Subsequent Events	6 Months Ended
Oct. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	(19) Subsequent Events On November 20, 2020, the Company filed a shelf registration statement on Form S-3 with the U.S. Securities and Exchange Commission (the “SEC”), pursuant to which the Company may offer and sell, at its option, securities having an aggregate offering price of up to $100,000,000. On the same date, the Company entered into the 2020 ATM Facility pursuant to which the Company may offer and sell shares of its common stock, par value $0.001 per share, having an aggregate offering price of up to $50,000,000 to or through AGP, as sales agent, from time to time, in an “At The Market Offering” (as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended) of the shares. The $50,000,000 of common stock that may be offered, issued and sold under the ATM Prospectus is included in the $100,000,000 of securities that may be offered, issued and sold by us under the Base Prospectus. Shares may be sold by any method deemed to be an “At The Market Offering.” Under the 2020 ATM Facility, AGP will also be able to sell shares of common stock by any other method permitted by law, including in negotiated transactions with the Company’s prior written consent. The Company will pay AGP commissions for its services in acting as its sales agent in the sale of the shares pursuant to the sales agreement. AGP is entitled to compensation at a fixed commission rate of the aggregate gross proceeds from the sale of the shares on the Company’s behalf. The sales agreement for the 2020 ATM Facility contains representations, warranties and covenants that are customary for transactions of this type. As of December 7, 2020 the balance of total cash, cash equivalents, and restricted cash is approximately $26.3 million mainly as a result of sales of approximately $11.9 million of the Company’s securities through its 2019 ATM Facility which occurred subsequent to October 31, 2020.

Subsequent Events

6 Months Ended

Oct. 31, 2020

(19) Subsequent Events

On November 20, 2020, the Company filed a shelf registration statement on Form S-3 with the U.S. Securities and Exchange Commission (the “SEC”), pursuant to which the Company may offer and sell, at its option, securities having an aggregate offering price of up to $100,000,000. On the same date, the Company entered into the 2020 ATM Facility pursuant to which the Company may offer and sell shares of its common stock, par value $0.001 per share, having an aggregate offering price of up to $50,000,000 to or through AGP, as sales agent, from time to time, in an “At The Market Offering” (as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended) of the shares. The $50,000,000 of common stock that may be offered, issued and sold under the ATM Prospectus is included in the $100,000,000 of securities that may be offered, issued and sold by us under the Base Prospectus. Shares may be sold by any method deemed to be an “At The Market Offering.” Under the 2020 ATM Facility, AGP will also be able to sell shares of common stock by any other method permitted by law, including in negotiated transactions with the Company’s prior written consent. The Company will pay AGP commissions for its services in acting as its sales agent in the sale of the shares pursuant to the sales agreement. AGP is entitled to compensation at a fixed commission rate of the aggregate gross proceeds from the sale of the shares on the Company’s behalf. The sales agreement for the 2020 ATM Facility contains representations, warranties and covenants that are customary for transactions of this type.

As of December 7, 2020 the balance of total cash, cash equivalents, and restricted cash is approximately $26.3 million mainly as a result of sales of approximately $11.9 million of the Company’s securities through its 2019 ATM Facility which occurred subsequent to October 31, 2020.