2. Significant Accounting Policies

Basis of Presentation

The accompanying condensed financial statements are prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) for interim financial information to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments, consisting of normal recurring accruals and revisions of estimates, considered necessary for a fair presentation of the accompanying condensed financial statements have been included. Interim results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2018 or any other future period. These condensed financial statements should be read in conjunction with the Company’s audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. Subsequent events have been evaluated through the date of issuance, which is the same as the date this Form 10-Q is filed with the Securities and Exchange Commission (the “SEC”).

Segment Information

Operating segments are defined as components of an enterprise engaging in business activities for which discrete financial information is available and regularly reviewed by the chief operating decision maker in deciding how to allocate resources and in assessing performance. All long-lived assets are held in the U.S. The Company views its operations and manages its business in one operating segment.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires the Company’s management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual amounts may differ from those estimates.

Cash and Cash Equivalents

The Company considers cash and all highly liquid investments with a maturity of three months or less at the date of purchase to be cash equivalents. Cash equivalents consist primarily of money market instruments, U.S. government treasury obligations, U.S. government agency obligations, corporate obligations and repurchase agreements that are maintained by an investment manager.

Investments

Investments consist primarily of investments in U.S. Treasuries and corporate debt securities, which could also include commercial paper, that are maintained by an investment manager. Management determines the appropriate classification of marketable securities at the time of purchase and reevaluates such classification as of each balance sheet date. Available-for-sale securities are carried at fair value, with the unrealized gains and losses reported in other comprehensive income (loss). Realized gains and losses and declines in value judged to be other-than-temporary on available-for-sale securities are included in other income (expense). The Company considers and accounts for other-than-temporary impairments according to the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 320, Investments — Debt and Equity Securities (“ASC 320”). The cost of securities sold is based on the specific-identification method. Discounts and premiums on debt securities are amortized to interest income and expensed over the term of the security.

Revenue Recognition

Commencing with reporting periods beginning January 1, 2018, the Company recognizes revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers. The Company’s contract revenues consist of revenues from license and collaboration agreements. License and collaboration revenue is primarily generated through agreements with strategic partners for the development and potential commercialization of our product candidates. The terms of the agreement typically include non-refundable upfront fees, funding of research and development activities, payments based upon achievement of milestones and potential royalties on net product sales. Non-refundable upfront fees and funding of research and development activities are considered fixed consideration, while milestone payments and royalties are identified as variable consideration.

The Company recognizes revenues from license and collaboration agreements to depict the transfer of promised goods or services in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. In order to determine the appropriate amount of revenue to be recognized as the Company fulfills its obligations under a contract, the Company follows the following steps for in-scope transactions: 1) identification of the contract with a customer, 2) identification of the separate performance obligations in the contract, 3) determination of the transaction price, 4) allocation of the transaction price to the separate performance obligations in the contract, and 5) recognition of revenue when or as the Company satisfies a performance obligation.

The Company’s performance obligations may include license rights, research and development services, services associated with regulatory submission and approval processes and services related to potential commercialization processes. Significant judgment may be required to determine the level of effort required under an arrangement and the period over which the Company expects to satisfy its performance obligations under the arrangement. If the Company cannot reasonably estimate when its performance obligations either are satisfied or become inconsequential, then revenue recognition is deferred until the Company can reasonably make such estimates. Revenue is then recognized over the remaining estimated period of performance using the cumulative catch-up method.

License Agreements

If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, upfront fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that may be bundled with other promises, the Company will utilize judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, upfront fees. Because the drug development process is lengthy and the Company’s collaboration agreements typically cover activities over several years, this approach may result in the deferral of significant amounts of revenue into future periods. Each reporting period, the Company evaluates the measure of progress and, if necessary, adjusts the measure of performance and related revenue recognition.

Milestone Payments

At the inception of each arrangement that includes milestone payments, the Company evaluates whether the milestones are considered probable of being achieved and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the value of the associated milestone (such as a regulatory submission by the Company) is included in the transaction price. Milestone payments that are not within the control of the Company, such as approvals from regulators, are not considered probable of being achieved until those approvals are received. When the Company’s assessment of probability of achievement changes and variable consideration becomes probable, any additional estimated consideration is allocated to each performance obligation based on the estimated relative standalone selling prices of the promised good or service underlying each performance obligation and recorded in license, collaboration, and other revenues based upon when the customer obtains control of each element.

Royalty Payments

For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (a) when the related sales occur, or (b) when the performance obligation to which some or all of the royalty has been allocated has been satisfied. To date, none of the Company’s products have been approved and therefore the Company has not earned any royalty revenue from product sales.

Research and Development Expenses

Research and development expenses represent costs associated with the ongoing development of novel therapeutics and companion imaging agents for personalized targeted therapies and include salaries and employee benefits, supplies, facility costs related to research activities, and expenses for clinical trials. The Company records accruals for clinical trial expenses based on the estimated amount of work completed. The Company monitors patient enrollment levels and related activities to the extent possible through internal reviews, correspondence, and discussions with research organizations. In the event that a clinical trial is terminated early, the Company records, in the period of termination, an accrual for the estimated remaining costs to complete and close out the trial pursuant to ASC Topic 420, Exit or Disposal Cost Obligations, as a terminated trial does not provide any future economic benefit to the Company. See Note 11 – Restructuring Costs of the Notes to Condensed Financial Statements contained herein for amounts paid during the three and nine months ended September 30, 2018 related to the Company’s restructuring activities.

Upfront payments made in connection with business collaborations and research and development arrangements are evaluated under ASC Subtopic 730-20, Research and Development Arrangements. Amounts related to future research and development, including clinical drug supply, are capitalized as prepaid research and development and are expensed over the service period based upon the level of services provided. As of September 30, 2018, the Company had approximately $7.8 million of capitalized research and development costs included in prepaid expenses, other assets and other noncurrent assets.

Acquired In-Process Research and Development Expense

The Company has acquired and may continue to acquire the rights to develop and commercialize new drug candidates. In accordance with ASC Subtopic 730-25, Accounting for Research and Development Costs, the upfront payments to acquire a new drug compound, as well as future milestone payments when paid or payable, are immediately expensed as acquired in-process research and development (“IPR&D”) in transactions other than a business combination provided that the drug has not achieved regulatory approval for marketing and, absent obtaining such approval, has no alternative future use. Upon obtaining regulatory approval for marketing, any related milestone payments may be capitalized and amortized over the life of the asset.

Stock-Based Compensation

The Company accounts for its stock-based compensation pursuant to ASC Topic 718, Compensation — Stock Compensation (“ASC 718”), which requires the recognition of the fair value of stock-based compensation in net income (loss). Stock-based compensation consists of stock options, which are granted at exercise prices at or above the fair market value of the Company’s common stock on the dates of grant, service-based restricted stock units (“RSUs”) and shares available for purchase under the Company’s 2010 Employee Stock Purchase Plan (“ESPP”). For RSUs and stock options issued by the Company, stock-based compensation expense is recognized ratably over the service period and forfeitures are accounted for as they occur. The Company recognizes compensation cost based on the grant date fair value estimated in accordance with the provisions of ASC 718.

Net Loss Per Share

Basic net loss per share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method and the if-converted method. For purposes of this calculation, stock options, warrants, RSUs and shares to be purchased under the ESPP are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive.

Common stock equivalents

As of September 30, 2017 and 2018, the following number of potential common stock equivalents were outstanding:


	As of September 30,
	2017	2018
Outstanding common stock options	6,265,333	5,309,344
Outstanding warrants	756,647	722,000
Outstanding RSUs	478,087	1,510,460
Shares to be purchased under the ESPP	18,323	11,410
Total	7,518,390	7,553,214

These common stock equivalents were excluded from the determination of diluted net loss per share in the three and nine month periods ended September 30, 2017 and 2018 due to their anti-dilutive effect on earnings. For additional information on the outstanding warrants, see Note 8 – Warrants of the Notes to Condensed Financial Statements contained herein.