Another Study Links African-American Race to Poorer Response to HCV Therapy

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Another Study Links African-American Race to Poorer Response to HCV

Therapy

Alison Palkhivala

May 8, 2006 (Vienna) — A new study suggests that African Americans

infected with genotype (GT)-2 or GT-3 hepatitis C virus (HCV) have a

poorer response rate than whites infected with the same genotypes.

However, the issue of how genotype affects the way African Americans

respond differentially to HCV therapy remains open, because other

studies have had different findings. Large, multicenter trials are in

order.

" African Americans have lower sustained virologic response rates

(SVRs) than [whites] with the same genotypes (ie, 2 and 3), although

their responses at the end of the treatment were not that different, "

lead investigator Anastasios Mihas, MD, told Medscape via

email. " This implies that African Americans tend to relapse following

the completion of the treatment. " Dr. Mihas is chief of clinical

research, associate director of hepatology, and professor of medicine

at Virginia Commonwealth University School of Medicine in Richmond.

Dr. Mihas and colleagues performed a detailed analysis of the charts

of their patients with HCV GT-2 and GT-3 with respect to demographic

features, end-of-treatment virologic response (EOTVR), and SVR.

" African Americans are usually grossly underrepresented in

traditional registration trials, despite the fact that they have the

highest prevalence of HCV in the United States, " Dr. Mihas said. " GT-

2 and -3 are rare among African Americans — 95% of African-American

patients with hepatitis C are infected with genotype 1. Thus, our

knowledge regarding natural history of disease and responses to

treatment is very limited. "

Patients with HIV or hepatitis B virus coinfection as well as those

with other chronic liver disorders, chronic liver failure, or a

transplanted liver were excluded from the analysis. Also excluded

were patients who had been treated with interferon or pegylated

interferon monotherapy. Dr. Mihas presented the results of the

analysis at the 41st annual meeting of the European Association for

the Study of the Liver.

Of the 232 white and 37 African-American patients with HCV GT-2 or GT-

3 whose data were included in the analysis, there were no racial

differences with respect to demographics or histologic and virologic

characteristics. Among the white patients, 58% were GT-2 and 42% were

GT-3. In contrast, 83% of African Americans were GT-2 and 17% were GT-

3 (P = .004). Overall, 46% of white patients and 62% of African-

American patients received interferon (usually pegylated) in

combination with ribavirin. A significantly higher proportion of

whites (84%) obtained SVR compared with 44% of African Americans (P

= .008). In addition, 92% of white patients obtained an EOTVR

compared with 82% of African-American patients, but this difference

was not statistically significant.

" A very interesting finding was the almost equal distribution of

genotypes 2 and 3 in...[whites], " said Dr. Mihas. " In contrast, [more

than two thirds] of African Americans were genotype 2. This may

explain why their response rates to antiviral therapy are inferior to

those of [white] patients. "

" This is an important observation, " according to Lennox Jeffers, MD,

who reviewed the research for Medscape. " However, the numbers are

extremely small. We will need a larger study in patients from

throughout the country. Single-center studies are usually difficult

to interpret. "

Dr. Jeffers is a professor of medicine and chief of hepatology at the

Miami Veterans Affairs Medical Center in Florida. He is also director

of the Center of Excellence for Hepatitis C at the University of

Miami Hospital and Clinics. He was senior author on a recently

published multicenter trial (J Viral Hepat. 2006;13:242-249)

demonstrating that African Americans infected with HCV GT-1 but not

GT-2 or GT-3 have a lower SVR rate than non–African Americans.

According to Dr. Mihas, the findings of his study " suggest that other

more effective forms of treatment, [such as] antiproteases and

antipolymerases, will be necessary for eradicating HCV from [African-

American] patients. Meanwhile, our efforts should be directed [at]

improving their candidacy [via] more aggressive and better screening

techniques and increasing their compliance to the antiviral therapy

[through such measures as] use of growth factors and psychiatric

support, and thereby enhancing the obtained SVRs. "

" The bottom line, " said Dr. Jeffers, " is we need a larger multicenter

study to answer the question, 'do blacks respond poorly regardless of

genotype?' "