Stonegate Capital Partners Initiates Coverage on AB Science S.A. (ENXTPA: AB)

Dallas, Tx -- February 10th, 2026 -- AB Science S.A. (ENXTPA: AB): Stonegate Capital Partners Initiates Coverage on AB Science S.A. (ENXTPA: AB). AB Science is a late-stage biotech advancing masitinib, an oral, selective tyrosine kinase inhibitor designed to modulate maladaptive neuroinflammation through mast-cell and microglia/macrophage pathways. The Company is positioning masitinib as an add-on therapy across ALS, progressive MS, and AD, while maintaining earlier-stage upside through AB8939 in AML. The combination of a treatment for ALS along with the optionality that comes with the rest of the Company’s portfolio makes us excited to monitor the development of AB’s Masitinib asset.

Masitinib in ALS: Masitinib’s ALS program is supported by prior Phase 2B/3 data in a pre-planned normal progressor population, where AB has reported statistically significant functional benefit and improved median progression-free survival. The confirmatory Phase 3 (AB23005) is FDA-authorized and approved under CTIS steps 1–2 in the EU, requires riluzole, and permits edaravone in the US if initiated prior to baseline, with a 48-week design built around regulator-aligned endpoints. We are optimistic that this pathway will lead to commercialization before the end of the decade and have modeled accordingly.

Masitinib in ALS Pathway: EMA did not grant conditional marketing authorization based on the earlier dataset due to remaining uncertainty around robustness in a heterogeneous ALS population, including baseline-severity considerations in a subset of patients. It is believed that Phase 3 success probability is improved because AB23005 prospectively addresses these issues through enrollment criteria intended to reduce heterogeneity, greater statistical power, and endpoints aligned to EMA and FDA expectations, while preserving the clinically relevant 48-week assessment window. This updated approach allows us to look past the previous hurdles.

Masitinib in MS and AD: In progressive MS, the Phase 3 trial is authorized in the US and 12 EU countries with ~94 sites initiating, and targets time to confirmed EDSS progression, consistent with the clinical objective of slowing disability accumulation. In AD, prior add-on data showed statistically significant effects on cognition and daily function at 24 weeks, supporting a confirmatory Phase 3 authorized in the US and key European countries with co-primary cognitive and functional endpoints at 24 weeks and longer-horizon secondary outcomes.

AB8939: AB8939 is a Phase 1 AML asset, differentiated by dual targeting of microtubules and ALDH pathways intended to address both proliferating blasts and resistant stem-like populations. Dose escalation is complete and the program is now in combination cohorts with venetoclax and venetoclax plus azacitidine, setting up additional data-driven milestones.

Financing: AB Science’s financing approach is expected to balance traditional capital markets activity with non-dilutive alternatives where feasible, including regional partnering, structured funding options, and grand options. Near-term funding priorities should remain centered on executing late-stage masitinib programs while progressing AB8939 combinations, with capital decisions likely tied to the cadence of clinical milestones and the Company’s ability to raise on favorable terms around value inflection points.

Valuation: We use a Discounted Cash Flow Model when valuing AB. Our model returns a valuation range of €3.65 to €6.69 with a mid-point of €4.89.