LeonaBio (LONA) investor relations material

Strategic update and clinical development overview

• Licensed rights to lasofoxifene, a late-stage asset for metastatic breast cancer, diversifying the pipeline and prompting a rebrand focused on innovation and patient impact.

• Lasofoxifene targets ER-positive, HER2-negative metastatic breast cancer, especially in patients with ESR1 mutations, a key resistance mechanism after standard therapies.

• The breast cancer market is large and growing, with significant unmet need for differentiated therapies in the ESR1-mutant segment.

• Lasofoxifene's unique receptor modulation and compatibility with combination regimens position it as a strong candidate in this evolving landscape.

Clinical data and trial progress

• Phase II ELAINE 2 trial showed lasofoxifene plus abemaciclib achieved a median PFS of 13 months and a 56% response rate in heavily pretreated patients.

• ELAINE 1 demonstrated lasofoxifene monotherapy outperformed fulvestrant, with a median PFS of 5.6 vs. 3.7 months and strong activity against difficult ESR1 mutations.

• Lasofoxifene offers tissue-selective benefits, improving bone density and vaginal health, and avoids toxicities seen with other agents.

• ELAINE 3, a 600-patient phase III trial, is enrolling to compare lasofoxifene/abemaciclib vs. fulvestrant/abemaciclib in ESR1-mutant patients, with top-line data expected in 2027.

Expert perspectives and evolving treatment paradigm

• Experts highlighted the need for better oral regimens to delay chemotherapy and improve quality of life for metastatic breast cancer patients.

• Combination strategies, especially with abemaciclib, are seen as critical to overcoming resistance and achieving longer PFS.

• Lasofoxifene's potency against multiple ESR1 mutations and favorable tolerability profile were emphasized as key differentiators.

• Routine ESR1 mutation testing is now standard, enabling targeted therapy selection and supporting the relevance of ongoing trials.