At LeonaBio, We Are Focused on Addressing Devastating Diseases Where Current Treatment Options Are Limited
Breast Cancer
Estrogen receptor–positive (“ER⁺”) breast cancer accounts for roughly 70% of all breast cancer cases and is driven by estrogen-mediated signaling. While endocrine therapies, including, aromatase inhibitors, selective estrogen receptor modulators (“SERMs”), or selective estrogen receptor degraders (“SERDs”), remain the backbone of treatment, resistance frequently emerges in the metastatic setting. A major mechanism of resistance is the development of mutations in the estrogen receptor ESR1, which arise in approximately 30-40% of patients following prior endocrine therapy and result in constitutive receptor activation, reduced sensitivity to existing therapies, and poor clinical outcomes.
Lasofoxifene is a SERM being developed for the potential treatment of ER+, ESR1-mutated metastatic breast cancer. Lasofoxifene has demonstrated activity against estrogen receptors harboring ESR1 mutations and has shown promising clinical activity in Phase 2 trials in this patient population. Lasofoxifene is currently being advanced in a registrational Phase 3 clinical trial as a targeted therapy for people with ER+, HER2-, ESR1-mutated metastatic breast cancer whose disease has progressed after treatment with a CDK4/6 inhibitor. The ongoing ELAINE-3 Phase 3 trial is evaluating lasofoxifene in combination with the CDK4/6 inhibitor, abemaciclib, with the goal of establishing a new standard of care for this genetically defined population.
Amyotrophic Lateral Sclerosis (ALS)
Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig’s disease, is a devastating and fatal neurodegenerative disease. The progression of the disease is caused by motor neuron degeneration, which leads to a loss of muscle function over time. Globally, approximately 75 thousand people are affected by ALS, with 40% of cases occurring in the United States. Approximately 10% of ALS cases are inherited whereas for approximately 90% of individuals, ALS occurs without any known family history. There is no cure for ALS – approved therapies modestly slow progression and improve survival.
ATH-1105, a novel small molecule positive modulator of the HGF signaling, is being developed for the potential treatment of ALS. In preclinical ALS models, ATH-1105 demonstrated consistent and robust beneficial effects on multiple aspects of ALS pathology. ATH-1105 demonstrated favorable safety and pharmacokinetic profiles in healthy adults, as observed in the completed Phase 1 clinical trial (NCT06432647), and planning for a Phase 2a clinical trial in people living with ALS is underway. We believe ATH-1105, with its differentiated multimodal mechanism of action, has the potential to treat people living with ALS by addressing the complex pathology and mitigating neurodegenerative outcomes of ALS.