In short
Clinical trials are studying RLY-2608 in people with PIK3CA-related overgrowth and malformations, and in people with PIK3CA-mutated advanced breast cancer. These studies look at safety, tolerability, and how well RLY-2608 works in different patient groups.
Key points
- Clinical trials of RLY-2608 are being done in two main patient groups: people with PIK3CA-related overgrowth and malformations, and people with PIK3CA-mutated HR+/HER2-negative advanced or metastatic breast cancer. One study is Phase 2 and looks at safety, dose selection, and volumetric response. The other is Phase 3 and compares RLY-2608 plus fulvestrant with capivasertib plus fulvestrant. Both trials are authorised and are studying how well the treatment works in their target populations.
Clinical trials overview
These studies are testing RLY-2608 in two different disease areas: PIK3CA-related overgrowth spectrum and malformations, and PIK3CA-mutated hormone-receptor positive, HER2-negative advanced or metastatic breast cancer.
Both trials are listed as authorised, which means they have approval to run. One study is Phase 2 and the other is Phase 3.
Phase 3 study in advanced breast cancer
The Phase 3 study, NCT06982521, is comparing RLY-2608 plus fulvestrant with capivasertib plus fulvestrant in people with PIK3CA-mutated, hormone-receptor positive, HER2-negative locally advanced or metastatic breast cancer.
This is a larger trial with 540 participants and is also interventional. The study is designed to compare how well the treatments work, using progression-free survival as the main outcome.
Progression-free survival means the time from randomization until the cancer gets worse on scans, or the person dies from any cause. The summary says the trial will compare efficacy in the overall group and in kinase populations by BICR, which means blinded independent central review.
How the trials measure results
The Phase 2 study measures safety profile by looking at dose-limiting toxicities, side effects, serious side effects, vital signs, ECGs, and safety laboratory tests. A dose-limiting toxicity is a side effect that may stop a dose from being used as planned.
The same study also measures whether the affected tissue changes in size, using volumetric response at Week 24. This is important in overgrowth conditions because the size of the affected area is part of the disease burden.
The Phase 3 breast cancer study uses RECIST v1.1 for checking radiographic progression, which means cancer growth seen on imaging scans. The main question is whether RLY-2608 plus fulvestrant can delay progression better than the comparison treatment.
Who may take part
People may be considered for the Phase 2 study if they have PIK3CA-related overgrowth spectrum or PIK3CA-driven malformations. The study title and summary show that the trial is focused on these mutation-driven overgrowth conditions.
People may be considered for the Phase 3 study if they have PIK3CA-mutated HR+/HER2- locally advanced or metastatic breast cancer. The trial is built for a specific cancer group, so not every person with breast cancer would match the study.
Key patient terms
Interventional study means the research team gives a treatment and watches what happens.
Randomization means participants are assigned to treatment groups by chance, which helps make the comparison fair.
Fulvestrant is part of the breast cancer study treatment plan, and the trial compares it with another treatment combination.
Placebo is used in the Phase 2 overgrowth study as a comparison with the active study drug in Part 3.