Northwest Biotherapeutics

From Wikipedia, the free encyclopedia
Jump to: navigation, search
NorthWest Biotherapeutics, Inc.
Type Public
Traded as NASDAQNWBO
Industry Pharmaceuticals
Headquarters Bothell, Washington
Products
Website www.nwbio.com

Northwest Biotherapeutics is a development-stage[1]:8 American pharmaceutical company that focuses on developing immunotherapies against different types of cancer.

Business model[edit]

Northwest relies upon the contract manufacturing organization Cognate Bioservices for services supporting manufacture of product for clinical trials. The relationship with Cognate is long term, having begun before 2007 and slated to extend through the first quarter of 2016.[1]:15 Due to cash flow issues common to development-stage companies, Northwest compensates Cognate through a combination of cash and stock payments.[1]:16 Further, Cognate has provided Northwest with at least one short-term loan, provided and paid in mid-2013.[1]:16 As of 2014, Northwest is undergoing an increase in activities as a result of expanding clinical trials, which has led to increasing reliance on Cognate for services, and subsequent renegotiation of the agreement with Cognate.[1]:15,[2]

Mission[edit]

NWBO's stated goals stress product quality and purity, innovation, and efficient production.[3]

Technology[edit]

The DCVax technology upon which NWBO's therapies rely involves injecting cancer patients with dendritic cells, which contain high levels of the same antigens found in tumor cells. The immune system, alerted by these antigens, attacks the cancer as well as the injected cells.

Dendritic cells[edit]

Northwest Biotherapeutics currently has three different cancer treatments in various levels of clinical trial. One thing in common to all three products is the use of dendritic cells, one of many types of white blood cells. The dendritic cell is most famous for its ability to scout and retrieve protein segments that it encounters in the body. One dendritic cell can retrieve a very large number of such protein segments. After collecting a load of protein segments, the dendritic cell returns to a nearby lymph node to present the segments to T-cells and B-cells. If the T-cells or B-cells determine a segment is foreign, they multiply, then set off to attack any cell that appears to contain that foreign or mutated protein. In this way, the mutated proteins associated with a cancer tumor make that tumor a target of these T-cells and B-cells.

The internal machinery of all cells is made primarily of proteins. All cells present copies of segments of these proteins, onto the outside of the cell membrane. This allows the immune system to monitor whether or not the cell contains mutated proteins. These presented proteins and protein segments are scavenged by the dendritic cells and to a lesser extent by other immune cells. If the immune system detects the cell to have a mutation, it will try to kill it. Again, the process is the dendritic cell returning to the lymph node with the scavenged proteins, un-mutated and mutated alike. These proteins are then presented to the T-Cells and B-Cells in the lymph node(s). The T-Cells, amazingly, are each pre-programmed to recognize one single type of mutated protein. Always a mutated type. Never a natural type. So all these scavenged proteins get presented to all the T-Cells, and if a T-Cell recognizes it's mutant protein, then it replicates massively, then tracks back from where the dendritic cell came, checking cells for its programmed target protein. If it finds that protein on the outside of a cell, it will try to kill it by injecting sodium hydroxide, or hydrogen peroxide into the cell, unless stopped by the cell’s defenses, or defenses presented by other nearby cells.

A single mutation would often kill a cell simply because the cell often loses some important internal function. However, if the cell lives, it is not necessarily yet a cancer. A mutation is not necessarily a horrible thing, but if enough of the right mutations accumulate, the cell can become cancer. If the immune system kills all cells with mutations, then a cancer will never develop. However, the immune system is not perfect. One of the mutations that a cancer cell often develops allows the cell to excrete chemical signals that tell the immune system to become less aggressive in that local area. Other mutations cause the cell to raise flags that signal that it is a healthy cell, i.e. not a proper target.

One example of the normal utility of these white flags is when a physical injury to tissue occurs. Many cells are torn open in such damage, spilling their contents. The contents pose a hazard to local tissues for multiple reasons, so it is important that they be cleaned up ASAP. The immune system sends the appropriate cells to devour these spilled contents. Chemical messengers excite this action in that local area. The resulting excited response is one form of inflammation. The nearby healthy tissue is in some danger of being accidentally devoured by this excited cleanup crew. To reduce that hazard, those cells raise these white flags that pronounce the cells to be normal, intact, healthy tissue. This helps the cleanup crew avoid collateral damage. But with a cancer cell, an exaggerated expression of these flags due to some mutation would tend to fend off the T-cells that might otherwise target and kill the cell. There are actually many types of such flags, with functions much more complex than described here.

The basic principle behind the DCVax line of products is that if one injects or creates a large enough number of dendritic cells carrying mutant proteins matching a cancer, these dendritic cells will excite enough T-cells and B-cells to overwhelm the cancer's many defenses.

One of the intuitive obstacles to this premise of overwhelming the cancer is the notion that if the cancer can hide from the dendritic cells, or T-Cells and B-Cells in the body under normal circumstances, then why would having more of the same immune components make any difference? Clinicals do report efficacy for the modern dendritic cell therapies. The exact degree of efficacy is still being determined, but these therapies do have demonstrated benefits. So why? Here is one likely part of the answer to that question; When a T-Cell finds a target protein on a tumor cell, it can release chemical messengers announcing the find, that other T-Cells can detect. So even if that T-Cell decides not to kill the tumor cell due to local chemical suppressors or white flags, the next T-Cell to come along and find a target mutant protein in the area, can weigh into its decision, the scent created by the first T-cell announcing its find. In this way, the response is not linear. In other words, the second T-cell that finds the antigen may not respond with the same likelihood or severity as the first. Eventually, as more T-Cells find local mutant proteins, the stench grows strong enough, that many or all of the local T-Cells begin to ignore the suppression chemicals and white flags, and opt to kill the cell, having inferred that they have indeed located an enemy cell from the strength of the stench. Although this description of the nonlinear response is somewhat speculative, the point is that there are many possible explanations for the reported threshold for efficacy.

The above descriptions of the T-cells making decisions is called anthropomorphizing and is offensive to some, while others consider it a useful tool for communicating these apparent behaviors, in spite of being incorrect. T-cells are single cells, therefore they don't have brains.

DCVax-L[edit]

DCVax-L is a solid-tumor cancer therapy currently in phase III clinical testing in the US for newly diagnosed GBM, a common and aggressive form of brain cancer. It is also under clinical trial in the UK, and Germany. In Germany, it is being used on all "gliomas" not just newly diagnosed GBM. In this variation of the DCVax line, the tumor is removed through surgery, and some of the tumor presented to the aforementioned dendritic cells for the scavenging of tumor proteins. These dendritic cells, laden with tumor proteins, are then injected under the skin near lymph nodes. The dendritic cells then travel to the local lymph node where the dendritic cells present the proteins to the T and B Cells as previously described.

These dendritic cells are grown in the lab starting from stem cells extracted from the patient's blood. Only a sugar cube sized sample of the tumor is needed for subsequent presentation to the dendritic cells. The tumor sample is first broken down into constituent proteins using a caustic process known as lysing. (Thus the L in the name DCVax-L.) After the resulting "tumor lysate" is presented to the dendritic cells, they are ready for injection under the skin near the selected lymph node(s). Note that there are roughly 500 different lymph nodes in the body. Most are peripheral, some are internal.

DCVax-Direct:

DCVax-Direct is the latest addition to the DCVax line, and is currently in phase 1 trials in the US. With DCVax-Direct, there is no need to surgically remove the tumor. In fact, the tumor is fuel for the immune response once that response is fully excited. DCVax-Direct is currently being tested on patients with inoperable tumors.

In the DCVax-Direct procedure, the dendritic cells are developed as in the DCVax-L process, with some improvements and or modifications to that process. A relatively new, patented, automated manufacturing process is used, and the dendritic cells are grown to a precise age that was found to be highly optimum by Northwest. This too is patented.


At least two adjuncts are added to the dendritic cells. One adjunct is to excite one aspect of the body’s immune response, while another excites a more tumor specific response. This mixture is then injected into the patient's tumor. There, the dendritic cells scavenge tumor proteins, and then find their way to the local lymph node for presentation of the tumor proteins to T-Cells and B-Cells. The activated T-Cells and B-Cells then travel to the tumor and kill tumor cells. The ruptured tumor cells release mutant proteins that are picked up by dendritic cells and other immune cells, and carried to the lymph nodes to excite still more B and T-Cells. This cycle repeats, spiraling upward and then leveling off at a high but safe level. Or, at least that is what is expected to be seen in the ongoing phase 1 trial, which finished enrollment this last July, 2014.

DCVax-L + DCVax-Direct combined may prove to well address virtually all forms of solid tumor cancers, operable and inoperable. One exception might be prostate cancer.

DCVax-Prostate:

Northwest completed phase II clinicals for DCVax-Prostate some time ago, and received permission from the FDA to move forward with a phase III. The phase III trial is expected to be quite large, and Northwest has been seeking partnering to take on that endeavor. The DCVax-Prostate process is similar to DCVax-L, but rather than using the patient's tumor as the protein source, Northwest utilizes a synthetic protein that was determined to be a very common mutated protein located on prostate cancer cells. This method is very different, and is expected to be far more effective than the current approved immunotherapy for prostate.

Dendreon uses PAP, while NWBO uses PSMA. Terminology aside, what matters here according to representatives at NWBO is Dendreon’s target antigen is not expressed on all prostrate cancers. They have to screen their patients to see the expression of their target. NWBO’s target antigen is expressed on all prostrate cancers. Additionally, with Dendreon’s target, the level of expression goes down as the cancer progresses. The level of expression on NWBO’s target goes up as the cancer progresses. As we learned from NWBO’s Chairman Linda Powers, if your target is getting harder and harder for the vaccine to find and hit as the cancer progresses, that’s not the characteristic you want in your target antigen. (Tch-1)

Another difference in the target antigens is NWBO’s target is bound to the membrane of the tumor cell. “If the DCVax® hits our target,” explains Linda Powers, “it hits the cell for sure. Dendreon’s target is secreted by the cell, so while the target is close by, it is not necessarily bound to the cell in every instance. Antibodies can come along and glom onto to the target and not hit the cell itself, which means accuracy is an issue. (Tch-1)

Production efficiency[edit]

The high cost of production for first generation dendritic cell therapies is often used as evidence that DCVax-Prostate and the other DCVax therapies will not be economically viable. These arguments consistently ignore the fact that Northwest Biotherapeutics has developed and regularly utilizes methods to freeze dendritic cells for transport and storage. This gives NWBO an enormous production cost advantage over these older therapies and over current would-be competitors, in part because it allows centralized processing of the patient samples at one enormous facility. Further, as mentioned, Northwest has developed and patented automated mfg processes that further reduce cost. The manufacturing processes are similar for all three of Northwest’s therapies. For each of the three, the production process is identical regardless of the patient, and even regardless of the solid tumor cancer type. Combined with centralized automatic mfg, this greatly simplifies large scale production, potentially allowing cost efficiency to reach levels unexpected for a product that is not a pill.[4]

Products[edit]

DCVax-L is now in Phase 3 trials in USA & Europe.

DCVax-Direct is a therapy to treat inoperable solid tumors in Phase 1 trials in the US.

DCVax-Prostate finished Phase 2 trials and has been approved for Phase 3 trials in the US.

Footnotes and references[edit]

  1. ^ a b c d e "Form 10-Q". EDGAR. U.S. Securities and Exchange Commission. 15 November 2013. 
  2. ^ "Northwest Biotherapeutics Gets Ready to Scale-Up Production". News: Bioprocessing. Gen. Eng. Biotechnol. News (paper) 34 (4). 15 February 2014. p. 24. 
  3. ^ http://www.nwbio.com/about_overview.php
  4. ^ (Tch-1) http://www.biomedreports.com/2010071547553/bio-showdown-northwest-biotherapeutics-vs-dendreon.html

External links[edit]