Dendreon Corporation (DNDN), Bristol Myers Squibb Co. (BMY), Sanofi SA (ADR) (SNY), Vical Incorporated (VICL): Understanding Why Cancer Vaccines Fail

Even more general, Sanofi SA (ADR) (NYSE:SNY)‘s TheraCys, one of the treatments for bladder cancer, involves putting bacteria called bacille calmette-guerin directly into the bladder through a catheter. The bacteria, which is also used in tuberculosis vaccines, attracts immune cells that also attack the bladder cancer.

Solving the vaccine problem
Provenge, Yervoy, and TheraCys work. All of them are FDA-approved. But they’re cumbersome and/or appropriate for only certain types of cancer. Developing a simple vaccine that could be injected would be much easier.

The obvious solution could be to just avoid using IFA that attracts immune cells to the injection site, but the IFA was there for a reason: to boost the immune response. Another adjuvant could be used, but there are no guarantees that the vaccine will stimulate the immune system enough. Oncothyreon Inc (USA) (NASDAQ:ONTY)‘s Stimuvax, for example, used a lipid to help train the immune system to recognize tumor cells expressing the cancer-associated marker MUC-1, but the drug failed to show an effect on lung cancer patients in a phase 3 trial reported last year.

Vical Incorporated (NASDAQ:VICL)‘s  Allovectin shouldn’t experience issues with having immune cells attracted to the injection site, because Allovectin is injected directly into the tumor. Vical Incorporated (NASDAQ:VICL) has some evidence that once the cells are trained locally, they can attack other distant sites where the tumor cells might have migrated to. Data from the pivotal phase 3 trial is expected in the middle of this year.

Still risky
The insights from the discovery at MD Anderson will help move cancer immunotherapies further along, but given the long list of failures, it’s still a risky area to invest in. While the payoffs for a successful cancer vaccine would be huge, most investors would be wise to watch from the sidelines until the technical problems get worked out.

The article Understanding Why Cancer Vaccines Fail originally appeared on Fool.com is written by Brian Orelli.

Fool contributor Brian Orelli has no position in any stocks mentioned. The Motley Fool owns shares of Dendreon.

Copyright © 1995 – 2013 The Motley Fool, LLC. All rights reserved. The Motley Fool has a disclosure policy.