How long is the resistance to Rucaparib?

Rucaparib (Rucaparib) is an oral PARP inhibitor, mainly used to treat ovarian cancer patients carrying BRCA1 or BRCA2 gene mutations. It has also shown potential efficacy in studies of breast and prostate cancer. PARP inhibitors block the DNA single-strand repair pathway of tumor cells, causing tumor cells carrying BRCA mutations to accumulate DNA damage, thereby inducing cell apoptosis. Its mechanism makes rucaparib generally have higher therapeutic sensitivity in patients with BRCA mutation-positive patients. However, drug resistance is a major concern in the clinical application of rucapanib.

As for the time to resistance to rucapanib, current clinical data show that there are large individual differences. The time to resistance is affected by multiple factors, including the genetic characteristics of the tumor, previous treatment history, drug metabolism rate, and the physiological state of the individual patient. Some patients may experience disease progression within months after receiving rucapanib, while others may maintain efficacy for a year or more. Typically, for BRCA mutation-positive ovarian cancer patients who have received multiple lines of chemotherapy, progression-free survival (PFS) shows an effective rate of 30% to 40% in clinical trials, but the occurrence of drug resistance is still inevitable.

The drug resistance mechanism mainly includes the recovery of tumor cellsDNA repair ability and the functional reversal of the BRCA gene or the compensatory activation of other DNA repair pathways. Some studies have shown that tumor cells restore BRCA function through secondary mutations or activate homologous recombination repair pathways, thus counteracting the effects of PARP inhibitors. In addition, differences in the tumor microenvironment, drug permeability, and patient absorption of drugs may also accelerate the emergence of drug resistance. Therefore, regular imaging examinations and molecular marker monitoring are very important for early identification of drug resistance.

Reference materials:https://www.drugs.com/mtm/rucaparib.html