New medication combined with hormone therapy for advanced breast cancer

Plain-English translation of NCT05860465 on ClinicalTrials.gov ↗ · Source last updated January 2026 · Translation generated June 2026 · How we translate trials

Phase 3 — Testing in thousands of people, comparing the treatment against what doctors currently use. This is the last big step before approval.

What is this trial?

This trial is testing a new medication called SPH4336 combined with standard hormone therapy drugs to treat advanced breast cancer that has stopped responding to previous treatments. About half of participants will receive the new medication along with hormone therapy, while the other half will receive a placebo (inactive pill) along with the same hormone therapy, so researchers can see if the medication truly makes a difference. The study will involve approximately 254 people across multiple locations.

Some patients with advanced breast cancer develop resistance to the treatments currently available, and their cancer continues to grow despite therapy. This trial exists to find out whether this new medication can help overcome that resistance and slow or stop the cancer's progression when added to hormone therapy.

Do you qualify?

You likely qualify if…

you have been diagnosed with locally advanced or metastatic breast cancer that has worsened despite treatment with previous drugs called CDK4/6 inhibitors combined with hormone therapy
you are in good enough health to participate, with a life expectancy of at least 3 months
you have measurable cancer that can be tracked on imaging or blood tests
your organ function (liver, kidney, heart, etc.) meets the study's safety requirements based on recent lab work
you are willing to use effective birth control throughout the study if you can become pregnant

You likely don't qualify if…

you have inflammatory breast cancer
you have cancer that has spread to your brain or central nervous system
you have a history of heart problems such as heart attack, unstable chest pain, or severe heart failure
you are pregnant, trying to become pregnant, or breastfeeding
you have active hepatitis B or C, HIV infection, or uncontrolled infections

What participation looks like

If you join this study, you will receive either the new medication (SPH4336) or a placebo, both combined with standard hormone therapy drugs given as tablets and injections. You'll have regular clinic visits for safety checks, blood tests, and imaging scans to see how your cancer is responding. The study involves both a Phase II portion (to test safety and early effectiveness) and a Phase III portion (to confirm whether the medication truly helps compared to placebo).

AI-generated summary from trial data · Jun 3, 2026 · Not medical advice

Trial locations(22 sites)

China

Affiliated Cancer Hospital, Sun Yat-sen University, Guangzhou, Guangdong

Liuzhou people's Hospital, Liuzhou, Guangxi

Anyang Cancer Hospital, Anyang, He'nan

The First Affiliated Hospital of Henan University of Science and Technology, Luoyang, He'nan

The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei