A team of researchers has demonstrated the efficacy and clinical benefit of a vaccine against a subject blood cancer, follicular lymphoma, in patients in first relapse. Since 2001, specialists from two centers of the University of Navarra, the University Clinic and research center Applied Medicine (CIMA), have been working together. The study is funded by the Leukemia & Lymphoma Society of New York. For the scientific presentation of the results of the research, Dr. Mercedes Rodriguez Calvillo intervened in the national congress of the association Spanish Hematology and Hemotherapy, held in Madrid.

According to Dr. Maurizio Bendandi, manager of the study, head of the Immunotherapy laboratory of CIMA and specialist in Hematology at the Clínica Universitaria de Navarra, "this is the first time that a vaccine against a cancer subject is capable of changing the history of the disease".

More than 5,000 people diagnosed with this tumor each year in Spain.

More than 5,000 people over 40 years of age are diagnosed with this cancer in Spain each year subject . Follicular lymphoma is a tumor of the lymphatic system whose cells have a surface protein, specifically an immunoglobulin, which can be used as a target. The vaccine, known as idiotypic, is produced from this protein and its purpose is to provoke a reaction in the patient's immune system, goal . "Usually the patient does not react against the tumor protein, since it is a known element and his immune system does not fight it. Using laboratory techniques, we have attached another protein called KLH, obtained from a mollusk, to the target protein. In this way, we were able to ensure that the tumor protein is also recognized as foreign".

In the case of follicular lymphoma, this protein is a tumor-specific antigen. "It is postulated that there are also antigens in other tumors, but so far none of them have been found that are found only in tumor cells, so that a vaccine against them would also be harmful to healthy tissues.

Stanford University developed the idiotypic vaccine in animals in the 1970s and applied it to humans 15 years ago. In 1992, its biological efficacy was proven: it is able to stimulate the human immune system. In 1999 Dr. Bendandi and other scientists at the U.S. National Cancer Center high school demonstrated that the biological efficacy was also clinical. According to researcher of the University of Navarra, "the immune system itself, stimulated by the vaccine, is capable of killing tumor cells that had resisted chemotherapy. It remained to be demonstrated that this result would be of real benefit to the patient".

Longer response than expected with chemotherapy alone

With the work of research developed at CIMA and the University Clinic "it is known that 50% of patients treated with chemotherapy relapse within 13 months. Moreover, each time they relapse, the duration of response tends to be shorter than the previous one."

"Our study has seen 25 patients over the past four and a half years. Of these, 4 patients have not responded to the vaccine and relapsed on schedule, 3 are finishing the study and 18 have responded successfully. None of these 18 relapsed during the two years of vaccination, and only one of them relapsed 10 months after the end of the two years of treatment, that is, when we had already stopped vaccinating him for almost a year. In other words, all patients who have responded to the vaccine and with sufficient follow-up have a second complete response that is longer than the first. Practically all of them have already reached and surpassed the 13-month mark and none of them have relapsed during the vaccination period, so this treatment has far exceeded the results expected with chemotherapy alone".

Research in California, Texas and Navarra

This is the first study with this design to investigate the efficacy of the vaccine in patients who have relapsed, although other clinical trials in this field are underway at two U.S. centers: the one led by Dr. Larry Kwak in Houston, Texas, and the one led by Dr. Ronald Levy at Stanford, California.

The vaccine, which is administered subcutaneously, is particularly useful as an adjunct to chemotherapy. "Some attempts have been made to apply the vaccine as a first treatment, but the results have not been satisfactory," says Dr. Bendandi.

In general terms, the procedure followed in the patients treated at the University Clinic consisted of treating the patient with conventional chemotherapy for 6 months in order to reduce the size of the tumor as much as possible. This is followed by a rest period of 3-6 months to reconstitute the integrity of the immune system. Finally, the vaccine is inoculated monthly for 4 months, before moving on to less frequent reminders.

Dr. Bendandi's team is formed by researchers Susana Inogés, Mercedes Rodríguez Calvillo, Ascensión López Díaz de Cerio, Margarita Legarrea, Silvia Gallego, Elena Soria, Natalia Zabalegui, Helena Villanueva and Fernando Pastor.

The work of research has been developed thanks to the partnership of several hospitals in Spain, included in the Geltamo and Pethema groups. In addition to the 25 people in the clinical trials carried out with the idiotypic vaccine, patients from the USA with lymphomas come to the Clínica Universitaria de Navarra to follow this treatment with the vaccine.