PARP Inhibitors

When talking about PARP inhibitors, a class of drugs that block the poly‑ADP ribose polymerase enzymes involved in DNA repair. Also known as PARP blockers, they exploit a weakness in cancer cells that can’t fix DNA breaks properly. DNA repair pathways, especially homologous recombination, become critical for tumor survival when PARP is inhibited. BRCA mutation carriers often lack this backup repair, making them especially sensitive to these drugs. This concept of synthetic lethality is the scientific engine that drives the therapy.

Key aspects of PARP inhibitor therapy

In practice, PARP inhibitors are approved for several cancer types: ovarian, breast, prostate, and pancreatic malignancies with homologous recombination deficiencies. The most widely used agent is olaparib, which showed a clear overall‑survival benefit in maintenance settings. Dosing schedules are usually oral, taken once or twice daily, but patient monitoring is essential because anemia, fatigue, and nausea are common adverse effects. Drug‑drug interactions matter too; strong CYP3A inhibitors can raise olaparib levels, so dose adjustments are often required.

The therapeutic landscape places PARP inhibitors alongside chemotherapy, immunotherapy, and other targeted agents. Compared with traditional chemotherapy, they tend to have a more favorable toxicity profile, yet they’re not interchangeable with immunotherapies that boost the immune response. Selecting the right patients involves testing for germline or somatic BRCA mutation and other homologous recombination markers. Clinical guidelines now recommend genetic testing before initiating therapy, ensuring that only those likely to benefit receive the drug.

Research is moving fast. Combination strategies, such as pairing PARP inhibitors with checkpoint inhibitors or anti‑angiogenic agents, aim to overcome resistance that often develops after several months of monotherapy. Biomarkers beyond BRCA, like loss of PALB2 or RAD51 dysfunction, are being explored to widen the pool of responders. Ongoing trials also examine dose‑sparing schedules to reduce hematologic toxicity while maintaining efficacy. As new data emerge, clinicians gain more tools to personalize treatment, balance benefits against side effects, and decide when to switch or add other therapies.

Below you’ll find a curated set of articles that dive deeper into the science, safety considerations, and practical tips around PARP inhibitors and related cancer treatments. These pieces cover everything from mechanism basics to real‑world dosing advice, helping you stay informed as the field evolves.