Most patients with hepatitis C in Africa have genotypes outside of the common and easily cured genotype 1a and genotype 1b, which has led to a suboptimal rate of sustained virologic response.
“The evidence indicates that the future desired expansion of HCV treatment in Africa may risk unacceptable rates of failure if first generation NS5A inhibitors are utilized without appropriate epidemiological and viral sequence data,” Kosh Agarwal, MD, from King’s College Hospital Trust in London, England, and colleagues wrote. “Global equity of access to curative treatment is required to avoid jeopardizing the hepatitis C elimination agenda.”
Agarwal and colleagues retrospectively analyzed data from 91 patients who were born in Africa and seen at the London center between 2010 and 2018. Base genotypes included genotype 1a or 1b (n = 20), genotype 2 (n = 5), genotype 3 (n = 3), genotype 4 (n = 14) and genotype 5 and 6 (n = 2).
The researchers noted 35 patients with “unusual” genotype 1 subtypes, and 12 patients who had unusual genotype 4 subtypes. Among 23 patients with initially unassigned genotype 1 subtypes, they identified 15 novel subtypes after sequencing.
To date, 63 patients have completed direct-acting antiviral treatment and follow-up, of whom 56 patients achieved SVR and seven failed treatment for an SVR rate of 89%.
“As expected, response rates in genotypes 1a or 1b were uniformly high. Similarly, all patients infected with genotype 2, 3, 4 and 5 achieved an SVR,” the researchers wrote. However, those patients with unusual genotype 1 or genotype 4 subtypes had an SVR rate of 75%.
In multivariate analysis with SVR as the outcome, unusual genotype 1 remained correlated with a higher risk for treatment failure (P = .016).
Additionally, the study cohort had high frequencies of resistance-associated polymorphisms, which “demonstrates the diversity of the virus in the African region,” the researchers wrote.
“We have shown that in a metropolitan United Kingdom cohort of African patients with HCV, most patients were infected with unusual and often novel African subtypes which were associated with reduced SVR rates,” Agarwal and colleagues concluded. “The reality of global migration means that these data are also relevant for clinicians in high income countries who should exercise caution in selecting regimens for African patients with unusual or un-subtypeable genotypes.” – by Talitha Bennett
Disclosures: The authors report no relevant financial disclosures.