BioMarin Pharmaceutical Inc. · NASDAQ:BMRN
BioMarin Pharmaceutical — Technical Presentation (February 2024)
22 slides from BioMarin Pharmaceutical's technical presentation, Feb 28, 2024
Slide 1: Disclosure – conflict of interest
Internal use Disclosure – conflict of interest ✓ I have the following potential conflict(s) of interest to report • Name of commercial company: BioMarin Pharmaceutical Inc. • Stock shareholder: BioMarin Pharmaceutical In. 28.02.202 1 4
Slide 2: Exploring actionable strategies to improve AAV5-hFVIII-SQ durability and optimize gene expression
Internal use Exploring actionable strategies to improve AAV5-hFVIII-SQ durability and optimize gene expression Presenter: Simon Harris Bridget Yates, Dafna J. Groeneveld, Stephen Scheeler, Britta Handyside, Isaac Villalpando, Suresh Agarwal, Stuart Bunting, Sylvia Fong
Slide 3: Disclosures
Internal use Disclosures • All are employees and shareholders of BioMarin Pharmaceutical Inc. 28.02.202 3 4
Slide 4: AAV gene therapy for haemophilia A: FVIII activity per CSA
Internal use AAV gene therapy for haemophilia A 250 Year 1 Week 312 CSA FVIII Activity Year 2 • Efficacy Year 3 Mean 9.8 IU/dL • Haemostatic benefit FVIII activity per CSA (IU/dL) Year 4 200 Year 5 Median 5.6 IU/dL relative Year 6 Week 312 OSA FVIII Activity to FVIII prophylaxis 150 Mean 17.0 IU/dL
Slide 5: Decline/variability in expression observed in AAV-FVIII trials
Internal use Decline/variability in expression observed AAV-FVIII trials • Understanding the mechanism leading loss of expression and variable response is needed to identify intervening strategies • Loss of expression maybe related to decrease AAV episome transcription • Variable response maybe rela
Slide 6: Decline of FVIII expression
Internal use Decline of FVIII expression Actionable strategy to reverse decline 28.02.202 6 4
Slide 7: Stable episomes persist following AAV-FVIII GT
Internal use Stable episomes persist following AAV- FVIII GT 6 months 6 months 2.6 to 4.1 years 8 to 12 years + PSDNase + BamHI + PSDNase + PSDNase + PSDNase JU** ANG FLO MG MZ VC TB AL EL X H-T dimer monomer TB: Haemophilia A dog untreated control 28.02.202 Sihn CR et al. Mol Ther Methods Clin Dev
Slide 8: Expression profiles in mice are similar to humans
Internal use Expression profiles in mice are similar to humans 0.8 Serum A1AT (mg/mL) 0.6 Individual mice: 6E13 vg/kg 0.4 0.2 0.0 0 10 20 30 40 50 60 Time (weeks) 28.02.202 Pasi KJ et al. Haemophilia 2021;27:947-56; Handyside et al.,Vector genome loss and epigenetic modifications mediate 8 4 decline
Slide 9: Multiple lines of evidence suggest low RNA production contributes to decline of FVIII expression
Internal use Multiple lines of evidence suggest low RNA production contributes to the decline of FVIII expression or low response to AAV-GT Longitudinal Murine Study: Decreased interaction of active histones with episomal genomes may mediate the decline in transgene expression over time (Handyside e
Slide 10: Genome accessibility may mediate decline in RNA expression in mice
Internal use Genome accessibility may mediate decline in RNA expression in mice Vector genome accessibility Interaction with active Histone H3H27ac Peak Final Peak Final (24 wk) (57 wk) (24 wk) (57 wk) * Measured by ATAC-Seq * Measured by CHIP-Seq 28.02.202 Handyside et al.,Vector genome loss and ep
Slide 11: Transcriptional regulation contributes to decline in expression in human
Internal use Transcriptional regulation contributes to decline in expression in human Effect of Accutane* on AAV5-hFVIII-SQ FVIII plasma levels decline following Accutane Rx in (valoctocogene roxaparvovec) occurs at clinical trial participant who received 6e13 vg/kg of the RNA level in primary human
Slide 12: Human Biopsy Analysis: In one non-responder, hepatocytes expressed little RNA
Internal use Human Biopsy Analysis: In one non- responder, hepatocytes expressed little RNA despite similar levels of vector genome Episomal vector are similar Low RNA to DNA ratio in low responder (P15) Ratio of RNA to DNA AAV episomes can persist over time and assimilate into chromatin with a typi
Slide 13: HDACi reverses drug-induced ROCTAVIAN silencing in vitro
Internal use HDACi reverses drug-induced ROCTAVIAN silencing in vitro Hypothesis: Modifying the chromatin interaction with AAV-episomes using epigenetic modulators may increase accessibility of vector genomes potentially reactivating vector genome expression 28.02.202 13 4
Slide 14: HDACi reverses drug-induced ROCTAVIAN silencing in vitro
Internal use HDACi reverses drug-induced ROCTAVIAN silencing in vitro ~48x • At all doses tested, no toxicity was observed in human primary hepatocytes ~37x • Romidepsin increased transgene expression without drug-induced silencing, though to a ~13x lesser degree Cmax 377 ng/mL= 1x Cmax 28.02.202 14
Slide 15: Modeling of HDACi Doses Needed to Reactivate Expression
Internal use Modeling of HDACi Doses Needed to Reactivate Expression • Modeling performed to predict exposures needed for a 3-fold increase in expression in in- vivo experiments using: • human and preclinical PK data (literature) • in vitro primary human hepatocyte data (in-house) Reactivation: <20%
Slide 16: Pilot mouse study indicated Romidepsin can increase AAV expression
Internal use Pilot mouse study indicated Romidepsin can increase AAV expression Potentiation model: Romidepsin treatment 4-weeks following in C57Bl/6 mice Human Equivalent Dose 0.3 mg/m2 1.5 mg/m2 6 mg/m2 • A single dose of HDACi moderately increased A1AT levels at doses ≤ 2 mg/kg (~40% of clinical
Slide 17: Variability of FVIII expression
Internal use Variability of FVIII expression Actionable strategy to improve FVIII secretion 28.02.202 17 4
Slide 18: Evaluating actionable strategies to increase FVIII secretion
Internal use Evaluating actionable strategies to increase FVIII secretion Increased BDD-FVIII synthesis can lead to misfolding and aggregation • B-domain deleted FVIII-SQ protein is inefficiently folded and secreted from the ER1 • Studies have demonstrated reducing ER stress with antioxidants can in
Slide 19: Phenylbutyrate significantly increases BDD-FVIII protein secretion
Internal use Phenylbutyrate significantly increases BDD-FVIII protein secretion Sodium phenylbutyrate (4-PBA) • Small molecular chaperone • Reduces UPR/ER stress1 • Approved in EU and US n=3 independent experiments 195 ng/mL = 1x Cmax 12 compounds were screened in HepG2 cells transduced with AAV5-hF
Slide 20: Phenylbutyrate has no effect on transgene transcriptional efficiency
Internal use Phenylbutyrate has no effect on transgene transcriptional efficiency 195 ng/mL= 1x Cmax Sodium phenylbutyrate had no effect on transgene expression in primary human hepatocytes Basseri, Sana et al. “The chemical chaperone 4-phenylbutyrate inhibits adipogenesis by modulating the unfolded
Slide 21: Key summaries
Internal use Key summaries • Two actionable strategies were identified to potentially improve patient outcomes following AAV5-hFVIII-SQ treatment • Epigenetic modulators (HDACi) show potential for reactivating AAV transgene expression both in vitro and in vivo at low doses • The use of chemical chap
Slide 22: Acknowledgements
Internal use Acknowledgements • This study was funded by BioMarin Pharmaceutical Inc. 28.02.202 22 4
BioMarin Pharmaceutical — Technical Presentation (February 2024) on 6ix