Can Olaparib shrink tumors?

Olaparib is a PARP inhibitor mainly used to treat solid tumors such as ovarian cancer, breast cancer, prostate cancer and pancreatic cancer with BRCA gene mutations. Its mechanism of action is by inhibiting the DNA repair function in tumor cells, thereby causing tumor cell death. It is especially effective on cancer cells with defective DNA repair abilities. Therefore, olaparib can not only delay disease progression, but also reduce tumor size in some patients.

In clinical trials and real-world treatment, some patients treated with olaparib did experience tumor shrinkage. Especially in patients with BRCA mutations whose disease is relatively sensitive, olaparib can induce a significant objective response (ORR), which is manifested as a significant reduction in tumor volume, and some patients even achieve complete remission. This reaction usually occurs weeks to months after taking the drug and can be monitored with imaging tests.

However, it needs to be clear that the main positioning of olaparib is still "maintenance treatment" and "delaying recurrence", that is, it is used after the initial treatment is effective to stabilize the disease and prevent the tumor from growing again. Not all patients can experience significant tumor shrinkage response, and the efficacy is affected by many factors, such as the type of gene mutation, the stage of tumor progression, and whether it is combined with other treatments.
In summary, olaparib has the potential to shrink tumors in specific groups, but it is not suitable or necessarily effective for all patients. It is recommended that patients undergo genetic testing before use to assess whether they are BRCA mutation positive, and cooperate with doctors to dynamically adjust treatment strategies based on imaging and biomarkers.
Reference: https://www.lynparza.com/