Recently, the US Food and Drug Administration (USFDA) approved Dendreon Corp.’s Provenge, for prostate cancer, and Bristol-Myers Squibb Co.’s Yervoy, for melanoma.

As one of the early-movers into the cancer immunotherapy space, Dendreon was successful in significantly reducing entry barriers for firms engaged in immunotherapy R&D. A US$ 6.25 Billion valuation underlined the first-mover advantage of Dendreon. This development indicates the huge opportunity awaiting biotech enterprises, and the potential inherent in the biotech companies that have already invested in immunotherapy-based cancer R&D.

The approvals for the two immunotherapy-based drugs, Provenge and Yervoy, are seen as a watershed moments in the war against cancer. Scientists are now gearing up to develop more such immunotherapies for various types of cancers, including lung, brain and kidney cancers.

Cancer immunotherapy is the use of the immune system to reject cancer. The immunotherapy stimulates and uses the patient’s immune system to attack the malignant tumor cells that are responsible for the disease, hoping for development of a long-term resistance to the cancer.

Cancer immunotherapy broadly includes:

� Passive immunotherapy: Passive immunotherapies involves the development and transfer of antibodies or other immune system components that are made outside of the body (i.e. in the laboratory) to tumor-bearing recipients. A good example of passive immunotherapy includes monoclonal antibodies (mAbs), developed in the 1970s.

� Active immunotherapy: Active immunotherapy involves therapies that stimulate the host’s intrinsic immune response to respond to cancer. Some of the therapies include cancer vaccines. Cancer vaccines cause the immune system to attack the cancer cells, honing in on one or more specific tumor antigens. Examples of cancer vaccines include tumor cell vaccines, antigen vaccines, DNA vaccines, vector-based vaccines among others.

� Combination immunotherapy: Combination immunotherapy most closely resembles the workings of the natural immune system, unlike active and passive immunotherapies that mimic some parts of our immune system.

Combination immunotherapy causes a direct and targeted killing of the tumor cells, and works on multiple fronts, including activating the immune system to produce a more robust and sustainable anti-tumor response.

Traditional cancer-targeting drugs have started showing more efficacy. However, they are successful to an extent in delaying the recurrence of cancer. The interest in immunotherapies is immense now, and the FDA approvals for Provenge and Yervoy have provided a boost for R&D in cancer drug therapies.

Pricing is proving to be a big hurdle for advancing immunotherapy. For instance, Yervoy costs about US$ 120,000 for a course of treatment and Provenge US$ 93,000. In addition to the pricing, the drugs come with significant side-effects.

Some of the companies that have reached the late-stage development phase for active immunotherapies include:

Table1. Cancer Immunotherapy Drugs: Late Stage Pipeline (Phase III Trials)

Source: CyberMedia Research, 2011

In the early stage pipeline, some of the key drug candidates include: 

Table 2. Cancer Immunotherapy Drugs: Early Stage Pipeline (Phase I / II Trials)

Source: CyberMedia Research, 2011

Within the active immunotherapy segment, melanoma and prostate cancer are the two disease indications attracting the most attention in clinical drug development. The market is getting increasingly competitive for these two disease indications. To sum it up, cancer immunotherapies represent a multi-billion dollar opportunity.