Rucaparib is a medication used in the treatment of certain cancers. It functions by targeting specific mechanisms within cancer cells, aiming to disrupt their growth and survival. This approach represents a type of therapy designed to be more selective than traditional chemotherapy, focusing on vulnerabilities unique to cancer cells. Rucaparib is part of a newer class of anticancer agents that have expanded treatment options for patients.
Understanding Rucaparib
Rucaparib is a targeted therapy, specifically a poly (ADP-ribose) polymerase (PARP) inhibitor. PARP is an enzyme naturally present in healthy cells, playing a role in the repair of damaged DNA. Rucaparib interferes with the function of these PARP enzymes. This medication is administered orally as a tablet.
PARP enzymes recognize and repair single-strand breaks in DNA. When DNA sustains damage, PARP enzymes activate, initiating a repair process that maintains the cell’s genetic integrity. By inhibiting these enzymes, rucaparib disrupts this DNA repair pathway.
How Rucaparib Targets Cancer
Rucaparib targets cancer cells by exploiting their DNA repair defects. Many cancer cells, particularly those with mutations in genes like BRCA1 and BRCA2, have impaired homologous recombination repair pathways, which fix complex double-strand DNA breaks. When rucaparib inhibits PARP, it prevents the repair of single-strand breaks, leading to an accumulation of DNA damage within these vulnerable cancer cells.
This accumulation of unrepaired DNA damage becomes overwhelming for cancer cells that lack other effective repair mechanisms. This concept is known as “synthetic lethality,” where the simultaneous disruption of two non-lethal pathways (PARP inhibition and a pre-existing DNA repair defect) leads to cell death. Healthy cells, which have intact homologous recombination pathways, can still repair DNA damage through alternative routes, making them less susceptible to rucaparib’s effects. Rucaparib also traps PARP enzymes on damaged DNA, hindering repair and promoting cancer cell death.
Key Applications in Cancer Treatment
Rucaparib is approved for ovarian, fallopian tube, primary peritoneal, and prostate cancers. For ovarian, fallopian tube, or primary peritoneal cancer, it serves as maintenance treatment for patients with recurrent disease who have responded to platinum-based chemotherapy. It is also indicated for patients with advanced ovarian cancer who have a BRCA mutation and have received two or more prior chemotherapies.
In prostate cancer, rucaparib is indicated for patients with metastatic castration-resistant prostate cancer (mCRPC) who have BRCA gene mutations. These patients have received androgen receptor-directed therapy and a taxane-based chemotherapy. Genetic testing for BRCA1/2 mutations is important to determine patient eligibility for rucaparib.
Navigating Treatment
Rucaparib is taken orally, as a 600 mg tablet twice daily, with or without food. Patients should adhere to the prescribed dosage and schedule. If a dose is missed, patients should take the next dose at its regularly scheduled time and not take a double dose. If vomiting occurs shortly after taking a dose, that dose should not be replaced.
Common side effects include nausea, fatigue, anemia (low red blood cell count), and changes in liver function tests. Nausea can be managed with anti-sickness medications, while fatigue may be addressed by optimizing underlying conditions like anemia or nutritional deficiencies. Liver function changes, along with low white blood cell counts or low platelet counts, are monitored through regular blood tests. It is important to communicate any side effects to the healthcare team, as dose adjustments or interruptions can manage adverse reactions.