Modified TB Vaccine as Therapy for Bladder Cancer

The human immune system can not only recognize and eliminate pathogens, but also cancer cells. Therefore, treatments with weakened pathogens can help the immune system fight cancer. Researchers at the Max Planck Institute for Infection Biology in Berlin have genetically modified the BCG tuberculosis vaccine so that it stimulates the immune system in a more targeted manner. As a result, the new vaccine provides significantly better protection against tuberculosis. A clinical study with bladder cancer patients has now shown that treatment with VPM1002 can successfully prevent tumor recurrence in almost half of the patients who did not previously respond to BCG therapy. The results could lead to the early approval of the drug in bladder cancer therapy.

As early as the end of the 19th century, doctors observed that some cancer patients contracted the tumor if they suffered from a high fever due to a bacterial infection. This was the cornerstone of cancer immunotherapy. These treatments can specifically stimulate the immune system. This supports the body's immune system in the fight against the tumor, which leads to the decline of a tumor.

The tuberculosis vaccine Bacille Calmette-Guérin (BCG), which was introduced in the 1920s, contains weakened pathogens of bovine tuberculosis, which can also be transmitted to humans. In tests in the 1970s, BCG was shown to be effective against bladder cancer, one of the most common tumor diseases in Europe.

Treatment of the bladder with weakened pathogens

Immunotherapy of solid tumors is often unsuccessful, but the use of BCG in bladder tumors has become a standard therapy. During treatment, the bladder is repeatedly flushed with the weakened pathogen over a period of six weeks. This triggers an immune response, which is not specifically directed against the tumor, but activates the body's own killer cells, which kill the changed cells.

However, the proportion of patients who can completely fight cancer after BCG therapy is low. In addition, rinsing with BCG has such serious side effects as fever, incontinence or flu-like symptoms that many patients stop the therapy prematurely. The tumor comes back in 30 to 40 percent of the patients. In such cases, the bladder must be removed completely.

Further development of the vaccine

Stefan Kaufmann from the Max Planck Institute for Infection Biology in Berlin, together with colleagues, has further developed the BCG vaccine. The researchers modified the weakened tuberculosis bacteria so that they are better recognized by the immune system. "Like BCG, the new vaccine VPM1002 is absorbed by phagocytes of the immune system, which can then better recognize their goals - tuberculosis bacteria and cancer cells," explains Kaufmann. VPM1002 has already shown improved protection against the infection of tuberculosis bacteria.

VPM1002 is developed by the largest vaccine manufacturer in the world, the Serum Institute of India in collaboration with the Hanover-based Vakzine Projekt Management GmbH (VPM). Now, under the leadership of Cyrill A. Rentsch, University Hospital Basel, Switzerland, together with the Swiss Working Group for Clinical Cancer Research (SAKK), a clinical study (SAKK 06/14) was carried out to determine whether the use of VPM1002 helps remove the bladder Can prevent bladder cancer patients. A phase I study showed that the new vaccine is safe and well tolerated.

In a phase II study, bladder cancer patients were treated in which the cancer had returned after the tumor had been removed and followed by standard BCG therapy. "Over 49 percent of the patients treated with VPM1002 were tumor-free after 60 weeks in the bladder," says Leander Grode, who developed VPM1002 together with Stefan Kaufmann and is now VPM's managing director. The tumor-free patients thus avoid removing the bladder.

Fast approval in Europe

The impressive results encourage the developers to apply for early market approval as soon as possible. As a result, bladder cancer patients who no longer respond to conventional therapy can benefit from the new drug as quickly as possible and thus avoid removal of the bladder when the therapy with VPM1002 responds. Discussions with the European Medicines Agency are now planned in order to get Europe-wide approval as quickly as possible.

The Serum Institute of India is a strong partner who can quickly produce the required amount of medicines and whose strategy also goes into cancer therapy. “I am very impressed with the positive results of VPM1002 in the treatment of bladder cancer. With the latest and unique manufacturing methods, we will be able to easily meet the worldwide need for VPM1002 and thus be able to make this therapy available to every patient,” says Adar C. Poonawalla, Managing Director of SIIPL.

The technology underlying the VPM1002 vaccine was licensed from Max Planck Innovation, the technology transfer organization of the Max Planck Society. "We are glad that with VPM we have found the right licensee to further develop the already excellent basic research results from the MPG. Although VPM was not an established vaccine company at the time, the company was able to demonstrate the effectiveness and safety of the vaccine against bladder cancer with great determination and perseverance. We would be delighted if these results made it possible for patients to have effective therapy in the near future,” says Dieter Link, patent and license manager at Max Planck Innovation.

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