The number of people treated for hepatitis C virus (HCV) by the Veterans Health Administration (VA) surged after the introduction in recent years of numerous highly effective direct-acting antivirals (DAAs), after which treatment success rates also rose dramatically.

Publishing their findings in Alimentary Pharmacology and Therapeutics, researchers analyzed data from electronic records of all those who received hep C treatment from the VA between 1999 and 2015. In 2013, 5.7 million people received health care from the VA, which is the largest integrated health care system in the United States, including 154 medical centers and 875 ambulatory care and community-based outpatient clinics.

All told, 78,947 people received 105,369 treatments for HCV from the VA during the study period, of whom 57,445 achieved a sustained virologic response 12 weeks after completing therapy (SVR12, considered a cure).

The study authors divided their analysis into mini-eras defined by successive advancements in hep C treatments, including: interferon, 1999 to 2000; pegylated interferon, 2001 to 2010; Victrelis (boceprevir) and Incivek (telaprevir), the first DAAs, 2011 to 2013; Sovaldi (sofosbuvir) and Olysio (simeprevir), DAAs with much higher success rates, 2014; and Harvoni (ledipasvir/sofosbuvir) and Viekira Pak (ombitasvir/paritaprevir/ritonavir; dasabuvir), 2015.

Between 2001 and 2002, the number of people receiving HCV treatment doubled, from 2,726 to 6,679, with the introduction of pegylated interferon. Between 2001 and 2010, the annual treatment rate peaked in 2002 at 6,679 and then declined steadily. After Victrelis and Incivek were approved, the treatment rate rose to 4,900 in 2012 but dropped to 2,609 in 2013, the lowest rate since 2000. The treatment rate increased to 9,180 in 2014, following Sovaldi and Olysio’s approvals and then to 31,028 in 2015 after Harvoni and Viekira Pak were approved.

The annual proportion of those treated for HCV who were cured rose from 19.2 percent in 1999 to 36 percent in 2010 and to 90.5 percent in 2015.

The number of people achieving an SVR each year was 387 to 394 between 1999 and 2000, 618 to 2,204 between 2001 and 2010, 1,273 to 2,296 between 2011 and 2013, 7,377 in 2014 and 28,084 in 2015 (this last number amounted to nearly half of those cured since 1999).

During the 2015 VA fiscal year (October 2014 to September 2015), the VA allocated $696 million to offset the cost of DAAs. During this period, the monthly treatment rates rose ninefold and ranged from 727 in July 2015 to 6,868 in September of that year. The study authors concluded that the rise in monthly treatment rates largely correlated to the availability of these funds.

Between 2010 and 2015, the annual number of people cured of HCV increased 21.4-fold all told, including 52.3-fold among those with cirrhosis, 48.6-fold among those with decompensated cirrhosis, 39.1-fold among those with genotype 1, 48.5-fold among those with hepatocellular carcinoma (HCC, the most common form of liver cancer) and 80.7-fold among those older than 60.

To read a press release about the study, click here.

To read the study, click here.