Nivolumab, an immunotherapy drug, has been described as a potential “game-changer” in promising results presented at the European Cancer Congress.
In a study of head and neck cancer, more patients taking the drug survived for longer compared with those who were treated with chemotherapy.
In another study, combining nivolumab with another drug shrank tumors in advanced kidney cancer patients.
Immunotherapy works by harnessing the immune system to destroy cancer cells.
Advanced head and neck cancer has very poor survival rates.
In a trial of more than 350 patients, published in the New England Journal of Medicine, 36% treated with nivolumab (Opdivo) were alive after one year compared with 17% who received chemotherapy.
Patients also experienced fewer side effects from immunotherapy.
The benefits were more pronounced in patients whose tumors had tested positive for HPV (human papillomavirus). These patients survived an average of 9.1 months with nivolumab and 4.4 months with chemotherapy.
Normally, this group of patients are expected to live less than six months.
Early data from a study of 94 patients with advanced kidney cancer showed that the double hit of nivolumab and ipilimumab resulted in a significant reduction in the size of tumors in 40% of patients.
Of these patients, one in 10 had no sign of cancer remaining.
This compares with 5% of patients showing tumor reduction after standard therapy.
Nivolumab and ipilimumab both work by interrupting the chemical signals that cancers use to convince the immune system they are healthy tissue.
The US researchers have developed personalized cancer vaccines that target unique genetic errors in a patient’s tumor.
Safety tests on three people, published in the journal Science, showed the immune system could be trained to fight skin cancers.
The research team, mainly based in St Louis and Oklahoma City, says the early results mark a “significant step” towards personalized cancer vaccines.
UV light can transform healthy skin cells into deadly melanomas by damaging the DNA.
The tumors are a genetic mess, containing hundreds of random mutations that are different in every patient.
The mutations can change the proteins that stick out from the surface of cells and act like identifying flags.
The team analyzed the genetic mutations to predict the new and unique flags that would be flown by the cancer cells.
A computer algorithm then analyzed the new flags, known as neoantigens, to decide which would be the best targets for a vaccine.
Personalized vaccines were given to three patients with advanced tumors in 2013. All had already been treated with another therapy – ipilimumab.
One was in remission and has stayed cancer-free; another still has stable tumors; and the third patient’s tumor shrank in the months after the vaccine before returning to its original size and remaining stable.
The team is, at this stage, testing just the safety of the vaccine and whether it provokes an immune response.
They say it was successful on both counts.
One of the researchers, Dr. Gerald Linette, said: “Our team is very encouraged by the quality of the immune response directed against the melanoma neoantigens in all three patients.
“Our results are preliminary, but we think the vaccines have therapeutic potential.”
His colleague, Dr Beatriz Carreno, added: “These findings represent a significant step toward more personalized immunotherapies.”
The personalized vaccine approach has a number of hurdles to clear.
For a start, proper clinical trials are needed to prove that the immune boost actually makes a difference to controlling the tumor.
There are also questions about cost and the time it takes – currently three months – to develop each person’s vaccine.
However, if the approach proves successful it could be useful in other highly mutated cancers such as those found in the lung.
They may also have a role in breast and ovarian cancers in women with BRCA mutations, such as Angelina Jolie, which also tend to be very mutated.