The Company and Basis of Presentation

6 Months Ended

Jun. 30, 2015

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The Company and Basis of Presentation

Organization and Description of Business

ProNAi Therapeutics, Inc. (together with its subsidiaries, collectively referred to as the “Company”), a Delaware corporation, is a clinical-stage oncology company pioneering a novel class of therapeutics based on its proprietary DNAi technology platform. The core of the Company’s scientific expertise is its understanding of DNAi oligonucleotides, which are rationally designed DNA sequences that modulate the transcription of oncogenes known to be involved in cancer cell survival and proliferation. The Company’s lead DNAi product candidate, PNT2258, targets BCL2, a widely overexpressed oncogene that is an important gatekeeper of the programmed cell death pathway known as apoptosis and has been linked to many forms of cancer.

The Company’s primary activities since inception have been conducting research and development activities, conducting preclinical and clinical testing, recruiting personnel, performing business and financial planning, and raising capital to support development activities.

The Company has not generated any product revenue related to its primary business purpose to date, nor has it generated any income, and is subject to a number of risks and uncertainties, which include dependence on key individuals, the need for development of commercially viable products, the need to obtain regulatory approval for its products and commercialize them and the need to obtain adequate additional financing to fund the development of its product candidates.

Initial Public Offering

On July 15, 2015, the Company’s Registration Statement on Form S-1 (File No. 333-204921) relating to the initial public offering (IPO) of its common stock was declared effective by the Securities and Exchange Commission (SEC). Pursuant to such Registration Statement, the Company sold an aggregate of 9,315,000 shares of its common stock at a price of $17.00 per share for aggregate cash proceeds of approximately $143.6, net of underwriting discounts and commissions and offering costs.

On July 21, 2015, immediately prior to the closing of the IPO, all outstanding shares of convertible and redeemable convertible preferred stock converted into 17,971,273 shares of common stock. The IPO closed on July 21, 2015.

Reverse Stock Split

On June 29, 2015, the Company’s board of directors approved an amendment to the Company’s amended and restated certificate of incorporation to effect a reverse split of the Company’s common stock, convertible preferred stock and redeemable convertible preferred stock at a 7.45-to-1 ratio (the “Reverse Stock Split”). The Reverse Stock Split became effective on July 2, 2015, upon the filing of the amendment to the Company’s amended and restated certificate of incorporation. The authorized shares and par value of the common, convertible preferred and redeemable convertible preferred stock were not adjusted as a result of the Reverse Stock Split. All issued and outstanding common stock, convertible preferred stock, redeemable convertible preferred stock, warrants for preferred stock, options for common stock and per share amounts contained in the condensed consolidated financial statements have been retroactively adjusted to reflect this Reverse Stock Split for all periods presented.