science

Giredestrant

Giredestrant is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Giredestrant rather than just read about it. In short: Giredestrant (also known as GDC-9545, RG6171, or RO7197597) is an investigational oral selective estrogen receptor degrader (SERD) developed by Genentech, a member of the Roche Group, for the treatment of estrogen receptor-positive (ER+), HER2-negative advanced breast cancer, as well as endometrial cancer, ovarian cancer, and other solid tumors. It is a potent, nonsteroidal compound that antagonizes estrogen effects…

Key takeaways

Giredestrant belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Giredestrant to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Giredestrant from memory before moving on to harder problems.

Reference excerpt

Giredestrant (also known as GDC-9545, RG6171, or RO7197597) is an investigational oral selective estrogen receptor degrader (SERD) developed by Genentech, a member of the Roche Group, for the treatment of estrogen receptor-positive (ER+), HER2-negative advanced breast cancer, as well as endometrial cancer, ovarian cancer, and other solid tumors. It is a potent, nonsteroidal compound that antagonizes estrogen effects by competitively binding to both wild-type and mutant estrogen receptors with nanomolar potency. Giredestrant works by inducing an inactive conformation of the estrogen receptor ligand-binding domain and promoting proteasome-mediated degradation of the receptor protein. As of May 2025, giredestrant is in clinical trials and has received Fast Track designation from the Food and Drug Administration (FDA) for ER+, HER2-negative second- and third-line metastatic breast cancer.

Mechanism of action Giredestrant is a nonsteroidal SERD that binds the estrogen receptor (ER), including wild-type and mutant forms (e.g., ESR1 mutation), inducing a conformational change in the receptor's ligand-binding domain. This promotes proteasome-mediated ER degradation, preventing ER-mediated signaling critical for tumor growth in ER+ breast cancer. Compared to selective estrogen receptor modulators (SERMs) or aromatase inhibitors, giredestrant's degradation mechanism better addresses resistance in ESR1-mutated tumors.

Research In clinical trials, giredestrant has been evaluated in patients with ER+, HER2-negative breast cancer and other solid tumors, including endometrial and ovarian cancers, including those with ESR1 mutations, both as a single agent and in combination with other therapies. Its orally bioavailable.

Breast Cancer acelERA (NCT04576455): A Phase II study compared giredestrant (30 mg oral daily) to physician's choice of endocrine therapy (e.g., fulvestrant, aromatase inhibitors) in patients with 1–2 prior lines of systemic therapy for ER+, HER2-negative advanced breast cancer. At the clinical cutoff (February 18, 2022), the hazard ratio (HR) for progression-free survival (PFS) was 0.81 (95% CI, 0.60–1.10; P = 0.1757), showing no statistically significant improvement. A stronger PFS trend was observed in ESR1-mutated tumors (HR 0.60, 95% CI, 0.35–1.03). pionERA (NCT04478266): A Phase III, randomized, open-label study evaluating giredestrant versus fulvestrant, both combined with a CDK4/6 inhibitor (palbociclib, ribociclib, or abemaciclib), in patients with ER+, HER2-negative advanced breast cancer resistant to prior adjuvant endocrine therapy. lidERA (NCT04546002): A Phase III study comparing adjuvant giredestrant to physician's choice of endocrine monotherapy in ER+, HER2-negative early breast cancer. persevERA (NCT04687236): A Phase III study comparing giredestrant plus palbociclib and placebo versus letrozole plus palbociclib and placebo in first-line metastatic ER+, HER2-negative breast cancer. This trial did not show a significant improvement of the giredestrant group over the control group. evERA (NCT05306340): A Phase III trial evaluating giredestrant with everolimus in ER+, HER2-negative advanced breast cancer post-CDK4/6 inhibitors. morpheus (NCT04802759): A Phase I study assessing giredestrant with various combinations, including the immune checkpoint inhibitor atezolizumab, in metastatic breast cancer.

Other Indications Endometrial Cancer: Phase II trials are evaluating giredestrant for recurrent or persistent endometrial cancer. Ovarian Cancer: Phase II studies are exploring giredestrant in rare ovarian cancers.

Safety and adverse effects Giredestrant is generally well-tolerated, with a safety profile similar to endocrine therapies like fulvestrant. Common adverse events from the acelERA study and other trials include fatigue, nausea, arthralgia, diarrhea, hot flashes, headache, and musculoskeletal pain. ematologic effects (e.g., thrombocytopenia, anemia), liver enzyme elevations, and ovarian cysts (a class effect of SERDs) have been reported. Bradycardia was observed at higher doses but mitigated at the 30 mg dose used in pivotal trials.

References

Illustrations

Worked examples

Example 1 — a first encounter with Giredestrant

Start with the simplest possible case. Write down what Giredestrant claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Giredestrant before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Giredestrant ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Giredestrant

In research: Giredestrant appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Giredestrant in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Giredestrant is common in secondary-school and first-year university syllabi. It links to neighbouring topics Anilines, Antineoplastic drugs, Azetidines, so understanding it makes those chapters shorter.
In everyday life: Look for Giredestrant outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Giredestrant in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Giredestrant means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Giredestrant out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Giredestrant in simple terms?

Why does Giredestrant matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Giredestrant?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Giredestrant.