Description of Business and Basis of Presentation	12 Months Ended
Dec. 31, 2019
Description of Business and Basis of Presentation
Description of Business and Basis of Presentation	1. Description of Business and Basis of Presentation Organization Aridis Pharmaceuticals, Inc. (the “Company” or “we” or “our”) was established as a California limited liability corporation in 2003. The Company converted to a Delaware C corporation on May 21, 2014. Our principal place of business is in San Jose, California. We are a late-stage biopharmaceutical company focused on developing new breakthrough therapies for infectious diseases and addressing the growing problem of antibiotic resistance. The Company has a deep, diversified portfolio of clinical and pre-clinical stage non-antibiotic anti-infective product candidates that are complimented by a fully human monoclonal antibody discovery platform technology. The Company’s suite of anti-infective monoclonal antibodies offers opportunities to profoundly alter the current trajectory of increasing antibiotic resistance and improve the health outcome of many of the most serious life-threatening infections particularly in hospital settings. Basis of Presentation and Consolidation The accompanying consolidated financial statements have been prepared in accordance with the United States generally accepted accounting principles, or GAAP. The consolidated financial statements include the accounts of the Company and its two wholly-owned subsidiaries, Aridis Biopharmaceuticals, Inc. and Aridis Pharmaceuticals, C.V. All intercompany balances and transactions have been eliminated in consolidation. The Company operates in one segment. Management uses one measurement of profitability and does not segregate its business for internal reporting. Reclassifications Certain prior period amounts have been reclassified to conform to the current period presentation. These reclassifications had no effect on previously reported net loss, stockholders' equity (deficit) or cash flow activities. Reverse Stock Split On August 3, 2018, the Company effected a 1 for 6.417896 reverse stock split of the Company’s common stock. The par value and the number of authorized shares of the common and convertible preferred stock were not adjusted as a result of the reverse stock split. All common stock share and per-share amounts for all periods presented in this Annual Report on Form 10-K have been adjusted retroactively to reflect the reverse stock split. Initial Public Offering On August 13, 2018, the Company's registration statement on Form S-1 relating to its initial public offering of its common shares (the "IPO") was declared effective by the SEC. The IPO closed on August 16, 2018 and the Company issued and sold 2,000,000 common shares at a public offering price of $13.00 per share. Gross proceeds totaled $26.0 million and net proceeds totaled $22.8 million after deducting underwriting discounts and commissions of $1.8 million and other offering expenses of approximately $1.4 million. The underwriters of the IPO partially exercised their over-allotment option, and on August 30, 2018, the Company issued and sold 192,824 common shares at a public offering price of $13.00 per share for gross proceeds totaling approximately $2.5 million and net proceeds of approximately $2.3 million after deducting underwriting discounts and commissions of approximately $175,000 million. In connection with the IPO, the holders of a majority of the Series A Preferred Stock approved the mandatory conversion of the Series A Preferred Stock into one share of common stock for every 6.417896 shares of Series A Preferred Stock which converted immediately prior to the consummation of the IPO. Upon conversion, a total of 5,744,586 shares of common stock were issued for the converted Series A Preferred Stock which includes the accrued dividends upon conversion. All warrants to purchase Series A Preferred Stock became warrants to purchase common stock, adjusted for the 1 for 6.417896 shares reverse stock split. Going Concern The Company had recurring losses from operations since inception and negative cash flows from operating activities during the years ended December 31, 2019 and 2018. Management expects to incur additional operating losses in the foreseeable future as the Company continues its product development programs. At December 31, 2019, the Company had cash and cash equivalents of $20.9 million. Our research and development expenses and resulting cash burn during the year ended December 31, 2019, were largely due to costs associated with launching the Phase 3 study of AR-301 for the treatment of VAP caused by the Staphylococus aureus bacteria, the Phase 2 study of AR-105 for the treatment of VAP caused by the Pseudomonas aeruginosa bacteria, and the Phase 1/2 study of AR-501 for the treatment of chronic lung infections associated with cystic fibrosis. Current clinical development activities are focused on AR-301 and AR-501. While no further development resources will be allocated towards AR-105, we will continue to analyze the full data set to better understand these top-line results. We expect our expenses to increase in connection with our ongoing development activities, particularly as we continue the research, development and clinical trials of, and seek regulatory approval for, our therapeutic candidates. On March 11, 2020, the World Health Organization declared the COVID-19 outbreak a pandemic. The COVID-19 pandemic is affecting the United States and global economies and may affect the Company’s operations and those of third parties on which the Company relies, including by causing disruptions in the supply of the product candidates and the conduct of current and future clinical trials. Additionally, as the duration of the COVID-19 pandemic is difficult to assess or predict, the impact of the COVID-19 pandemic on the global financial markets may reduce our ability to access capital, which could negatively impact the Company’s short-term and long-term liquidity. These effects could have a material impact on the Company’s liquidity, capital resources, operations and business and those of the third parties on which the Company relies. The Company plans to fund its losses from operations through current cash on hand and future debt and equity financings which we may obtain through one or more public or private equity offerings, debt financings, government or other third-party funding, strategic alliances and licensing or collaboration arrangements. The Company may be unable to secure additional financing or other sources of funding on acceptable terms, or at all. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate its research and development programs or future commercialization efforts, which could adversely affect its future business prospects and its ability to continue as a going concern. The Company believes that its current available cash and cash equivalents will not be sufficient to fund its planned expenditures and meet the Company’s obligations for at least the one-year period following its financial statement issuance date. The accompanying consolidated financial statements have been prepared on a going concern basis that contemplates the realization of assets and discharge of liabilities in their normal course of business. There is substantial doubt about the Company’s ability to continue as a going concern for one year after the date that these consolidated financial statements are issued. These consolidated financial statements do not include any adjustments that might be necessary from the outcome of this uncertainty.

1. Description of Business and Basis of Presentation

Organization

Aridis Pharmaceuticals, Inc. (the “Company” or “we” or “our”) was established as a California limited liability corporation in 2003. The Company converted to a Delaware C corporation on May 21, 2014. Our principal place of business is in San Jose, California. We are a late-stage biopharmaceutical company focused on developing new breakthrough therapies for infectious diseases and addressing the growing problem of antibiotic resistance. The Company has a deep, diversified portfolio of clinical and pre-clinical stage non-antibiotic anti-infective product candidates that are complimented by a fully human monoclonal antibody discovery platform technology. The Company’s suite of anti-infective monoclonal antibodies offers opportunities to profoundly alter the current trajectory of increasing antibiotic resistance and improve the health outcome of many of the most serious life-threatening infections particularly in hospital settings.

Basis of Presentation and Consolidation

The accompanying consolidated financial statements have been prepared in accordance with the United States generally accepted accounting principles, or GAAP. The consolidated financial statements include the accounts of the Company and its two wholly-owned subsidiaries, Aridis Biopharmaceuticals, Inc. and Aridis Pharmaceuticals, C.V. All intercompany balances and transactions have been eliminated in consolidation. The Company operates in one segment. Management uses one measurement of profitability and does not segregate its business for internal reporting.

Reclassifications

Certain prior period amounts have been reclassified to conform to the current period presentation. These reclassifications had no effect on previously reported net loss, stockholders' equity (deficit) or cash flow activities.

Reverse Stock Split

On August 3, 2018, the Company effected a 1 for 6.417896 reverse stock split of the Company’s common stock. The par value and the number of authorized shares of the common and convertible preferred stock were not adjusted as a result of the reverse stock split. All common stock share and per-share amounts for all periods presented in this Annual Report on Form 10-K have been adjusted retroactively to reflect the reverse stock split.

Initial Public Offering

On August 13, 2018, the Company's registration statement on Form S-1 relating to its initial public offering of its common shares (the "IPO") was declared effective by the SEC. The IPO closed on August 16, 2018 and the Company issued and sold 2,000,000 common shares at a public offering price of $13.00 per share. Gross proceeds totaled $26.0 million and net proceeds totaled $22.8 million after deducting underwriting discounts and commissions of $1.8 million and other offering expenses of approximately $1.4 million. The underwriters of the IPO partially exercised their over-allotment option, and on August 30, 2018, the Company issued and sold 192,824 common shares at a public offering price of $13.00 per share for gross proceeds totaling approximately $2.5 million and net proceeds of approximately $2.3 million after deducting underwriting discounts and commissions of approximately $175,000 million.

In connection with the IPO, the holders of a majority of the Series A Preferred Stock approved the mandatory conversion of the Series A Preferred Stock into one share of common stock for every 6.417896 shares of Series A Preferred Stock which converted immediately prior to the consummation of the IPO. Upon conversion, a total of 5,744,586 shares of common stock were issued for the converted Series A Preferred Stock which includes the accrued dividends upon conversion. All warrants to purchase Series A Preferred Stock became warrants to purchase common stock, adjusted for the 1 for 6.417896 shares reverse stock split.

Going Concern

The Company had recurring losses from operations since inception and negative cash flows from operating activities during the years ended December 31, 2019 and 2018. Management expects to incur additional operating losses in the foreseeable future as the Company continues its product development programs. At December 31, 2019, the Company had cash and cash equivalents of $20.9 million.

Our research and development expenses and resulting cash burn during the year ended December 31, 2019, were largely due to costs associated with launching the Phase 3 study of AR-301 for the treatment of VAP caused by the Staphylococus aureus bacteria, the Phase 2 study of AR-105 for the treatment of VAP caused by the Pseudomonas aeruginosa bacteria, and the Phase 1/2 study of AR-501 for the treatment of chronic lung infections associated with cystic fibrosis. Current clinical development activities are focused on AR-301 and AR-501. While no further development resources will be allocated towards AR-105, we will continue to analyze the full data set to better understand these top-line results. We expect our expenses to increase in connection with our ongoing development activities, particularly as we continue the research, development and clinical trials of, and seek regulatory approval for, our therapeutic candidates.

On March 11, 2020, the World Health Organization declared the COVID-19 outbreak a pandemic. The COVID-19 pandemic is affecting the United States and global economies and may affect the Company’s operations and those of third parties on which the Company relies, including by causing disruptions in the supply of the product candidates and the conduct of current and future clinical trials. Additionally, as the duration of the COVID-19 pandemic is difficult to assess or predict, the impact of the COVID-19 pandemic on the global financial markets may reduce our ability to access capital, which could negatively impact the Company’s short-term and long-term liquidity. These effects could have a material impact on the Company’s liquidity, capital resources, operations and business and those of the third parties on which the Company relies.

The Company plans to fund its losses from operations through current cash on hand and future debt and equity financings which we may obtain through one or more public or private equity offerings, debt financings, government or other third-party funding, strategic alliances and licensing or collaboration arrangements. The Company may be unable to secure additional financing or other sources of funding on acceptable terms, or at all. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate its research and development programs or future commercialization efforts, which could adversely affect its future business prospects and its ability to continue as a going concern. The Company believes that its current available cash and cash equivalents will not be sufficient to fund its planned expenditures and meet the Company’s obligations for at least the one-year period following its financial statement issuance date.

The accompanying consolidated financial statements have been prepared on a going concern basis that contemplates the realization of assets and discharge of liabilities in their normal course of business. There is substantial doubt about the Company’s ability to continue as a going concern for one year after the date that these consolidated financial statements are issued. These consolidated financial statements do not include any adjustments that might be necessary from the outcome of this uncertainty.