Cancer immunotherapy advances in the United States

Sue Scott, cured of metastatic cancer, in Bethesda, Maryland, February 8, 2018 AFP - SAUL LOEB

Sue Scott had already organized her funeral. It was in the winter of 2013, she was 36 years old and her cervical cancer metastasized at full speed.

Chemotherapy, radiotherapy, operations ... everything had failed. Tumors were now lodged in his liver and colon. But Sue won one last chance: an experimental test at the clinical center of the National Institutes of Health.

In this publicly funded research hospital, doctors were trying to replace the immune systems of patients with lymphocytes (white blood cells) programmed to specifically target cancers related to HPV, a sexually transmitted and widely spread virus.

A few months later ... Sue's tumors had completely disappeared. In March, she celebrated five years of complete remission. The doctors consider it cured.

"My greatest reward is to be a source of hope for other people," says this real estate agent in Washington, who also volunteers for cancer patients.

The clinical trial she has been involved in is a breakthrough in the fight against cancer. This is the first time that researchers have shown that immunotherapy, already effective against blood and skin cancer, can also be used successfully against cervical cancer.

What's more, Sue's healing has led physicians to an unexpected discovery that could kill other types of tumors. Christian Hinrichs, a doctor at the National Cancer Institute, told him the good news in February during a control visit.

"We've got some genetic sequence from you that you can put into anyone's cells to attack the cancer in the same way," says Hinrichs. "We are trying to see if it works clinically."

A rescued doctor -

Dr. Hinrichs, 46, has survived a rare cancer himself, since it affects six people in a million.

Dr. Christian Hinrichs, February 7, 2018 in Bethesda, Maryland (AFP - SAUL LOEB)

When he was in his twenties, the young surgeon learned that he had melanoma in his right eye. But after each laser or radiotherapy treatment, the cancer returned. He had to resolve to remove the eye in 2005.

"I am influenced in my research by having experienced cancer myself and the fear that it comes back each time," says the researcher at AFP. "I really wanted to find a cure to prevent the cancer from coming back."

The vocation of white blood cells is to attack intruders. But when the intruder is a tumor that can mutate, hide or grow on such a scale that it overflows the immune system, lymphocytes often fail.

Immunotherapy is supposed to solve this problem. It works well against blood cancers, such as lymphoma or leukemia, because in these cases, the cancers carry on them a kind of flag or signal on their surface (tumor antigens), which make them easily identifiable.

But most cancers do not have this "flag".

In Sue's case, the cancer was carrying HPV antigens - a signal recognizable by the immune system.

"This cancer is very interesting because the virus is in the middle," says Miriam Merad, a professor of oncology at Icahn School of Medicine in Mount Sinai, New York.

Dr. Hinrichs' work, she says, is "absolutely crucial" to understand why immunotherapy works in some people and not others ... which remains a mystery. Still to develop new clinical trials to confirm the breakthrough.

A suprise -

For Sue, this is how the doctors proceeded: they operated to remove one of his tumors, and then isolated the lymphocytes that were attacking him.

The researchers then "cultivated" these lymphocytes, and produced billions more, which they then reinjected into their blood ... provoking a real immune invasion.

Dr. Christian Hinrichs, National Cancer Institute, with Arrica Wallace and Sue Scott. February 8, 2018 in Bethesda, Maryland (AFP - SAUL LOEB)

This treatment was successful in another patient, a 41-year-old mother, Aricca Wallace, living in Kansas City. She too is considered cured after five years without a tumor.

But the trial failed among the sixteen other women who participated.

Examining the data from the two healed patients, Dr. Hinrichs found that two-thirds of the cells that successfully eradicated Sue's cancer attacked another signal or flag, the KK-LC-1 protein.

But this protein is also expressed in cancers that affect half a million people worldwide, including one of the most deadly breast cancers, as well as some stomach cancers. The doctors had therefore found their new target.

"It was a big surprise," recalls the doctor. "It reminds us that science sometimes takes us in different directions than we had anticipated."

The next step is to launch clinical trials to treat cancers where this famous protein KK-LC-1 is expressed in about a year. International patients may apply to participate.

There is no guarantee of success, but the approach is "promising," says AFP Ronald Gress, deputy director of the National Cancer Institute. "It's one of the most amazing options, but at the same time, it's an option that could really help patients."

Sue, for his part, can not believe that his cells may be able to heal, one day, other patients.

"You tell me that I have something in me that can help others, it's pretty crazy," she says.

Source: https://www.sciencesetavenir.fr/sante/l-immunotherapie-contre-le-cancer-progresse-aux-etats-unis_122397