Forward-looking statements This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that involve substantial risks and uncertainties. All statements

An Expression Makes a World of

Difference February 2021 Exhibit 99.1

Forward-looking statements This

presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that involve substantial risks and uncertainties. All statements, other than statements of historical facts, contained in

this presentation, including statements regarding our strategy, research and clinical development plans, collaborations, future operations, future financial position, future revenues, projected costs, prospects, plans and objectives of management,

are forward-looking statements. The words "anticipate," "believe," "estimate," "expect," "intend," "may," "plan," "predict," "project,"

"target," "potential," "will," "would," "could," "should," "continue," and similar expressions are intended to identify forward-looking statements, although not all

forward-looking statements contain these identifying words. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking

statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various important factors, including our ability to: advance the development

of our programs, including SY-1425, SY-2101 and SY-5609, under the timelines we project in current and future clinical trials; demonstrate in any current and future clinical trials the requisite safety, efficacy and combinability of our drug

candidates; replicate scientific and non-clinical data in clinical trials; successfully develop a companion diagnostic test to identify patients with the RARA biomarker; obtain and maintain patent protection for our drug candidates and the freedom

to operate under third party intellectual property; obtain and maintain necessary regulatory approvals; identify, enter into and maintain collaboration agreements with third parties, including our ability to perform under our collaboration

agreements with Incyte Corporation and Global Blood Therapeutics; manage competition; manage expenses; raise the substantial additional capital needed to achieve our business objectives; attract and retain qualified personnel; and successfully

execute on our business strategies; risks described under the caption "Risk Factors" in our Annual Report on Form 10-K for the year ended December 31, 2019, our Quarterly Report on Form 10-Q for the quarter ended September 30, 2020,

and our Current Report on Form 8-K filed on January 19, 2021, each of which is on file with the Securities and Exchange Commission (SEC); and risks described in other filings that we may make with the SEC in the future. In addition, the extent to

which the COVID-19 outbreak continues to impact our workforce and our discovery research, supply chain and clinical trial operations activities, and the operations of the third parties on which we rely, will depend on future developments, which are

highly uncertain and cannot be predicted with confidence, including the duration and severity of the outbreak, additional or modified government actions, and the actions that may be required to contain the virus or treat its impact. Any

forward-looking statements contained in this presentation speak only as of the date this presentation is made, and we expressly disclaim any obligation to update any forward-looking statements, whether because of new information, future events or

Accelerating our vision Targeted

hematology therapy franchise Gene control discovery engine Selective CDK inhibitor franchise Fully integrated biopharmaceutical company

Rapidly advancing toward being a

commercial-stage company Leading gene control platform 3 clinical programs Experienced leadership team Well-funded beyond multiple data readouts 2 potential NDAs in 2024

Program Indication Early Clinical

IND- Enabling Mid-Clinical Pivotal Pivotal Commercial Rights SY-1425 (oral RAR agonist) Newly diagnosed HR-MDS (w/aza) Newly diagnosed unfit AML (w/ven+aza) SY-2101 (oral ATO) Newly diagnosed APL (w/ATRA) SY-5609 (oral CDK7 inhibitor)

Select solid tumors Advancing a growing clinical-stage pipeline for targeted patient populations SY-1425 is approved in Japan as Amnolake (tamibarotene) for patients with relapsed/refractory APL Americas, Europe, Australia, Israel

& Russia Ph3 Q12021 Ph2 2H2021 Dose confirm 2H2021; Ph3 2022 Expansion 2H 2021

SY-1425 Selective oral RARa

Clear vision for SY-1425 in

RARA-positive cancers Now Registration strategy in MDS Triplet strategy in unfit AML Next Registration-enabling studies Commercialization Vision Foundation of care for all RARA+ patients

Compelling data and clear path forward

for SY-1425 1de Botton, ASH 2020; 2Fiore, ASH 2020 SY-1425/aza induces high CR rates, rapid onset of action and meaningful durability in RARA+ ND unfit AML1 SY-1425 safety profile supports multiple combination opportunities New translational data

suggest RARA biomarker selects for AML patients less likely to respond to ven/aza2 HR-MDS is closely related to AML with opportunity to set new standard of care Strong rationale in targeted subset ~ 30% of AML and MDS patients RARA+ Phase 3 trial w/

aza in RARA+ ND HR-MDS Phase 2 trial with ven/aza in RARA+ ND unfit AML

High CR rates, rapid onset of action,

and clinically meaningful durability in RARA-positive ND unfit AML 89% of CRs were deep molecular or cytogenetic CRs Responses seen irrespective of mutation or cytogenetic risk Response rates in RARA-negative patients comparable to

historical rates for single-agent aza1-3 1.2 months Time to response 10.8 months Duration of response 18 months Overall survival for complete responders Data from 18 response evaluable RARA-positive and 28 response evaluable RARA-negative patients

presented at ASH 2020 meeting 61% CR/CRi Rate 67% Transfusion independence 67% ORR 1Dombret, Blood 2015; 2Fenaux, JCO 2010; 3Thepot, American Journal of Hematology 2014

Generally well-tolerated combination

in ND unfit AML patients No increase in neutropenia, anemia and thrombocytopenia compared to single-agent aza Majority of non-hematologic AEs are low grade and reversible aIncludes all enrolled ND unfit patients, N=51. Data presented at ASH 2020

ND HR-MDS represents ideal

opportunity for SY-1425 in combination with azacitidine HR-MDS and AML on a disease continuum; distinguished only by % blasts in marrow More than half of patients progress to AML1 Neutropenia may lead to infection-related complications,

including death2 HR-MDS is closely related to AML HMAs are only approved agents Low CR rates ranging from 5-25%, with OS estimated between 15-25 months1, 3-4 Only 45% of patients achieve transfusion independence3 Opportunity to set new

standards of care Single-agent SY-1425 demonstrated clinical activity in R/R HR-MDS Analyses of RARA+ "low blast count" AML patients in Phase 2 trial demonstrated CR/CRi rate of 67% (n=6) No additive neutropenia/anemia Our data suggest

strong potential for SY-1425 in MDS 1Greenberg, Blood 2012; 2Toma, Haematologica 2012; 3VIDAZA (azacitidine) USPI; 4DACOGEN (deitabine) USPI

Initiating Phase 3 trial in ND

RARA-positive HR-MDS patients FDA feedback supports: Focus on RARA+ population CR as primary endpoint for accelerated/ full approval Azacitidine as appropriate comparator Key Milestones Initiate registration trial 1Q 2021 Potential NDA 2024 Phase 3

trial 190 patients randomization (2:1) SY-1425 + azacitidine Azacitidine alone Primary endpoint CR rate

New translational data support the

potential for the RARA biomarker to enrich for patients unresponsive to standard of care 30% of patients do not respond to upfront treatment with ven/aza Venetoclax resistance associated with monocytic phenotype,1-3 which includes low BCL2 and

high MCL-1 expression Most RARA+ patients, including those who achieved CR/CRi in SY-1425 trial, have this monocytic phenotype4 Analysis of SY-1425 Trial Patient Samples Monocytic Expression Signature p=7x10-5 1Zhang, Nature

2018; 2Kuusanm ki, Haematologica 2019; 3Pei, Cancer Discovery 2020; 4Fiore, ASH 2020

Randomized portion of trial ~80

patients SY-1425 + venetoclax + azacitidine Venetoclax + azacitidine randomization (1:1) Safety lead-In ~15 patients Initiating randomized Phase 2 trial of triplet regimen in ND RARA-positive unfit AML patients Plan to also evaluate triplet as

salvage strategy for patients in control arm who don't respond to ven/aza Key Milestones Initiate Phase 2 trial w/safety lead-in 2H 2021 Initial data from Phase 2 trial 2022 Primary endpoint Composite CR rate

ND HR-MDS and unfit AML represent

significant market opportunities ~30% of all AML and MDS patients are RARA-positive Newly diagnosed HR-MDS ~15,000 new cases annually in US and EU Expected to grow into $1B+ market No new approved agents, aside from HMAs, in a decade Existing

options offer limited efficacy Sources: Epidiemology and Sales projections from DRG Myelodysplastic Syndromes-Landscape & Forecast-Report 2020 and from DRG Acute Myelogenous Leukemia-Landscape & Forecast-Report 2020; Prevalence of

RARA-positive patients based on data presented at ESH 2017 and ESH 2019; Resistant Ven population - Dinardo, NEJM 2020; Dinardo, Blood 2019 Newly diagnosed unfit AML Over 18,000 new cases annually in US and EU Expected to grow into $2B+ market

~1/3 of patients don't respond to SOC ven/aza and have poor prognosis

SY-2101 Novel oral form of arsenic

Our vision for SY-2101 Now Acquired

asset Next Registration-enabling study Commercialization Vision Standard of care for APL patients

SY-2101: Highly synergistic with our

advancing targeted heme franchise Strategic opportunity as we accelerate toward becoming a commercial-stage company Potential to become standard of care in APL Novel oral capsule of arsenic trioxide (ATO) Clinical-stage asset with opportunity

for accelerated approval based on molecular CR Potential NDA filing in 2024 Orphan drug designation granted in US and EU Issued patents provide opportunity to extend exclusivity Capitalizes on our expertise to build a leadership position in targeted

therapies for hematologic disorders

IV ATO is transformative therapy for

APL patients but comes with heavy treatment burden >80% Cure rates IV ATO oral ATRA Significant opportunity to reduce treatment burden, increase access and reduce health care costs and utilization Current course of treatment involves up to

140 two- to four-hour infusions over nearly a year Induction - up to 60 days of daily infusions until CR is achieved Consolidation - 80 days of 5 days/week for 4 weeks/cycle for 4 cycles/treatment course NCCN AML treatment guidelines

(Nov 2020) Trisenox (arsenic trioxide) USPI Standard of care

Opportunity for SY-2101 to become

standard of care in significant market APL is ~10 % of AML Newly diagnosed APL Genetic fusion of RARA and PML genes ~2,000 patients diagnosed in US and Europe annually1,2 ~$250 million overall market opportunity3 Opportunity to become the standard

of care and be served with targeted sales force 1Tallman 2008 Semin Hematol 2NCI Surveillance, Epidemiology and End Results Program - 2020 Acute Myeloid Leukemia 3IBM Truven Redbook pricing for Trisenox

Completed Phase 1 PK study of

SY-2101 Ravandi et al 2020 Haematologica Trisenox (arsenic trioxide) USPI Three dosing cohorts: 5, 10 and 15 mg orally Once daily 12 patients with advanced hematologic malignancies Median age: 76.5 Prior lines of therapy: Up to 5 Generally

well-tolerated with low-grade AEs Lower adverse events in liver enzymes (8.3%) compared to IV ATO (~44% ) Lower QTc prolongation (8.3%) compared to IV ATO (25%) Good bioavailability, with generally dose proportional PK Achieves exposure levels

(AUC and Cmax) in range of approved IV ATO dose Dosing Patient population Safety Pharmacokinetics

Advancing SY-2101 toward

registration-enabling Phase 3 trial FDA feedback supports: Molecular CR as primary endpoint for accelerated approval Event-free survival (EFS) as primary endpoint for full approval Dose confirmation study SY-2101 + ATRA Pivotal Phase 3 Trial ~150

newly diagnosed APL patients Primary endpoints Molecular CR rate and EFS in comparison to historical IV ATO data Key Milestones Initiate dose confirmation study 2H 2021 Confirmatory dose/PK data 1H 2022 Initiate Phase 3 2022 Potential NDA 2024

SY-5609 Selective oral CDK7

Our vision for SY-5609 Now Phase 1

trial Initial combination with fulvestrant Next Phase 1 expansion Additional combinations Vision Transformative targeted therapy for difficult-to-treat cancers

CDK7i disrupts the CDK and

transcriptional activity needed to progress through the cell cycle Altered Rb pathway Activating mutations in cell signaling CDK1 CDK2 Selective CDK7 inhibition attacks two fundamental processes in cancer Cell Cycle Transcription CDK7i MYC MYB MCL1

MCL1 Apoptosis CDK7i has been shown preclinically to decrease expression of these transcription factors and proteins Transcription Transcription CDK4/6 M G2 S G1 Apoptosis

Three-pronged development strategy

to maximize potential of SY-5609 Compelling preclinical data + Strong mechanistic rationale + High unmet need Leveraging Rb pathway alterations Overcoming CDK4/6 resistance Exploiting transcriptional and cell cycle dependencies

Rb alterations associated with

deeper and more sustained responses in preclinical studies of breast, lung and ovarian cancers 29% of basal breast cancer patients1 ~1/3 of HR+ breast cancer patients post CDK4/6 inhibitors2 75-90% of small cell lung cancer patients3 67% of

high-grade serous ovarian cancer patients4 Supports Phase 1 trial enriched for populations with Rb alterations 1TCGA Breast Cancer Integrated Analysis, Nature 2012 2Spring et al., San Antonio Breast Cancer Symposium 2018 3Cancer Med. 2019 Apr; 8(4):

1459-146 4TCGA Ovarian Cancer Integrated Analysis, Nature 2011 No Rb alterations Rb alterations % TGI Tumor growth inhibition in all breast, lung and ovarian cancer PDX models tested Data presented in October 2019 at EORTC-NCI-AACR Conference

Overcoming treatment resistance:

SY-5609 induces robust responses in preclinical HR+ breast cancer models Palb: palbociclib, 50mg/kg once daily, oral; Flv: fulvestrant, 2.5mg/kg once weekly, sub-cutaneuous, SY-5609: 6 mg/kg once daily, oral CDK4/6 inhibitor resistant model CDK4/6

inhibitor and hormonal resistant model 0 10 20 30 Days 40 0 500 1000 1500 2500 Tumor Volume (mm3) 2000 50 Vehicle SY-5609 SY-5609 + Flv Flv Palb Vehicle SY-5609 SY-5609 + Flv Flv Palb 0 10 20 30 Days 40 0 500 1000 1500 2500 Tumor Volume (mm3) 2000

50 Data presented in October 2019 at EORTC-NCI-AACR Conference

Targeting dependencies on

transcription and cell cycle control induces robust responses in preclinical colorectal and pancreatic cancer models 67% (20/30) of models demonstrated 50% TGI 23% (7/30) demonstrated deep responses of 90% TGI Deep responses enriched

in BRAF-mutant (5/10) models CRC data presented in May 2020 at ASCO Virtual Symposium; pancreatic cancer data is internal company data KRAS-mutant model 75% (6/8) of models demonstrated 50% TGI Regressions seen in 50% (4/8) of models

Responses observed in CDKN2A-mutant and non-mutant and TP53-mutant and non-mutant models BRAF-mutant model Colorectal Cancer Pancreatic Cancer 0 10 Days 20 0 500 1000 1500 2000 Tumor Volume (mm3) 2500 30 Vehicle SY-5609 (6mpk QD) Vehicle SY-5609 0