Chronic Hepatitis B and C: Chronic Lack of Effective Treatment
The following article is from Pharmalive.com (The Pulse of the Pharmaceutical Industry).
The first interesting statistic I noticed is the statement that with the easier to treat genotypes they claim an 80% success rate and when factoring in the harder to treat (read genotype 1) the overall rate is around 50%.
While admitting I am no math whiz, it appears that the success rate for Genotype 1 must be well below 50% to end up with a 50% success rate when combined with the 80% claimed for other, more treatable, genotypes.
The authors of this article call current pharmaceutical therapies for chronic viral hepatitis b and c “inadequate”, “sub-optimal” and “far from perfect”. Remember, this is the “Pulse of the Pharmaceutical Industry” speaking.
Certainly, in my opinion, if I were to choose between the Roche or Schering therapies, I would choose Roche. For a few reasons, it seems to be the superior choice.
The authors are pointing out opportunity for pharmaceutical companies to come up with better solutions than currently exist. Especially for the harder to treat varieties like HCV genotype 1. This opportunity is what will drive these drug companies to continue to scramble to develop new treatments.
As I’ve said all along, their shareholder-driven need for profits will, ultimately, work to the advantage of patients.
Chronic Hepatitis B and C: Chronic Lack of Effective Treatment
LONDON, Jan. 12, 2005–The World Health Organization (WHO) estimates that one-third of the entire world’s population has been exposed to hepatitis B (HBV) resulting in an estimated
350-400million chronically infected patients globally. Most of these patients reside in Southeast Asia and Sub-Saharan Africa and in most cases are infected at birth. However the seven major pharmaceutical markets* (including the USA) are estimated to harbour up to seven million chronic carriers, with transmission occurring primarily through sexual contact during adulthood. Additionally, while Hepatitis C (HCV) infection is less common, the WHO estimates the numbers of chronically infected individuals at a further 200m. Perhaps most frightening of all however, is that less than one third of patients with either chronic hepatitis B or C (CHB or CHC) are actually receiving treatment.
Viral hepatitis – a significant public health problem
Globally, HCV infection is less common than HBV infection. However in the west, HCV (7.5m chronic carriers in the seven major markets) is more common than HBV. Historically this has been due to transmission through contaminated blood or blood products and is currently a result of shared utensils used for intravenous drug use.
Recently completed research by independent market analyst Datamonitor** has revealed that despite increasing HBV and HCV disease awareness and diagnosis, treatment rates of patients with chronic viral hepatitis remain low, and despite the large pool of CHB and CHC patients, less than one-third of these are currently receiving medical treatment. One underlying reason is the low rate of disease diagnosis, on average 54% for HBV and 40% for HCV, says Datamonitor infectious diseases analyst Brigitte de Lima. “Chronic liver disease (CLD) is a long-term consequence of HBV and HCV and commonly leads to liver cirrhosis or hepatic decompensation within 10-40 years following primary infection.”
“Furthermore, long-term CHB and CHC cause a type of liver cancer known as hepatocellular carcinoma (HCC). Both diseases combined account for over 80% of HCC cases and almost half a million lives annually. Once diagnosed, prognosis for HCC can be as low as six to eight months.”
Diagnosis and treatment – still sub-optimal in the seven major markets
Although HCV diagnosis rates are lower than those for HBV, they have increased considerably in the past two years, while those for HBV have remained flat. Key to the enhanced identification of new patients among both high-risk groups and the general population has been education and awareness campaigns organized by both the private and the public sector, de Lima says.
“In addition to the low rates of diagnosis, inadequate therapies also account for the sub-optimal treatment levels. Although up to 80% of CHC patients with the easy-to-treat viral genotypes 2 and 3 can currently be cured, the larger prevalence of the less responsive genotype 1 translates into only half of the total patient pool achieving virus eradication.”
“In the case of CHB the scenario is even worse, with viral eradication occurring in less than 5% of all patients. Current CHB therapy therefore focuses on long-term suppression of virus replication rather than virus clearance. Similar to CHC, the proportion of patients less responsive to treatment, namely those infected with the HBeAg-negative variant of HBV, is increasing globally.”
Sub-optimal current first-line therapies for CHB and CHC are unable to benefit the already predominant and increasing pools of difficult-to-treat patients, leaving ample scope for opportunistic manufacturers willing to invest in potent, tolerable drugs in a market largely driven by therapy cost, de Lima says.
Prescription choice – largely driven by cost-considerations
The pharmaceutical HBV market is currently dominated by two antivirals, GlaxoSmithKline (GSK)’s Zeffix (lamivudine, LAM) andGilead’s Hepsera (adefovir dipivoxil, ADV). Datamonitor’s research reveals that the preference of the former for first-line therapy is predominantly cost-driven, as the price of Zeffix is substantially lower than that of Hepsera, de Lima says. “ADV is commonly reserved for second-line therapy following the development of resistance to LAM, which can occur in up to 67% of patients after four years of therapy. For CHC, the standard of care is now pegylated interferon (pegIFN) and ribavirin (RBV) combination therapy.”
“Similarly, the HCV market consists of two major players; Schering-Plough, who markets PegIntron and Rebetol, and Roche, with its drugs Pegasys and Copegus. The lack of clinical differentiation between the two rival pegIFNs and the absence of any alternative anti-HCV drugs has led to physician prescription choice being driven almost exclusively by cost and special deals provided by the manufacturers.”
Current therapies – compromise is necessary
Current therapies for either disease are far from being perfect solutions. None of the HBV drugs cure the disease and long-term therapy with LAM is associated with development of resistance, while ADV entails a high financial expenditure. Pegylated IFN combination therapy might be effective in some forms of CHC disease, but it is also a therapy dreaded by most patients due to the injectable mode of delivery and the high incidence of severe side effects elicited over the entire course of the treatment, de Lima says.
“Given the clear limitations of the current HBV and HCV therapies, major players in both pharmaceutical markets have developed different strategies aimed at increasing treatment rates. In the case of CHC, these focus on treating patients with normal alanine aminotransferase (ALT) levels, prolonging treatment for slow responders and maintaining non-responders on pegIFN monotherapy. The main strategy for CHB patients is the extension of therapy, especially for HBeAg-negative patients, as most patients relapse following cessation of therapy.”
The current stalemate in the CHB and CHC treatment markets is only susceptible to being broken with the launch of new developmental drugs, which will have to combine high potency and good tolerability at a reasonable cost. Crucially, new drugs are more likely to gain market share if, in addition to winning the battles against the more responsive variants of the diseases, they are also effective in the difficult-to-treat CHB and CHC
patients. Drugs with high potency in the latter patients are the key to meeting the growing therapeutic needs and consequently boosting treatment rates, de Lima says.
“The future viral hepatitis treatment landscape is predicted to follow the HIV precedent, in that drug monotherapy is likely to become obsolete and novel, potent drugs will be administered simultaneously as part of a combination. Furthermore, the focus needs to shift from patients with easily treatable variants of the disease to those that obtain little benefit from current therapies, as these are steadily accumulating in the total patient pools. New strategies are awaited to take the lead in this long-standing battle against the hepatitis viruses.”
*The seven major pharmaceutical markets are the USA, the UK ,France, Germany, Italy, Spain and Japan
**Stakeholder Insight: Hepatitis B and C
Datamonitor plc (DTM.L) is a premium business information company specialising in industry analysis. We help our clients, 5000 of the world’s leading companies, to address complex strategic issues. Through our proprietary databases and wealth of expertise, we provide clients with unbiased expert analysis and in-depth forecasts for six industry sectors: Automotive, Consumer Markets, Energy, Financial Services, Healthcare, Technology. Datamonitor maintains its headquarters in London and has regional offices in New York,San Francisco,Sydney,Tokyo, Frankfurt,ShanghaiandHong Kong.