Nature of the Business	6 Months Ended
Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	1. Nature of the Business Decibel Therapeutics, Inc. (the “Company”) was formed on November 26, 2013. The Company is a clinical-stage biotechnology company dedicated to discovering and developing transformative treatments for hearing and balance disorders, one of the largest areas of unmet need in medicine. The Company aims to restore and improve hearing and balance through the restoration and regeneration of functional hair cells and non-sensory support cells within the inner ear. On February 5, 2021, the Company’s board of directors approved a 1-for-5.3 reverse stock split of the Company’s common stock. All share and per share amounts in the condensed consolidated financial statements and notes thereto have been retroactively adjusted for all periods presented to give effect to the reverse stock split. On February 17, 2021, the Company completed an initial public offering (“IPO”), issuing and selling 7,062,000 shares of common stock at a public offering price of $18.00 per share, and on February 24, 2021, the Company issued and sold an additional 600,000 shares pursuant to the underwriters’ partial exercise of their option to purchase additional shares. The aggregate net proceeds received by the Company from the offering were $125.0 million. Upon closing of the Company’s IPO, all outstanding shares of convertible preferred stock automatically converted into shares of common stock. In March 2022, the Company filed a universal shelf registration on Form S-3 to register for sale from time to time up to $200.0 million of common stock, preferred stock, debt securities, warrants and/or units in one or more offerings. Further, in March 2022, the Company entered into an Open Market Sale AgreementSM (the “Sales Agreement”) with Jefferies LLC (“Jefferies”) pursuant to which, from time to time, the Company may offer and sell shares of its common stock having an aggregate offering price of up to $20.0 million. Sales of common stock through Jefferies may be made by any method that is deemed an “at-the-market” offering as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended. Jefferies is entitled to compensation at a rate equal to 3.0% of the gross proceeds from any shares of common stock sold under the Sales Agreement. As of June 30, 2022, the Company had not sold any shares of common stock pursuant to the Sales Agreement. Liquidity Since its inception, the Company’s operations have been focused on organizing and staffing, business planning, raising capital, establishing the Company’s intellectual property portfolio and performing research and development of its product candidates, programs and platform. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including but not limited to, risks associated with completing preclinical studies and clinical trials, obtaining regulatory approvals for product candidates, development by competitors of new biopharmaceutical products, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Programs currently under development will require significant additional research and development efforts, including preclinical and clinical testing and will need to obtain regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize revenue from product sales. As of June 30, 2022, the Company had cash, cash equivalents and available-for-sale securities of $125.6 million. The Company has determined that its existing capital resources will be sufficient to meet its projected operating expenses and capital expenditure requirements for at least twelve months from the date of issuance of these condensed consolidated financial statements. The Company expects to experience negative cash flows from operations and net losses for the foreseeable future as it continues to invest significantly in research and development of its product candidates, preclinical and clinical development and platform. Management’s conclusion with respect to its ability to fund its operations is based on estimates that are subject to risks and uncertainties that may prove to be incorrect. If actual results differ from management’s estimates, the Company may be required to seek additional funding or curtail planned activities to reduce operating expenses, which may have an adverse impact on the Company’s ability to achieve its business objectives. Impact of the COVID-19 Pandemic The worldwide COVID-19 pandemic has affected and may affect in the future the Company’s ability to initiate and complete preclinical studies, delay the initiation and completion of the Company’s current and planned clinical trials, disrupt regulatory activities or have other adverse effects on the Company’s business, results of operations, financial condition and prospects. In addition, the pandemic has caused substantial disruption to global supply chains and may adversely impact economies worldwide, both of which could adversely affect the Company’s business, operations and ability to raise funds to support its operations. The Company is following, and plans to continue to follow, recommendations from federal, state and local governments regarding workplace policies, practices and procedures. In response to the COVID-19 pandemic and in accordance with direction from state and local governmental authorities, the Company previously restricted access to its facility to those individuals who must perform critical research, translational medicine and laboratory support activities that must be completed on site, limited the number of such people that can be present at its facility at any one time, and required that most of its employees work remotely. In February 2022, the Company re-opened its facility to all of its employees. Screening and enrollment in the Company’s ongoing Phase 1b clinical trial of DB-020 in Australia and the United States had been adversely impacted by the COVID-19 pandemic. Patient screening and enrollment were paused in the second quarter of 2020 in both Australia and the United States, and screening for enrollment did not resume until early in the third quarter of 2020 in Australia and early in the fourth quarter of 2020 in the United States. The Company has also experienced delays in site start-up and the withdrawal of some sites in the United States. In addition, the Company and the third-party manufacturers, contract research organizations (“CROs”), and academic collaborators that it engages have faced in the past and may face in the future disruptions that could affect its ability to initiate and complete preclinical studies or clinical trials. This includes disruptions in procuring items and providing adequate resources that are essential for its research and development activities, such as, for example, raw materials used in the manufacture of its product candidates, laboratory supplies for its preclinical studies and clinical trials, or animals that are used for preclinical testing, in each case, for which there may be shortages because of ongoing efforts to address the COVID-19 pandemic, including supply chain disruptions. Due to recent increased quarantine mandates in China, the receipt of shipments and data from some of the Company's vendors had been more difficult and unpredictable. This caused some delays in preclinical studies for the Company's gene therapy programs. The quarantine mandates have been largely resolved as of June 2022. The Company has been working with its CROs to assess the impact of the increased mandates on its activities, and contingency planning is on-going. The Company cannot be certain what the overall impact of the COVID-19 pandemic will be on its business. The extent of the impact of COVID-19 on its business will depend on the length and severity of the pandemic, including the extent there is any resurgence of the COVID-19 virus or any variant strains of the virus, the availability and effectiveness of vaccines and the impact of the foregoing on its preclinical studies, current and planned clinical trials, employees and vendors, which is uncertain and cannot be predicted. The pandemic has the potential to adversely affect its business, financial condition, results of operations and prospects.

Nature of the Business

6 Months Ended

Jun. 30, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

1. Nature of the Business

Decibel Therapeutics, Inc. (the “Company”) was formed on November 26, 2013. The Company is a clinical-stage biotechnology company dedicated to discovering and developing transformative treatments for hearing and balance disorders, one of the largest areas of unmet need in medicine. The Company aims to restore and improve hearing and balance through the restoration and regeneration of functional hair cells and non-sensory support cells within the inner ear.

On February 5, 2021, the Company’s board of directors approved a 1-for-5.3 reverse stock split of the Company’s common stock. All share and per share amounts in the condensed consolidated financial statements and notes thereto have been retroactively adjusted for all periods presented to give effect to the reverse stock split.

On February 17, 2021, the Company completed an initial public offering (“IPO”), issuing and selling 7,062,000 shares of common stock at a public offering price of $18.00 per share, and on February 24, 2021, the Company issued and sold an additional 600,000 shares pursuant to the underwriters’ partial exercise of their option to purchase additional shares. The aggregate net proceeds received by the Company from the offering were $125.0 million. Upon closing of the Company’s IPO, all outstanding shares of convertible preferred stock automatically converted into shares of common stock.

In March 2022, the Company filed a universal shelf registration on Form S-3 to register for sale from time to time up to $200.0 million of common stock, preferred stock, debt securities, warrants and/or units in one or more offerings. Further, in March 2022, the Company entered into an Open Market Sale AgreementSM (the “Sales Agreement”) with Jefferies LLC (“Jefferies”) pursuant to which, from time to time, the Company may offer and sell shares of its common stock having an aggregate offering price of up to $20.0 million. Sales of common stock through Jefferies may be made by any method that is deemed an “at-the-market” offering as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended. Jefferies is entitled to compensation at a rate equal to 3.0% of the gross proceeds from any shares of common stock sold under the Sales Agreement. As of June 30, 2022, the Company had not sold any shares of common stock pursuant to the Sales Agreement.

Liquidity

Since its inception, the Company’s operations have been focused on organizing and staffing, business planning, raising capital, establishing the Company’s intellectual property portfolio and performing research and development of its product candidates, programs and platform.

The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including but not limited to, risks associated with completing preclinical studies and clinical trials, obtaining regulatory approvals for product candidates, development by competitors of new biopharmaceutical products, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Programs currently under development will require significant additional research and development efforts, including preclinical and clinical testing and will need to obtain regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize revenue from product sales.

As of June 30, 2022, the Company had cash, cash equivalents and available-for-sale securities of $125.6 million. The Company has determined that its existing capital resources will be sufficient to meet its projected operating expenses and capital expenditure requirements for at least twelve months from the date of issuance of these condensed consolidated financial statements. The Company expects to experience negative cash flows from operations and net losses for the foreseeable future as it continues to invest significantly in research and development of its product candidates, preclinical and clinical development and platform. Management’s conclusion with respect to its ability to fund its operations is based on estimates that are subject to risks and uncertainties that may prove to be incorrect. If actual results differ from management’s estimates, the Company may be required to seek additional funding or curtail planned activities to reduce operating expenses, which may have an adverse impact on the Company’s ability to achieve its business objectives.

Impact of the COVID-19 Pandemic

The worldwide COVID-19 pandemic has affected and may affect in the future the Company’s ability to initiate and complete preclinical studies, delay the initiation and completion of the Company’s current and planned clinical trials, disrupt regulatory

activities or have other adverse effects on the Company’s business, results of operations, financial condition and prospects. In addition, the pandemic has caused substantial disruption to global supply chains and may adversely impact economies worldwide, both of which could adversely affect the Company’s business, operations and ability to raise funds to support its operations.

The Company is following, and plans to continue to follow, recommendations from federal, state and local governments regarding workplace policies, practices and procedures. In response to the COVID-19 pandemic and in accordance with direction from state and local governmental authorities, the Company previously restricted access to its facility to those individuals who must perform critical research, translational medicine and laboratory support activities that must be completed on site, limited the number of such people that can be present at its facility at any one time, and required that most of its employees work remotely. In February 2022, the Company re-opened its facility to all of its employees. Screening and enrollment in the Company’s ongoing Phase 1b clinical trial of DB-020 in Australia and the United States had been adversely impacted by the COVID-19 pandemic. Patient screening and enrollment were paused in the second quarter of 2020 in both Australia and the United States, and screening for enrollment did not resume until early in the third quarter of 2020 in Australia and early in the fourth quarter of 2020 in the United States. The Company has also experienced delays in site start-up and the withdrawal of some sites in the United States. In addition, the Company and the third-party manufacturers, contract research organizations (“CROs”), and academic collaborators that it engages have faced in the past and may face in the future disruptions that could affect its ability to initiate and complete preclinical studies or clinical trials. This includes disruptions in procuring items and providing adequate resources that are essential for its research and development activities, such as, for example, raw materials used in the manufacture of its product candidates, laboratory supplies for its preclinical studies and clinical trials, or animals that are used for preclinical testing, in each case, for which there may be shortages because of ongoing efforts to address the COVID-19 pandemic, including supply chain disruptions. Due to recent increased quarantine mandates in China, the receipt of shipments and data from some of the Company's vendors had been more difficult and unpredictable. This caused some delays in preclinical studies for the Company's gene therapy programs. The quarantine mandates have been largely resolved as of June 2022. The Company has been working with its CROs to assess the impact of the increased mandates on its activities, and contingency planning is on-going.

The Company cannot be certain what the overall impact of the COVID-19 pandemic will be on its business. The extent of the impact of COVID-19 on its business will depend on the length and severity of the pandemic, including the extent there is any resurgence of the COVID-19 virus or any variant strains of the virus, the availability and effectiveness of vaccines and the impact of the foregoing on its preclinical studies, current and planned clinical trials, employees and vendors, which is uncertain and cannot be predicted. The pandemic has the potential to adversely affect its business, financial condition, results of operations and prospects.