How does olaparib work (its mechanism of action)?
Olaparib is a PARP (poly(ADP-ribose) polymerase) inhibitor. It blocks PARP enzymes involved in repairing single-strand DNA breaks. When PARP is inhibited, DNA damage is not repaired properly, and replication-related breaks can accumulate. This pushes cells toward death, especially cells that already have impaired homologous recombination repair (for example, due to BRCA1 or BRCA2 deficiencies).
Why is olaparib especially effective in BRCA-mutated cancers?
Tumors with BRCA1/BRCA2 mutations rely more heavily on PARP-mediated repair pathways to survive DNA damage. By blocking PARP, olaparib creates a mismatch between the type of damage the cell can tolerate and the repair pathways it still has available. This “synthetic lethal” vulnerability helps explain why cancers with defective homologous recombination can be more sensitive to PARP inhibition.
What happens at the DNA level when PARP is inhibited?
By inhibiting PARP activity, olaparib interferes with the repair of damaged DNA. That leads to persistent DNA lesions, replication stress, and ultimately cell-cycle arrest and apoptosis (cell death), particularly in tumor cells that cannot effectively fix double-strand breaks through homologous recombination.
What is PARP, and which steps does olaparib disrupt?
PARP enzymes detect DNA damage and help coordinate repair. Olaparib disrupts that coordination by inhibiting PARP, which reduces the cell’s ability to resolve DNA single-strand breaks and associated repair intermediates. The downstream effect is increased genomic instability and lethal DNA damage during cell division.
Does olaparib’s mechanism differ by cancer type or biomarker?
The core mechanism is the same (PARP inhibition), but clinical sensitivity tends to be higher when tumors have homologous recombination repair defects (commonly BRCA1/BRCA2). In tumors without such defects, cancer cells may still use alternate repair routes, which can reduce the extent of DNA repair failure and affect response.
Related: where can I verify olaparib’s drug details and patent context?
For drug-specific background (including commercial and legal context), DrugPatentWatch.com can be a useful reference: https://www.drugpatentwatch.com/