Shareholders' Equity | Shareholders’ Equity On November 16, 2015, the Company amended its Amended and Restated Certificate of Incorporation to increase the number of authorized shares of common stock from 149.0 million to 249.0 million . The stockholders of the Company approved the increase in authorized shares at a special meeting of the stockholders held on November 16, 2015. On November 18, 2016, upon the stockholder approval of a one-for-forty reverse stock split and the amendment to the Company’s amended and restated certificate of incorporation, the number of authorized shares of common stock was reduced to 25.0 million . In June 2017, the Company's stockholders approved a certificate of amendment to its amended and restated certificate of incorporation to increase the number of authorized shares of common stock from 25.0 million to 50.0 million , which was effective on June 16, 2017. Common Stock July 2017 financing In July 2017, the Company entered into an underwriting agreement with Maxim Group, LLC, pursuant to which the Company sold 5,000 shares of Series B 8% Mandatorily Convertible Preferred Stock (the "Preferred Stock") and related warrants (the “Warrants”) to purchase up to 9,000 shares of Preferred Stock for net proceeds of approximately $4.0 million excluding proceeds from the exercise of the Warrants. In addition to the 8% cumulative dividend, each share of Preferred Stock includes an 8% original issue discount such that the public offering price of each share of Preferred Stock was $1,000 , compared to a stated value of $1,080 . The Preferred Stock is convertible into common stock by dividing the stated value by the conversion price. The conversion price equal to the lesser of (i) $1.22 , subject to certain adjustments, and (ii) 87.5% of the lowest volume weighted average price of our common stock during the ten trading days ending on, and including, the date of the notice of conversion. The conversion price described in (ii) is subject to a floor of $0.35 , except in the event of anti-dilution adjustments.The Warrants consist of three tranches with expirations in October 2017, January 2018 and July 2018. Each tranche allows the holders to purchase up to 3,000 shares of Preferred Stock at a price of $1,000 per share. If fully exercised, each tranche would provide the Company with $3.0 million of additional financing ( $9.0 million in total) before underwriting discounts and commissions. Upon exercise, the Warrant holders receive shares of Preferred Stock that are convertible into common stock on the same terms described above. Through December 31, 2017, holders of Preferred Stock converted 4,998 shares of the Preferred Stock into 13,899,219 shares of the Company’s common stock. Additionally, investors exercised Warrants for the issuance of 7,918.38 shares of Preferred Stock and simultaneously converted those shares into 24,433,834 shares of common stock. The Company received gross proceeds of $7,918,380 from the exercise of the Warrants. The Company assessed the warrants as meeting the criteria for equity classification and allocated the proceeds based on the relative fair values of the base instruments (the Series B preferred stock and the warrants). The Company performed a valuation of the Preferred Stock and associated warrants. The warrants were valued using a Monte Carlo simulation model. Based upon that valuation, the Company allocated the net proceeds between the Preferred Stock and Warrants of approximately $3.5 million and $500,000 , respectively. In addition, the Company evaluated the conversion feature of the Preferred Stock to assess whether it met the definition of a beneficial conversion feature (“BCF”). Assuming all 5,000 shares of Preferred Stock will convert into common stock at the $0.35 floor price, and taking the 8% original issue discount into consideration, the Company will issue 15,428,571 shares of common stock, which provides an effective conversion price of $0.28 for accounting purposes. As the fair value of a share of common stock of $0.38 exceeded the effective conversion price of $0.28 at the issuance date, the Preferred Stock contained a BCF. The intrinsic value of the BCF of $1,548,544 was recorded as a discount to the Preferred Stock and a credit to additional paid in capital. The BCF was immediately recorded as a dividend. To the extent that warrant holders exercise their warrants and the conversion price of the Preferred Stock is less than the market price of the stock on the date of exercise, the Company recognizes a BCF. For warrant exercises between the initial closing and December 31, 2017, the Company recognized an additional BCF of $735,852 . The total BCF recognized during 2017 was $2,284,396 .The Company also recognized a dividend related to the 8% original issue discount as the investors are entitled to received $5,400,000 in common stock, which exceeded their $5,000,000 investment. Accordingly, the Company recognized a $400,000 dividend at closing. Additionally, as Warrants are exercised and shares of Preferred Stock are issued the investors benefit from the 8% original issue discount and the Company records a dividend to reflect the original issue discount. For warrant exercises and related conversions of preferred stock between the initial closing and December 31, 2017, the Company recognized an additional dividend of $633,470 . The total original issue discount recognized during 2017 was $1,033,470 and resulted in the issuance of 1,318,898 shares of common stock. August 2016 financing In August 2016, the Company raised approximately $6.6 million (after deducting underwriting discount and offering expenses) from the initial sale of 863,750 shares of the Company's common stock, 881,250 base warrants to purchase shares of common stock at an exercise price of $7.68 per share, and 311,250 pre-funded warrants to purchase shares of common stock at an exercise price of $0.40 per share. The underwriters partially exercised their option to purchase additional shares and warrants and purchased an additional 37,500 shares of the Company's common stock at a price of $6.00 per share and 111,965 pre-funded warrants to purchase shares of common stock at an exercise price of $0.40 per warrant. The pre-funded warrants have a term of ten years , and the base warrants have a term of five years from the date of issuance. The base warrants also provide for a weighted average adjustment to the exercise price if the Company issues, or is deemed to issue, additional shares of common stock at a price per share less than the effective price of the warrants, subject to certain exceptions. (see "Warrant Liability" below). Due to the potential variability of their exercise price, the base warrants did not qualify for equity treatment. The pre-funded warrants were substantially paid for at the time of the offering and have an exercise price of $0.40 per share and qualified for equity treatment. Through December 31, 2016, 208,750 pre-funded warrants were exercised and resulted in proceeds to the Company of $83,500 . During the year ended December 31, 2017, 102,500 pre-funded warrants were exercised and the Company received $41,000 in proceeds. February 2015 financing In February 2015, the Company raised approximately $14.5 million (after commissions and offering expenses) from the sale of 666,250 shares of common stock and warrants to purchase 466,375 shares of common stock at an exercise price of $26.40 per share, to various investors in an underwritten public offering. Each unit, consisting of one share of common stock and 0.7 warrant, was priced at $24.00 . The warrants have a term of five years from the date of issuance. The warrants also provide for a weighted-average adjustment to the exercise price if the Company issues or is deemed to issue additional shares of common stock at a price per share less than the then effective price of the warrants, subject to certain exceptions. Controlled Equity Offering On April 18, 2013, the Company entered into a Controlled Equity Offering SM Sales Agreement (the Sales Agreement) with Cantor Fitzgerald & Co., as agent (Cantor), pursuant to which the Company may offer from time to time through Cantor, shares of our common stock having an aggregate offering price of up to $25.0 million (of which $17.0 million was initially registered for offer and sale). Under the Sales Agreement, Cantor may sell shares by any method permitted by law and deemed to be an “at-the-market” offering as defined in Rule 415 promulgated under the Securities Act, as amended, including sales made directly on the NYSE American, on any other existing trading market for our common stock or to or through a market maker. The Company may instruct Cantor not to sell shares if the sales cannot be effected at or above the price designated by us from time to time. The Company is not obligated to make any sales of the shares under the Sales Agreement. The offering of shares pursuant to the Sales Agreement will terminate upon the earlier of (a) the sale of all of the shares subject to the Sales Agreement or (b) the termination of the Sales Agreement by Cantor or the Company, as permitted therein. Cantor will receive a commission rate of 3% of the aggregate gross proceeds from each sale of shares and the Company has agreed to provide Cantor with customary indemnification and contribution rights. The Company will also reimburse Cantor for certain specified expenses in connection with entering into the Sales Agreement. On April 22, 2013, NYSE American approved the listing of 264,831 shares of our common stock in connection with the Sales Agreement. As of September 21, 2015, the registration statement previously filed with the SEC to facilitate the sale of registered shares of the Company's common stock under the Controlled Equity Offering expired. The Company filed a new registration statement with the SEC that was declared effective on January 19, 2016 to facilitate the sale of additional shares under the Controlled Equity Offering. Under the terms of the prospectus, the Company may sell up to $15,081,494 of the Company's common stock through the aforementioned Controlled Equity Offering. Pursuant to Instruction I.B.6 to Form S-3 (the Baby Shelf Rules), the Company may not sell more than the equivalent of one-third of its public float during any 12 consecutive months so long as the Company's public float is less than $75.0 million . During the year ended December 31, 2016 , the Company sold 77,141 shares of common stock under the Sales Agreement that resulted in net proceeds to the Company of approximately $691,187 of which $48,977 represented the recovery of deferred offering costs that had been incurred as of December 31, 2015. There were no sales during 2017. As of December 31, 2017 , the Company had approximately $14.3 million available to be sold under the Sales Agreement. Stock Options In February 2005, the Company adopted an Equity Incentive Plan (Plan). Pursuant to the Plan, a committee appointed by the Board of Directors may grant, at its discretion, qualified or nonqualified stock options, stock appreciation rights and may grant or sell restricted stock to key individuals, including employees, nonemployee directors, consultants and advisors. Option prices for qualified incentive stock options (which may only be granted to employees) issued under the plan 100% of the fair market value of the common stock on the date the option is granted (unless the option is granted to a person who, at the time of grant, owns 10% of the total combined voting power of all classes of stock of the Company; in which case the option price may not be 110% of the fair market value of the common stock on the date the option is granted). Option prices for nonqualified stock options issued under the Plan are at the discretion of the committee and may be equal to, greater or less than fair market value of the common stock on the date the option is granted. The options vest over periods determined by the Board of Directors and are exercisable no later than ten years from date of grant (unless they are qualified incentive stock options granted to a person owning more than 10% of the total combined voting power of all classes of stock of the Company, in which case the options are exercisable no later than five years from date of grant). Initially, the Company reserved 150,000 shares of common stock for issuance under the Plan which was subsequently increased to 300,000 shares. Options to purchase 59,812 common shares have been granted under the Plan and are outstanding as of December 31, 2017 . Additionally, 6,500 shares of restricted common stock have been granted to management and 1,000 shares of restricted common stock have been granted to members of the Company's board of directors. The plan expired in January 2016. On March 11, 2016, the Company's Board of Directors adopted the 2016 Equity Incentive Plan (the 2016 Plan) and reserved 250,000 shares of common stock for issuance under the 2016 Plan. The 2016 Plan was approved by the Company's stockholders at its 2016 Annual Meeting of Stockholders. During the year ended December 31, 2016, the Company's Board of Directors granted 48,444 stock options and 7,862 restricted stock units to certain directors, officers and employees. The options have an exercise price equal to the closing stock price on the date of grant. The stock options vest over a period of four years and the restricted stock units vest over a period of two years . There were no grants of stock options or restricted stock units during 2017. The following table summarizes stock option activity for the Company during the three years ended December 31, 2017 : Options Weighted Average Exercise Price Weighted Average Contractual Term Aggregate Intrinsic Value Outstanding December 31, 2014 232,869 $ 53.20 Granted 46,075 $ 21.60 Exercised (1,250 ) $ 10.80 Forfeited or expired (9,697 ) $ 70.40 Outstanding December 31, 2015 267,997 $ 47.20 Granted 48,444 $ 11.61 Exercised — $ — Forfeited or expired (153,776 ) $ 40.63 Outstanding December 31, 2016 162,665 $ 43.11 Granted — $ — Exercised — $ — Forfeited or expired (71,009 ) $ 65.06 Outstanding December 31, 2017 91,656 $ 42.31 5.68 $ — Vested or expected to vest at December 31, 2017 73,448 As of December 31, 2017 , the total unrecognized compensation cost related to unvested stock options amounted to $194,420 , which will be amortized over the weighted-average remaining requisite service period of approximately 10 months . Warrants In July 2017, the FASB issued ASU No. 2017-11, which changes the classification analysis of certain equity-linked financial instruments (or embedded features) with down round features. When determining whether certain financial instruments should be classified as liabilities or equity instruments, a down round feature no longer precludes equity classification when assessing whether the instrument is indexed to an entity’s own stock. ASU No. 2017-11 also clarifies existing disclosure requirements for equity-classified instruments. As a result, a freestanding equity-linked financial instrument (or embedded conversion option) no longer would be accounted for as a derivative liability at fair value as a result of the existence of a down round feature. For freestanding equity classified financial instruments, ASU No. 2017-11 requires entities to recognize the effect of the down round feature when calculating earnings per share. That effect is treated as a dividend and as a reduction of income available to common shareholders in basic earnings per share. ASU No. 2017-11 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted, including adoption in an interim period. If an entity early adopts ASU No. 2017-11 in an interim period, adjustments should be reflected as of the beginning of the interim period in either of the following ways: 1. Retrospectively to outstanding financial instruments with a down round feature by means of a cumulative-effect adjustment to the statement of financial position as of the beginning of the first fiscal year and interim period(s) in which ASU No. 2017-11 is effective or 2. Retrospectively to outstanding financial instruments with a down round feature for each prior reporting. The Company has elected to adopt ASU No. 2017-11 effective July 1, 2017 retrospectively to outstanding financial instruments with a down round feature by means of a cumulative-effect adjustment to the Company’s beginning accumulated deficit as of January 1, 2017. The January 1, 2017 cumulative-effect adjustment to the Company’s financial position is as follows: As Reported Cumulative Effect Adjustment Adjusted Derivative Liability $ 573,560 $ (573,560 ) $ — Additional Paid-In Capital $ 102,354,844 $ 6,481,770 $ 108,836,614 Accumulated Deficit $ (96,223,442 ) $ (5,908,210 ) $ (102,131,652 ) In February 2011, the Company completed a common stock private placement and issued warrants to purchase 70,467 shares of the Company’s common stock at $90.00 per share. The warrants had a term of five years and contained a provision whereby the warrant exercise price would be decreased in the event that certain future common stock issuances are made at a price less than $62.00 . Due to the potential variability of their exercise price, these warrants did not qualify for equity treatment, and therefore were recognized as a liability. As a result of the January 2012, October 2012, and February 2015 financings and shares sold through the Company's Controlled Equity Offering, the exercise price of the warrants was adjusted to $57.60 and the number of warrants was proportionately increased to 91,670 net of exercises. In February 2016, the remaining warrants to purchase 91,670 shares of the Company's common stock expired. In connection with the January 2012 underwritten public offering, the Company issued to the investors warrants to purchase 118,618 shares of the Company’s common stock at $56.40 per share. The warrants had a term of five years from the date of issuance. In January 2017, the remaining 35,454 warrants expired. In connection with the October 2012 underwritten public offering, the Company issued to the investors warrants to purchase 112,500 shares of the Company’s common stock at $106.00 per share. The warrants had a term of five years from the date of issuance. In October 2017, the remaining 111,119 warrants expired. In connection with the February 2015 underwritten public offering, the Company issued to the investors warrants to purchase 466,369 shares of the Company’s common stock at $26.40 per share. The warrants have a term of five years and contain a provision whereby the warrant exercise price would be decreased in the event that certain future common stock issuances are made at a price less than $26.40 . Due to the potential variability of their exercise price, these warrants did not qualify for equity treatment, and therefore were recognized as a liability. During 2016, the exercise price of these warrants was adjusted to $20.00 to reflect the shares sold under the Company's controlled equity offering and the August 2016 public offering. The Company initially valued these warrants using a binomial lattice simulation model assuming (i) dividend yield of 0% ; (ii) expected volatility of 97% ; (iii) risk free rate of 1.53% and (iv) expected term of five years . Based upon these calculations, the Company allocated $4,197,375 of the underwritten public offering to the freestanding warrants. For the years ended December 31, 2016 and 2015, the Company revalued these warrants using the binomial lattice simulation model and recorded a credit to other income of 2,024,611 and 2,238,600 , respectively. As a result of the July 2017 financing, the exercise price of these warrants was adjusted to $10.55 and the Company recorded a dividend of $6,984 . As of the July 1, 2017 adoption of ASU No. 2017-11, the Company reclassified the remaining warrant liability of 7,302 to additional paid in capital. As of December 31, 2017 warrants to purchase 466,369 shares of the Company's common stock remain outstanding. In connection with the August 2016 underwritten public offering, the Company issued 311,250 pre-funded warrants to purchase shares of common stock to certain investors. These pre-funded warrants were substantially paid for at the time of issuance, have a term of ten years from the date of issuance and an exercise price of $0.40 per share. During 2016, pre-funded warrants to purchase 208,750 shares of common stock were exercised. In June 2017, the remaining pre-funded warrants to purchase 102,500 shares of common stock were exercised and the Company received $41,000 . Also in connection with the August 2016 underwritten public offering, the Company issued 993,115 warrants to purchase shares of the common stock with an initial exercise price of $7.68 per share. The warrants contain a provision whereby the warrant exercise price would be proportionately decreased in the event that future common stock issuances are made at a price less than $7.68 per share. Due to the potential variability of their exercise price, these warrants did not qualify for equity treatment, and therefore were recognized as a liability. These warrants are traded on the NYSE American (symbol IMUC.WS). The Company initially valued these warrants using the closing price on August 12, 2016 at $2.30 , which was the first day the warrants were traded on the NYSE American. Accordingly, the Company allocated 2,284,395 of the total proceeds from the August 2016 offering to the base warrants. As of December 31, 2016, the warrants were valued using the last trading price of the year at $0.50 , accordingly, the warrant liability was adjusted to $496,608 and the Company recorded a credit to other income of $1,787,787 . As of the July 1, 2017 adoption of ASU No. 2017-11, the Company reclassified the remaining warrant liability of $20,560 to additional paid in capital. As a result of the July 2017 financing, the exercise price of these warrants was adjusted to $4.15 and the Company recorded a dividend of $34,772 . As of December 31, 2017, warrants to purchase 993,115 shares of the Company's common stock remain outstanding. In connection with the July 2017 underwritten public offering, the Company issued three tranches of warrants with expirations in October 2017, January 2018 and July 2018. Each tranche allows the holders to purchase up to 3,000 shares of Preferred Stock at a price of $1,000 per share. If fully exercised, each tranche would provide the Company with $3.0 million of additional financing ( $9.0 million in total). Upon exercise, the Warrant holders receive shares of Preferred Stock that are subject to the 8% original issue discount. The Preferred Stock is convertible into common stock using a conversion price equal to the lesser of (i) $1.22 , subject to certain adjustments, and (ii) 87.5% of the lowest volume weighted average price of our common stock during the ten trading days ending on, and including, the date of the notice of conversion. The conversion price described in (ii) is subject to a floor of $0.35 , except in the event of anti-dilution adjustments. The exercises through December 31, 2017, are summarized below: Granted Exercised Remaining Series 1 warrants $ 3,000,000 $ 3,000,000 $ — Series 2 warrants 3,000,000 2,845,200 154,800 Series 3 warrants 3,000,000 2,073,200 926,800 Totals $ 9,000,000 $ 7,918,400 $ 1,081,600 The table below reconciles the beginning and ending balances for all warrant liabilities measured at fair market value for the three years ended December 31, 2017. 2017 2016 2015 Beginning Balance, January 1 $ 573,560 $ 1,958,775 $ 597,719 Issuance of warrants and effect of repricing — 2,427,183 4,286,314 Exercise of warrants — — — (Gain) or loss included in earnings — (3,812,398 ) (2,925,258 ) Transfers in and/or out of Level 3 — — — Cumulative effect of adoption of ASU No. 2017-11 (573,560 ) — — Ending Balance December 31, $ — $ 573,560 $ 1,958,775 |