FDA approves Eli Lilly’s Inluriyo for adults with ER+, HER2-, ESR1-mutated advanced or metastatic breast cancer

An estimated 50% of patients with ER+, HER2– metastatic breast cancer will develop an ESR1 mutation during or after exposure to an aromatase inhibitor

Eli Lilly and Company announced that the U.S. Food and Drug Administration (FDA) has approved Inluriyo (imlunestrant, 200 mg tablets), an oral estrogen receptor antagonist, for the treatment of adults with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2–), ESR1-mutated advanced or metastatic breast cancer (MBC) whose disease progressed after at least one line of endocrine therapy (ET).

In the Phase 3 EMBER-3 trial, Inluriyo reduced the risk of progression or death by 38% versus ET. Among patients with ESR1-mutated MBC, Inluriyo significantly improved progression-free survival (PFS) versus fulvestrant or exemestane.

Inluriyo is a treatment for ER+, HER2–, ESR1-mutated MBC. Some breast cancers develop ESR1 mutations that can cause estrogen receptors to become overactive and drive cancer growth. Inluriyo binds, blocks, and facilitates the degradation of these receptors, helping to slow disease progression. Its once-daily dosing provides patients with an oral treatment option.

"This therapy reflects our commitment to developing treatments that improve outcomes for people with breast cancer and represents an important step toward advancing innovative, all-oral treatment approaches," said Jacob Van Naarden, executive vice president and president of Lilly Oncology. "We are deeply grateful to the patients, investigators, Lilly team members and clinical care teams who made this advancement possible. This therapy has the potential to make the treatment journey more manageable for those living with breast cancer."

The Inluriyo label contains a warning and precaution for embryo-fetal toxicity. See Important Safety Information below and full Prescribing Information for additional information.

In EMBER-3, the majority of adverse events (AEs) with Inluriyo were low grade (Grade 1-2) and the most common adverse reactions (≥10%), including laboratory abnormalities, were hemoglobin decreased, musculoskeletal pain, calcium decreased, neutrophils decreased, AST increased, fatigue, diarrhea, ALT increased, triglycerides increased, nausea, platelets decreased, constipation, cholesterol increased, and abdominal pain. In the study, 4.6% of patients permanently discontinued treatment due to AEs. Dose reductions and dose interruptions occurred in 2.4% and 10% of patients, respectively.

"The approval of Inluriyo expands the metastatic breast cancer treatment landscape for patients who test positive for the ESR1 mutation," said Jean Sachs, CEO, Living Beyond Breast Cancer. "Eligible patients will now have access to an additional treatment option, offering them the potential for flexibility in their daily lives and disease management, and—above all—renewed hope for the future."

Inluriyo is also being studied in the ongoing Phase 3 EMBER-4 trial in the adjuvant setting for people with ER+, HER2– early breast cancer (EBC) at increased risk of recurrence, which is enrolling approximately 8,000 patients worldwide.

Inluriyo is expected to be available in the United States in the coming weeks.