Common Stock	12 Months Ended
Apr. 30, 2020
Equity [Abstract]
Common Stock	(10) Common Stock As of April 30, 2020, the Company has 100,000,000 shares authorized with a par value of $0.001 per share and 12,939,420 shares issued. On August 13, 2018, the Company entered into a common stock purchase agreement with Aspire Capital which provided that, subject to certain terms, conditions and limitations, Aspire Capital was committed to purchase up to an aggregate of $10.0 million of shares of the Company’s common stock over a 30-month period that did not exceed 19.99% of the outstanding common stock on the date of the agreement. The number of shares the Company could issue within the 19.99% was 183,591 shares. Shareholder approval was not needed since the number of common stock offered for sale in the common stock purchase agreement did not exceed 19.99% of the outstanding common stock on the date of the agreement. In consideration for entering into the agreement, the Company issued to Aspire Capital 21,429 shares of common stock as a commitment fee. The agreement was cancelled on October 24, 2019, and as of that date, the Company had sold 162,162 shares of common stock with an aggregate market value of $949,259 at an average price of $5.85 per share pursuant to this common stock purchase agreement. On October 24, 2019, the Company entered into a new common stock purchase agreement with Aspire Capital which provides that, subject to certain terms, conditions and limitations, Aspire Capital is committed to purchase up to an aggregate of $10.0 million of shares of the Company’s common stock over a 30-month period that does not exceed 19.99% of the outstanding common stock on the date of the agreement. The number of shares the Company can issue within the 19.99% limit is 1,219,010 shares. At the 2019 annual meeting of stockholders, held on December 20, 2019, the Company’s stockholders approved an additional 5,400,000 shares to be issued pursuant to the common stock purchase agreement in excess of the 19.99% limit. In consideration for entering into the agreement, the Company issued to Aspire Capital 194,805 shares of common stock as a commitment fee. As of April 30, 2020, the Company has sold 1,399,205 shares of common stock with an aggregate market value of approximately $1.1 million at an average price of $0.82 per share pursuant to this common stock purchase agreement. On January 7, 2019, the Company entered into the 2019 ATM Facility with A.G.P/Alliance Global Partners, under which the Company may issue and sell to or through A.G.P., acting as agent and/or principal, shares of the Company’s common stock having an aggregate offering price of up to $25 million. As of April 30, 2020, under the 2019 ATM Facility the Company has issued 5,101,405 shares of its common stock with an aggregate market value of approximately $3.8 million at an average price of $0.74 per share and paid AGP a sales commission of approximately $122,530 related to those shares. On April 8, 2019, the Company sold 1,542,000 shares of common stock, which includes the sale of 642,000 shares of the Company’s common stock sold by the Company pursuant to the exercise, in full, of the over-allotment option by the underwriters in a public offering, prefunded warrants to purchase up to 3,385,680 shares of common stock and common warrants to purchase up to 4,927,680 shares of common stock in an underwritten public offering. The net proceeds to the Company from the offering were approximately $15.7 million, after deducting underwriter’s fees and offering expenses payable by the Company.

Common Stock

12 Months Ended

Apr. 30, 2020

(10) Common Stock

As of April 30, 2020, the Company has 100,000,000 shares authorized with a par value of $0.001 per share and 12,939,420 shares issued.

On August 13, 2018, the Company entered into a common stock purchase agreement with Aspire Capital which provided that, subject to certain terms, conditions and limitations, Aspire Capital was committed to purchase up to an aggregate of $10.0 million of shares of the Company’s common stock over a 30-month period that did not exceed 19.99% of the outstanding common stock on the date of the agreement. The number of shares the Company could issue within the 19.99% was 183,591 shares. Shareholder approval was not needed since the number of common stock offered for sale in the common stock purchase agreement did not exceed 19.99% of the outstanding common stock on the date of the agreement. In consideration for entering into the agreement, the Company issued to Aspire Capital 21,429 shares of common stock as a commitment fee. The agreement was cancelled on October 24, 2019, and as of that date, the Company had sold 162,162 shares of common stock with an aggregate market value of $949,259 at an average price of $5.85 per share pursuant to this common stock purchase agreement.

On October 24, 2019, the Company entered into a new common stock purchase agreement with Aspire Capital which provides that, subject to certain terms, conditions and limitations, Aspire Capital is committed to purchase up to an aggregate of $10.0 million of shares of the Company’s common stock over a 30-month period that does not exceed 19.99% of the outstanding common stock on the date of the agreement. The number of shares the Company can issue within the 19.99% limit is 1,219,010 shares. At the 2019 annual meeting of stockholders, held on December 20, 2019, the Company’s stockholders approved an additional 5,400,000 shares to be issued pursuant to the common stock purchase agreement in excess of the 19.99% limit. In consideration for entering into the agreement, the Company issued to Aspire Capital 194,805 shares of common stock as a commitment fee. As of April 30, 2020, the Company has sold 1,399,205 shares of common stock with an aggregate market value of approximately $1.1 million at an average price of $0.82 per share pursuant to this common stock purchase agreement.

On January 7, 2019, the Company entered into the 2019 ATM Facility with A.G.P/Alliance Global Partners, under which the Company may issue and sell to or through A.G.P., acting as agent and/or principal, shares of the Company’s common stock having an aggregate offering price of up to $25 million. As of April 30, 2020, under the 2019 ATM Facility the Company has issued 5,101,405 shares of its common stock with an aggregate market value of approximately $3.8 million at an average price of $0.74 per share and paid AGP a sales commission of approximately $122,530 related to those shares.

On April 8, 2019, the Company sold 1,542,000 shares of common stock, which includes the sale of 642,000 shares of the Company’s common stock sold by the Company pursuant to the exercise, in full, of the over-allotment option by the underwriters in a public offering, prefunded warrants to purchase up to 3,385,680 shares of common stock and common warrants to purchase up to 4,927,680 shares of common stock in an underwritten public offering. The net proceeds to the Company from the offering were approximately $15.7 million, after deducting underwriter’s fees and offering expenses payable by the Company.