by Thomas R. Collins – The state of treatment for Hepatitis C patients waiting for a liver transplant leaves a lot to be desired — the use of interferon means a lot of patients can’t tolerate these regimens — but the outlook is promising for this pool of patients, an expert said here at the 18th International Congress of the International Liver Transplant Society.
New, direct-acting antiviral medications now being developed might greatly widen the population that can be treated, and with better results, said Gregory Everson, MD, Director of the Section of Hepatology at the University of Colorado School of Medicine.
These medications, including new protease inhibitors and inhibitors of the proteins NS5a and NS5b, can be effective without the use interferon, which would be a huge leap forward in treatment, Dr Everson said.
“This is what we’re all waiting for,” he said. “Because once we get to interferon-free treatment, once we drop interferon… if we have a tolerable and highly effective regimen, all of a sudden the patient population that can be treated pre-transplant expands considerably.”
Today, though, most of the experience is with interferon-based therapy.
“A very sick, high-MELD patient is really not a candidate for this therapy,” Dr Everson said. “The best candidate is the patient who’s not so sick.”
There is also a serious risk for infections with current regimens, he said. Plus, they require a longer duration of treatment, compared to the newer drugs in development.
In addition to very sickest waiting-list patients, many patients with moderate sickness also cannot tolerate inferferon regimens. These limitations mean that only about 15 percent of the Hep-C transplant candidates can be treated with current regimens, including the triple therapy combination of peg-interferon, ribavirin and either boceprevir or telaprivir, two protease inhibitors.
Plus, he said, there are limitations to the effects they can be expected to have in Hep-C waiting list patients. If telaprevir and boceprevir results in trials involving chronic Hep-C patients1,2 are matched exactly in pre-transplant patients, the maximum response rate would be about 55 percent, Dr Everson said.
But realistically, the response rate will probably turn out to be about 40 percent, he said.
By 2014 or 2015, the picture could change dramatically, Dr Everson commented.
“Maybe all the patients will be candidates — but at least 50 percent will be candidates, by my calculations,” he said. As many as 65 percent of those patients could achieve a sustained virologic response or at least have that level of a virologic response after transplant. This could be accomplished in as little as 12 weeks of treatment, he said.
“Probably you could even transplant these people within four to six weeks with a good chance you’re going to prevent post-transplant infection,” he said.
“Overall,” Dr Everson concluded, “I think within two, three or four years the palette of therapy for Hepatitis C in the pre-transplant setting is going to look extremely promising.”
- Jacboson et al N Engl J Med 2011; 364: 2405-2416
- Poordad et al N Engl J Med 2011; 364: 1195-1206