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When Can Hepatitis B Patients Stop Taking Antivirals? Experts Finally Have Some Answers

Image courtesy of foto76 at FreeDigitalPhotos.net
Image courtesy of foto76 at FreeDigitalPhotos.net

By Christine Kukka

With the help of antivirals, many patients today have undetectable viral load (HBV DNA), a relatively healthy liver and cleared the hepatitis B “e” antigen (HBeAg). So when can they consider stopping their daily entecavir or tenofovir pill?

For years, experts have admitted the endgame of antiviral treatment has been “ill-defined.” While antivirals reduce viral load and the risk of liver damage, they rarely cure people. Recently, after years of observing patients and with the help of better diagnostic tools, experts are getting better at identifying when might be safe to stop.

Historically, in addition to reducing viral load to undetectable levels, the goals of antiviral treatment were:

  • Triggering HBeAg seroconversion: About 21 percent of HBeAg-positive patients with liver damage treated with either tenofovir or entecavir for 12 months are able to lose the hepatitis B “e” antigen (HBeAg) and develop the “e” antibody (HBeAb). This HBeAg “seroconversion” indicates the immune system is fighting the infection and slowing viral replication.
  • And reducing liver damage and even clearing the hepatitis B surface antigen (HBsAg): About 1-3 percent of patients treated with antivirals lose HBsAg after years of treatment. This is called a “functional cure.” Unfortunately, if you have HBeAg-negative hepatitis B, only 1-2 percent of you will lose HBsAg after five to eight years of antiviral treatment.*

If you are among the lucky few who achieve HBeAg seroconversion or clear HBsAg, when is it safe to stop your daily antiviral? Here are the newest guidelines detailing when it may be safe to stop from the 2017 European Association for the Study of the Liver (EASL).

Image courtesy of Taoty at FreeDigitalPhotos.net
Image courtesy of Taoty at FreeDigitalPhotos.net

When is it safe to stop antivirals after you’ve achieved HBeAg seroconversion? Stop too early, and HBeAg can reappear. EASL recommend non-cirrhotic patients who experience HBeAg seroconversion and continue to have undetectable HBV DNA for 12 months longer can stop antivirals, as long as there is frequent monitoring after.

When is it safe to stop if you have HBeAg-negative hepatitis B and have undetectable viral load after years of antiviral treatment? EASL guidelines say non-cirrhotic, HBeAg-negative patients who have had at least three years of antiviral treatment, undetectable viral load and no signs of liver damage can stop treatment, as long as there is frequent follow-up monitoring.

When is it safe to stop antivirals if you’ve lost HBsAg? EASL recommends stopping antivirals after losing HBsAg, even if a patient does not develop the hepatitis B surface antibody (HBsAb). Recently, experts have decided that patients who lose HBsAg may be “functionally” cured, even if no surface antibodies appear.

Researchers also have a new way to determine if it’s safe for patients who had HBeAg seroconversion to stop antivirals – by measuring their HBsAg levels. The lower your HBsAg levels, the more likely you are to maintain HBeAg seroconversion after you stop antivirals.

For example, patients may be HBeAg-negative and have no signs of liver damage, but if their HBsAg levels remain high, these patients remain at risk of reactivation and should continue antiviral treatment. (Read more about HBsAg quantification testing here.)

These antiviral “stopping rules” are still in development and are still frustratingly vague for many patients, but slowly researchers are developing tools and compiling more research in order to develop better guidelines when it’s safe to stop the daily antiviral treatment plan.

 *The statistics and recommendations cited are found at EASL2017 Clinical Practice Guidelines.

Hepatitis B Foundation Expert Timothy Block Predicts Transformational New Therapies for Hepatitis B

Hepatitis B Foundation President Timothy Block
Hepatitis B Foundation President Timothy Block

By Christine Kukka

For more than 25 years, Timothy Block, Ph.D,, has worked tirelessly to find a cure for hepatitis B, promoting research, writing papers, mentoring students and collaborating with experts around the world to find a cure for the 240 million people living with this deadly liver disease.

Today, the cofounder and president of the Hepatitis B Foundation, the Baruch S. Blumberg Institute and the Pennsylvania Biotechnology Center, is optimistic and believes there are new therapies in sight for those living with chronic hepatitis B.

An unprecedented number of researchers are scrutinizing every stage of the hepatitis B virus (HBV) replication cycle to find its vulnerabilities and develop drugs to permanently disable it. The cure Block wants would completely eradicate the infection so no one would ever wake up worrying about the risk of liver damage or cancer to themselves or a loved one.

This global, active march towards a cure is in stark contrast to 1991 when Block began his solitary quest, after a friend’s devastating hepatitis B infection made him rethink his career and start focusing on the liver disease that infects more than one in three people worldwide.

Twenty-five years ago, the only available treatment was conventional interferon, which was largely ineffective. The first antiviral, lamivudine, appeared shortly thereafter. It would be one of several to emerge from HIV’s drug arsenal. Since then, more antivirals designed to disrupt HBV’s replication process have been developed that target the polymerase—the essential enzyme needed for HBV replication.

“But they are not cures,” Block explained during a recent webinar. “They’re good at reducing viral load (HBV DNA), but they don’t get rid of the virus, and considerable viral DNA and  hepatitis B surface antigen (HBsAg) remain in liver cells.” Nor do current antivirals get rid of the HBV chromosome called cccDNA that embed in liver cells and stubbornly remain, ready to churn out more virus if a person stops taking antiviral drugs, or if their immune system weakens due to advancing age or another illness.

There are other roadblocks that make hepatitis B far harder to cure than hepatitis C. HBV generates massive amounts of HBsAg that appear to overwhelm the immune system’s B cells, whose job is to produce antibodies to eradicate HBV’s antigens. When newborns or young children are infected, these B-cells become paralyzed or “exhausted” by the flood of HBsAg engulfing them and they don’t generate the antibodies needed to fight infection. In contrast, when healthy adults are infected, these B-cells act quickly and aggressively to eradicate HBsAg within six months.

“Now for the first time, we’re looking beyond the polymerase to find more targets that are essential for HBV replication,” Block explained. HIV researchers have already done this and have identified more than 30 different “targets” in the HIV replication process. Hepatitis B researchers are also expanding their target range.

There are now new drugs in development, some have even reached Phase II clinical trials, that target new HBV reproductive terrain. They employ a variety of strategies ranging from immune system enhancers to molecular weapons designed to halt cccDNA integration into liver cells.

“If you can suppress cccDNA, the game would be over,” Block said, “but cccDNA is small, tough target. It’s so small compared to other material, that it’s almost impossible to distinguish from other molecules.” However, biologicals that are able to “inhibit” or block cccDNA from entering a liver cell could stop the virus from hijacking and reproducing in liver cells. Here are some types of drug strategies currently in development that could lead to a cure:

Restructured versions of tenofovir: There are two new tenofovir “prodrug” compounds, called TAF and CMX 157, that are more effective at reaching liver cells and impeding HBV replication. TAF is now in Phase III clinical trials and is expected to reach the U.S. Food and Drug Administration (FDA) this month (November 2016).

Molecular agents that target and disable HBV replication:

  • A new agent, called the CRISPR/Cas9 system, may be able to operate on a molecular level to search out and destroy HBV cccDNA molecules.
  • One of the more advanced molecular strategies, already in Phase II trials, is a “silencing” RNA process. This approach uses RNAi gene silencers to target and destroy HBV RNA to prevent viral reproduction. “CccDNA remains,” Block explained, “but all of its gene products it needs are choked.”

Entry inhibitors: Some of these drugs resemble HBsAg, but they work as decoys to prevent the virus from entering or binding to the liver cell. One is in Phase II clinical trial.

Capsid inhibitors: This approach interferes with the viral DNA’s ability to connect or glue together during the replication process. Several of these drugs are in Phase II clinical trials.

HBsAg inhibition and eradication: “There are 1 million more HBsAg as the actual virus,” Block observed. “Why are there so many? What is it doing in the blood? Why is it able to exhaust our B-cells?” Because HBsAg appears to hold a key in stopping infection, researchers are working to develop a way to eradicate HBsAg. Two of these HBsAg eradicator products are in Phase II trials.

Adaptive and innate host defense: This approach involves a two-step strategy, first reducing viral load to undetectable levels by helping liver cells become “in-hospitable” hosts to HBV’s reproductive efforts, and then introducing a vaccine or some other immune enhancer that can break the B-cell exhaustion cycle while firing up immune cells to aggressively fight and eradicate the infection. There are several of these drugs in Phase I and II clinical trials.

Block told his webinar audience that ideally one of these drugs would emerge as a single, simple cure. “But every infectious disease today, such as hepatitis C and HIV, is almost always treated with a combination of drugs. We might see two direct-acting antivirals and maybe a third drug that work as an immune system activator.”

When asked which patients would get first access to a new cure, Block predicted that people with high viral loads and liver damage would be treated first based on medical need. “As drugs get safer, I hope we will  treat people in the immune tolerant phase (with high viral load but no signs of liver damage yet), before they begin to have signs of liver damage.”

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You’ve Lost the Hepatitis B Surface Antigen, Go Celebrate, But Keep Monitoring

By Christine Kukka

Image courtesy of stockimages at FreeDigitalPhotos.net
Image courtesy of stockimages at FreeDigitalPhotos.net

After years of living with “inactive’ chronic hepatitis B—with low viral load and no signs of liver damage–some patients may finally lose the hepatitis B surface antigen (HBsAg) and even develop surface antibodies.

This event merits a celebration and a huge sigh of relief, but if you think you will never have to get another blood draw or worry about your liver, think again. We hate to be the bearer of bad news, but hepatitis B really never goes away.

Image courtesy of stockimages at FreeDigitalPhotos.net
Image courtesy of stockimages at FreeDigitalPhotos.net

Think herpes, mono, or chicken pox and shingles. Children infected with chickenpox get rid of the infection and the ugly blisters, but very small amounts of the chickenpox (varicella) virus remains in the spinal nerves. As we grow older and our immune systems weaken with age,  our bodies aren’t able to suppress the varicella virus any more and it reactivates, causing painful shingles.

The hepatitis B virus (HBV) behaves in the same way. When we lose HBsAg and even develop surface antibodies (anti-HBs), there are still HBV lurking in our livers. When we’re healthy, our immune systems suppress the virus and prevent any reactivation, but old age or another disease or medical condition can weaken our bodies and allow the viral infection to reactivate.

So, even after we clear HBsAg, we need to stay vigilant and continue to get our liver health monitored regularly. Here is what you need to know:

First, what are my chances of ever getting rid of HBsAg and developing the surface antibody? It can happen, especially in older adults after a long period of “inactive” hepatitis B infection.

About 1 to 3 percent of people with chronic hepatitis B lose HBsAg each year, and about half of all people with chronic infections who live up to age 75 will lose HBsAg, depending on the amount of HBV DNA in their blood.

Your chances of losing HBsAg and developing the surface antibody increase if you have a healthy lifestyle and avoid alcohol, cigarettes and obesity (fatty liver). Another report found that people with the hepatitis B strain or genotype C have higher rates of clearing HBsAg over time than those with genotype B.

Image courtesy of taoty at FreeDigitalPhotos.net
Image courtesy of taoty at FreeDigitalPhotos.net

Once you clear HBsAg, the chance of developing surface antibodies over the next two, five and 10 years are 24 percent, 58 percent and 78 percent respectively, according to a recent report in the September 2016 journal of Epidemiology and Infection.

After I clear HBsAg, how often do I need to get my liver health monitored? According to Dr. Robert Gish, medical director of the Hepatitis B Foundation and professor consultant of gastroenterology and hepatology at Stanford University, once you have cleared HBsAg, 12 months later you need to:

  • Check all of your liver enzymes and liver function
  • Get your platelet count and hepatitis B blood tests done, and
  • Have an ultrasound of your liver and spleen.

These tests become your new “baseline” that your doctor can refer too in the years ahead while monitoring your liver health.

Your baseline ultrasound should examine your liver and measure its portal vein (it should be under 12 mm) and spleen (it should be under 12 cm) to make sure it’s normal with no signs of cirrhosis or portal hypertension.

If you had cirrhosis before you cleared HBsAg: You need to be surveyed for liver cancer (with an ultrasound, alpha fetoprotein (AFP) blood test and a Des-gamma-carboxy prothrombin (DCP) test) every six months for at least five years, because cirrhosis puts you at high risk of liver cancer. Once an ultrasound finds no evidence of cirrhosis and all other tests are normal, including the cancer tests, then the testing can become less frequent and your doctor can prescribe a new monitoring schedule.

If you’ve had elevated liver enzymes (called ALT or SGPT) in the past, (higher than 19 in women and 30 in men), you need to continue to get tested every six months until you’ve had two consecutive healthy ALT readings. If your ALT remains elevated, make sure you are not drinking alcohol and do not have fatty liver disease. Talk to your doctor about a new monitoring schedule.

Tell all of your current and future doctors you’ve had hepatitis B, and beware of immune-suppressing drugs used to treat various cancers and rheumatoid arthritis. Our immune systems, which are working to keep the residual HBV in our bodies in check, can also take a hit from medications that deliberately suppress our immune systems in order to fight cancer, psoriasis or rheumatoid arthritis.

According to medical guidelines, all oncologists and other specialists who use these powerful drugs are supposed to test all  their patients for hepatitis B and carefully monitor anyone who had hepatitis B in the past, which is indicated by a positive test for the hepatitis B core antibody (anti-HBc).

Even if you’ve cleared HBsAg, doctors may pre-emptively treat you with antivirals during and after your treatment for cancer, immune disorders such as arthritis or psoriasis, and hepatitis C and monitor your HBsAg and viral load regularly to make sure your hepatitis B does not reactivate.

These screening guidelines exist, but no one is perfect and your oncologist may not know you’ve been infected, may forget to screen you for hepatitis B, or may not understand the testing. So, tell everyone if you have an active or resolved hepatitis B infection. The last thing you want is to be battling both cancer and a reactivated hepatitis B infection simultaneously.

While hepatitis B never really goes away, once you clear HBsAg your risk of liver damage and liver cancer diminish tremendously. It’s worth a celebration, but you need to continue to be monitored as you age.

Is a Cure for Hepatitis B Coming? Experts Say Yes

How far are we from finding a cure for hepatitis B? We are close, said Timothy Block, PhD, president and co-founder of the Hepatitis B Foundation and its research arm, the Baruch S. Blumberg Institute. He points out that hepatitis C, once thought to be incurable, is today cured with new combination treatments.

Image courtesy of suphakit73 at FreeDigitalPhotos.net.
Image courtesy of suphakit73 at FreeDigitalPhotos.net.

Experts believe a cure for hepatitis B will also soon be developed. And the need for a cure has never been greater, with more than 240 million people worldwide living with chronic hepatitis B, causing 1 million deaths per year from related liver failure and liver cancer.

“Treatments are available,” explained Block, “but we have become a little too comfortable with the medications that are currently approved for use.” While these drugs are effective, interferon has many side effects and daily antivirals require lifelong use. These drugs work in only half of the infected population and reduce death rates by only about 40 to 70 percent.

What will a cure look like?

The available antivirals are similar and combining them offers no advantage. They have limited effectiveness against cccDNA, the seemingly indestructible “mini-chromosome” of the hepatitis B virus that continues to produce virus particles in infected liver cells, even in people being treated. A cure, therefore, would have to destroy or silence cccDNA and provide long-term immunity. Because one-drug treatments can lead to drug resistance, a cure would almost certainly involve combination therapy, similar to hepatitis C. Continue reading "Is a Cure for Hepatitis B Coming? Experts Say Yes"