The findings of a new study suggests the side effects of Lynparza, Rubraca and similar poly-ADP ribose polymerase (PARP) inhibitors may increase the risk of some types of blood cancer.
In a report published in The Lancet Haematology on December 18, French researchers found an association between PARP inhibitors and an increased risk of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML).
The drugs are used in a number of cancer treatments; ovarian cancer in particular. However, the researchers indicate there have long been concerns of their potential link to cancers of the blood.
In the study, researchers reviewed a number of randomized controlled clinical trials which compared PARP inhibitor therapy with placebos and other cancer drugs treated for cancer. Ultimately, they looked at data from 5,693 patients who took drugs like Lynparza and Rubraca, as well as 3,406 patients in control groups.
According to their findings, PARP inhibitors use more than doubled the risk of cancer when compared to patients who were given a placebo. Incidence of either cancer in PARP inhibitor patients was 0.73%, compared with only 0.47% among the control subjects.
In the 104 cases linked to MDS or AML diagnoses, 47, or 45%, of the patients died. The median treatment duration was 9.8 months and the latency period before cancer was detected was 17.8 months from first PARP inhibitor exposure.
“PARP inhibitors increased the risk of myelodysplastic syndrome and acute myeloid leukemia versus placebo treatment,” the researchers concluded. “These delayed and often lethal adverse events should be studied further to improve clinical understanding, particularly in front-line maintenance setting.”
The researchers noted that the association to ovarian cancer in particular may be because clinical trials involving this form of cancer generally had a longer follow-up than other types of cancer.