SCY-078 th Tr 8 th Trends in Medical My Mycology Belgrade, Serbia - PowerPoint PPT Presentation

A New Path for Antifungal Treatments SCY-078 th Tr 8 th Trends in Medical My Mycology Belgrade, Serbia October 2017

Fo Forwar ard Looking g Stat atement Statements contained in this presentation maybe, "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These risks and uncertainties include, but are not limited, to risks inherent in SCYNEXIS' ability to successfully develop SCY-078 and obtain FDA approval for SCY-078. These and other risks are described more fully in SCYNEXIS' filings with the Securities and Exchange Commission, including without limitation, its most recent Annual Report on Form 10-K under the caption "Risk Factors" and other documents subsequently filed with or furnished to the Securities and Exchange Commission. All forward-looking statements contained in this presentation speak only as of the date on which they were made. SCYNEXIS undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made. 2

SCYNEXIS at a Glance • Company created in 2000 Spin-off of Sanofi, initially as a contract service business • Transitioned to a biotechnology company in late 2014 • • SCY-078 discovered at SCYNEXIS Part of an internal platform of enfumafungin semi-synthetic derivatives • (triterpenoids) • Glucan synthase inhibitors • Public Company since May 2014 Nasdaq-listed: SCYX • • Based in Jersey City, NJ, USA 3

SCY-078 Novel Glucan Synthase Inhibitor Key Attributes (GSI) • Activity against: • Candida spp • Aspergillus spp • Pneumocystis spp • Active against azole- and most echinocandin-resistant strains Structurally district • ORAL and IV formulations from other GSIs (echinocandins) • Favorable Safety profile > 300 exposed CAS • Low risk of Drug-Drug Interactions IC 50 against purified glucan synthase from • C. albicans is 0.6 ng/mL • High tissue penetration (V dss > 8 L/kg) Different enzyme-drug interaction → • lower impact of common FKS mutations Oral Bioavailability • 4

SCY-078 Addressing Critical Needs Invasive Candidiasis ü Activity against resistant strains (azole and echinocandins) ü Ease of transition from IV to oral, without sacrificing efficacy Aspergillosis SCY-078 SCY 078 ü Invasive: Alternative approach to improve outcomes (e.g., combination therapy) Broad Spectrum ü Chronic: Oral alternative for azole–resistant IV and Oral strains Active vs. Resistant Strains High Tissue Penetration Vulvovaginal Candidiasis ü Oral fungicidal agent with high tissue penetration and activity in vaginal milieu Prophylaxis ü Oral, well-tolerated agent with activity vs . Candida/Aspergillus/Pneumocystis and low risk for DDIs 5

Potent and rapid in vitro activity against Candida spp Fungicidal against azole-susceptible and resistant isolates 6 AAC AAC, March 2017 - Vo Volume 61 - Is Issue 3

SCY-078 is less affected by FKS mutations than echinocandins (36 isolates) 7 AAC AAC, Au Augu gust 2017 - Vo Volume 61 - Is Issue 8

A collection of 100 isolates of the emerging pathogen Candida auris MIC values of SCY-078 ranged from 0.0625 µg/ml to 2 µg/ml Mode was 1 µg/ml - MIC50 = 0.5 µg/ml - MIC90 = 1 µg/ml 8 AAC AAC, July 2017 - Vo Volume 61 - Is Issue 7

SC SCY-078 078 CSP CS MCF MC AN ANF MIC 50 MI MI MIC 50 MIC 50 MI MI MIC 50 50 50 50 50 MIC 90 MI MIC 90 MI MI MIC 90 MI MIC 90 ( µ g/mL) 90 90 90 90 0.25 0.5 US Study1 2009 a US NA NA (N=15) (N=15) 0.5 0.5 US US Study 2 2012 b 0.5 0.5 NA NA (N=19) (N=19) 2 1 US US Study 3 2013 c 0.5 0.5 2 2 (N=43) (N=43) 1 1 2 4 0.25 0.25 1 1 US US Study 4 2013 d d (N=19) (N=19) 0.25 0.5 2 2 EU EU Study 1 2012 e 0.25 0.5 NA NA (N=27) (N=27) 0.5 1 0.25 0.5 EU Study 2 2015 f EU f NA NA (N=32) (N=32) 0.5 1 EU EU Study 3 2016 g 1 1 2 2 (N=36) (N=36) 2 2 4 4 a Pf Pfaller et et al. JAC 2013, b Ji Jimenez-Or Ortigosa et et al. AA AAC 2014, c Pf Pfaller et et al. AA AAC 2017, d Sh Shell et et al. AA AAC 2017, e Da Data on on file (Eu Eurofin), ), f Ma Marcos-Sa Sabrano et et al. JAC 2017 , g Bor Borrot oto-Es Esoda et et al. AS ASM Microbe e 2017 9

SCY-078 was highly active in vitro against invasive Candida and non-Candida yeast isolates in both sessile and planktonic forms Fi Figure 1 . SEM images of the activity of SCY-078 against bio fi lms (a) C. albicans, untreated control. (c) C. albicans treated with SCY-078 (0.062 mg/L). 10

SCY-078 PK/PD Target Exposure for Invasive Candidiasis - Preclinical Target therapeutic exposure, expressed as the plasma AUC 0–24 , was comparable across 3 murine models, with an upper value of 11.2 µg ・ h/ml (15.4 µM ・ h); Efficacy target 11 AAC AAC, , April il 2017 - Vo Volume 61 - Is Issue 4

SCY-078 In Vitro Activity vs. Aspergillus spp. Broad activity against Aspergillus spp, including azole–resistant strains Itraconazole-resistant Aspergillus spp (MIC, >4 μ g/ml) as determined by CLSI broth • microdilution methods SCY-078 MEC μ g/mL a (range) 0.25 (0.03-1) A. fumigatus (21) Wild-type 0.12 (0.06-0.12) A. flavus (23) Aspergillus spp 0.12 (0.03-0.25) A. terreus (18) Azole-Resistant A. fumigatus (6) (0.03 – 0.5) Aspergillus strains a MEC that encompasses 90% of isolates tested by CLSI broth microdilution method Pfaller M. A and Col., J. Antimicrobial Agents and Chemotherapy, 2013; 68(4); 858-863 & 2013; 57(2); 1065-1068. 12

MI MIC values (µg/mL mL) alone & in n combina nation n for SCY-078 078 with ot other antifungal agents ag agai ainst A. A. fum umigatus us (t (test pe performed d in du dupl plicate, repr presentative value di displ played) d) SCY-078 SC 078 with SC SCY-078 078 with SC SCY-078 078 with Is Isavuco conazole (IS (ISA) Voriconazole (VRC) Vo Am Ampho hoter ericin n B (Am AmB) MIC MI MIC MI FI FICI MI MIC MI MIC FICI FI MI MIC MI MIC FI FICI Interpretation* Interpretation* Interpretation* Alone Al ne Combo Co Al Alone ne Combo Co Al Alone ne Co Combo SCY- SC SCY- SC SCY- SC SC SCY 078 078 SC SCY- SCY- SC SCY- SC 078 078 SCY- SC SC SCY- 078 078 - ISA IS ISA IS VRC VR VR VRC Am AmB Am AmB + 078 078 078 078 078 078 + 078 078 078 078 + St Strai 078 078 IS ISA In In In n VRC VR AmB Am WT WT 4 1 0. 0.016 016 0. 0.5 0.50 0. 50 SY SY 4 1 0. 0.125 125 0. 0.25 25 0. 0.27 27 SY SY 4 4 0.016 0. 016 0. 0.5 0. 0.13 13 SY SY WT WT 4 1 0. 0.125 125 0. 0.25 25 0.28 0. 28 SY SY 4 0. 0.25 25 0. 0.5 0. 0.16 16 0.19 0. 19 SY SY 4 2 0. 0.016 016 0.5 0. 0.25 0. 25 SY SY WT WT 4 1 0.063 0. 063 0. 0.25 25 0. 0.27 27 SY SY 8 0.5 0. 0.5 0. 0.125 0. 125 0. 0.31 31 SY SY 4 4 0.016 0. 016 1 0. 0.25 25 SY SY WT WT 4 1 0.25 0. 25 0. 0.25 25 0. 0.31 31 SY SY 8 2 0. 0.25 25 0. 0.5 0. 0.28 28 SY SY 4 4 0.016 0. 016 1 0. 0.25 25 SY SY Az Azole- 4 >8 >8 0. 0.063 063 >8 >8 1. 1.02 02 AD AD 8 >16 >16 0. 0.031 031 >16 >16 1.00 1. 00 AD AD 4 2 0. 0.125 125 2 1. 1.03 03 AD AD R Azole- Az 4 >8 >8 0. 0.125 125 >8 >8 1.03 1. 03 AD AD 4 >16 >16 1 >16 >16 1.25 1. 25 AD AD 4 4 0. 0.016 016 1 0.25 0. 25 SY SY R SC SCY-078 078 in combination with Voriconazole, Isavuconazole and Amphotericin B de demon onstrates synergistic activity ag ac agai ainst the maj ajority of A. A. fumigat atus is isola lates tested 13

Neutropenic mice model 110 • 100 of disseminated 90 aspergillosis (IV inoculum) 80 Percent survival 70 Treatment for 7 days: • 60 SCY-078 PO at 7.5 and 10 • 50 mg/kg q12h Vehicle Vehicle 40 F16216 - Vehicle PO q12h SCY-078 7.5mg dose SCY-078 7.5mg dose Caspofungin IP at 5mg/kg • F16216 - SCY-078 7.5mg/kg PO q12h 30 SCY-078 10mg dose SCY-078 10mg dose F16216 - SCY-078 10mg/kg PO q12h Ambisome IV at 10mg/kg • 20 Caspofungin Caspofungin F16216 - Caspofungin 5mg/kg IP q24h Ambisome Ambisome 10 F16216 - AmBisome 10mg/kg IV q24h Observation for 14 days • 0 0 50 100 150 200 250 300 350 Treatment Monitoring SCY-078 exposure Number of hours post-infection • needed for efficacy A. fumigatus (F16216) AUC 0-24hr 15 - 20 μ M•hr • Azole-resistant - TR34 L98H 14

SCY-078 in Combination with Azole for Invasive Pulmonary Aspergillosis -Rabbit Model Neutropenic rabbit model of • pulmonary aspergillosis Cumulative Survival Probability (%) 100 Treatment for 12 days • 75 Control 66% N=6 / group (QD doses): • SCY2.5 SCY-078 (IV) at 2.5 or SCY7.5 • 7.5mg/kg ISA40 50 SCY2.5+ISA40 33% Isavuconazole (PO) 40mg/kg • SCY7.5+ISA40 SCY-078 2.5 + Isavuconazole • 25 SCY-078 7.5 + Isavuconazole • £ Preliminary results 0 • 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Time Study conducted at Cornell • Combination of SCY-078 + Isavuconazole University, NY by Dr. Tom resulted in improved survival Walsh 15