VBI Vaccines, Inc. (VBIV) has had a big couple of months. During the middle of July, the company announced the details of a pivotal program that will see it advance its lead development asset, a hepatitis B vaccine called Sci-B-Vac, into two phase 3 global studies. Shortly after the hepatitis B update, the company put out interim data from a phase 1 study of one of its secondary development assets, a drug called VBI-1501A. This one is another vaccine that is targeting preventative treatment of cytomegalovirus (CMV), which is a very common and potentially very serious virus for which – as things stand – no preventative vaccines are on the market in the US. The data demonstrated that the vaccine was safe across the sample population and that it was able to show early stage efficacy signals, with a detectable and dose dependent immune response reported at interim stage.
Each of these updates has teed up catalysts across the coming twelve months.
As of this week, however, VBI has given markets yet another update and, with it, another catalyst to keep an eye on near term.
On August 15, 2017, VBI announced that the FDA has accepted its Investigational New Drug Application (IND) for an asset called VBI-1901. Unlike the two assets mentioned above, this one is and immunotherapy drug and is designed to target a type of cancer called glioblastoma multiforme (GBM). This IND acceptance is the first step on a long regulatory pathway, but it’s a major hurdle nonetheless and it serves to further strengthen VBI’s secondary pipeline (i.e. the portfolio of development assets that are in place as supportive of the lead program, in this case Sci-B-Vac).
The mechanism of action (MOA) that underpins this development stage drug is an interesting one. I noted earlier that VBI-1901 differs from VBI-1501A and Sci-B-Vac in that it is not a vaccine, but that is not strictly correct. The drug was developed using the same platform that VBI uses to create its development stage vaccine candidates, what’s called its enveloped virus-like particle (eVLP) platform. Further, the science that dictates how the treatment works is very closely linked to that of the above-mentioned CMV vaccine, VBI-1501A.
How could CMV possibly be linked to GBM?
There is a growing body of research that suggests that GBM tumors, and specifically GBM cancer cells, are susceptible to CMV infection. Here is some literature on the subject. And some more. The data that supports this research points to more than 90% of GBM cells expressing antigens associated with the CMV virus. It is in this expression that VBI has rooted its GBM candidate’s MOA. The drug is comprised of two elements: a CMV vaccine and what’s called a granulocyte-macrophage colony-stimulating factor (GM-CSF). GM-CSF is an adjuvant that plays a role in signaling to dendritic cells that a cell is pathogenic (in this case, the GBM cell) and stimulating an immune response against the cell in question. The way it works, then, is relatively simple in concept: the vaccine part of the drug seeks out the GBM cells by targeting the antigens associated with the CMV virus. It then carries the adjuvant, the GM-CSF, to the cells, which alerts the immune system to their presence by the recruiting of dendritic cells to the location of the GBM cells. The idea is that the immune system will attack the GBM cells and help to control cancer growth or, ideally, remove the cancer cells from the body altogether.
For a type of cancer like GBM, which is incredibly difficult to treat because of its location in the brain, immunotherapy is one of the most promising approaches in the development space right now. As yet, however, no company has been able to demonstrate that its asset is worthy of mainstream use against this type of cancer. VBI is trying to change that with its novel approach and, as the latest IND approval shows, there is credence to the hypothesis that this type of approach can work.
For those not familiar with how this process is structured, VBI submits an IND to the FDA, which outlines the concept of the drug and details how the company intends to carry it into the clinic. If the FDA accepts the IND (as is the case here) the company is then free to initiate a clinical trial investigating the drug in human patients against the protocol described in the submitted IND.
That’s the stage VBI is that now and it in this clinical trial that rests the catalyst associated with this program. Specifically, initiation of the study, a phase 1/2a, which management expects should come at some point during the second half of this year. It’s this initiation that presents markets with the initial catalyst and secondary catalysts are rooted in enrollment and completion, as well as any interim report on progress.
Keep in mind that this isn’t the primary program, and the real action is going to be rooted in any clinical success for the hepatitis B asset, at least near term. With that said, it does add yet another shot on goal for a company that already has multiple shots in its pipeline, further reducing risk for anybody looking to pick up an exposure ahead of these shots being taken.