PHARMACOLOGY AND THERAPEUTICS ADVISORY COMMITTEE (PTAC), PHARMAC

FROM May 2007: PTAC minutes for web publishing

Pegylated interferon with ribavirin for HCV genotypes 2 & 3 without cirrhosis

The Committee reviewed an application from clinicians on behalf of the New Zealand
Society of Gastroenterology to widen access to pegylated interferon alpha 2a with
ribavirin (Pegasys) for the treatment of patients with chronic hepatitis C genotype 2 and 3

without cirrhosis, with treatment limited to 24 weeks. The applicants considered that
patients with chronic hepatitis C genotype 2 and 3 without cirrhosis represent about 10%
of the hepatitis C patient population, approximately 40 patients per year.

The Committee noted that, at present, funding for pegylated interferon alpha 2a with
ribavirin (Pegasys) and pegylated interferon alpha 2b with ribavirin (Pegatron) is limited
to chronic hepatitis C, genotype 1, 4, 5 or 6 infection or HIV co-infection, or genotype 2
or 3 with bridging fibrosis or cirrhosis (Metavir stage 3 or 4 or equivalent) or patients
unsuitable for liver biopsy due to coagulopathy.

The Committee noted that these patients currently have funded access to standard
interferon therapy alpha 2a or 2b (with or without ribavirin). However, the Committee
noted that a study by Fried et al (NEJM 2002;347:975-82) demonstrated that pegylated
interferon alpha 2a with ribavirin significantly improved sustained viral response
compared with standard interferon alpha 2b therapy with ribavirin (78% vs 61%) over 48
weeks.

The Committee noted that there was no data comparing 24 weeks pegylated interferon
alpha 2a with ribavirin against 24 weeks standard interferon alpha with ribavirin, and
noted that such a study would likely never be done.
The Committee considered that although the applicants requested that treatment be
limited to 24 weeks it may be possible for some patients to stop treatment at 16 weeks
for those with a rapid virological response; however, this would require four-weekly viral
load testing.

The Committee noted guidance issued by the UK National Institute of Health and Clinical
Excellence (NICE) in August 2006 that recommended the use of pegylated interferon
alpha with ribavirin in patients with mild chronic hepatitis C. The Committee also noted a
Canadian Agency for Drugs and Technology in Health (CADTH) technology assessment
report on interferon (pegylated and non-pegylated) treatment for chronic hepatitis C.
The Committee considered that the treatment of hepatitis C genotype 2 and 3 without
cirrhosis with pegylated interferon alpha 2a and ribavirin was associated with clinical
benefit and noted that the NICE guidance considered that there was a reasonable cost
per QALY.

The Committee recommended that access to pegylated interferon alpha 2a with
ribavirin on the Pharmaceutical Schedule be widened to include treatment of hepatitis C
genotype 2 and 3 without cirrhosis for up to 24 weeks. The Committee gave this
recommendation a medium priority.

The Committee further recommended that the Special Authority criteria for pegylated
interferon alpha 2a with ribavirin and pegylated interferon alpha 2b with ribavirin be
amended to include a stopping rule for patients who fail to achieve virological response
(at least a 2-log reduction) after 12 weeks of treatment. The Committee recommended
that the application be reviewed by the anti-infective Sub-Committee for further advice
regarding appropriate Special Authority criteria.

The Decision Criteria relevant to this recommendation are: (i) The health needs of all
eligible people within New Zealand; (iii) The availability and suitability of existing
medicines, therapeutic medical devices and related products and related things; (iv) The
clinical benefits and risks of pharmaceuticals; (v) The cost-effectiveness of meeting
health needs by funding pharmaceuticals rather than using other publicly funded health
and disability support services.