1. Basis of Presentation

Cabaletta Bio, Inc. (the Company or Cabaletta) was incorporated in April 2017 in the State of Delaware as Tycho Therapeutics, Inc. and, in August 2018, changed its name to Cabaletta Bio, Inc. The Company is headquartered in Pennsylvania. Cabaletta is a clinical-stage biotechnology company focused on the discovery and development of T cell therapies for B cell-mediated autoimmune diseases.

Principal operations commenced in April 2018, when the Company executed sponsored research agreements with the Trustees of the University of Pennsylvania (Penn).

On October 16, 2019, the Company effected a 1-for-1.5 reverse split of the Company’s issued and outstanding shares of common stock, par value $0.00001 per share (Common Stock). Upon the effectiveness of the reverse stock split: (i) all shares of outstanding Common Stock were adjusted; (ii) the conversion price of the Series A, Series A-1, Series A-2 and Series B preferred stock (collectively, the Preferred Shares) was adjusted; (iii) the number of shares of Common Stock for which each outstanding option to purchase Common Stock is exercisable was adjusted; and (iv) the exercise price of each outstanding option to purchase Common Stock was adjusted. All of the outstanding Common Stock share numbers (including shares of Common Stock subject to the Company’s options and as converted for the outstanding convertible preferred stock shares), share prices, exercise prices and per share amounts contained in the condensed financial statements have been retroactively adjusted in the condensed financial statements to reflect this reverse stock split for all periods presented. The par value per share and the authorized number of shares of Common Stock and convertible preferred stock were not adjusted as a result of the reverse stock split.

On October 29, 2019, the Company completed its initial public offering (IPO) of 6,800,000 shares of Common Stock at an offering price of $11.00 per share. The Company received net proceeds of $66,164 after deducting underwriting discounts, commissions and estimated offering expenses. In connection with the IPO, the Company’s outstanding shares of convertible preferred stock were automatically converted into 12,904,534 shares of Common Stock. After the IPO, the Company had a total of 23,552,854 outstanding shares of Common Stock. In November 2019, the underwriters partially exercised their option and purchased an additional 475,501 shares of Common Stock resulting in net proceeds to the Company of approximately $4,864, after deducting underwriting discounts and commissions. The financial statements as of September 30, 2019, including share and per share amounts, do not include the effects of the IPO.

Risks and Uncertainties

The Company is subject to risks common to companies in the biotechnology industry including, but not limited to, new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing. As a result, the Company is unable to predict the timing or amount of increased expenses or when or if the Company will be able to achieve or maintain profitability. Further, the Company is currently dependent on Penn for much of its preclinical research, clinical research and development activities, and expects to be dependent upon Penn for initial manufacturing activities (Note 6). Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to commercialization. Even if the Company is able to generate revenues from the sale of its product candidates, if approved, it may not become profitable. If the Company fails to become profitable or is unable to sustain profitability on a continuing basis, then it may be unable to continue its operations at planned levels and be forced to reduce its operations.

Liquidity

The Company expects that its operating losses and negative cash flows will continue for the foreseeable future. As of the issuance date of these unaudited condensed financial statements as of and for the nine months ended September 30, 2019, the Company expects that the $71,028 net proceeds from its IPO and the partial exercise of the underwriters’ option to purchase additional shares together with its cash and cash equivalents as of September 30, 2019 will be sufficient to fund its operating expenses and capital expenditure requirements through at least the first quarter of 2022. The future viability of the Company beyond that date is dependent on its ability to raise additional capital to finance its operations.