Itovebi (Inavolisib)

Itovebi targets the PI3K/AKT signaling pathway, which is frequently dysregulated in certain breast cancers.

• Hormone receptor‑positive/HER2‑negative advanced breast cancer: aims to inhibit tumor cell proliferation and disease progression.

• Inavolisib selectively inhibits the PI3Kα isoform, blocking the downstream PI3K/AKT signaling cascade. This interruption reduces phosphorylation of AKT and other effectors, leading to decreased tumor cell growth, survival, and angiogenesis. By targeting a key driver of oncogenic signaling, the drug seeks to limit the proliferation of cancer cells that rely on PI3Kα activity.

Adverse reactions reported with PI3Kα inhibition include both frequent and less common events.

Common Side Effects

• Hyperglycemia: elevated blood glucose levels.
• Diarrhea: loose or watery stools.
• Nausea: feeling of sickness.
• Rash: skin redness or irritation.
• Fatigue: persistent tiredness.
• Elevated liver enzymes: increased ALT/AST.

Serious or Rare Side Effects

• Severe hyperglycemia requiring medical intervention.
• Pneumonitis: inflammation of lung tissue.
• Neutropenia: low neutrophil count increasing infection risk.
• Hepatotoxicity: significant liver injury.
• Colitis: inflammation of the colon.
• Thromboembolic events: blood clot formation.

When prescribing Itovebi, clinicians should consider several safety measures.

• Blood glucose monitoring: check fasting glucose and HbA1c regularly.
• Liver function tests: assess ALT, AST, and bilirubin before and during therapy.
• Infection surveillance: watch for signs of neutropenia or opportunistic infections.
• Hepatic impairment: avoid use in patients with severe liver dysfunction.
• Renal impairment: adjust or monitor dosing in moderate to severe renal disease.
• Store at ambient temperature: keep in the original packaging, protect from moisture and direct sunlight.

Inavolisib may interact with other medicines that affect its metabolism or pharmacodynamic profile.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): may increase drug exposure.
• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine): may reduce efficacy.
• Antidiabetic agents (e.g., insulin, sulfonylureas): risk of severe hyperglycemia.

Moderate Interactions (Monitor Closely)

• Moderate CYP3A4 inhibitors (e.g., erythromycin): may modestly raise plasma levels.
• Anticoagulants (e.g., warfarin): monitor INR for potential changes.
• Proton pump inhibitors: observe for altered absorption.
• Herbal supplements containing St. John’s wort: may decrease drug concentration.