LeonaBio (LONA) Status Update summary

Strategic transformation, licensing, and pipeline expansion

• Secured exclusive global license (excluding Asia and select Middle East countries) for lasofoxifene, a selective estrogen receptor modulator, targeting metastatic breast cancer with ESR1 mutations.

• Announced acquisition of rights to develop and commercialize lasofoxifene, diversifying the pipeline with a late-stage oncology program.

• Continued advancement of ATH-1105 for ALS, positioning for meaningful data readouts from both programs in 2027.

• Plans to rebrand to reflect a broader mission and commitment to transformative therapies.

• Collaboration with Sermonix leverages expertise in SERM biology and clinical development.

Lasofoxifene clinical and commercial update

• Lasofoxifene targets ER-positive, HER2-negative metastatic breast cancer with ESR1 mutations, addressing a growing market projected to reach $41.7 billion by 2030.

• Demonstrated 13 months median progression-free survival in phase II ELAINE-2 trial when combined with abemaciclib, outperforming current standards.

• ELAINE-3 phase III trial is over 50% enrolled, targeting double-digit PFS in a second-line setting, with top-line data expected mid-2027.

• Lasofoxifene offers a differentiated mechanism, strong tolerability, and quality-of-life benefits, including improvements in urogenital symptoms and bone health.

• If approved, lasofoxifene could achieve peak annual U.S. sales approaching $1 billion, with potential for broader use in earlier lines and combination therapies.

ATH-1105 ALS program status

• ATH-1105 is an orally available, CNS-penetrant small molecule modulating the HGF system, showing robust neuroprotection in preclinical ALS models.

• Demonstrated preservation of motor function, reduced neurodegeneration, and favorable biomarker changes in animal studies.

• Completed phase I study in healthy volunteers with favorable safety, PK, and target engagement data.

• Phase II proof-of-concept trial in ALS patients is planned to start in early 2026, assessing efficacy, safety, and biomarker validation.

• Potential for ATH-1105 to impact ALS progression and expand into other neurodegenerative diseases.