Rare side effect of cancer treatment caused death of patient, inquest hears

The daughter of a Dublin woman who died as a result of a rare but known side effect of a powerful new treatment for cancer said her mother might still be alive if she had not been given the drug.

An inquest at Dublin Coroner's Court heard Ann Healy (66) of Glasnamana Road, Finglas, died on December 3rd, 2018, in the Mater hospital, Dublin, as a result of developing a serious complication of diabetes known as diabetic ketoacidosis from receiving the drug, pembrolizumab, to treat her lung cancer.

Evidence was heard that Ms Healy, who came originally from Paulstown, Co Kilkenny, had no previous history of diabetes.

Her daughter, Amy Healy, said her mother, who had been diagnosed with stage IV lung cancer in May 2018, had become suddenly unwell at their home on November 29th, 2018.

At the time, Ms Healy said her mother had been responding well to radiation therapy and immunotherapy with no complications.

She expressed hope that other cancer patients would be told to look out for such dangerous side effects of pembrolizumab.

In relation to her mother, she remarked: “I feel she could still be alive.”

Prof Michaela Higgins, a consultant oncologist at the Mater hospital, acknowledged that the drug could cause adverse side effects in between one in a hundred and one in a thousand patients.

Short life expectancy

She told the coroner, Dr Crona Gallagher, that the Health Products Regulatory Authority (HPRA) as well as the manufacturer of pembrolizumab, Merck Sharp & Dohme, had been notified about the link between Ms Healy's death and the drug.

Asked about the health of the patient, Prof Higgins said Ms Healy, who was a smoker, would have had a short life expectancy without treatment given the very advanced nature of her lung cancer.

The oncologist said stage IV lung cancer was regarded as incurable with treatment designed as a way of “controlling symptoms and prolonging life but not curing”.

While new drugs for the treatment of cancer had known side effects, Prof Higgins said they were generally less severe.

The inquest heard Ms Healy had received five cycles of treatment of pembrolizumab intravenously at three weeks apart.

Prof Higgins said medical staff checked every three weeks to ensure the drug was still licensed for use.

The consultant stressed it was a very good drug that was now giving a significant minority of lung cancer patients a prolonged life expectancy of up to five years where previously it would have been just months.

“I would recommend it again to someone like Ms Healy,” she added.

Prof Higgins said it had been working “extraordinarily well on her – better than any other patient before or since”.

Discussion

The inquest heard the hospital had introduced some changes to how people were advised about the side effects of the drug with information being imparted in a more “patient-friendly format” with more discussion before treatment was provided.

Dr Yvonne McCartney, who carried out an autopsy on Ms Healy’s body, said diabetic ketoacidosis could develop rapidly with just one dose of pembrolizumab.

However, she found no evidence of any tumour.

Dr Gallagher remarked that the absence of a tumour showed how well the patient had responded to the treatment.

The coroner returned a narrative verdict and said she would notify the HPRA about the case to consider if the provision of further information about the drug would be useful.

Dr Gallagher said it was an unfortunate and tragic case given the drug was providing a better quality of life and longer life expectancy for patients.