Alternative Options to PARP Inhibitors May Be Available
Written by: Lauren Schwab, Legal Assistant
Law Offices of Thomas J. Lamb, P.A.
Recent studies of Poly (ADP-ribose) polymerase, or PARP, inhibitors shows this class of drug may be linked to an increased risk of secondary myelodysplastic syndrome and acute myeloid leukemia (MDS/AML) in patients with cancer.
PARP inhibitors are used to treat several different types of cancers, including ovarian, breast, pancreatic, and prostate cancers. PARP inhibitors work by stopping the PARP protein found in our cells from repairing the cells, essentially inhibiting cancer cells any further growth, and subsequently killing them off.
What The Studies Show
According to February 2021 article, "PARP inhibitors may increase risk for myelodysplastic syndrome, AML", recent studies show patients using PARP inhibitors are at nearly double the risk for developing MDS/AML compared to the placebo group:
According to results of the analysis, use of PARP inhibitors significantly increased risk for myelodysplastic syndrome and AML compared with placebo (OR = 2.63; 95% CI, 1.13-6.14).
The analysis of data from VigiBase showed 99 cases of myelodysplastic syndrome and 79 cases of AML associated with PARP inhibitor use.
Among 96 patients with available data, median treatment duration was 9.8 months (interquartile range [IQR], 3.6-17.4), and among 58 patients with available data, median latency period since first exposure to a PARP inhibitor was 17.8 months (IQR, 8.4-29.2). Researchers observed a high rate of mortality (45%) among 104 patients with reported outcomes. Cytopenia was co-reported in 71 (40%) of the 178 cases of myelodysplastic syndrome or AML, of which anemia was most frequent type (34%).
The study included PARP inhibitor drugs such as Lynparza (olaparib), Zejula (veliparib), Rubraca (rucaparib) and ABT-888 (veliparib). Researchers acknowledge the number of MDS/AML incidences in correlation with PARP inhibitors may be underestimated in the study, and further research is needed to confirm the results.
PARP Inhibitors Not The Only Option for Cancer Treatment
Interestingly, PARP inhibitors are not the only class of drug available for treatment of cancer patients. As we have reported in earlier articles, Vascular Endothelial Growth Factor (VEGF inhibitors) and immune checkpoint inhibitors have also been used "off-label" for treatment of cancer patients.
In our August 2020 article, "Vascular Endothelial Growth Factor (VEGF) Inhibitors: Increased Risk Of Aneurysm And Artery Dissection", we address the risks associated with VEGF inhibitors, such as aneurysm and artery dissection. VEGF inhibitors include drugs such as Avastin (bevacizumab), Iclusig (ponatinib), Ofev (nintedanib), and many others. You can find a more comprehensive list of VEGF inhibitors in our previously mentioned August 2020 article.
We will continue to monitor the safety profiles for these PARP inhibitors, including whether the FDA mandates any label changes which add warnings about an increased risk of MDS/AML.
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