Immunotherapy, a new path in the search for a cure for cancer

Immunotherapy, a new path in the search for a cure for cancer

The last few years have seen a new era of treatment in the fight against cancer.

We are referring to immunotherapy, considered by many to be the “fourth pillar” in the fight against cancer, the other three being surgery, chemotherapy and radiotherapy.

Immunotherapy works in a totally different way if compared with the last two, as it uses antibodies that will not directly affect the cells of the tumour but the immune system, activating an attack on the malignant cells through our own defences. In a sense, it follows a principle formulated by Hippocrates more than 2,000 years ago: “Our body contains the cure for everything.”

Unlike chemotherapy, which requires cyclic and sometimes almost chronic administration, as in the case of metastatic disease, immunotherapy has already cured several patients with advanced melanoma with just four administrations (e.g., ipilimumab).

This cure develops as a sustained response; remaining over time thanks to the immunological memory of the human body.

In Portugal, we have a melanoma incidence rate of nine new cases per 100,000 inhabitants. This type of tumour is considered to be a rare skin tumour, representing a total of 10% of all cases of skin tumours but with a high mortality rate. In advanced stages of melanoma, the life expectancy at five years was, until now, between 10% and 22%. However, the arrival of these new drugs promises a very positive change in these percentages.

We have two broad categories of molecules, and therefore antibodies, that can be used to maintain a high activity of the immune system.

The first to be developed were antibodies against CTLA-4 (e.g., ipilimumab tremelimumab) and later antibodies directed against the DP-1 or its PDL-1 receptor. These molecules are resulting in a substantial increase in the response and survival rate in the treatment of melanoma and, more recently, of the lung.

When in May 2015 Jimmy Carter (former president of the United States of America) was diagnosed with malignant melanoma with brain and liver metastases, he was given an average life expectancy of six to 12 months. However, his oncologist started him on a new medication: pembrolizumab, which had recently been approved by the Food & Drug Administration.

Approximately six months after starting this therapy, Carter declared that he was disease free, something that was almost unthinkable until recently in this type of condition. In the clinical trials that led to the approval of this drug, the survival rate among patients with advanced melanoma, every two weeks, was good: 74% of patients were alive after one year.

Of course, this therapy’s progress must go hand in hand with prevention, screening and early detection. We believe, however, that these coming years promise to change the game in the fight against cancer for some patients, by changing the course and outcome of these diseases step by step.

The HPA has three oncology day care centres and a team qualified to deal with tumours and follow up on these new therapies. It has a multidisciplinary team in the areas of medical oncology, dermatology, surgery and radiology, who work together permanently in the treatment of these patients.

Article submitted by the HPA Health Group