Response To HCV Therapy By Hispanics
   Reported by Jules Levin

There were two other studies reported at the Dallas AASLD meeting, which reported response to HCV therapy for hispanics. The first was a study conducted and reported by Karen Lindsay from the University of Southern California. This study compared the response rates to standard interferon, Peg Intron (Schering pegylated interferon, and Rebetron (interferon+ribivarin) among causaians, blacks, and hispanics. Data was analyzed from 2173 patients (2042 caucasians, 85 blacks, and only 46 hispanics) with chronic hepatitis C, elevated ALT, and compensated liver disease who participated in 3 large, recent randomized controlled treatment trials. The following treatment regimens were evaluated: IFN a2b 3 MU TIW (3X/week) for 48 weeks, Peg-IFN a2b at a dose of 0.5, 1.0 or 1,5 ug/kg once-weekly for 48 weeks, and IFN a2b 3 MU TIW + ribivarin 1000-1200 mg daily. Sustained virologic response was defined as non-detectable HCV RNA (<100 copies/ml) 24 weeks after stopping therapy.

Results: 67% of Caucasians were infected with HCV genotype 1, compared to 94% of Blacks and 85% of Hispanics. Genotype 1 does not respond as well to therapy as genotype 2 or 3. As you can see from the table below the response rate for Hispanics was less than the rate for caucasians and blacks. However, the number of blacks and hispanics in this study were too small to draw generalized conclusions about response.

Table 1: Percentage of patients with SVR

The authors of the study concluded that Pegylated IFN therapy improved SVR rates compared to standard IFN. They also said the study was too small to draw conclusions for hispanics. Also reported at Dallas was a study conducted in Puerto Rico. This study was different because the number of patients (n=173) was much larger, but also because I assume the patients were Puerto Ricans. This could matter, because there are differences in response to HCV therapy based on cultural and geographical differences.

RESPONSE TO INTERFERON ALFA 2B AND RIBAVIRIN IN HISPANICS WITH HEPATITIS C
    Humberto J Munoz, Javier Arroyo, Betty Chinea, Henry Gonzalez, UPR Sch of Med, San Juan, PR; Federico Rodriguez, Doris Toro, Vamc, San Juan, PR; Esther Torres, UPR Sch of Med, San Juan, PR

The reported response rates of patients with chronic hepatitis C (CHC) to combined treatment with interferon (IFN) and ribavirin are 42% in naive patients and 48% in relapsers previously treated with IFN. A lower response rate has been reported in African-Americans, independent of genotype. Little data exist for Hispanics. The influence of ethnicity in response to treatment has not been defined.

Aim: To evaluate the response of Hispanics with CHC to combination therapy with IFN and ribavirin. Methods: 172 patients with CHC were entered into treatment protocols with combination therapy from October 1997 to December 1998 at the University Hospital and the SJ VA Medical Center. 57 patients were naive, 42 were relapsers and 73 were non-responders to previous therapy with IFN. All patients had a prior liver biopsy and positive HCV-RNA. Informed consent was obtained. Treatment was given as per protocol for 12 to 48 weeks and patients were followed for 24 weeks after end of treatment. Monitoring for laboratories and safety was done periodically. The protocol was approved by the IRB of the MSC and the VAMC.

Results: Sustained response was 23% for naÔve, 45% for relapsers and 8% for non-responders. Relapse was 14% for naive, 0% for relapsers and 4% for non-responders. 28% of the cases could not be analyzed for response due to missing data. Age, gender, risk factors, fibrosis, cirrhosis and viral titers were not significantly different in responders and non-responders. The rate of response found in naive was lower than previously reported in other populations. Although genotype was not determined in this study, we have previously reported a prevalence of 83% for genotype I in Puerto Rico. The response rate for treatment-naÔve caucasians with genotype 1 is similar to the 23% seen in this study for Hispanics. The response rate of the relapsers was similar to the previously data reported.

Conclusions: Response rate to combination therapy for untreated CHC in Hispanics is lower than previously reported. Response rate of relapsers, similar to the previously reported, was expected since these patients had showed a response to INF. Ethnic factors may play a role in the response to therapy, and should be further studied to determine proper treatment strategies for this population. Supported in part by RCRII P20RR 1112603 and Schering-Plough.