chemistry

Inavolisib

Inavolisib is a chemistry 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 Inavolisib rather than just read about it. In short: Inavolisib, sold under the brand name Itovebi by Genentech, a member of the Roche group, is an anti-cancer medication used for the treatment of breast cancer. It is an inhibitor and degrader of mutated phosphatidylinositol 3-kinase (PI3K) alpha (PIK3CA).

Key takeaways

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

Reference excerpt

Inavolisib, sold under the brand name Itovebi by Genentech, a member of the Roche group, is an anti-cancer medication used for the treatment of breast cancer. It is an inhibitor and degrader of mutated phosphatidylinositol 3-kinase (PI3K) alpha (PIK3CA). The most common adverse reactions include gastrointestinal disorders, high blood glucose, and infections. Inavolisib was approved for medical use in the United States in October 2024.

Medical uses Inavolisib is indicated in combination with palbociclib and fulvestrant for the treatment of adults with endocrine-resistant, PIK3CA-mutated, hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer, as detected by an FDA-approved test, following recurrence on or after completing adjuvant endocrine therapy.

Side effects The most common adverse reactions include gastrointestinal disorders (stomatitis, diarrhea, nausea, and vomiting), skin and subcutaneous tissue disorders (rash, dry skin, and alopecia), infections, and laboratory abnormalities, the most notable of which is increased fasting blood glucose. 6% of those treated with inavolisib in the INAVO120 trial had to discontinue treatment due to adverse effects.

Synthesis Inavolisib can be developed as a derivative of 1,3-oxazole or by stereo-controlled N-arylation of alpha-amino acids.

Metabolism and biotransformation Inavolisib has an oral bioavailability of 76%, which is not significantly affected by diet. After absorption, inavolisib is extensively distributed (155 L) and is primarily metabolized through hydrolysis. 49% of a single dose of inavolisib is excreted in urine, 48% in feces, and only a minority of the dose is excreted unchanged.

Molecular mechanisms of action Inavolisib is a PI3Kα inhibitor with a high degree of selectivity over beta-, gamma-, and delta-isoforms of PI3K. When binding to the catalytic portion of PI3K alpha, p110α, inavolisib's carbonyl group forms a hydrogen bond with Tyr836 (conserved) in p110α. The difluoromethyl group can interact with the hydroxyl group presented on Ser774 (conserved) in p110α, which is 3.2Å nearer than that of the equivalent residue Ser754 in p110δ. Additionally, the amide group can interact with Gln859 (non-conserved). This results in a very high selectivity regarding PI3Kα isoforms. Inhibition of PI3Kα reduces the proliferation and increases apoptosis of cancer cell lines that are dependent on PI3Kα activity. In addition to its kinase inhibitory ability, clinically relevant concentrations of inavolisib have been shown to specifically degrade the mutated forms of p110α in a manner that is dependent on receptor tyrosine kinase activity. Such ability prevents the activation of downstream signalling pathways, even with rebound upstream RTK activity. The exact mechanism behind this mutant-specific degradation activity has not been fully elucidated.

History Efficacy was evaluated in INAVO120 (NCT04191499), a randomized, double-blind, placebo-controlled, multicenter trial in 325 participants with endocrine-resistant, PIK3CA-mutated HR-positive, HER2-negative locally advanced or metastatic breast cancer whose disease progressed during or within twelve months of completing adjuvant endocrine therapy and who had not received prior systemic therapy for locally advanced or metastatic disease. Primary endocrine resistance was defined as relapse during the first two years of adjuvant endocrine therapy. Secondary endocrine resistance was defined as relapse while on adjuvant endocrine therapy after at least two years or relapse within twelve months of completing adjuvant endocrine therapy. The results show that inavolisib doubles progression-free survival, from 7.3 months in the placebo group to 15.0 months. Inavolisib was also shown to extend overall survival by 7 months (27.0 months in the placebo group vs 34.0 months in the inavolisib group).

Society and culture

Legal status In October 2024, the US Food and Drug Administration (FDA) approved inavolisib for the treatment of PIK3CA-mutated breast cancer based on the results from the INAVO120 trial. The FDA granted the application for inavolisib priority review and breakthrough therapy designations. In May 2025, the Committee for Medicinal Products for Human Use of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Itovebi, intended for the treatment of adults with PIK3CA-mutated, estrogen receptor (ER)-positive, HER2-negative locally advanced and metastatic breast cancer. The applicant for this medicinal product is Roche Registration GmbH. Inavolisib was authorized for medical use in the EU in June 2025.

Names Inavolisib is the international nonproprietary name. Inavolisib is sold under the brand name Itovebi.

Research Inavolisib is being studied in multiple settings and in combination with other molecules, including the treatment of advanced/metastatic breast cancer, one of which is a head-to-head trial against alpelisib, and the treatment of solid tumors other than breast cancer.

References

External links Clinical trial number NCT04191499 for "A Study Evaluating the Efficacy and Safety of Inavolisib + Palbociclib + Fulvestrant vs Placebo + Palbociclib + Fulvestrant in Patients With PIK3CA-Mutant, Hormone Receptor-Positive, Her2-Negative, Locally Advanced or Metastatic Breast Cancer (INAVO120)" at ClinicalTrials.gov

Illustrations

Worked examples

Example 1 — a first encounter with Inavolisib

Start with the simplest possible case. Write down what Inavolisib claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, 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 Inavolisib 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 Inavolisib 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 Inavolisib

In research: Inavolisib appears in chemistry 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 Inavolisib 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: Inavolisib is common in secondary-school and first-year university syllabi. It links to neighbouring topics Acetamides, Antineoplastic drugs, Benzoxazepines, so understanding it makes those chapters shorter.
In everyday life: Look for Inavolisib 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.

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How to study Inavolisib in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Inavolisib 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 Inavolisib out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Inavolisib in simple terms?

Why does Inavolisib matter?

Because it connects several chemistry 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 Inavolisib?

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 Inavolisib.