PART I. FINANCIAL INFORMATION [Item 1. Unaudited Financial Statements](index=5&type=section&id=Item%201.%20Unaudited%20Financial%20Statements) The company presents its unaudited condensed consolidated balance sheets, statements of comprehensive loss, cash flows, and related notes [Condensed Consolidated Balance Sheets](index=5&type=section&id=Condensed%20Consolidated%20Balance%20Sheets) | ASSETS (In thousands) | March 31, 2021 | December 31, 2020 | | :--- | :--- | :--- | | Cash and cash equivalents | $64,386 | $115,243 | | Short-term investments | $206,949 | $177,822 | | Total current assets | $278,947 | $298,864 | | Total assets | $279,672 | $300,613 | | **LIABILITIES AND STOCKHOLDERS' EQUITY** | | | | Total current liabilities | $24,568 | $18,872 | | Total long-term liabilities | $26,899 | $29,553 | | Total liabilities | $51,467 | $48,425 | | Total stockholders' equity | $228,205 | $252,188 | [Condensed Consolidated Statements of Comprehensive Loss](index=6&type=section&id=Condensed%20Consolidated%20Statements%20of%20Comprehensive%20Loss) | (In thousands, except share and per share data) | Three Months Ended March 31, 2021 | Three Months Ended March 31, 2020 | | :--- | :--- | :--- | | Revenue: License fees | $379 | $379 | | Total revenues | $379 | $379 | | Operating expenses: Research and development | $21,870 | $9,562 | | Operating expenses: General and administrative | $5,672 | $5,917 | | Total operating expenses | $27,542 | $15,479 | | Loss from operations | $(27,163) | $(15,100) | | Net loss | $(27,723) | $(15,236) | | Comprehensive loss | $(27,710) | $(15,188) | | Net loss per share attributable to common stockholders—basic and diluted | $(0.54) | $(0.56) | [Condensed Consolidated Statements of Cash Flows](index=7&type=section&id=Condensed%20Consolidated%20Statements%20of%20Cash%20Flows) | (In thousands) | Three Months Ended March 31, 2021 | Three Months Ended March 31, 2020 | | :--- | :--- | :--- | | Net cash used in operating activities | $(22,589) | $(15,925) | | Net cash used in investing activities | $(29,228) | $(19,053) | | Net cash provided by financing activities | $960 | $54,998 | | Net (decrease) increase in cash, cash equivalents and restricted cash | $(50,857) | $20,020 | | Cash, cash equivalents and restricted cash—end of period | $64,501 | $44,744 | [Notes to Condensed Consolidated Financial Statements](index=8&type=section&id=Notes%20to%20Condensed%20Consolidated%20Financial%20Statements) - Syndax Pharmaceuticals, Inc is a clinical-stage biopharmaceutical company incorporated in Delaware in 2005, focusing on developing cancer therapies[22](index=22&type=chunk) - The company's financial statements are prepared in conformity with U.S GAAP, and the interim results are **not necessarily indicative of future periods**[23](index=23&type=chunk) - The COVID-19 pandemic could impact clinical development timelines, manufacturing, and regulatory efforts, posing a **material adverse effect** on business, financial condition, results of operations, and growth prospects[26](index=26&type=chunk)[27](index=27&type=chunk) - Revenue from contracts with customers is solely derived from a license agreement with Kyowa Kirin, Co, Ltd (KKC) for entinostat in Japan and Korea, with **$0.4 million recognized** for the three months ended March 31, 2021 and 2020[30](index=30&type=chunk)[34](index=34&type=chunk) Net Loss per Share Attributable to Common Stockholders (In thousands, except share and per share data): | Metric | Three Months Ended March 31, 2021 | Three Months Ended March 31, 2020 | | :--- | :--- | :--- | | Net loss attributable to common stockholders | $(27,723) | $(19,142) | | Net loss per share—basic and diluted | $(0.54) | $(0.56) | | Weighted-average common shares | 51,499,831 | 34,328,640 | - The company has significant license agreements for its product candidates: AbbVie License Agreement for Menin Assets (SNDX-5613), UCB License Agreement for axatilimab, and Bayer Agreement for entinostat[38](index=38&type=chunk)[39](index=39&type=chunk)[45](index=45&type=chunk) - The E2112 trial for entinostat **did not achieve its primary endpoint**, leading the company to deprioritize the entinostat program[43](index=43&type=chunk) Fair Value Measurements (In thousands): | Asset Category | March 31, 2021 (Total Carrying Value) | December 31, 2020 (Total Carrying Value) | | :--- | :--- | :--- | | Cash and cash equivalents | $64,386 | $115,243 | | Short-term investments | $206,949 | $177,822 | | Total assets at fair value | $271,335 | $293,065 | Accrued Expenses and Other Current Liabilities (In thousands): | Category | March 31, 2021 | December 31, 2020 | | :--- | :--- | :--- | | Accrued clinical costs | $8,997 | $7,132 | | Accrued compensation and related costs | $1,579 | $3,213 | | Total accrued expenses and other current liabilities | $11,414 | $11,246 | Stock-Based Compensation Expense (In thousands): | Category | Three Months Ended March 31, 2021 | Three Months Ended March 31, 2020 | | :--- | :--- | :--- | | Research and development | $903 | $532 | | General and administrative | $1,864 | $1,297 | | Total | $2,767 | $1,829 | - The company entered into a loan and security agreement with Hercules Capital, Inc in February 2020 for up to **$30.0 million**, with **$20.0 million funded**[61](index=61&type=chunk)[63](index=63&type=chunk) Changes in Stockholders' Equity (In thousands, except share data): | Metric | Balance as of Dec 31, 2020 | Stock-based compensation expense | Net loss | Balance as of Mar 31, 2021 | | :--- | :--- | :--- | :--- | :--- | | Additional Paid-In Capital | $820,815 | $2,767 | — | $824,542 | | Accumulated Deficit | $(568,628) | — | $(27,723) | $(596,351) | | Total Stockholders' Equity | $252,188 | $2,767 | $(27,723) | $228,205 | [Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations](index=20&type=section&id=Item%202.%20Management's%20Discussion%20and%20Analysis%20of%20Financial%20Condition%20and%20Results%20of%20Operations) Management discusses the company's business overview, clinical progress, financial results, liquidity, and capital resources [Company Overview](index=20&type=section&id=Company%20Overview) - Syndax Pharmaceuticals is a clinical-stage biopharmaceutical company focused on cancer therapies, with lead product candidates **SNDX-5613** and **axatilimab**[77](index=77&type=chunk) - The company has no approved products, incurring significant net losses since inception, with a **net loss of $27.7 million** and an **accumulated deficit of $596.4 million** as of March 31, 2021[78](index=78&type=chunk) Key Financials (In millions): | Metric | March 31, 2021 | | :--- | :--- | | Net Loss | $(27.7) | | Accumulated Deficit | $(596.4) | | Cash, Cash Equivalents and Short-term Investments | $271.3 | [Clinical Developments](index=20&type=section&id=Clinical%20Developments) - SNDX-5613 showed positive data in R/R acute leukemias, with an **overall response rate (ORR) of 48%** and **67% of responders achieving MRD- status**[80](index=80&type=chunk)[81](index=81&type=chunk)[82](index=82&type=chunk) - Enrollment is complete for the Phase 2 expansion of axatilimab in cGVHD, with topline data from the pivotal **AGAVE-201 trial anticipated in 2023**[83](index=83&type=chunk)[84](index=84&type=chunk)[85](index=85&type=chunk) [COVID-19 Business Update](index=21&type=section&id=COVID-19%20Business%20Update) - The company has implemented business continuity plans to mitigate COVID-19 impacts, though the pandemic could still **materially adversely affect** business operations[86](index=86&type=chunk)[90](index=90&type=chunk) - Supply chain for key product candidates is currently adequate, but the pandemic could cause **disruptions** and **delays in trial activities**[87](index=87&type=chunk)[88](index=88&type=chunk) - Persistent disruption of global financial markets due to COVID-19 could **hinder access to additional capital**, negatively affecting operations[89](index=89&type=chunk) [Financial Overview](index=21&type=section&id=Financial%20Overview) - The company has not generated product revenues to date, with all revenue derived from the **KKC license agreement** for entinostat[91](index=91&type=chunk)[92](index=92&type=chunk) - Research and development expenses are central to the business model and are expected to increase, totaling **$327.1 million** from inception through March 31, 2021[95](index=95&type=chunk) - General and administrative expenses are expected to increase with headcount and preparation for **potential commercialization**[99](index=99&type=chunk)[100](index=100&type=chunk)[101](index=101&type=chunk) [Results of Operations](index=24&type=section&id=Results%20of%20Operations) Comparison of Three Months Ended March 31, 2021 vs. 2020 (In thousands): | Metric | 2021 | 2020 | Change ($) | Change (%) | | :--- | :--- | :--- | :--- | :--- | | License fees | $379 | $379 | $0 | 0% | | Research and development | $21,870 | $9,562 | $12,308 | 129% | | General and administrative | $5,672 | $5,917 | $(245) | -4% | | Loss from operations | $(27,163) | $(15,100) | $12,063 | 80% | | Interest expense | $(623) | $(449) | $(174) | 39% | | Interest income | $120 | $333 | $(213) | -64% | | Net loss | $(27,723) | $(15,236) | $12,487 | 82% | - The significant **increase in R&D expenses (129% YoY)** was driven by increased clinical activities for SNDX-6352 and SNDX-5613, and a **$2.0 million milestone expense**[107](index=107&type=chunk) - General and administrative expenses **decreased slightly** due to reduced pre-commercialization activities, partially offset by higher employee expenses[109](index=109&type=chunk) [Liquidity and Capital Resources](index=25&type=section&id=Liquidity%20and%20Capital%20Resources) - As of March 31, 2021, the company had **$271.3 million in cash**, cash equivalents, and short-term investments, expected to fund operations for at least the next 12 months[112](index=112&type=chunk) - Recent financing activities include public offerings in December 2020 (**$135.0 million net proceeds**) and May 2020 (**$107.9 million net proceeds**)[113](index=113&type=chunk)[114](index=114&type=chunk) - A new At-the-Market (ATM) equity offering program was established in March 2021, allowing the sale of up to **$75.0 million in common stock**[119](index=119&type=chunk) - Future funding requirements are substantial and the company anticipates needing **additional capital** through equity, debt, or collaborations[121](index=121&type=chunk)[122](index=122&type=chunk)[124](index=124&type=chunk) Summary of Cash Flows (In thousands): | Activity | Three Months Ended March 31, 2021 | Three Months Ended March 31, 2020 | | :--- | :--- | :--- | | Net cash used in operating activities | $(22,589) | $(15,925) | | Net cash used in investing activities | $(29,228) | $(19,053) | | Net cash provided by financing activities | $960 | $54,998 | - Net cash used in operating activities **increased to $22.6 million** in Q1 2021 from $15.9 million in Q1 2020, primarily due to higher net loss[126](index=126&type=chunk)[127](index=127&type=chunk) - Net cash used in investing activities **increased to $29.2 million** in Q1 2021, mainly due to purchases of short-term investments[128](index=128&type=chunk) - Net cash provided by financing activities **significantly decreased to $1.0 million** in Q1 2021 from $55.0 million in Q1 2020, which included proceeds from stock offerings[131](index=131&type=chunk)[132](index=132&type=chunk) [Item 3. Quantitative and Qualitative Disclosures About Market Risk](index=28&type=section&id=Item%203.%20Quantitative%20and%20Qualitative%20Disclosures%20About%20Market%20Risk) The company's primary market risk exposure is interest rate sensitivity affecting its investments and variable-rate debt - The company's primary market risk exposure is interest rate sensitivity, affecting its **$64.4 million in cash/cash equivalents** and **$206.9 million in short-term investments**[136](index=136&type=chunk) - An immediate **100 basis point change** in interest rates would **not materially affect** the fair market value of cash equivalents and short-term investments[136](index=136&type=chunk) - The **$20.0 million outstanding term loan** bears a variable interest rate; a 100 basis point adverse change could increase interest expense by approximately **$0.5 million**[137](index=137&type=chunk) [Item 4. Controls and Procedures](index=28&type=section&id=Item%204.%20Controls%20and%20Procedures) Management concluded that disclosure controls and procedures were effective with no material changes to internal controls - As of March 31, 2021, management concluded that disclosure controls and procedures were **effective at the reasonable assurance level**[140](index=140&type=chunk) - There were **no material changes** in internal control over financial reporting during the most recent fiscal quarter[141](index=141&type=chunk) PART II. OTHER INFORMATION [Item 1. Legal Proceedings](index=30&type=section&id=Item%201.%20Legal%20Proceedings) The company reports no involvement in any material legal or arbitration proceedings as of the reporting date - As of March 31, 2021, the company was **not involved in any material legal or arbitration proceedings**, and no governmental proceedings were pending or contemplated[143](index=143&type=chunk) [Item 1A. Risk Factors](index=30&type=section&id=Item%201A.%20Risk%20Factors) The company outlines significant risks related to its business, financial position, intellectual property, and stock ownership [Risks Related to Our Business and Industry](index=30&type=section&id=Risks%20Related%20to%20Our%20Business%20and%20Industry) - The **COVID-19 pandemic** could adversely impact business operations, clinical trials, supply chain, and access to capital[146](index=146&type=chunk)[147](index=147&type=chunk)[148](index=148&type=chunk)[149](index=149&type=chunk) - **Failure to successfully complete clinical development**, obtain regulatory approval, and commercialize product candidates would significantly harm business prospects[152](index=152&type=chunk)[153](index=153&type=chunk) - Interim clinical trial data may change, and **preliminary results are not predictive of final outcomes**, as shown by the entinostat E2112 trial's failure[157](index=157&type=chunk)[158](index=158&type=chunk) - The company **relies on third-party suppliers** for manufacturing, and any failure to comply with cGMPs could delay or prevent product development[169](index=169&type=chunk)[170](index=170&type=chunk) - Product candidates may cause **undesirable side effects**, leading to trial delays, regulatory denial, or market withdrawal[176](index=176&type=chunk)[177](index=177&type=chunk) - The company faces **significant competition** from other biotechnology and pharmaceutical companies with greater resources and experience[181](index=181&type=chunk)[183](index=183&type=chunk)[185](index=185&type=chunk) - **Dependence on sublicensees and licensors** for product development means their actions could adversely affect the company's business[186](index=186&type=chunk)[187](index=187&type=chunk) - Relationships with healthcare providers are subject to **anti-kickback and fraud laws**, with potential for significant penalties for non-compliance[208](index=208&type=chunk)[211](index=211&type=chunk) - Significant disruptions to **IT systems or data security incidents** could result in financial, legal, and reputational harm[212](index=212&type=chunk)[213](index=213&type=chunk)[215](index=215&type=chunk) [Risks Related to Our Financial Position and Capital Needs](index=44&type=section&id=Risks%20Related%20to%20Our%20Financial%20Position%20and%20Capital%20Needs) - The company has incurred net losses since inception and anticipates continued losses, with an **accumulated deficit of $596.4 million** as of March 31, 2021[217](index=217&type=chunk)[218](index=218&type=chunk) - Without product revenue, **profitability depends on successful commercialization**, which is uncertain and requires significant future capital[219](index=219&type=chunk)[221](index=221&type=chunk)[222](index=222&type=chunk) - **Additional capital will be required** to fund planned operations, and if not available, the company may have to delay or discontinue product development[223](index=223&type=chunk)[224](index=224&type=chunk) - The loan agreement with Hercules Capital **places restrictions on operating and financial flexibility**, and a default could accelerate repayment[228](index=228&type=chunk)[229](index=229&type=chunk) - **Changes in tax laws** or their interpretation could adversely affect the company's financial condition[230](index=230&type=chunk) - The company's ability to use **net operating loss carryforwards (NOLs)** may be limited due to ownership changes, potentially increasing future tax liability[231](index=231&type=chunk)[232](index=232&type=chunk) [Risks Related to Intellectual Property](index=47&type=section&id=Risks%20Related%20to%20Intellectual%20Property) - **Failure to obtain or protect intellectual property rights** could impair the company's ability to compete effectively[234](index=234&type=chunk)[235](index=235&type=chunk)[236](index=236&type=chunk) - Patent protection for product candidates might expire before commercialization, limiting market exclusivity; entinostat's composition of matter patent **expired in 2017**[237](index=237&type=chunk)[239](index=239&type=chunk) - **Protecting intellectual property rights globally is expensive** and challenging, as foreign laws may offer less protection[243](index=243&type=chunk)[244](index=244&type=chunk)[245](index=245&type=chunk) - **Breaching license agreements** for key products could result in losing development and commercialization rights[246](index=246&type=chunk)[249](index=249&type=chunk)[250](index=250&type=chunk)[254](index=254&type=chunk)[255](index=255&type=chunk)[258](index=258&type=chunk) - **Changes in patent law** could diminish patent value and increase prosecution and enforcement costs[259](index=259&type=chunk)[260](index=260&type=chunk)[261](index=261&type=chunk) - Failure to comply with procedural requirements for patent maintenance can lead to **loss of patent rights**[262](index=262&type=chunk)[263](index=263&type=chunk)[264](index=264&type=chunk) - Claims of **misappropriation of intellectual property** or inability to protect trade secrets could harm the business[269](index=269&type=chunk)[272](index=272&type=chunk) [Risks Related to Ownership of Our Common Stock and Other General Matters](index=52&type=section&id=Risks%20Related%20to%20Ownership%20of%20Our%20Common%20Stock%20and%20Other%20General%20Matters) - The market price of the common stock is **highly volatile** due to various factors, potentially leading to loss of investment[273](index=273&type=chunk)[274](index=274&type=chunk) - Future equity or debt offerings may **dilute existing stockholders** and impose restrictions on the business[275](index=275&type=chunk)[276](index=276&type=chunk)[277](index=277&type=chunk) - **Lack of research coverage** by analysts or adverse opinions could negatively impact stock price and trading volume[279](index=279&type=chunk) - Principal stockholders and management own a significant percentage (**29.2% as of March 31, 2021**) of voting stock, allowing them to exert significant influence[280](index=280&type=chunk) - As an 'emerging growth company,' the company may use **reduced disclosure requirements**, which could make its stock less attractive[281](index=281&type=chunk)[283](index=283&type=chunk)[284](index=284&type=chunk) - **Failure to maintain effective internal control** over financial reporting could adversely affect investor confidence and stock value[288](index=288&type=chunk)[289](index=289&type=chunk) - Provisions in charter documents and Delaware law may have **anti-takeover effects**, discouraging acquisitions[290](index=290&type=chunk) [Item 2. Unregistered Sales of Equity Securities and Use of Proceeds](index=56&type=section&id=Item%202.%20Unregistered%20Sales%20of%20Equity%20Securities%20and%20Use%20of%20Proceeds) The company reports no unregistered sales of equity securities or use of proceeds during the period - **No unregistered sales of equity securities** or use of proceeds were reported for the period[291](index=291&type=chunk) [Item 3. Defaults upon Senior Securities](index=56&type=section&id=Item%203.%20Defaults%20upon%20Senior%20Securities) The company reports no defaults upon senior securities during the period - **No defaults upon senior securities** were reported for the period[292](index=292&type=chunk) [Item 6. Exhibits](index=57&type=section&id=Item%206.%20Exhibits) This section lists all exhibits filed with the report, including corporate documents and officer certifications - Exhibits include Amended and Restated Certificate of Incorporation, Amended and Restated Bylaws, Certifications of Principal Executive and Financial Officers, and financial statements in **iXBRL format**[294](index=294&type=chunk)

Part I [Business](index=6&type=section&id=Item%201.%20Business) Syndax Pharmaceuticals is a clinical-stage biopharmaceutical company focused on developing cancer therapies, with lead candidates SNDX-5613 and axatilimab, and a strategy reliant on pipeline advancement and third-party manufacturing - The company's two lead product candidates are **SNDX-5613** for acute leukemias and **axatilimab** for chronic Graft Versus Host Disease (cGVHD)[23](index=23&type=chunk) - Development of entinostat, a Class I HDAC inhibitor, has been deprioritized to focus resources on the SNDX-5613 and axatilimab programs[23](index=23&type=chunk)[44](index=44&type=chunk) - The company relies entirely on third-party contract manufacturers for all raw materials, active pharmaceutical ingredients, and finished products for both clinical trials and future commercial supply[74](index=74&type=chunk)[178](index=178&type=chunk) Product Pipeline Overview | Product Candidate | Target | Phase | Indication(s) | | :--- | :--- | :--- | :--- | | **SNDX-5613** | Menin inhibitor | Phase 1/2 (AUGMENT-101) | MLLr leukemias, NPM1c AML | | **Axatilimab** | CSF-1R mAB | Phase 2 (AGAVE-201) | Chronic GVHD | | **Entinostat** | Class I HDAC inhibitor | Under review | Deprioritized | [Pipeline and Strategy](index=6&type=section&id=Item%201.%20Business%20-%20Pipeline%20and%20Strategy) The company's strategy centers on advancing SNDX-5613 and axatilimab through clinical trials, while deprioritizing the entinostat program due to failed Phase 3 results - The Phase 1/2 AUGMENT-101 trial for SNDX-5613 is ongoing, with the Phase 2 portion expected to begin in Q2 2021 and potentially serve as the basis for registration[25](index=25&type=chunk)[31](index=31&type=chunk) - The pivotal Phase 2 AGAVE-201 trial for axatilimab in cGVHD began in January 2021, with topline data anticipated in 2023[29](index=29&type=chunk)[38](index=38&type=chunk) - The company deprioritized the entinostat program after the Phase 3 E2112 trial did not meet its primary endpoint of a statistically significant overall survival benefit[44](index=44&type=chunk) [Collaborations and Licensing](index=12&type=section&id=Item%201.%20Business%20-%20Collaborations%20and%20Licensing) Syndax maintains key collaborations and in-licensing agreements for its pipeline assets, including entinostat, axatilimab, and SNDX-5613, involving potential milestone and royalty payments - The company has an exclusive license agreement with Kyowa Kirin (KKC) for the development and commercialization of entinostat in Japan and Korea, which includes potential development, regulatory, and sales milestone payments up to **$75 million**, plus royalties[69](index=69&type=chunk)[70](index=70&type=chunk)[71](index=71&type=chunk) - Axatilimab is licensed from UCB, with potential future payments up to **$119.5 million** in development/regulatory milestones and **$250.0 million** in sales-based milestones, plus low double-digit royalties[96](index=96&type=chunk)[97](index=97&type=chunk) - SNDX-5613 is licensed from Vitae (AbbVie), with potential future payments up to **$99 million** in development/regulatory milestones and **$70.0 million** in sales-based milestones, plus royalties[99](index=99&type=chunk)[100](index=100&type=chunk) [Intellectual Property](index=15&type=section&id=Item%201.%20Business%20-%20Intellectual%20Property) The company's intellectual property is primarily in-licensed, with key patents for axatilimab, SNDX-5613, and entinostat expiring between 2029 and 2037 - The in-licensed composition-of-matter patents for axatilimab will expire in August 2034 or later[78](index=78&type=chunk) - The in-licensed patents for the menin inhibitor asset (SNDX-5613) are expected to expire between June 2037 and September 2037[83](index=83&type=chunk) - A key patent for entinostat, covering its crystalline polymorph B (RE45,499), is licensed from Bayer and expires in August 2029. The original composition of matter patent for entinostat expired in September 2017[87](index=87&type=chunk)[250](index=250&type=chunk) [Risk Factors](index=28&type=section&id=Item%201A.%20Risk%20Factors) The company faces substantial risks from COVID-19, high drug development costs, a history of net losses, reliance on third-party manufacturing, and the need for significant additional capital - The COVID-19 pandemic could adversely impact business operations, including delaying clinical trials due to site initiation issues, patient enrollment challenges, and supply chain disruptions[150](index=150&type=chunk)[151](index=151&type=chunk)[152](index=152&type=chunk) - The company has incurred net losses since inception and expects to continue incurring them for the foreseeable future, with no product revenue to date[228](index=228&type=chunk)[229](index=229&type=chunk) - The company is entirely dependent on third-party suppliers for manufacturing and distribution of its clinical drug supplies and will be for any commercial products, posing risks related to quality, capacity, and regulatory compliance[178](index=178&type=chunk)[180](index=180&type=chunk) - The company's success is highly dependent on its ability to protect its intellectual property, which is largely in-licensed, and it faces risks of patent expiration, litigation, and challenges in foreign jurisdictions[245](index=245&type=chunk)[255](index=255&type=chunk) - The company will require substantial additional capital to fund operations, and future financing may not be available on acceptable terms, potentially leading to dilution for existing stockholders[234](index=234&type=chunk)[235](index=235&type=chunk) [Unresolved Staff Comments](index=59&type=section&id=Item%201B.%20Unresolved%20Staff%20Comments) The company reports no unresolved staff comments from the SEC - None[304](index=304&type=chunk) [Properties](index=59&type=section&id=Item%202.%20Properties) The company leases its headquarters in Waltham, Massachusetts, and an additional office in New York, New York, which are deemed sufficient for future operations - The company's headquarters is a leased office space of **12,207 square feet** in Waltham, Massachusetts, with the lease expiring March 1, 2022[305](index=305&type=chunk) - An additional **4,039 square feet** of office space is leased in New York, New York, with that lease expiring August 31, 2022[305](index=305&type=chunk) [Legal Proceedings](index=60&type=section&id=Item%203.%20Legal%20Proceedings) The company is not currently a party to any material legal proceedings - Not currently a party to any material legal proceedings[307](index=307&type=chunk) [Mine Safety Disclosures](index=60&type=section&id=Item%204.%20Mine%20Safety%20Disclosures) This item is not applicable to the company - Not applicable[308](index=308&type=chunk) Part II [Market for Registrant's Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities](index=61&type=section&id=Item%205.%20Market%20for%20Registrant's%20Common%20Equity%2C%20Related%20Stockholder%20Matters%20and%20Issuers%20Purchases%20of%20Equity%20Securities) The company's common stock trades on Nasdaq under "SNDX", with no history or future expectation of cash dividends, as earnings are retained for development - Common stock trades on the Nasdaq Global Select Market under the symbol **"SNDX"**[311](index=311&type=chunk) - The company has never declared or paid cash dividends and does not intend to in the foreseeable future[313](index=313&type=chunk) [Selected Financial Data](index=62&type=section&id=Item%206.%20Selected%20Financial%20Data) Selected financial data shows consistent license revenue, persistent net losses reaching **$77.1 million** in 2020, and a significant increase in cash and investments to **$293.1 million** by year-end 2020 Selected Consolidated Statement of Operations Data (in thousands) | | 2020 | 2019 | 2018 | 2017 | 2016 | | :--- | :--- | :--- | :--- | :--- | :--- | | Revenue | $1,517 | $1,517 | $1,517 | $2,108 | $1,220 | | Research and development | $50,435 | $42,994 | $60,106 | $48,201 | $31,665 | | General and administrative | $22,505 | $16,062 | $17,287 | $15,861 | $13,321 | | Loss from operations | $(71,423) | $(57,539) | $(75,876) | $(61,954) | $(43,766) | | Net loss | $(73,158) | $(56,047) | $(73,961) | $(60,802) | $(44,472) | | Net loss per share | $(1.87) | $(1.84) | $(2.92) | $(2.90) | $(3.22) | Selected Consolidated Balance Sheet Data (in thousands) | | Dec 31, 2020 | Dec 31, 2019 | Dec 31, 2018 | Dec 31, 2017 | Dec 31, 2016 | | :--- | :--- | :--- | :--- | :--- | :--- | | Cash, cash equivalents, short-term and long term investments | $293,065 | $59,775 | $80,911 | $133,220 | $105,330 | | Total assets | $300,613 | $63,525 | $83,938 | $137,186 | $109,013 | | Accumulated deficit | $(568,628) | $(495,470) | $(439,423) | $(366,111) | $(305,293) | | Total stockholders' equity | $252,188 | $31,600 | $53,047 | $104,319 | $84,139 | [Management's Discussion and Analysis of Financial Condition and Results of Operations](index=63&type=section&id=Item%207.%20Management's%20Discussion%20and%20Analysis%20of%20Financial%20Condition%20and%20Results%20of%20Operations) In 2020, net loss increased to **$73.2 million** due to higher R&D and G&A expenses, while cash and investments significantly increased to **$293.1 million** from equity offerings, expected to fund operations for at least 12 months Comparison of Results of Operations (in thousands) | | Year Ended Dec 31, 2020 | Year Ended Dec 31, 2019 | Change ($) | Change (%) | | :--- | :--- | :--- | :--- | :--- | | Total revenues | $1,517 | $1,517 | $0 | 0% | | Research and development | $50,435 | $42,994 | $7,441 | 17% | | General and administrative | $22,505 | $16,062 | $6,443 | 40% | | Loss from operations | $(71,423) | $(57,539) | $(13,884) | 24% | | Net loss | $(73,158) | $(56,047) | $(17,111) | 31% | - The **$7.4 million** increase in R&D expense in 2020 was primarily due to increased clinical trial activities for SNDX-5613 (**$5.3 million**) and axatilimab (**$3.7 million**), and a **$2.0 million** milestone expense for the axatilimab program[350](index=350&type=chunk)[352](index=352&type=chunk) - The company believes its cash, cash equivalents, and short-term investments of **$293.1 million** as of December 31, 2020, will be sufficient to fund operations for at least the next 12 months[358](index=358&type=chunk) Cash Flow Summary (in thousands) | | Year Ended Dec 31, 2020 | Year Ended Dec 31, 2019 | | :--- | :--- | :--- | | Net cash used in operating activities | $(71,260) | $(50,612) | | Net cash provided by (used in) investing activities | $(142,530) | $12,781 | | Net cash provided by financing activities | $304,424 | $28,570 | [Quantitative and Qualitative Disclosures about Market Risk](index=75&type=section&id=Item%207A.%20Quantitative%20and%20Qualitative%20Disclosures%20about%20Market%20Risk) The company's primary market risk is interest rate sensitivity on investments and its variable-rate term loan, though a 100 basis point change is not expected to materially affect financial position - The primary market risk is interest rate sensitivity on cash equivalents, short-term investments, and the variable-rate Loan Agreement with Hercules[391](index=391&type=chunk)[392](index=392&type=chunk) - An immediate 100 basis point change in interest rates is not expected to have a material effect on the fair market value of the company's cash and investments[391](index=391&type=chunk) [Financial Statements and Supplementary Data](index=76&type=section&id=Item%208.%20Financial%20Statements%20and%20Supplementary%20Data) This section presents the company's audited consolidated financial statements for 2020, reflecting increased net losses and a strengthened cash position, with an unqualified opinion from Deloitte & Touche LLP - The financial statements were audited by Deloitte & Touche LLP, which issued an unqualified opinion[431](index=431&type=chunk)[435](index=435&type=chunk) Consolidated Balance Sheet Highlights (in thousands) | | Dec 31, 2020 | Dec 31, 2019 | | :--- | :--- | :--- | | Cash and cash equivalents | $115,243 | $24,609 | | Short-term investments | $177,822 | $35,166 | | Total Assets | $300,613 | $63,525 | | Total Liabilities | $48,425 | $31,925 | | Accumulated Deficit | $(568,628) | $(495,470) | | Total Stockholders' Equity | $252,188 | $31,600 | Consolidated Statement of Operations (in thousands) | | Year Ended Dec 31, 2020 | Year Ended Dec 31, 2019 | | :--- | :--- | :--- | | Total revenues | $1,517 | $1,517 | | Research and development | $50,435 | $42,994 | | General and administrative | $22,505 | $16,062 | | Net loss | $(73,158) | $(56,047) | [Changes in and Disagreements with Accountants on Accounting and Financial Disclosure](index=76&type=section&id=Item%209.%20Changes%20in%20and%20Disagreements%20with%20Accountants%20on%20Accounting%20and%20Financial%20Disclosure) The company reports no changes in or disagreements with its accountants on accounting and financial disclosure - None[396](index=396&type=chunk) [Controls and Procedures](index=76&type=section&id=Item%209A.%20Controls%20and%20Procedures) Management concluded that disclosure controls and internal control over financial reporting were effective as of December 31, 2020, with an auditor attestation report omitted due to emerging growth company status - Management concluded that disclosure controls and procedures were effective as of December 31, 2020[397](index=397&type=chunk) - Management concluded that internal control over financial reporting was effective as of December 31, 2020[398](index=398&type=chunk) - The company is exempt from providing an auditor's attestation report on internal controls because it is an "emerging growth company"[399](index=399&type=chunk) [Other Information](index=76&type=section&id=Item%209B.%20Other%20Information) There is no other information to report in this item - None[400](index=400&type=chunk) Part III [Directors, Executive Officers and Corporate Governance](index=77&type=section&id=Item%2010.%20Directors%2C%20Executive%20Officers%20and%20Corporate%20Governance) The information required for this item, regarding directors, executive officers, and corporate governance, is incorporated by reference from the company's 2021 Proxy Statement - Information is incorporated by reference from the company's 2021 Proxy Statement[403](index=403&type=chunk) [Executive Compensation](index=77&type=section&id=Item%2011.%20Executive%20Compensation) The information required for this item, regarding executive compensation, is incorporated by reference from the company's 2021 Proxy Statement - Information is incorporated by reference from the company's 2021 Proxy Statement[404](index=404&type=chunk) [Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters](index=77&type=section&id=Item%2012.%20Security%20Ownership%20of%20Certain%20Beneficial%20Owners%20and%20Management%20and%20Related%20Stockholder%20Matters) The information required for this item, regarding security ownership, is incorporated by reference from the company's 2021 Proxy Statement - Information is incorporated by reference from the company's 2021 Proxy Statement[405](index=405&type=chunk) [Certain Relationships and Related Transactions, and Director Independence](index=77&type=section&id=Item%2013.%20Certain%20Relationships%20and%20Related%20Transactions%2C%20and%20Director%20Independence) The information required for this item, regarding related party transactions and director independence, is incorporated by reference from the company's 2021 Proxy Statement - Information is incorporated by reference from the company's 2021 Proxy Statement[406](index=406&type=chunk) [Principal Accountant Fees and Services](index=77&type=section&id=Item%2014.%20Principal%20Accountant%20Fees%20and%20Services) The information required for this item, regarding principal accountant fees and services, is incorporated by reference from the company's 2021 Proxy Statement - Information is incorporated by reference from the company's 2021 Proxy Statement[407](index=407&type=chunk) Part IV [Exhibits and Financial Statement Schedules](index=78&type=section&id=Item%2015.%20Exhibits%20and%20Financial%20Statement%20Schedules) This section lists exhibits filed with the Form 10-K, including corporate governance and material contracts, with financial statements referenced under Item 8 and schedules omitted - The financial statements required by this item are located under Item 8 of the report[409](index=409&type=chunk) - All financial statement schedules have been omitted because they are not required or the necessary information is provided in the Consolidated Financial Statements or Notes[410](index=410&type=chunk) [Form 10-K Summary](index=83&type=section&id=Item%2016.%20Form%2010-K%20Summary) This item is not applicable - Not applicable[419](index=419&type=chunk)

Pipeline and Clinical Trials - Syndax is developing SNDX-5613, a Menin Inhibitor Program, targeting acute leukemias, with Phase 1 data expected late in Q1 or early in Q2 and Phase 2 initiation expected in Q2[6, 8, 12] - AUGMENT-101 is a Phase 1/2 trial testing SNDX-5613 in MLL-r and NPM1 acute leukemia[10] - Axatilimab, an Anti-CSF-1R program, is in a global pivotal trial (AGAVE201) for chronic GVHD (cGVHD), with FPFV (First Patient First Visit) in Q4 2020 and topline results expected in 2023[7, 8, 21] - The AGAVE201 trial randomizes patients with recurrent or refractory active cGVHD after at least 2 lines of systemic therapy in a 1:1:1 ratio to receive Axatilimab at doses of 03 mg/kg Q2W (70 patients), 1 mg/kg Q2W (70 patients), or 3 mg/kg Q4W (70 patients)[19, 20] Financial Highlights - Syndax had $2931 million in cash and short-term investments as of December 31, 2020[23] - Shares outstanding as of December 31, 2020, were 514 million, including 479 million common shares and pre-funded warrants to purchase 36 million common shares[23] - Research and Development expenses for Q1 2021 are guided at $25-30 million, and for FY 2021 at $90-100 million[23] - Total Operating Expenses for Q1 2021 are guided at $30-35 million, and for FY 2021 at $110-120 million, including approximately $20 million non-cash stock compensation expense per quarter[23] Business Development - Business development is a core strength, with clinical development leadership enabling competitive advantage[22] - Axatilimab was acquired from UCB, and Menin-MLL inhibitors were acquired from Allergan/Vitae[22]

Syndax Pharmaceuticals, Inc. (NASDAQ:SNDX) Q4 2020 Results Conference Call March 8, 2021 4:30 PM ET Company Participants Maghan Meyers - Argot Partners Dr. Briggs Morrison - Chief Executive Officer Daphne Karydas - Chief Financial Officer Michael Metzger - President, Chief Operating Officer Dr. Michael Meyers - Chief Medical Officer Dr. Peter Ordentlich - Chief Scientific Officer Conference Call Participants Philip Nadeau - Cowen & Company Bert Hazlett - BTIG Konstantinos Aprilakis - Stifel David Lebowitz - ...

Determined to realize a future in which people with cancer live longer and better than ever before Syndax 參 AXATILIMAB CONFERENCE CALL| DECEMBER 2020 Forward-looking statements disclosure This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as "may," "will," "expect," "plan," "anticipate" and similar expressions (as well as other words or expressions referencing future events or circumstances) are intended to identify fo ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) 35 Gatehouse Drive, Building D, Floor 3 Waltham, Massachusetts 02451 (Address of Principal Executive Offices) (Zip Code) or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Delaware 32-0162505 (State or Other Jurisdiction of Incorporation or Organization) For the transition period from to Commission File Number: 001-37708 Syndax Pharmaceuticals, Inc. (Exact Name of Registran ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-37708 Syndax Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 32-0162505 (State or Other Ju ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-37708 Syndax Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 32-0162505 (State or Other J ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended December 31, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number: 001-37708 Syndax Pharmaceuticals, Inc. (Exact name of Registrant as specified in its charter) (State or Other Jurisdiction of Incorporat ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-37708 Syndax Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 32-0162505 (State or Oth ...