Table of Contents
- Trial overview
- Who was studied
- What the trial measured
- Trial phase and size
- Treatment details
- Why this research matters
Trial overview
The clinical trial listed here studied Vepdegestrant in people with ER+, HER2– advanced or metastatic breast cancer.[1] It was a Phase 1 study, which means the main goal was to learn about safety and the best dose for later research.[1]
The trial was completed and enrolled 30 participants.[1] It tested Vepdegestrant in combination with everolimus.[1]
Who was studied
This study focused on patients with ER+, HER2– advanced or metastatic breast cancer.[1] ER+ means the cancer has estrogen receptors, and HER2– means the cancer does not have high HER2 levels.[1]
Advanced or metastatic breast cancer means the cancer is not limited to one small area and may have spread to other parts of the body.[1] The trial data provided here do not list other eligibility details such as age limits or prior treatments.[1]
What the trial measured
The main outcome was first-cycle dose-limiting toxicities, often called DLTs.[1] DLTs are side effects that are serious enough to limit treatment dosing early in the study.[1]
The study also measured adverse events, which are health problems or side effects that happen during the trial.[1] These were tracked by type, how often they happened, how severe they were, when they happened, how serious they were, and whether they seemed related to the study treatment.[1]
Another endpoint was laboratory abnormalities, which means unusual blood test or lab results.[1] The study tracked these by type, frequency, severity, and timing.[1]
The trial also aimed to determine a recommended phase 2 dose (RP2D) for the combination.[1] This is the dose chosen after early testing for use in later studies.[1]
Trial phase and size
This was an interventional study, meaning the researchers gave a treatment and watched what happened.[1] Interventional trials are different from observation-only studies because they actively test a therapy.[1]
The study was small, with 30 enrolled participants, which is common in Phase 1 research.[1] Small early trials are usually designed to answer safety and dose questions before larger studies begin.[1]
Treatment details
The trial combined Vepdegestrant with everolimus.[1] The source data also list PF-07850327 and everolimus tablet forms among the interventions, but the main study title and summary identify the trial as ARV-471, which is Vepdegestrant, in combination with everolimus.[1]
Because this article is based only on the trial data provided, it does not add extra details about dosing schedules, treatment length, or how the drugs were given beyond what is listed.[1]
Why this research matters
Early trials like this help researchers learn whether a new treatment combination can be studied more safely in larger groups.[1] In this case, the focus was on a specific breast cancer group: patients with ER+, HER2– advanced or metastatic disease.[1]
By measuring side effects, lab changes, and the best dose, the study aimed to support the next step of clinical research.[1] That makes Phase 1 studies an important first step in testing new cancer treatment combinations.[1]



