Developer · AB · France

AB Science

Paris-based pharmaceutical company (Euronext Paris: AB, founded 2001) specializing in protein kinase inhibitors. Its lead compound masitinib (AB1010) is approved in veterinary medicine (Masivet) and has been developed in humans across neurology (ALS, progressive MS, Alzheimer's disease), mast-cell diseases, asthma and oncology. Since April 2026 the company has focused its resources on two priority programs - masitinib Phase 3 in ALS (study AB23005, de-risked by a EUR 25M clinical-trial-failure insurance policy) and AB8939 Phase 1/2 in acute myeloid leukemia - discontinuing its mastocytosis, mast-cell-activation-syndrome and progressive-MS trials in July 2026. Stephane Ledermann was Chairman & CEO as of July 2026 (co-founder Alain Moussy was CEO through at least April 2026).

ab-science.com ↗

1compound
3programs
3indications
Phase 3lead asset

Phase distribution

  • Phase 33

Modality

  • Small molecule 1

Mechanism focus

Pipeline (1)

Deals & partnerships

  • Apr 16, 2026FinancingEUR 25M clinical-trial-failure insurance secured for the ALS Phase 3 (AB23005)AB Science received a binding offer for a Clinical Trial Funding Insurance policy from Medical & Commercial International (Lloyd's Syndicate 1902) covering EUR 25M (potentially up to EUR 39M) of AB23005 trial costs with zero deductible in the event of clinical failure (efficacy, safety, recruitment, regulatory hold, GCP breach, IDMC stop, or CMC failure). Effective from first patient enrolled, conditional on AB Science mobilizing the study financing and premium (~EUR 8M); the binding offer is activatable until 2026-12-31. The same release announced a voluntary temporary halt of new-patient recruitment in AB Science's European studies during a strategic reorganization prioritizing ALS and AML.Masitinibsource ↗

Catalysts · 1 upcoming · 3 reported

Recently reported

  • 2020-12-16met

    MasitinibforAlzheimer's diseaseTopline data

    AB09004 topline (2020-12-16): masitinib 4.5 mg/kg/day met the ADAS-cog primary endpoint in mild-to-moderate Alzheimer's disease as add-on to standard of care (published values: between-group difference -2.15, 97.5% CI -3.48 to -0.81, p<0.001; ADCS-ADL co-primary difference +1.82, p=0.038); the independent titrated 6.0 mg/kg/day group was inconclusive.

    source ↗

  • 2020-02-20met

    MasitinibforMultiple sclerosisTopline data

    AB07002 Phase 2b/3 topline (2020-02-20): masitinib 4.5 mg/kg/day met the primary endpoint in progressive MS, significantly reducing overall EDSS deterioration vs placebo (published value: between-group difference -0.097, 97% CI -0.192 to -0.002, p=0.0256); the independent uptitrated 6.0 mg/kg/day group was inconclusive.

    source ↗

  • 2019-07-07met

    MasitinibforAmyotrophic lateral sclerosisFull results

    AB10015 Phase 2/3 published (Mora et al., ALS-FTD 2020, epub 2019-07-07): in the prespecified primary population (normal progressors, ALSFRS-R decline <1.1 pts/month), masitinib 4.5 mg/kg/day + riluzole slowed 48-week ALSFRS-R decline by 3.4 points vs placebo (95% CI 0.65-6.13, p=0.016; 27% slowing), with significant ALSAQ-40, FVC and time-to-event secondaries; no effect in the broader population or 3.0 mg/kg/day cohorts.

    source ↗

Recent activity

  • Jul 10, 2026Phase changeMasitinib·Multiple sclerosisPhase 3AB Science discontinued the AB20009 (MAXIMS) trial - one of three non-priority studies terminated ('no prospect of a rapid resumption'; explicitly not related to any safety concern; the company intends to close the studies out per regulations). The MS *program* is kept as suspended, not discontinued: the sponsor's stated position (April/May 2026) is that MS Phase 3 development will be pursued through partnerships. Flip to discontinued if no partner materializes.source ↗
  • Apr 16, 2026Phase changeMasitinib·Multiple sclerosisPhase 3New-patient recruitment voluntarily halted across AB Science's European studies during a strategic reorganization (European authorities had questioned the company's resources/structure for running EU trials). Strategic priorities announced the same day: focus on ALS Phase 3 + AB8939 AML; 'continuation, via partnerships, of Phase III development in multiple sclerosis and Alzheimer's disease'. CT.gov flipped NCT05441488 to SUSPENDED on 2026-05-06.source ↗
  • Apr 16, 2026Phase changeMasitinib·Alzheimer's diseasePhase 3AB Science deprioritized Alzheimer's disease in its strategic reorganization: new-patient recruitment voluntarily halted across its European studies, internal resources focused on ALS Phase 3 + AB8939 AML, and 'continuation, via partnerships, of Phase III development in multiple sclerosis and Alzheimer's disease, indications requiring commercial capabilities that AB Science does not possess in-house' (restated in the 2026-05-13 annual results). AB21004 had still not started and was not among the trials formally discontinued on 2026-07-10. Program suspended pending a partner; flip to discontinued if the sponsor abandons the indication.source ↗
  • Oct 17, 2024Phase changeMasitinib·Amyotrophic lateral sclerosisPhase 3CHMP confirmed its negative opinion on the conditional MAA after re-examination (initial negative opinion 2024-06-27); the EU filing is closed and the program reverts to confirmatory Phase 3. The agreed path forward is the new confirmatory study AB23005 (FDA + first EU authorizations announced 2025-07-24; registered as NCT07174492 on 2025-09-16; per the 2026-07-10 update it has not yet begun and will start after a substantial protocol amendment is re-authorized). Health Canada had issued a Notice of Non-compliance-Withdrawal on 2024-02-26 (reconsideration eligibility granted 2024-04-03).source ↗
  • Aug 24, 2022Phase changeMasitinib·Amyotrophic lateral sclerosisFiled (NDA)AB Science filed an application for conditional marketing authorization to the EMA for masitinib in ALS (based on AB10015 plus long-term survival follow-up), while confirmatory AB19001 continued. A Health Canada NDS was also under review in this period (filing authorized 2022-02-21; Notice of Deficiency 2022-12-13).source ↗
  • Jun 28, 2022Phase changeMasitinib·Multiple sclerosisPhase 3Confirmatory Phase 3 AB20009 (MAXIMS, NCT05441488) started per ClinicalTrials.gov actual start date: masitinib titrated to 4.5 mg/kg/day vs placebo, target 800 patients with primary progressive or non-active secondary progressive MS, primary endpoint time to confirmed progression over 96 weeks.source ↗
  • Feb 2, 2021Phase changeMasitinib·Amyotrophic lateral sclerosisPhase 3Confirmatory Phase 3 AB19001 (NCT03127267) actual start date per ClinicalTrials.gov: masitinib 4.5 or 6.0 mg/kg/day + riluzole vs placebo + riluzole, 48-week ALSFRS-R primary endpoint. Context: AB10015 had completed (primary completion 2016-12-05) and the first EU MAA (Alsitek) had been refused in 2018. Note: a company-wide voluntary hold on masitinib studies ran 2021-06-01 until resumption authorizations later in 2021 (FDA authorized resuming AB19001 enrollment on 2021-11-18).source ↗
  • Dec 16, 2020ReadoutMasitinib·Alzheimer's diseasemetAB09004 topline (2020-12-16): masitinib 4.5 mg/kg/day met the ADAS-cog primary endpoint in mild-to-moderate Alzheimer's disease as add-on to standard of care (published values: between-group difference -2.15, 97.5% CI -3.48 to -0.81, p<0.001; ADCS-ADL co-primary difference +1.82, p=0.038); the independent titrated 6.0 mg/kg/day group was inconclusive.source ↗
  • Feb 20, 2020ReadoutMasitinib·Multiple sclerosismetAB07002 Phase 2b/3 topline (2020-02-20): masitinib 4.5 mg/kg/day met the primary endpoint in progressive MS, significantly reducing overall EDSS deterioration vs placebo (published value: between-group difference -0.097, 97% CI -0.192 to -0.002, p=0.0256); the independent uptitrated 6.0 mg/kg/day group was inconclusive.source ↗
  • Jul 7, 2019ReadoutMasitinib·Amyotrophic lateral sclerosismetAB10015 Phase 2/3 published (Mora et al., ALS-FTD 2020, epub 2019-07-07): in the prespecified primary population (normal progressors, ALSFRS-R decline <1.1 pts/month), masitinib 4.5 mg/kg/day + riluzole slowed 48-week ALSFRS-R decline by 3.4 points vs placebo (95% CI 0.65-6.13, p=0.016; 27% slowing), with significant ALSAQ-40, FVC and time-to-event secondaries; no effect in the broader population or 3.0 mg/kg/day cohorts.source ↗
  • Apr 1, 2013Phase changeMasitinib·Amyotrophic lateral sclerosisPhase 2/3AB10015 (NCT02588677) start per ClinicalTrials.gov (April 2013, month precision): randomized, double-blind, placebo-controlled Phase 2/3 of masitinib 3.0 or 4.5 mg/kg/day + riluzole vs placebo + riluzole in 394 ALS patients, with a blinded Phase 2 -> Phase 2/3 transition and a prospectively-declared primary population of 'normal progressors' on 4.5 mg/kg/day.source ↗
  • Jan 1, 2012Phase changeMasitinib·Alzheimer's diseasePhase 3Pivotal AB09004 (NCT01872598) started per ClinicalTrials.gov (January 2012, month precision): randomized, double-blind, placebo-controlled, four-arm study of masitinib 4.5 mg/kg/day, 4.5-to-6.0 titrated, and (initially) 3.0 mg/kg/day vs placebo, as add-on to cholinesterase inhibitor and/or memantine in mild-to-moderate AD; co-primary ADAS-Cog and ADCS-ADL at week 24. Registered PHASE3; AB Science communicates it as 'Phase 2b/3'.source ↗

Trials recruiting · 1 recruiting of 9 sponsored

  • Phase 3Masitinibn=49556 sites · France, Italy, Spain

    Efficacy and Safety of Masitinib Versus Placebo in the Treatment of ALS Patients (masitinib 4.5 or 6.0 mg/kg/day + riluzole)

    Amyotrophic Lateral SclerosisNCT03127267 ↗

Competitive landscape

Other companies developing against AB Science's targets or indications.