DAAs improve patient and graft survival after liver transplant

In the era of direct-acting antiviral (DAA) availability, the outcomes of liver transplantation for hepatitis C virus (HCV)-infected patients have improved significantly, according to a new study.

“Our study is one of the largest studies that demonstrated the significant improvement of graft and patient survivals among liver transplant recipients over the past 15 years. It is probably the only study that attempted to identify the contributing factors of these improvements among HCV and non-HCV patients,” senior author Surakit Pungpapong, MD, associate professor of medicine at the Mayo Clinic Jacksonville, Florida, told Medical Economics.

The researchers reported their results at the 2017 Digestive Disease Week in Chicago.

The study included 3,575 liver transplant patients at two centers; 1,437, or 40%, of the patients, had HCV infections.

The researchers performed subgroup analyses by dividing both HCV and non-HCV patients into three groups based on the year of liver transplant: era 1 (prior to 2006), era 2 (2006-2010) and era 3 (after 2010, which is following the availability of first-generation DAA for clinical trials, compassionate uses, or after U.S. Food and Drug Administration approvals). Then they compared graft and patient survivals between these patients to identify the pattern of improvement.

These time periods allowed comparison of HCV and non-HCV transplant recipients with enough follow-up in the DAA era (post 2010) for them to calculate 5-year survival rates.

The results show significant improvement of graft and patient survivals in both HCV and non-HCV patients over the past 15 years. Among non-HCV recipients, marked improvement of graft and patient survivals was noted between the liver transplants performed prior to 2006 (era 1) and those performed between 2006-2010 (era 2), but only minimal improvement was observed between the liver transplants performed between 2006-2010 (era 2) and those after 2010 (era 3).

In contrast, the significant improvement of both graft and patient survivals were observed between the liver transplants between 2006-2010 (era 2) and those performed after 2010 (era 3, DAAs era) among HCV recipients, while only modest improvement between the liver transplants performed prior to 2006 (era 1) and those performed between 2006-2010 (era 2) was observed, said Pungpapong.

“The results confirmed our hypothesis that the pattern of survival improvement was distinctly different between HCV and non-HCV patients. Observed improvement in non-HCV patients paralleled the reported trend of progressive improvement of liver transplant outcomes nationwide due to better patient selections, organ allocations (due to MELD score implementation), peri-operative and post-operative managements,” he said.

Pungpapong attributed the improvement of graft and patient survival in HCV patients in recent years to a positive impact of DAA therapy.

Interferon-free and ribavirin-free DAA combinations that appeared after 2014 might improve these results.

“We believe that we would observe further improvement of graft and patient survivals in HCV patients, especially with the highly effective second-generation and third-generation DAA regimens,” said Pungpapong. “With the eradication of HCV before or soon after liver transplantation, we should expect that the liver transplant outcome, both graft and patient survivals in HCV patients, would be among the best when compared to the outcome of the patients with other diagnoses.”