Hepatitis C: New Dangers, New Hopes
What Are the Treatment Options?
Unlike HIV, it's possible to cure HCV disease -- to completely eliminate the virus from the body. But the first HCV medications (alpha interferon and ribavirin) had cure rates well below 50% for people co-infected with HIV and HCV. Those who underwent the long and difficult treatment often had harsh side effects, so the next generation of HCV meds has been eagerly anticipated.
The first new drugs to receive FDA approval -- the protease inhibitors Incivek and Victrelis -- more than doubled the likelihood of curing HCV while shortening the treatment duration by half. These meds improved cure rates both for those who had never taken HCV treatment and for those who had experienced a prior treatment failure. Data released earlier this year showed that these drugs also improved cure rates in co-infected people, although the improvements were less than those seen in people with HCV only.
Unfortunately, treatment with these two new drugs proved to be more challenging than expected. First, clinical trials can't recreate the real-world situations of people with HCV. Studies select participants with few physical or psychosocial health issues, and provide much interaction with experts. In reality, these new drugs require very knowledgeable doctors, committed patients, and perfect adherence to even begin to replicate the successes seen in the clinical trials. In addition, the drugs must be taken with interferon, adding more side effects to this already difficult regimen. Dr Mark Nelson of London's Chelsea and Westminster Hospital told Aidsmap that the two new drugs were similar to the first-generation HIV protease inhibitors: "Incivek and Victrelis are relatively difficult to take and relatively toxic compared to the second generation. If you have minimal liver disease, probably the best option is to wait."
What's in the Pipeline?
The need for more HCV treatment options is clear, and new research offers great hope of increasing cure rates and reducing side effects. These experimental meds take a variety of approaches to clearing the body of HCV, including combinations of protease inhibitors and other classes of drugs such as polymerase inhibitors and NS5A inhibitors, often in interferon-free regimens.
"It has been widely reported that the combination of sofosbuvir and daclatasvir was very effective -- perhaps up to 100% effective for people with HCV genotype 1."
One of the most exciting interferon-free combinations is sofosbuvir (GS-7977) and daclatasvir, two drugs originally researched by Pharmasset and Bristol-Myers Squibb. Although the final data from the phase II trials have not been released, it has been widely reported that the combination was very effective -- perhaps up to 100% effective for people with HCV genotype 1 (see "My Fight for a Hepatitis C Cure" in this issue), with few side effects. Unfortunately, such revolutionary advances in treatment and the opportunity for new blockbuster HCV medications have made some drug companies wary of collaborations, slowing even bigger developments in treatment. Perhaps most notoriously, Gilead Sciences purchased sofosbuvir from Pharmasset and announced that it will not work with Bristol-Myers Squibb to further test it in combination with daclatasvir. They will instead test it with their own drugs, most likely delaying FDA approval of an interferon-free HCV regimen for at least two years.
Other combinations have also shown good results. In 2010, a Roche study of two new drugs, danoprevir and mericitabine, showed that this interferon-free combination could suppress HCV in people who did not have HIV. Viral loads fell 100,000-fold in just 13 days in one trial.
Last year, Boehringer Ingelheim studied two of its drugs without interferon -- the protease inhibitor BI 201335 and the polymerase inhibitor BI 207127 -- in people without HIV. After 16 weeks of treatment, 60% of people in the trial had an SVR (sustained viral response, meaning an undetectable HCV viral load) 12 weeks after treatment ended, which is now regarded as an indication of a cure.
A trial of the protease inhibitor asunaprevir and daclatasvir found that 90% of people who had HCV genotype 1 had an SVR after 12 weeks of treatment, in spite of failing earlier treatment with interferon.
The ASPIRE trial of the protease inhibitor simeprevir (taken with interferon) reported cure rates of over 80% in people without HIV -- both in those new to treatment and those who had failed earlier treatment.
Unfortunately, there has yet to be a single trial of an interferon-free regimen in people co-infected with both HCV and HIV. Researchers are concerned about how effective the new drugs will be without interferon in people who are immune suppressed. They also don't know how people with other complications will respond to the new meds.
Several more drugs will likely be approved for use with interferon over the next few years. The first interferon-free combinations may not hit the market for three to five years, and their approval for co-infected people will take even longer. Of course, knowledge gained from mono-infection trials and pressure from advocates could hasten that process, and any drugs approved for people with only HCV can also be prescribed for people with both HIV and HCV (although insurance reimbursement may be a problem). For comprehensive information on HCV drugs in the pipeline, click on "Hepatitis C" at natap.org, read the TAG report at pipelinereport.org, or check out "Experimental HCV Drugs" at hivandhepatitis.com.
As more experimental drugs are developed, the biggest obstacle to affordable, safe, and convenient treatments could be the lack of collaboration in the industry. Similarly, any new HCV drugs that are approved will be in high demand, meaning a high price tag.
What If I Have Both HIV and HCV?
Despite the development of new meds, treating HIV/HCV coinfection is still very difficult. There are many concerns about how new HCV meds might affect a person's ability to manage HIV infection. The specifics of any treatment regimen will vary depending on the types of HCV and HIV, a person's overall health, treatment history, liver function, and response to different medications. As additional treatments are developed, there is great hope that such complications will become less of an issue.
The next landmark in HCV treatment will be a regimen that is interferon-free, easy to take, and tolerable both for people with HIV and for those who have advanced liver disease. While the current evidence is promising that such a treatment will eventually become available, the reality is that it will take years to reach the market. In the meantime, it is crucial that efforts are made to raise awareness about sexually transmitted HCV and to encourage those at risk to get tested in order to slow its spread. HCV is a serious but preventable condition, and increasing the amount of knowledge on the topic is the first step to empowering people to reduce the risk of its transmission.
Aaron Arnold is the Data Manager of the M2M Project at Pittsburgh AIDS Task Force. Mark Milano is the editor of Achieve.
This article was provided by ACRIA and GMHC. It is a part of the publication Achieve. Visit ACRIA's website and GMHC's website to find out more about their activities, publications and services.
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