Pioneering immunotherapy drugs could soon be offering new hope to patients with hard-to-treat advanced cancers.
Early clinical trials of one experimental agent, nivolumab, have proved so promising that an application to “fast track” its use for lung cancer is being made in the US.
Another drug, ipilimumab, is already marketed in the UK for melanoma, or malignant skin cancer.
New data to be presented later this month indicates that nivolumab can significantly improve the survival of patients with advanced melanoma, lung and kidney cancers.
Both drugs are produced by the pharmaceutical company Bristol Myers Squibb (BMS) , which has invested heavily in immune-based treatments for cancer.
“The quality of survival that we’re seeing with immune-based therapies is very promising”
A further two agents from the same BMS stable have now entered clinical trials.
The drugs work in different ways but share the same goal − to help a patient’s own immune system fight cancer.
Cancers have a sinister ability to disarm elements of the immune system through biological pathways known as “immune checkpoints”.
The new therapies suppress these pathways, allowing immune cells to recognise, attack and destroy the tumours.
An important aspect of the current and planned research involves investigating combinations of the drugs.
Dr Michael Giordano, head of global development for oncology at BMS, said: “In my view, immunotherapy will represent a treatment option that has the potential for multiple tumour types and will give patients hope and potentially the expectation of long-term survival.
“That’s what I’m excited about,” he said. “The data to date are supporting the view that we can achieve that goal, because we’re seeing activity across multiple tumour types including lung cancer, renal (kidney) cancer, and melanoma.
“And these are advanced, metastatic (spreading) cancers.”
Dr Giordano was speaking as BMS prepares to present results from a battery of trials at the annual meeting of the American Society of Clinical Oncology taking place in Chicago.
He said one of the most ground-breaking looked at using ipilimumab to prevent relapse after surgery.
“These are important results because they extend the potential for therapy to situations where there is minimal or no tumour present,” Dr Giordano said.
The new nivolumab data showed two year survival for heavily pre-treated melanoma with almost half of patients responding to treatment.
More than half of non-small cell lung cancer patients previously treated with three or more therapies also survived two years after receiving the drug.
Up to 71% of patients with advanced kidney cancer who had previously been treated with drugs that target tumour blood vessels lived a year with the treatment.
All were “end-of-the-line” patients who had been given only weeks or months to live.
The promising early results have allowed BMS to seek accelerated regulatory approval for nivolumab in the US.
A “rolling submission” staged application process has now started aimed at making the drug available as a third-line therapy for advanced lung cancer that has failed to respond to two previous treatments.
Talks are also taking place with European regulators with a view to licensing the drug for lung cancer and melanoma in the EU.
Nivolumab works by blocking a protein called programmed cell death 1 (PD-1) which when activated kills or neutralises immune system T-cells.
Many cancer cells make the agent that activates PD-1, thereby shielding themselves from T-cell attack.
Since PD-1 also acts as a vital “brake” on the immune system, suppressing it can lead to unwanted inflammatory side effects.
These can be overcome with anti-inflammatory drugs, Dr Giordano said.
“Most oncologists would say the type of side effects is different, but the severity is something they would find manageable,” he added.
“The quality of survival that we’re seeing with immune-based therapies is very promising.”