Excelsior Biopharma Inc. (科懋生物科技股份有限公司) is a Taiwanese biopharmaceutical company focused on developing novel therapeutics for central nervous system disorders, with a primary focus on Alzheimer's disease. The company is headquartered in Taiwan and operates as an industry sponsor for clinical development programs.
Alzheimer disease (AD) represents the most common cause of dementia worldwide, affecting an estimated 55 million people globally as of 2022, with projections suggesting this number will rise to 139 million by 2050 [1](https://pubmed.ncbi.nlm.nih.gov/36194143/). This devastating neurodegenerative disorder is characterized by progressive cognitive decline, memory loss, and behavioral changes that profoundly impact both patients and their families [2](https://pubmed.ncbi.nlm.nih.gov/21371647/). The pathophysiology of AD involves a complex interplay of amyloid-beta accumulation, tau protein pathology, neuroinflammation, synaptic dysfunction, and neuronal loss across multiple brain regions [3](https://pubmed.ncbi.nlm.nih.gov/27029868/).
The amyloid cascade hypothesis, first proposed by Hardy and Higgins in 1992, remains the dominant framework for understanding AD pathogenesis [4](https://pubmed.ncbi.nlm.nih.gov/1568428/). This hypothesis posits that the accumulation of amyloid-beta (Aβ) peptides in the brain is the primary trigger that initiates a pathological cascade leading to neurofibrillary tangle formation, synaptic loss, and ultimately neuronal death [5](https://pubmed.ncbi.nlm.nih.gov/27029868/).
Amyloid-beta is generated through proteolytic cleavage of the amyloid precursor protein (APP) by β-secretase (BACE1) and γ-secretase complexes. The resulting Aβ peptides, particularly Aβ42 and Aβ40, have a propensity to aggregate into oligomers, protofibrils, and eventually insoluble plaques [6](https://pubmed.ncbi.nlm.nih.gov/36194143/). Soluble oligomeric Aβ species are now recognized as the most neurotoxic species, rather than the plaques themselves, which may represent a downstream epiphenomenon [7](https://pubmed.ncbi.nlm.nih.gov/27029868/).
The amyloid cascade hypothesis has led to intensive drug development efforts targeting Aβ production, aggregation, and clearance. Despite numerous clinical trial failures, the approval of lecanemab (Leqembi) in 2023 and donanemab in 2024 has provided proof-of-concept that amyloid removal can slow clinical decline in early AD patients [8](https://pubmed.ncbi.nlm.nih.gov/35478022/).
While amyloid-beta is considered the upstream trigger in the amyloid cascade, tau protein pathology represents the downstream mediator of neurotoxicity [9](https://pubmed.ncbi.nlm.nih.gov/20374740/). Tau is a microtubule-associated protein that stabilizes neuronal microtubules. In AD, tau becomes hyperphosphorylated, leading to its aggregation into paired helical filaments (PHFs) and ultimately neurofibrillary tangles (NFTs) [10](https://pubmed.ncbi.nlm.nih.gov/30093684/).
The progression of tau pathology follows a characteristic pattern, beginning in the entorhinal cortex and hippocampus before spreading to neocortical regions [11](https://pubmed.ncbi.nlm.nih.gov/20185045/). This spreading is thought to occur through prion-like propagation of tau seeds between neurons [12](https://pubmed.ncbi.nlm.nih.gov/20374740/). The density and distribution of NFTs correlate strongly with cognitive impairment, making tau an important therapeutic target [13](https://pubmed.ncbi.nlm.nih.gov/30093684/).
Chronic neuroinflammation has emerged as a critical component of AD pathophysiology [14](https://pubmed.ncbi.nlm.nih.gov/31793266/). Activated microglia, the resident immune cells of the brain, surround amyloid plaques and release pro-inflammatory cytokines, chemokines, and complement proteins that contribute to synaptic dysfunction and neuronal loss [15](https://pubmed.ncbi.nlm.nih.gov/31793266/).
The Trem2 gene variant, expressed exclusively in microglia, has been identified as a significant risk factor for AD, highlighting the importance of microglial function in disease pathogenesis [16](https://pubmed.ncbi.nlm.nih.gov/36194143/). Microglia undergo phenotypic changes in AD, transitioning from a homeostatic state to a disease-associated microglia (DAM) profile characterized by upregulated genes involved in phagocytosis, lipid metabolism, and inflammation [17](https://pubmed.ncbi.nlm.nih.gov/31793266/).
Approximately 70% of AD risk is attributable to genetic factors, with heritability estimates higher for early-onset than late-onset disease [18](https://pubmed.ncbi.nlm.nih.gov/24086075/). Autosomal dominant mutations in APP, PSEN1, and PSEN2 cause early-onset familial AD, while the APOE ε4 allele represents the strongest genetic risk factor for late-onset AD [19](https://pubmed.ncbi.nlm.nih.gov/24086075/).
Genome-wide association studies (GWAS) have identified over 40 loci associated with AD risk, including CLU, PICALM, CR1, BIN1, and TREM2 [20](https://pubmed.ncbi.nlm.nih.gov/18541569/). These risk genes implicate pathways including immune response, lipid metabolism, endocytic trafficking, and synaptic function in AD pathogenesis [21](https://pubmed.ncbi.nlm.nih.gov/17424855/).
The current pharmacotherapy for AD includes symptomatic treatments targeting cholinergic neurotransmission and glutamate excitotoxicity [22](https://pubmed.ncbi.nlm.nih.gov/32791656/). Acetylcholinesterase inhibitors (donepezil, rivastigmine, galantamine) provide modest cognitive benefits in mild-to-moderate AD, while memantine is approved for moderate-to-severe disease [23](https://pubmed.ncbi.nlm.nih.gov/32791656/).
Disease-modifying therapies targeting amyloid (lecanemab, donanemab) and tau (gosuranemab, tilavonemab, semorinemab) represent the next generation of AD treatments [24](https://pubmed.ncbi.nlm.nih.gov/32191547/). Amyloid-targeting antibodies have demonstrated slowing of cognitive decline in trials, albeit with associated amyloid-related imaging abnormalities (ARIA) as a safety concern [25](https://pubmed.ncbi.nlm.nih.gov/34050332/).
| Attribute | Details |
|-----------|---------|
| Name | Excelsior Biopharma Inc. |
| Headquarters | Taiwan |
| Industry | Biopharmaceuticals |
| Focus Area | Central Nervous System / Alzheimer's Disease |
| Founded | Taiwan |
Excelsior's lead clinical candidate is EX039, an oral small molecule therapeutic currently in Phase 2 development for the treatment of mild Alzheimer's disease.
The lead clinical program is being conducted under NCT05413655, a Phase 2 randomized, double-blind, placebo-controlled study evaluating EX039 as an add-on to acetylcholinesterase inhibitors.
Trial Design:
While the precise mechanism of EX039 is proprietary, the company's development approach aligns with current trends in AD therapeutic development targeting multiple pathophysiological pathways beyond amyloid and tau. Small molecule approaches that enhance synaptic function, modulate neuroinflammation, or improve neuronal metabolism represent active areas of investigation [26](https://pubmed.ncbi.nlm.nih.gov/33302565/).
The trial uses established AD clinical endpoints including:
| Candidate | Indication | Phase | Status |
|-----------|------------|-------|--------|
| EX039 | Alzheimer's Disease (Mild) | Phase 2 | Recruiting |
The global AD drug market is projected to grow significantly from approximately $4 billion in 2023 to over $13 billion by 2032, driven by increasing disease prevalence and the introduction of disease-modifying therapies [27](https://pubmed.ncbi.nlm.nih.gov/32843743/). However, significant unmet need remains for treatments that can prevent, halt, or reverse disease progression, particularly for patients with moderate-to-severe disease [28](https://pubmed.ncbi.nlm.nih.gov/21371647/).
Taiwan represents an important region for clinical development, with well-established medical infrastructure and regulatory frameworks that support international clinical trials [29](https://pubmed.ncbi.nlm.nih.gov/32843743/). The Taiwanese biopharmaceutical sector has grown substantially over the past two decades, with government initiatives supporting drug development for strategically important diseases [30](https://www.excelsiorgroup.com.tw).
Excelsior's development program for EX039 represents an important contribution to the AD therapeutic pipeline. Key considerations for future development include: