-world finding that flies in the face of reported response rates closer to 90%, according to Dr. Arpita Sheth who presented a poster at the Interscience Conference on Antimicrobial Agents and Chemotherapy.
Of 42 patients at the Veterans Affairs hospital in East Orange, N.J., who started on triple therapy with the protease inhibitor boceprevir, 9 had to drop out because of previously recognized adverse events, including thrombocytopenia, neutropenia, anemia, and depression. Five other patients did not comply with treatment, and treatment failed in 10. About half of the patients were new to therapy and the rest either non- responders to dual-therapy or triple-therapy relapsers.
Dr. Arpita Sheth
Of the 18 who completed treatment, 9 achieved SVR [sustained virological response] at 3 months and 5 at 6 months. The four remaining patients relapsed.
"The incremental gain of adding protease inhibitors to the traditional regimen of ribavirin and interferon has a potential SVR rate of 33% (14/42) among retreaters and naive-to-treatment patients. Treatment should be evaluated at a more realistic number of 33% success [rather] than the 80%-90% SVR rate so frequently quoted from the FDA registration trials," concluded Dr. Sheth, a fellow at Rutgers New Jersey Medical School in Newark, in her presentation.
The real-world rate is lower, at least in Newark’s VA population. To avoid disappointment, "we should always make our patients aware of that; we’ve seen a lot of patients get upset that they didn’t really get cured" with triple therapy, she said at the meeting. The findings from the study conducted by Dr. Sheth and her associates was published earlier (N. Engl. J. Med. 2011;364:1207-17).
The results probably had something to do with "the patient population we had. They do have some underlying history that includes depression, alcohol use, drug use, and a lot of other things. Even though [most] said they were compliant, I don’t think [compliance was] what they reported," Dr. Sheth said.
About a third of patients in the study required erythropoietin to maintain their hemoglobin at 10 g/dL or higher while on triple therapy.
Dr. Sheth and her team reported that they have no disclosures.