Is the combination of Inavolisib and Fulvestrant more effective?

Inavolisib (Inavolisib) is an oral PI3Kα selective inhibitor, mainly targeting hormone receptor-positive (HR+) and HER2-negative advanced breast cancer patients who carry PIK3CA mutations. Fulvestrant (Fulvestrant) is a selective estrogen receptor degrader (SERD) that can directly inhibit estrogen receptor signaling. The basis of the research on the combined use of the two is to simultaneously block the PI3K pathway and the estrogen receptor signaling pathway, thereby more effectively inhibiting the proliferation and survival of tumor cells.

Clinical studies have shown that the treatment combination of inaliset combined with fulvestrant shows better efficacy than single drug in patients with PIK3CA mutations. For example, in some phase II and phase III studies, the combination treatment group showed longer progression-free survival (PFS) and higher objective response rate (ORR). This synergistic effect is mainly reflected in the fact that inaliset inhibits the PI3K pathway to weaken cell proliferation signals, while fulvestrant destroys estrogen-driven tumor growth, thus forming a double hit.

In addition, the safety profile of combined medications is also controllable. Although combination therapy may bring about typical adverse reactions of PI3K inhibitors such as hyperglycemia, rash, diarrhea, etc., most of them are predictable and manageable toxicities, and do not significantly increase the incidence of serious side effects. In clinical practice, doctors can adjust the dosage according to the patient's tolerance to achieve a balance between efficacy and safety.

In summary, inaliset combined with fulvestrant has better therapeutic potential in the treatment of breast cancer patients with HR+/HER2- and PIK3CA mutations. With the release of more Phase III clinical study results, this combination is expected to become the first- or second-line standard treatment option for this type of patients in the future, bringing new hope to patients with drug resistance or relapse.

Reference materials:https://www.drugs.com/