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 No. 001-38359 resTORbio, Inc. (Exact name of registrant as specified in its charter) Delaware 81-3305277 (State or other jurisdiction of incorpo ...

[PART I. FINANCIAL INFORMATION](index=3&type=section&id=PART%20I.%20FINANCIAL%20INFORMATION) Presents unaudited condensed consolidated financial statements and management's discussion and analysis for the period [Item 1. Condensed Consolidated Financial Statements (Unaudited)](index=4&type=section&id=Item%201.%20Condensed%20Consolidated%20Financial%20Statements%20(Unaudited)) Presents unaudited condensed consolidated financial statements, including balance sheets, statements of operations, and cash flows, showing increased net loss [Condensed Consolidated Balance Sheets](index=4&type=section&id=Condensed%20Consolidated%20Balance%20Sheets) Total assets increased to $122.0 million from $109.9 million, driven by higher cash, while liabilities and equity also grew | Financial Metric | Sep 30, 2019 (in thousands) | Dec 31, 2018 (in thousands) | | :--- | :--- | :--- | | **Assets** | | | | Cash and cash equivalents | $23,621 | $7,042 | | Marketable securities | $93,641 | $100,986 | | Total current assets | $121,281 | $109,534 | | Total assets | $121,963 | $109,939 | | **Liabilities & Equity** | | | | Total current liabilities | $12,193 | $5,716 | | Total liabilities | $12,199 | $5,735 | | Total stockholders' equity | $109,764 | $104,204 | [Condensed Consolidated Statements of Operations and Comprehensive Loss](index=5&type=section&id=Condensed%20Consolidated%20Statements%20of%20Operations%20and%20Comprehensive%20Loss) Net loss significantly increased to $24.4 million for Q3 2019 and $53.8 million for nine months, primarily due to higher R&D expenses | Metric (in thousands) | Three Months Ended Sep 30, 2019 | Three Months Ended Sep 30, 2018 | Nine Months Ended Sep 30, 2019 | Nine Months Ended Sep 30, 2018 | | :--- | :--- | :--- | :--- | :--- | | Research and development | $22,118 | $6,765 | $47,523 | $26,716 | | General and administrative | $3,043 | $2,267 | $8,498 | $6,629 | | **Total operating expenses** | **$25,161** | **$9,032** | **$56,021** | **$33,345** | | **Net loss** | **($24,448)** | **($8,407)** | **($53,849)** | **($31,857)** | | Net loss per share | ($0.68) | ($0.30) | ($1.51) | ($1.23) | [Condensed Consolidated Statements of Cash Flows](index=8&type=section&id=Condensed%20Consolidated%20Statements%20of%20Cash%20Flows) Net cash used in operations increased to $48.0 million, offset by $56.5 million from financing, resulting in a $16.6 million cash increase | Cash Flow Activity (in thousands) | Nine Months Ended Sep 30, 2019 | Nine Months Ended Sep 30, 2018 | | :--- | :--- | :--- | | Net cash used in operating activities | ($48,036) | ($27,805) | | Net cash provided by (used in) investing activities | $8,155 | ($92,626) | | Net cash provided by financing activities | $56,460 | $89,938 | | **Net increase (decrease) in cash** | **$16,579** | **($30,493)** | | Cash at end of period | $23,621 | $22,856 | [Notes to Financial Statements](index=10&type=section&id=Notes%20to%20Financial%20Statements) Details accounting policies, financing activities including $49.8 million from public offering, and a $2.5 million milestone payment to Novartis - The company completed a public offering in March/April 2019, raising net proceeds of approximately **$49.8 million**. Additionally, an at-the-market (ATM) offering program was established, selling approximately 688,000 shares for net proceeds of **$6.7 million** through September 30, 2019[23](index=23&type=chunk)[24](index=24&type=chunk) - As of September 30, 2019, the company had **$117.3 million** in cash, cash equivalents, and marketable securities, which management believes is sufficient to fund operations for at least the next twelve months[25](index=25&type=chunk) - Under the license agreement with Novartis, the company made a **$2.5 million** milestone payment in May 2019 upon initiating a Phase 3 clinical trial. Future potential payments include up to **$1.8 million** for clinical milestones, **$42 million** for regulatory milestones, and **$125 million** for commercial milestones, plus tiered royalties[52](index=52&type=chunk)[53](index=53&type=chunk) Stock-Based Compensation | Expense Category | Three Months Ended Sep 30, 2019 (in thousands) | Nine Months Ended Sep 30, 2019 (in thousands) | | :--- | :--- | :--- | | Research and development | $633 | $1,409 | | General and administrative | $569 | $1,399 | | **Total stock-based compensation** | **$1,202** | **$2,808** | [Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations](index=21&type=section&id=Item%202.%20Management's%20Discussion%20and%20Analysis%20of%20Financial%20Condition%20and%20Results%20of%20Operations) Discusses the company's clinical programs for RTB101, increased R&D expenses, higher net loss, and liquidity position of $117.3 million [Overview](index=21&type=section&id=Overview) Introduces resTORbio as a clinical-stage biopharmaceutical company developing RTB101 for aging-related diseases, including Phase 3 and 1b/2a trials - The company's lead product candidate, RTB101, is being evaluated in a Phase 3 program (PROTECTOR 1 & 2) to reduce clinically symptomatic respiratory illness in adults 65 and older. PROTECTOR 1 has completed enrollment of 1,024 patients, with top-line data expected in early Q1 2020[87](index=87&type=chunk) - A Phase 1b/2a clinical trial of RTB101 for Parkinson's disease was initiated in April 2019. The trial will enroll 45 patients to evaluate safety and tolerability, with data expected in 2020[88](index=88&type=chunk) - The company expects to incur increasing operating losses as it advances its clinical programs, expands its pipeline, and prepares for potential commercialization[96](index=96&type=chunk) [Results of Operations](index=27&type=section&id=Results%20of%20Operations) R&D expenses significantly increased to $22.1 million for Q3 and $47.5 million for nine months, driven by clinical trial costs Three Months Ended September 30 | Metric (in thousands) | Three Months Ended Sep 30, 2019 | Three Months Ended Sep 30, 2018 | | :--- | :--- | :--- | | Research and development | $22,118 | $6,765 | | General and administrative | $3,043 | $2,267 | | **Net loss** | **($24,448)** | **($8,407)** | - The increase in R&D expenses for Q3 2019 was primarily driven by **$17.0 million** in costs related to clinical trials, including the ongoing Phase 3 program, compared to **$2.6 million** for the Phase 2b trial in the same period of 2018[118](index=118&type=chunk) Nine Months Ended September 30 | Metric (in thousands) | Nine Months Ended Sep 30, 2019 | Nine Months Ended Sep 30, 2018 | | :--- | :--- | :--- | | Research and development | $47,523 | $26,716 | | General and administrative | $8,498 | $6,629 | | **Net loss** | **($53,849)** | **($31,857)** | - The increase in R&D expenses for the nine-month period was primarily due to **$30.6 million** in clinical trial costs and a **$2.5 million** milestone payment, compared to **$17.3 million** in clinical trial costs in the prior year period[123](index=123&type=chunk) [Liquidity and Capital Resources](index=28&type=section&id=Liquidity%20and%20Capital%20Resources) The company held $117.3 million in cash and equivalents, funded by equity offerings, sufficient for operations through 2020 - As of September 30, 2019, the company had **$117.3 million** in cash, cash equivalents, and marketable securities and an accumulated deficit of **$125.2 million**[129](index=129&type=chunk) - Management believes existing cash will be sufficient to fund operating expenses and capital expenditure requirements through 2020, including the completion of the PROTECTOR Phase 3 program[131](index=131&type=chunk) Cash Flow Summary | Cash Flow Summary (in thousands) | Nine Months Ended Sep 30, 2019 | Nine Months Ended Sep 30, 2018 | | :--- | :--- | :--- | | Net cash used in operating activities | ($48,036) | ($27,805) | | Net cash provided by (used in) investing activities | $8,155 | ($92,626) | | Net cash provided by financing activities | $56,460 | $89,938 | [Item 3. Quantitative and Qualitative Disclosures About Market Risk](index=31&type=section&id=Item%203.%20Quantitative%20and%20Qualitative%20Disclosures%20About%20Market%20Risk) Primary market risk is interest rate sensitivity on $117.3 million in cash and securities, with minor foreign currency exposure - The company's main market risk is interest rate sensitivity on its **$117.3 million** portfolio of cash and short-term marketable securities. A 100 basis point change in interest rates is not expected to have a material effect on the portfolio's fair market value[147](index=147&type=chunk) - The company is subject to fluctuations in foreign currency rates through its contracts with global CROs and manufacturers but has not engaged in hedging activities[148](index=148&type=chunk) [Item 4. Controls and Procedures](index=32&type=section&id=Item%204.%20Controls%20and%20Procedures) Management concluded disclosure controls and procedures were effective, with no material changes to internal controls during the quarter - Based on an evaluation as of September 30, 2019, the Chief Executive Officer and Vice President, Finance concluded that the company's disclosure controls and procedures were effective at the reasonable assurance level[152](index=152&type=chunk) - No changes occurred in the company's internal control over financial reporting during the quarter ended September 30, 2019, that have materially affected, or are reasonably likely to materially affect, internal controls[153](index=153&type=chunk) [PART II. OTHER INFORMATION](index=33&type=section&id=PART%20II.%20OTHER%20INFORMATION) Covers legal proceedings, risk factors, equity sales, and other miscellaneous disclosures [Item 1. Legal Proceedings](index=33&type=section&id=Item%201.%20Legal%20Proceedings) As of September 30, 2019, no material adverse legal proceedings were pending against the company - As of September 30, 2019, the company was not party to any legal proceedings expected to have a material adverse impact on its financial position, results of operations, or cash flow[155](index=155&type=chunk) [Item 1A. Risk Factors](index=33&type=section&id=Item%201A.%20Risk%20Factors) No material changes to the risk factors previously disclosed in the Annual Report on Form 10-K for 2018 - There have been no material changes to the risk factors set forth in the company's Annual Report on Form 10-K for the year ended December 31, 2018[156](index=156&type=chunk) [Item 2. Unregistered Sales of Equity Securities and Use of Proceeds](index=33&type=section&id=Item%202.%20Unregistered%20Sales%20of%20Equity%20Securities%20and%20Use%20of%20Proceeds) Details the use of $81.8 million from the January 2018 IPO proceeds for clinical trials and general corporate purposes - The company's January 2018 IPO generated aggregate net proceeds of approximately **$89.4 million**. As of September 30, 2019, approximately **$81.8 million** of these proceeds have been used to advance clinical trial programs and for general corporate purposes[158](index=158&type=chunk)[159](index=159&type=chunk) [Other Items (Items 3, 4, 5, 6)](index=33&type=section&id=Other%20Items%20(Items%203,%204,%205,%206)) Items 3, 4, and 5 are reported as not applicable or none, while Item 6 lists the exhibits filed - Item 3 (Defaults Upon Senior Securities), Item 4 (Mine Safety Disclosures), and Item 5 (Other Information) are all reported as not applicable or none[159](index=159&type=chunk)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 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, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 | --- | --- | --- | |---------------------------------------------------------------------------------------|--------------------------------------------------------------------------|-------- ...

PART I. FINANCIAL INFORMATION [Item 1. Condensed Consolidated Financial Statements (Unaudited)](index=4&type=section&id=Item%201.%20Condensed%20Consolidated%20Financial%20Statements%20(Unaudited)) This section presents the unaudited condensed consolidated financial statements, including balance sheets, statements of operations and comprehensive loss, statements of stockholders' equity, and statements of cash flows, along with detailed notes explaining significant accounting policies, financial instruments, and other relevant disclosures for the periods ended March 31, 2019 and 2018 [Condensed Consolidated Balance Sheets as of March 31, 2019 and December 31, 2018](index=4&type=section&id=Condensed%20Consolidated%20Balance%20Sheets%20as%20of%20March%2031%2C%202019%20and%20December%2031%2C%202018) | Metric | March 31, 2019 (in thousands) | December 31, 2018 (in thousands) | | :------------------------- | :---------------------------- | :------------------------------- | | Total Assets | $145,080 | $109,939 | | Total Liabilities | $4,624 | $5,735 | | Total Stockholders' Equity | $140,456 | $104,204 | | Cash & Cash Equivalents | $7,181 | $7,042 | | Marketable Securities | $135,910 | $100,986 | - Total assets increased by **$35.1 million**, primarily driven by a **$34.9 million** increase in marketable securities[9](index=9&type=chunk) - Total stockholders' equity increased by **$36.3 million**, while total liabilities decreased by **$1.1 million**[9](index=9&type=chunk)[10](index=10&type=chunk) [Condensed Consolidated Statements of Operations and Comprehensive Loss for the three months ended March 31, 2019 and 2018](index=5&type=section&id=Condensed%20Consolidated%20Statements%20of%20Operations%20and%20Comprehensive%20Loss%20for%20the%20three%20months%20ended%20March%2031%2C%202019%20and%202018) | Metric | Three Months Ended March 31, 2019 (in thousands) | Three Months Ended March 31, 2018 (in thousands) | | :----------------------------------- | :----------------------------------------------- | :----------------------------------------------- | | Research and development | $8,852 | $8,106 | | General and administrative | $2,839 | $2,094 | | Total operating expenses | $11,691 | $10,200 | | Net loss | $(11,069) | $(9,859) | | Net loss per share, basic and diluted| $(0.38) | $(0.46) | - Net loss increased by **$1.2 million**, from **$9.9 million** in Q1 2018 to **$11.1 million** in Q1 2019, primarily due to higher operating expenses[12](index=12&type=chunk) - Total operating expenses rose by **$1.5 million**, with both R&D and G&A contributing to the increase[12](index=12&type=chunk) [Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) for the three months ended March 31, 2019 and 2018](index=6&type=section&id=Condensed%20Consolidated%20Statements%20of%20Redeemable%20Convertible%20Preferred%20Stock%20and%20Stockholders%27%20Equity%20(Deficit)%20for%20the%20three%20months%20ended%20March%2031%2C%202019%20and%202018) | Metric | December 31, 2018 (in thousands) | March 31, 2019 (in thousands) | | :----------------------------------- | :------------------------------- | :---------------------------- | | Total Stockholders' Equity | $104,204 | $140,456 | | Additional Paid-In Capital | $175,635 | $222,882 | | Accumulated Deficit | $(71,393) | $(82,462) | - Stockholders' equity increased by **$36.3 million**, primarily driven by **$46.6 million** in net proceeds from a public offering[14](index=14&type=chunk) - Accumulated deficit increased by **$11.1 million**, reflecting the net loss for the period[14](index=14&type=chunk) [Condensed Consolidated Statements of Cash Flows for the three months ended March 31, 2019 and 2018](index=7&type=section&id=Condensed%20Consolidated%20Statements%20of%20Cash%20Flows%20for%20the%20three%20months%20ended%20March%2031%2C%202019%20and%202018) | Cash Flow Activity | Three Months Ended March 31, 2019 (in thousands) | Three Months Ended March 31, 2018 (in thousands) | | :--------------------------------- | :----------------------------------------------- | :----------------------------------------------- | | Net cash used in operating activities| $(12,049) | $(7,304) | | Net cash used in investing activities| $(34,628) | $(278) | | Net cash provided by financing activities| $46,816 | $89,938 | | Net increase in cash and cash equivalents| $139 | $82,356 | | Cash and cash equivalents at end of period| $7,181 | $135,705 | - Net cash used in operating activities increased to **$12.0 million** in Q1 2019 from **$7.3 million** in Q1 2018[17](index=17&type=chunk) - Investing activities resulted in a net cash outflow of **$34.6 million** in Q1 2019, primarily due to purchases of marketable securities[17](index=17&type=chunk) - Financing activities provided **$46.8 million** in Q1 2019 from a public offering, compared to **$89.9 million** from the IPO in Q1 2018[17](index=17&type=chunk) [Notes to Unaudited Condensed Consolidated Financial Statements](index=8&type=section&id=Notes%20to%20Unaudited%20Condensed%20Consolidated%20Financial%20Statements) [1. Organization](index=8&type=section&id=1.%20Organization) - resTORbio, Inc. is a clinical-stage biopharmaceutical company developing innovative medicines targeting aging-related diseases, primarily involved in research and development[19](index=19&type=chunk)[20](index=20&type=chunk) - The company has not generated product revenue and has an accumulated deficit of **$82.5 million** as of March 31, 2019[20](index=20&type=chunk)[22](index=22&type=chunk) - As of March 31, 2019, the company had **$143.1 million** in cash, cash equivalents, and marketable securities, which is believed to be sufficient to fund operations for at least the next twelve months[22](index=22&type=chunk) [2. Summary of Significant Accounting Policies](index=8&type=section&id=2.%20Summary%20of%20Significant%20Accounting%20Policies) - The unaudited condensed consolidated financial statements are prepared in accordance with U.S. GAAP, reflecting management's estimates, with no material changes in significant accounting policies during Q1 2019[23](index=23&type=chunk)[25](index=25&type=chunk)[26](index=26&type=chunk) | Description | March 31, 2019 (in thousands) | Level 1 (in thousands) | Level 2 (in thousands) | Level 3 (in thousands) | | :---------------------------------------- | :---------------------------- | :--------------------- | :--------------------- | :--------------------- | | Money market funds | $7,150 | $7,150 | $— | $— | | U.S. treasury securities (marketable) | $135,910 | $135,910 | $— | $— | | Total | $143,091 | $143,091 | $— | $— | - All assets measured at fair value (cash, money market funds, U.S. treasury securities) are classified as **Level 1**, indicating unadjusted, quoted prices in active markets[29](index=29&type=chunk) - The company is evaluating new accounting pronouncements (ASU 2016-02, 2016-18, 2017-11, 2018-07) but does not expect a material impact from most on its consolidated financial statements[32](index=32&type=chunk)[33](index=33&type=chunk)[34](index=34&type=chunk)[35](index=35&type=chunk) [3. Marketable Securities](index=11&type=section&id=3.%20Marketable%20Securities) | Description | Amortized Cost (in thousands) | Unrealized Gains (in thousands) | Unrealized Losses (in thousands) | Fair Value (in thousands) | | :---------------------------------------- | :---------------------------- | :------------------------------ | :------------------------------- | :------------------------ | | U.S. government agency securities and treasuries | $135,878 | $32 | $— | $135,910 | - As of March 31, 2019, marketable securities totaled **$135.9 million**, primarily U.S. government agency securities and treasuries, all classified as available-for-sale and maturing within one year or less[37](index=37&type=chunk)[39](index=39&type=chunk) [4. Property and equipment, net](index=11&type=section&id=4.%20Property%20and%20equipment%2C%20net) | Metric | March 31, 2019 (in thousands) | December 31, 2018 (in thousands) | | :----------------------------------- | :---------------------------- | :------------------------------- | | Total property and equipment, net | $318 | $321 | | Depreciation and amortization expense (Q1) | $27 | $9 | - Net property and equipment decreased slightly to **$318,000** as of March 31, 2019, from **$321,000** at December 31, 2018[40](index=40&type=chunk) - Depreciation and amortization expense increased to **$27,000** for the three months ended March 31, 2019, from **$9,000** in the prior year period[40](index=40&type=chunk) [5. Accrued Liabilities](index=12&type=section&id=5.%20Accrued%20Liabilities) | Accrued Liability | March 31, 2019 (in thousands) | December 31, 2018 (in thousands) | | :---------------------------------- | :---------------------------- | :------------------------------- | | Accrued payroll and related expenses| $557 | $1,189 | | Accrued research and development expenses| $524 | $1,028 | | Other | $164 | $510 | | Total accrued liabilities | $1,245 | $2,727 | - Total accrued liabilities decreased by **$1.48 million** to **$1.25 million** at March 31, 2019, primarily due to reductions in accrued payroll and R&D expenses[42](index=42&type=chunk) [6. License Agreements](index=12&type=section&id=6.%20License%20Agreements) - The company holds an exclusive, field-restricted, worldwide license from Novartis for RTB101 alone or in combination with everolimus[43](index=43&type=chunk) - The agreement includes potential milestone payments of up to **$4.3 million** for clinical, **$42 million** for regulatory, and **$125 million** for commercial achievements, plus tiered royalties[46](index=46&type=chunk) - A **$2.5 million** milestone payment was triggered in May 2019 upon the initiation of a Phase 3 clinical trial for the first indication[47](index=47&type=chunk) [7. Research Funding Agreement](index=12&type=section&id=7.%20Research%20Funding%20Agreement) - The company has a research funding agreement with the Silverstein Foundation to partially fund preclinical and Phase 2 clinical trial expenses for RTB101 in Parkinson's Disease[48](index=48&type=chunk) - An upfront sum of **$0.5 million** was received in 2018, which is recognized as a reduction to research and development expenses as qualifying expenses are incurred[49](index=49&type=chunk)[50](index=50&type=chunk)[51](index=51&type=chunk) [8. Preferred Stock and Common Stock](index=13&type=section&id=8.%20Preferred%20Stock%20and%20Common%20Stock) - As of March 31, 2019, the company had **10,000,000** shares of preferred stock authorized with none issued, and **35,255,344** common shares issued and outstanding[9](index=9&type=chunk)[52](index=52&type=chunk) | Metric | March 31, 2019 | December 31, 2018 | | :--------------------------------------- | :------------- | :---------------- | | Options issued and outstanding | 1,706,317 | 1,122,677 | | Unvested restricted stock units | 24,960 | 24,960 | | Options available for future grants | 1,889,155 | 1,350,582 | | Shares available for issuance under 2018 ESPP | 555,583 | 275,030 | | Total shares reserved for future issuance| 4,176,015 | 2,773,249 | - The total number of shares reserved for future issuance under equity plans increased to **4.18 million** as of March 31, 2019, from **2.77 million** at December 31, 2018[52](index=52&type=chunk) [9. Stock-based Compensation](index=13&type=section&id=9.%20Stock-based%20Compensation) | Metric | Three Months Ended March 31, 2019 (in thousands) | Three Months Ended March 31, 2018 (in thousands) | | :----------------------------------- | :----------------------------------------------- | :----------------------------------------------- | | Total stock-based compensation expense| $663 | $1,181 | | Research and development | $277 | $625 | | General and administrative | $386 | $556 | - Total stock-based compensation expense decreased by **$0.5 million** to **$0.7 million** for Q1 2019[58](index=58&type=chunk) - The company granted **604,440** stock options in Q1 2019 with a weighted-average exercise price of **$8.58**[59](index=59&type=chunk) - As of March 31, 2019, total unrecognized compensation expense for unvested options, restricted stock, and restricted stock units was approximately **$10.9 million**, to be recognized over weighted-average periods ranging from **0.05 to 3.30 years**[62](index=62&type=chunk)[63](index=63&type=chunk)[64](index=64&type=chunk)[67](index=67&type=chunk) [10. Commitments and Contingencies](index=16&type=section&id=10.%20Commitments%20and%20Contingencies) - The company is not a party to any litigation and has no contingency reserves established for litigation liabilities as of March 31, 2019[69](index=69&type=chunk) [11. Net Loss per Share](index=16&type=section&id=11.%20Net%20Loss%20per%20Share) - Basic and diluted net loss per share are computed using the two-class method; due to net losses, no income allocation or dilution from share-based awards was applied[70](index=70&type=chunk) | Potentially Dilutive Securities | As of March 31, 2019 | As of March 31, 2018 | | :------------------------------ | :------------------- | :------------------- | | Options issued and outstanding | 1,706,317 | 667,590 | - Potentially dilutive securities, totaling **1,706,317** options, were excluded from diluted net loss per share calculation as their inclusion would have been anti-dilutive[71](index=71&type=chunk) [12. Related Party Transactions](index=17&type=section&id=12.%20Related%20Party%20Transactions) - The company has an intellectual property license agreement with Novartis, an affiliate of which is a shareholder[73](index=73&type=chunk) - A research funding agreement exists with the Silverstein Foundation, a related party, from which **$0.5 million** was received in Q1 2018, but no funds were received in Q1 2019[74](index=74&type=chunk) [13. Subsequent Event](index=17&type=section&id=13.%20Subsequent%20Event) - In April 2019, the company amended its multi-year office lease for a new 7-year term, with an initial annual base rent of **$0.6 million**[75](index=75&type=chunk) - In May 2019, the company was awarded a 5-year grant of up to **$1.5 million** from the National Institutes of Health[76](index=76&type=chunk) [Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations](index=18&type=section&id=Item%202.%20Management%27s%20Discussion%20and%20Analysis%20of%20Financial%20Condition%20and%20Results%20of%20Operations) This section provides an overview of resTORbio's business, clinical development progress, and detailed analysis of its financial condition and results of operations for the three months ended March 31, 2019. It highlights the company's lead product candidate, RTB101, in Phase 3 trials for respiratory tract infections and a Phase 1b/2a trial for Parkinson's disease, along with its liquidity position and future funding needs [Overview](index=18&type=section&id=Overview) - resTORbio is a clinical-stage biopharmaceutical company developing innovative medicines targeting the biology of aging, with lead product candidate **RTB101**, an oral TORC1 inhibitor[79](index=79&type=chunk) - Initiated Phase 3 program (**PROTECTOR 1 and 2**) in May 2019 to evaluate **RTB101 10mg once daily** for reducing clinically symptomatic respiratory illness in elderly subjects (65+ excluding smokers/COPD), with top-line data expected in **mid-2020**[79](index=79&type=chunk)[85](index=85&type=chunk) - Initiated a Phase 1b/2a clinical trial of **RTB101** alone or in combination with sirolimus for Parkinson's disease in April 2019, with data expected in **2020**[80](index=80&type=chunk) - Phase 2 clinical trials showed **RTB101 10mg once daily** improved immune function and reduced incidence of laboratory-confirmed RTIs by **30.6%** and severe RTI symptoms by **52.1%** in high-risk elderly patients[82](index=82&type=chunk) - The company has incurred significant net losses (**$11.1 million** in Q1 2019) and has an accumulated deficit of **$82.5 million** as of March 31, 2019, with no product revenue generated to date[89](index=89&type=chunk) - A public offering in March 2019 generated approximately **$46.6 million** in net proceeds, expected to fund operations through **2020**[88](index=88&type=chunk)[90](index=90&type=chunk) [Novartis License Agreement](index=21&type=section&id=Novartis%20License%20Agreement) - The company holds an exclusive, worldwide license from Novartis for **RTB101** and its combination with everolimus, covering composition of matter, formulations, and methods of use[93](index=93&type=chunk) - The agreement includes potential milestone payments of up to **$4.3 million** for clinical, **$42 million** for regulatory, and **$125 million** for commercial achievements, plus tiered royalties[96](index=96&type=chunk) - A **$2.5 million** milestone payment was triggered in May 2019 upon the initiation of a Phase 3 clinical trial for the first indication[97](index=97&type=chunk) [Financial Operations Overview](index=21&type=section&id=Financial%20Operations%20Overview) - The company has not generated any revenue from product sales and does not expect to until **RTB101** receives regulatory approval and is commercialized[98](index=98&type=chunk) - Research and development expenses are expensed as incurred and are expected to increase substantially as product candidates advance through clinical development and manufacturing[100](index=100&type=chunk)[103](index=103&type=chunk) - General and administrative expenses are expected to increase due to anticipated headcount growth and costs associated with operating as a public company[108](index=108&type=chunk) - Other income, net, primarily consists of interest income earned on cash, cash equivalents, and marketable securities[109](index=109&type=chunk) [Revenue](index=21&type=section&id=Revenue) - The company has not generated any revenue from product sales and does not expect to until regulatory approval and commercialization of **RTB101**[98](index=98&type=chunk) [Operating Expenses](index=22&type=section&id=Operating%20Expenses) - Research and development expenses include personnel, third-party contract organizations, clinical trial sites, preclinical/clinical material production, and lab expenses, all expensed as incurred[100](index=100&type=chunk)[102](index=102&type=chunk) - R&D expenses are expected to increase substantially due to continued investment in product candidates, manufacturing, and clinical trials[103](index=103&type=chunk) - General and administrative expenses are expected to increase due to anticipated headcount and costs associated with operating as a public company[108](index=108&type=chunk) [Other Income, Net](index=23&type=section&id=Other%20Income%2C%20Net) - Other income, net, primarily consists of interest income earned on cash, cash equivalents, and marketable securities[109](index=109&type=chunk) [Results of Operations](index=23&type=section&id=Results%20of%20Operations) | Metric | Three Months Ended March 31, 2019 (in thousands) | Three Months Ended March 31, 2018 (in thousands) | | :----------------------------------- | :----------------------------------------------- | :----------------------------------------------- | | Research and development | $8,852 | $8,106 | | General and administrative | $2,839 | $2,094 | | Total operating expenses | $11,691 | $10,200 | | Net loss | $(11,069) | $(9,859) | | Other income, net | $631 | $341 | - Net loss increased to **$11.1 million** in Q1 2019 from **$9.9 million** in Q1 2018, driven by a **$1.5 million** increase in total operating expenses[110](index=110&type=chunk) [Comparison of the Three Months Ended March 31, 2019 and 2018](index=23&type=section&id=Comparison%20of%20the%20Three%20Months%20Ended%20March%2031%2C%202019%20and%202018) - Research and development expenses increased by **$0.7 million** to **$8.9 million** in Q1 2019, primarily due to higher costs from third-party contract organizations, clinical trials, preclinical studies, and personnel[112](index=112&type=chunk) - General and administrative expenses increased by **$0.7 million** to **$2.8 million** in Q1 2019, mainly due to increased personnel and professional services fees (intellectual property, legal, accounting, insurance, and consulting)[113](index=113&type=chunk) - Other income, net, increased to **$0.6 million** in Q1 2019 from **$0.3 million** in Q1 2018, primarily from interest income[114](index=114&type=chunk) [Liquidity, Capital Resources and Plan of Operations](index=24&type=section&id=Liquidity%2C%20Capital%20Resources%20and%20Plan%20of%20Operations) - The company completed a public offering in March 2019, generating approximately **$46.6 million** in net proceeds[115](index=115&type=chunk) - As of March 31, 2019, the company had **$143.1 million** in cash, cash equivalents, and marketable securities, and an accumulated deficit of **$82.5 million**[116](index=116&type=chunk) - Existing capital is expected to fund operations through **2020**, including the completion of a pivotal Phase 3 clinical program for **RTB101** and an NDA filing[118](index=118&type=chunk) - The company will require additional financing for future development and operations, with no current credit facility or committed sources of capital, and failure to raise capital could negatively impact business plans[118](index=118&type=chunk)[120](index=120&type=chunk)[121](index=121&type=chunk) | Cash Flow Activity | Three Months Ended March 31, 2019 (in thousands) | Three Months Ended March 31, 2018 (in thousands) | | :--------------------------------- | :----------------------------------------------- | :----------------------------------------------- | | Net cash used in operating activities| $(12,049) | $(7,304) | | Net cash used in investing activities| $(34,628) | $(278) | | Net cash provided by financing activities| $46,816 | $89,938 | - Cash used in operating activities increased to **$12.0 million** in Q1 2019, primarily due to the net loss and changes in operating assets and liabilities[123](index=123&type=chunk) - Cash used in investing activities was **$34.6 million** in Q1 2019, mainly for purchases of marketable securities (**$77.1 million**) offset by maturities (**$42.5 million**)[124](index=124&type=chunk) - Cash provided by financing activities was **$46.8 million** in Q1 2019 from the public offering, compared to **$89.9 million** in Q1 2018 from the IPO[125](index=125&type=chunk) [Contractual Obligations and Other Commitments](index=26&type=section&id=Contractual%20Obligations%20and%20Other%20Commitments) - There have been no material changes to the company's contractual obligations and commitments since those reported in the Annual Report on Form 10-K for the year ended December 31, 2018[127](index=127&type=chunk) [Off-Balance Sheet Arrangements](index=26&type=section&id=Off-Balance%20Sheet%20Arrangements) - The company does not have any off-balance sheet arrangements or holdings in variable interest entities[128](index=128&type=chunk) [Critical Accounting Polices and Estimates](index=26&type=section&id=Critical%20Accounting%20Polices%20and%20Estimates) - The financial statements are prepared under U.S. GAAP, requiring management estimates and assumptions, particularly for accrued research and development costs[129](index=129&type=chunk)[130](index=130&type=chunk) - Research and development costs are expensed as incurred, including personnel, lab supplies, and fees paid to third parties[131](index=131&type=chunk)[132](index=132&type=chunk) [Recently Issued and Adopted Accounting Pronouncements](index=26&type=section&id=Recently%20Issued%20and%20Adopted%20Accounting%20Pronouncements) - The company is evaluating the potential effects of ASU 2016-02 (Leases), ASU 2016-18 (Cash Flows), ASU 2017-11 (Down Round Features), and ASU 2018-07 (Share-Based Payment Accounting)[133](index=133&type=chunk)[135](index=135&type=chunk)[136](index=136&type=chunk)[137](index=137&type=chunk) - Most new pronouncements are not expected to have a material impact on the consolidated financial statements[135](index=135&type=chunk)[136](index=136&type=chunk) [Item 3. Quantitative and Qualitative Disclosures About Market Risk](index=27&type=section&id=Item%203.%20Quantitative%20and%20Qualitative%20Disclosures%20About%20Market%20Risk) This section discusses the company's exposure to market risks, primarily interest rate sensitivity on its investment portfolio and foreign currency fluctuations from global contracts - The company's primary market risk exposure is interest rate sensitivity on its **$143.1 million** in short-term marketable securities (U.S. treasury securities and money market funds)[138](index=138&type=chunk) - An immediate **100 basis point** change in interest rates is not expected to materially affect the fair value of the investment portfolio due to its short-term duration and low risk profile[138](index=138&type=chunk) - The company is subject to foreign currency fluctuations from global contracts but has not engaged in hedging activities[139](index=139&type=chunk) [Item 4. Controls and Procedures](index=28&type=section&id=Item%204.%20Controls%20and%20Procedures) This section confirms the effectiveness of the company's disclosure controls and procedures and reports no material changes in internal control over financial reporting during the quarter - The company's disclosure controls and procedures were evaluated and deemed effective at the reasonable assurance level as of March 31, 2019[143](index=143&type=chunk) - There were no material changes in internal control over financial reporting during the fiscal quarter ended March 31, 2019[144](index=144&type=chunk) PART II. OTHER INFORMATION [Item 1. Legal Proceedings](index=29&type=section&id=Item%201.%20Legal%20Proceedings) This section states that the company is not currently involved in any legal proceedings expected to have a material adverse impact on its financial condition - As of March 31, 2019, the company was not a party to any legal proceedings expected to have a material adverse impact on its financial position, results of operations, or cash flow[146](index=146&type=chunk) [Item 1A. Risk Factors](index=29&type=section&id=Item%201A.%20Risk%20Factors) This section confirms that there have been no material changes to the risk factors previously disclosed in the company's Annual Report on Form 10-K - There have been no material changes to the risk factors set forth in the Annual Report on Form 10-K for the fiscal year ended December 31, 2018[147](index=147&type=chunk) [Item 2. Unregistered Sales of Equity Securities and Use of Proceeds](index=29&type=section&id=Item%202.%20Unregistered%20Sales%20of%20Equity%20Securities%20and%20Use%20of%20Proceeds) This section details the proceeds from the company's initial public offering (IPO) and how those funds have been utilized since its closing - The company closed its initial public offering (IPO) on **January 30, 2018**, issuing **6,516,667** shares of common stock at **$15.00 per share**, generating approximately **$89.4 million** in net proceeds[148](index=148&type=chunk)[149](index=149&type=chunk) - As of March 31, 2019, approximately **$48.9 million** of the IPO proceeds have been used to advance product candidates through clinical trial programs, for working capital, and general corporate purposes[150](index=150&type=chunk) [Item 3. Defaults Upon Senior Securities](index=29&type=section&id=Item%203.%20Defaults%20Upon%20Senior%20Securities) This item is not applicable to the company - Not applicable[150](index=150&type=chunk) [Item 4. Mine Safety Disclosures](index=29&type=section&id=Item%204.%20Mine%20Safety%20Disclosures) This item is not applicable to the company - Not applicable[150](index=150&type=chunk) [Item 5. Other Information](index=29&type=section&id=Item%205.%20Other%20Information) This section indicates that there is no other information to report - None[150](index=150&type=chunk) [Item 6. Exhibits](index=29&type=section&id=Item%206.%20Exhibits) This section lists all exhibits filed as part of the Quarterly Report, including various agreements, certifications, and XBRL documents - The Exhibit Index includes amendments to offer letters and office leases, certifications of principal officers, and XBRL taxonomy documents[151](index=151&type=chunk)[152](index=152&type=chunk) [Signatures](index=31&type=section&id=Signatures) This section contains the official signatures of the company's principal executive and financial officers, certifying the report - The report is signed by Chen Schor, President and Chief Executive Officer, and John J. McCabe, Vice President, Finance, on May 15, 2019[154](index=154&type=chunk)

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, 2018 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 No. 001-38359 resTORbio, Inc. (Exact name of registrant as specified in its charter) Delaware 81-3305277 (State or other jurisdiction of incorpo ...