Results of several clinical trials show the revolutionary potential of immunotherapy in treating advanced cases of hard to treat types of cancer, such as bladder and lung cancer.
Improved survival rate
One has shown that the antibody Tecentriq a product of Genentech, a subsidiary of the Swiss pharmaceutical Roche, reduced advanced bladder tumours in a quarter of 119 patients tested, with a median survival of almost 15 months.
These results compare with a nine to 10 month survival rate typical with chemotherapy, the researchers said.
The findings were presented at the annual conference of the American Society of Clinical Oncology (ASCO), the world's largest cancer congress, held this weekend in Chicago.
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Tecentriq, which allows the immune system to attack the cancer cells, was shown to be effective with patients who had advanced bladder cancer and were too weak for chemotherapy.
"Up to half of patients with advanced bladder cancer are too frail to receive the only known survival-prolonging treatment," said lead study author Arjun Vasant Balar, a medical doctor and assistant professor of medicine at New York University.
"We are encouraged to see that atezolizumab immunotherapy may help address this major unmet need," Balar said.
The US Food and Drug Administration (FDA) recently authorised sales of Tecentriq on an expedited basis based on preliminary results of this clinical trial.
"This and other immunotherapies have brought new momentum to bladder cancer treatment, which until recently had seen practically no treatment advances in more than a decade," said Charles Ryan, a professor of clinical medicine and urology at the University of California at San Francisco who participated in the study.
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"The fact that this treatment appears safe for elderly patients, who too often have few good options, is all the more encouraging," Ryan said.
The researchers plan to carry out a more extensive clinical trial with Tecentriq as first treatment for advanced bladder cancer that mainly affects older people, the vast majority of whom are smokers or former smokers.
A new immunotherapy combined with an agent that kills cancer cells has also shown to be promising in treating patients suffering from the most aggressive form of lung cancer, which amounts to 10 to 15 percent of all lung tumours, according to the results of a separate clinical trial with 74 patients that was presented at ASCO Sunday.
This treatment combines a new immunotherapy, rovalpituzumab tesirine (Rova-T), developed by the start-up Stemcentrx that was recently acquired by the US laboratory AbbVie.
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This combination blocked tumour growth in 89 percent of patients with high levels of DLL3 protein, and resulted in a cancer regression in 39 percent of the group being tested, which included some who had been given only one more year to live.
"We've seen too few successes in recent years for small cell lung cancer, which makes these early signs of efficacy all the more encouraging," said lead study author Charles Rudin, a medical oncologist at Memorial Sloan Kettering Cancer Centre in New York.
A European study also presented at the ASCO conference showed encouraging results for an immunotherapy that targets the protein claudine18.2 in cases of advanced gastric cancer.
That immunotherapy, IMAB362 of Germany's Ganymed Pharmaceuticals, is also combined with chemotherapy.
The clinical study with 161 patients who suffered from aggressive gastric tumours showed that this antibody significantly prolonged their survival when combined with chemotherapy, with 13.2 months or 16.7 months against 8.4 or nine months in patients treated with chemotherapy alone.
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