Old news?

[NewlyDiscovered]

http://hbvadvocat.blogspot.ca/2013/12/gilead-begins-innovative-antiviral-plus.html?m=1

[NewlyDiscovered]

Great, thanks for the sharing!

[StephenCastlecrag]

We know Interferon is very useful in treating HepB, on its own or in combination. But at the moment, the weekly injection is costly, has many side effects and does not work for everyone. So if an oral way to cause our body to produce Interferon has less side effects, more effective and for more patients, it would cure more patients. Yes, it is not a new approach, but if can be approved very quickly and benefit many patients quickly.

[NewlyDiscovered]

From your explanation, 9620 does not sound like a new approach to treating hepB, since interferon is already available and delivered via injections? Rather, it seems to be a different way of administering a similar compound?

On the other hand, 4774 appears to be a new drug/approach being tested.

Thanks!

[StephenCastlecrag]

You are quite right, liver can regenerate. To regenerate a normal functional liver, the regeneration must be "orderly", for want of a better word. That is another complicated area. Our immune system does have ways to control/regulate excessive immune activities, such as Tregs immune cells and PD1 (programmed Cell Death 1) etc.

GS9620 is a TLR7 agonist. I think roughly, it can be described as an oral form of Interferon. GS9620 will induce some of own cells to produce Interferon.Viola, no weekly injection. So if it works and with less side-effect, it will allow GS9620 to be widely used in combination of  existing antivirals to treat HepB. So again keeping our fingers crossed.

As usual, these are just my own understanding.

[NewlyDiscovered]

Stephen

How about this one?

http://hbvadvocat.blogspot.ca/2013/12/a-study-evaluating-gs-9620-in.html?m=1

Is 9620 supposed to act in the same way as 4774?

Thanks!

[NewlyDiscovered]

Thats enlightening!  

Sounds like this could be some double-edged sword for the liver.

Hopefully, the liver cells are able to regenerate if damaged by such drugs (sorry, I have little idea how human body works haha).

Thanks!

[StephenCastlecrag]

The theory is this - this is my amateur understanding, so bound to be missing details or wrong. When a cell manufactures proteins within, fragments of the proteins, called epitopes are expressed on its surface through a MHC complex. An infected liver cell produces many viral proteins, so on its surface are also many MHC complexes with variou s-, e-, c-antigen epitopes. Our adaptive immune system, on encounter with the virus, through immune cells such as dendritic cells and macrophages, so called antigen presenting cells, APC, will present the viral antigens(epitopes) to the immune system, inducing it to produce cytoxic T cells that specifically recognise these MHC-HBV viral epitopes on infected liver cells. These T cells can then recognise infected liver cells and kill them.
The vaccine is supposed to induce our immune system to produce these T cells to clear the virus through the same route, but without using a real HBV virus.

The obvious questions are then:
Doesn't the HBV viruses induce the production of these T cells already?
If these T cells recognise and kill all the infected liver cells, will our liver be damaged completely?

As I say, therapeutic vaccine is tricky, I too would like to know the answers. May be studyforhope can enlighten us, again.

[NewlyDiscovered]

In addition to hk96 question, would the possible goal of this drug be just to enable the body to 'control' the hep B virus without further medication?

[HK_1966]

Reading a bit more into it, it seems like this is an attempt to train the immune system to recognise and eliminate the antigen and no longer just suppressing the virus like current drugs?

And again assuming it works as hoped, does it mean a carrier's body can be rid of the hbv virus from the liver for good?

Thanks again for sharing.

[StephenCastlecrag]

Therapeutic vaccine is tricky. China has two that went to phase 2 and phase 3 respectively, both did no better than the placebo groups. If it works, hopefully, it will be a finite course of injection and should lead to a cure. That is my understanding.

[NewlyDiscovered]

Thanks Stephen.

Assuming this drug works, do you think it would be a 'cure' (or closer to a 'cure')? Or would it be just another drug that a patient may have to take for life too?

Regards.

[StephenCastlecrag]

Not really, quite exciting news. One reader here was asked to take part in the trial.