Clinicians treating patients with hepatitis C who did not respond to first-line direct acting antivirals (DAA) treatment should delay re-treating if possible, until new “salvage” therapies arrive in Australia.
This was the message delivered by infectious diseases and hepatitis specialist Associate Professor Mark Douglas at GESA’s Australian Gastroenterology Week 2017.
The various DAA combinations now available on the PBS have a 90 % to 95 % cure rate, confirmed when viral load is undetectable 12 weeks post-treatment.
But there is a small cohort that does not respond – the group includes people with severe liver disease, people who did not historically respond to treatment, and people with certain virus genotypes, said Professor Douglas, from the the Westmead Institute for Medical Research in Sydney.
And options for treating this group are limited, given that 90% of patients who fail first-line DAA treatment develop a virus with mutations that make it resistant to treatment.
If a patient is resistant – detectable by a blood test -most DAA options now available on the PBS won’t work, he said.
If a patient is really ill clinicians may be able to “cobble together” a combination of DAAs outside of the PBS.
But if the patient can wait, he suggests clinicians hold off until three new “salvage therapies” which have shown promise become available in Australia – currently expected to arrive in 12-24 months.
The three “salvage” combinations are:
- Sofosbuvir + velpatasvir + voxelaprevir (Gilead)
- Pibrentasvir + Glecaprevir (Abbvie)
- Grazoprevir plus ruzasvir plus uprifosbuvir (Merck)
All have done well in phase 2 and 3 trials however each has pros and cons, said Professor Douglas. It is still unclear which ones will be PBS-listed in Australia and when.
The new generation direct acting antivirals (DAAs) are widely believed to have the potential to eliminate hepatitis C virus in Australia.
“I think that is possible if we can access patients, but we will need to rely on the good salvage therapies to mop up the people who fail first line treatments,” Professor Douglas said.
“And then obviously we need to have ongoing public health measures to stop people getting re-infected.”