Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ 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 COMMISSION FILE NUMBER 001-36576 MARINUS PHARMACEUTICALS, INC. (Exact name of registrant as specified in its charter) Delaware 20-0198082 (State or other jurisdiction of incorporation ...

[PART I – FINANCIAL INFORMATION](index=3&type=section&id=PART%20I%20%E2%80%93%20FINANCIAL%20INFORMATION) This section details the company's unaudited consolidated financial statements, management's analysis, market risk, and internal controls [Financial Statements](index=3&type=section&id=Item%201.%20Financial%20Statements) This section presents the unaudited consolidated financial statements for the quarter ended March 31, 2019 Consolidated Balance Sheets (in thousands) | | March 31, 2019 | December 31, 2018 | | :--- | :--- | :--- | | **Assets** | | | | Cash and cash equivalents | $60,848 | $67,727 | | Total current assets | $62,872 | $73,940 | | Total assets | $67,619 | $75,234 | | **Liabilities & Stockholders' Equity** | | | | Total current liabilities | $6,677 | $6,909 | | Total liabilities | $9,874 | $6,909 | | Total stockholders' equity | $57,745 | $68,325 | | Total liabilities and stockholders' equity | $67,619 | $75,234 | Consolidated Statements of Operations and Comprehensive Loss (in thousands) | | Three Months Ended March 31, 2019 | Three Months Ended March 31, 2018 | | :--- | :--- | :--- | | Research and development | $8,872 | $3,927 | | General and administrative | $3,667 | $2,187 | | Loss from operations | $(12,539) | $(6,114) | | Net loss | $(12,483) | $(5,999) | | Net loss per share—basic and diluted | $(0.24) | $(0.15) | Consolidated Statements of Cash Flows (in thousands) | | Three Months Ended March 31, 2019 | Three Months Ended March 31, 2018 | | :--- | :--- | :--- | | Net cash used in operating activities | $(11,664) | $(6,149) | | Net cash provided by (used in) investing activities | $4,868 | $(8) | | Net cash used in financing activities | $(83) | $(193) | | Net decrease in cash and cash equivalents | $(6,879) | $(6,350) | | Cash and cash equivalents—end of period | $60,848 | $27,181 | - The company is a clinical-stage pharmaceutical firm focused on developing its product candidate, ganaxolone, for epilepsy and neuropsychiatric disorders, with no product revenue and an accumulated deficit of **$193.9 million** as of March 31, 2019[21](index=21&type=chunk)[22](index=22&type=chunk) [Management's Discussion and Analysis of Financial Condition and Results of Operations](index=14&type=section&id=Item%202.%20Management's%20Discussion%20and%20Analysis%20of%20Financial%20Condition%20and%20Results%20of%20Operations) This section discusses the company's financial condition, R&D expenses, and future capital requirements - The company is developing ganaxolone in IV and oral formulations for multiple indications, including pivotal Phase 3 studies for CDKL5 deficiency disorder (CDD) and PCDH19-related epilepsy (PCDH19-RE), and Phase 2 studies for Refractory Status Epilepticus (RSE) and Postpartum Depression (PPD)[60](index=60&type=chunk)[61](index=61&type=chunk)[64](index=64&type=chunk) Research and Development Expenses by Program (in millions) | Program | Q1 2019 | Q1 2018 | | :--- | :--- | :--- | | CDKL5 disorder | $0.9 | $0.2 | | Postpartum depression | $2.4 | $1.0 | | Refractory status epilepticus | $0.5 | $0.4 | | PCDH19-RE | $0.7 | $0.1 | | General supportive studies | $1.2 | $0.4 | | Indirect research and development | $3.2 | $1.8 | | **Total** | **$8.9** | **$3.9** | - General and administrative expenses increased to **$3.7 million** in Q1 2019 from **$2.2 million** in Q1 2018, primarily due to **$1.0 million** in severance expenses for the former CEO and a **$0.5 million** increase in professional fees and other operational costs[81](index=81&type=chunk) - As of March 31, 2019, the company had **$60.8 million** in cash and cash equivalents, which is expected to fund operating expenses and capital requirements into the second half of 2020, but substantial additional financing will be needed to fund future operations[82](index=82&type=chunk)[87](index=87&type=chunk) - Net cash used in operating activities increased to **$11.7 million** for Q1 2019 from **$6.1 million** in Q1 2018, driven by a **$6.5 million** increase in net loss[83](index=83&type=chunk) [Quantitative and Qualitative Disclosure About Market Risk](index=24&type=section&id=Item%203.%20Quantitative%20and%20Qualitative%20Disclosure%20About%20Market%20Risk) The company's primary market risk is interest rate fluctuations on cash and cash equivalents - The company's principal market risk is interest rate fluctuations on its cash and cash equivalents[93](index=93&type=chunk) - Cash and cash equivalents totaled **$60.8 million** at March 31, 2019, consisting primarily of funds in cash and money market accounts, with no material effect expected from a **1.0%** change in interest rates[94](index=94&type=chunk) [Controls and Procedures](index=25&type=section&id=Item%204.%20Controls%20and%20Procedures) Management concluded disclosure controls and procedures were effective with no material changes in internal controls - Based on an evaluation as of March 31, 2019, the Executive Chairman and Chief Financial Officer concluded that the company's disclosure controls and procedures were effective[96](index=96&type=chunk) - There were no changes in internal control over financial reporting during the quarter ended March 31, 2019, that materially affected, or are reasonably likely to materially affect, internal controls[97](index=97&type=chunk) [PART II – OTHER INFORMATION](index=26&type=section&id=PART%20II%20%E2%80%93%20OTHER%20INFORMATION) This section covers legal proceedings, risk factors, equity sales, defaults, mine safety, and exhibits [Legal Proceedings](index=26&type=section&id=Item%201.%20Legal%20Proceedings) The company is not currently a party to any material legal proceedings - The company is not currently a party to any material legal proceedings[100](index=100&type=chunk) [Risk Factors](index=26&type=section&id=Item%201A.%20Risk%20Factors) This section details significant business risks, including ganaxolone's development, clinical trials, and intellectual property - The company has a history of significant losses, with an accumulated deficit of **$193.9 million** as of March 31, 2019, and expects to incur substantial future losses, requiring additional capital to fund operations[102](index=102&type=chunk)[108](index=108&type=chunk) - Future success is entirely dependent on the successful clinical development, regulatory approval, and commercialization of its only clinical-stage product candidate, ganaxolone[115](index=115&type=chunk) - The company faces risks of clinical trial delays or failures, as success in early studies does not guarantee favorable results in later, larger studies, noting ganaxolone previously failed a Phase 3 study for adult focal onset seizures[117](index=117&type=chunk)[120](index=120&type=chunk) - The company relies on third-party CROs to conduct clinical studies and CMOs for manufacturing, where any failure to perform or comply with regulations could delay development and approval[165](index=165&type=chunk)[172](index=172&type=chunk) - The company faces substantial competition from major pharmaceutical companies with existing products and greater resources, including Sage Therapeutics, which is developing a molecule with a similar mechanism of action[154](index=154&type=chunk)[156](index=156&type=chunk) - The company's ability to protect its intellectual property is uncertain, facing risks of patent infringement claims, challenges to patent validity, and difficulties in enforcing rights globally[205](index=205&type=chunk)[212](index=212&type=chunk)[216](index=216&type=chunk) [Unregistered Sales of Equity Securities and Use of Proceeds](index=77&type=section&id=Item%202.%20Unregistered%20Sales%20of%20Equity%20Securities%20and%20Use%20of%20Proceeds) The company reported no unregistered sales of equity securities during the period - None reported[256](index=256&type=chunk) [Defaults Upon Senior Securities](index=77&type=section&id=Item%203.%20Defaults%20Upon%20Senior%20Securities) The company reported no defaults upon senior securities - None reported[257](index=257&type=chunk) [Mine Safety Disclosures](index=77&type=section&id=Item%204.%20Mine%20Safety%20Disclosures) This item is not applicable to the company - Not applicable[257](index=257&type=chunk) [Other Information](index=77&type=section&id=Item%205.%20Other%20Information) The company reported no other information for this period - None reported[257](index=257&type=chunk) [Exhibits](index=77&type=section&id=Item%206.%20Exhibits) This section lists exhibits filed with the Form 10-Q, including employment agreements and certifications - Key exhibits filed include the employment agreement for Executive Chairman Scott Braunstein and the separation agreement for former CEO Christopher M. Cashman[258](index=258&type=chunk) - Certifications by the CEO and CFO as required by the Exchange Act are included as exhibits[258](index=258&type=chunk)

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10‑K ☑ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2018 ☐ 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 001‑36576 Marinus Pharmaceuticals, Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction ...