New Compounds for Spinal Muscular Atrophy

1. New Compounds for Spinal Muscular Atrophy CONFIDENTIAL Jill Heemskerk, PhD Office of Translational Research National Institute of Neurological Disorders and Stroke

2. Why NIH Chose SMA for a Drug Development Pilot Urgent unmet medical need Number one genetic killer of infants Incidence: 1 in 6000 live births No available treatments Scientific opportunity Known cause = loss of SMN1 gene Defined treatment strategy: increase SMN2 Compounds identified that increase SMN2 in vitro

3. Indoprofen:Starting Point for Medicinal Chemistry • Indoprofen increases SMN protein in vitro: • SMN reporter assay • SMN protein in patient fibroblasts • Indoprofen improves in utero survival of SMA mice -B. Stockwell: Lunn et al, 2004

4. Optimizing Indoprofen for SMA Chemistry Goals • Increase potency • Eliminate toxicity • Cox Inhibition • Improve BBB penetration Lactam Phenyl Acetic Chain Substitutions: alkyl, halo, methoxy, aryl, heteroaryl Varied at methyl site, length of chain, and CO2H Varied heterocycle Benzo Substitutions: alkyl, halo, methoxy, cyano, amino, aryl, heteroaryl CONFIDENTIAL

5. Chemistry Improves Potency and Activity Androphy/Zhou SMN-2 reporter assay ex6 ex7 ex8 Luciferase ~1300 Indoprofen analogs synthesized and tested luminescence Log concentration (µM) -AMRI CONFIDENTIAL

6. SMA Project Compounds Increase SMN-containing Gems in Patient Fibroblasts Untreated 100nM SP869 5mM VPA M. Lorson, University of Missouri Confidential

7. SMA Project Compounds Increase SMN Protein in Patient Fibroblasts: Western Blots 2.5 2.0 1.5 SMN:Actin 1.0 0.5 1 2 3 0.0 Patient Patient Carrier DMSO DMSO 0.1 uM Drug m Pt C D Pt C D SMN Actin Brenda Fung, CombinatoRx CONFIDENTIAL

8. Stop codon interrupts Luciferase: AUG UAA Luciferase Activity UGA - Compound + Compound SMA Project Compounds Stimulate Translational Read-through -Courtesy Ellen Welch, PTC Therapeutics CONFIDENTIAL

9. Indoprofen Positive Control SMA Project Compounds Induce Translational Read Through -E. Welch, A. Bhattacharyya PTC Therapeutics CONFIDENTIAL

10. Half-life Safety Pharmaceutics Potency Brain/Plasma IP Chemistry Efficacy Indoprofen Chemical Analogs are Drug-like PK: • Good brain penetrance • Orally bioavailable • Rodent half lives around 2 hours • Excellent human microsome stability Tox: • Well-tolerated in rodents (up to 50mg/kg, neonatal mice, 14 day dosing) • Favorable CYP, genotox, hERG, broad target profiles • Abolished Cox inhibition IP: • 2 NIH patents cover composition of matter CONFIDENTIAL

11. SMA Project FLOW PLAN Splice Protein Binding Microsome (h, r, cyno) Caco2 Solubility Cerep profile representative Gems Microsome (m, d) Rat PK, B/P Cerep Profile Metabolite ID hERG Cyno or dog PK Single and multiple dose tolerance Cyp inhibition Ames Western August2010 Candidate Mouse Model Mouse PK Confidential

12. Timeline to Phase I Clinical Trial 3Q ‘10 4Q’10 3Q’11 1Q’11 2Q’11 200gm Synthesis GLP Synthesis Radio Synthesis Dose Ranging Tox 14-Day GLP Tox 28-Day GLP Tox Safety Pharmacology ADME GMP Synthesis Formulation Development Regulatory Submission First in Human Trial CONFIDENTIAL

13. Lead Development John McCall Graham Johnson Paul Pearson Keith Houck Tony Bannon NINDS Amelie Gubitz SAIC Sabina Robinson Jim Romano CombinatoRx Jane Staunton Brenda Fung Yang Wang Shakira Olanrewaju AMRI Albany Keith Barnes John Lippert Nick Mayhew Ping Chen Steve Steffke Michelle Pilato AMRI Bothell Svetlana Dobritsa Michelle Luche Sangeeta Chitnis RTI Jim Matthews Ronnie Maitra Kimberly Ehman Acknowledgements • Lorson Lab • Chris Lorson • Virginia Mattis • Monique Lorson • PTC Therapeutics • Ellen Welch • Nikolai Naryshkin • Sergey Paushkin • Anu Bhattacharyya • Key Contributions • Elliot Androphy • Jianhua Zhou • Brent Stockwell • Charlotte Sumner • Arthur Burghes • Glenn Morris • Meg Winberg • Jill Jarecki