Subsequent Events	12 Months Ended
Dec. 31, 2020
Subsequent Events
Subsequent Events	15. Subsequent Events December 2019 PIPE Financing Warrants During January 2021, an aggregate of 1,250,000 shares of common stock were issued upon the exercise of the December 2019 PIPE Financing Warrants for total proceeds of $975,000. Exchange Note 2 3(a)(9) Exchange On January 4, 2021, the Company issued 1,413,606 shares of common stock to CVP in exchange for a $1.8 million reduction in the outstanding balance of the secured promissory note, Exchange Note 2, held by CVP. January 2021 Series 1 and Series Common Stock Purchase Warrants During January 2021, an aggregate of 2,475,044 shares of common stock were issued upon the exercise of Series 1 and Series 2 Warrants for total proceeds of $1.2 million. Series 3 Common Stock Purchase Warrant On January 8, 2021, in accordance with the May 2020 Modification of the 2019 Bridge Note Warrants and Inducement Offer, an investor received 406,250 Series 3 Warrants for the exercise of 406,250 2019 Bridge Note Warrants on the same date (see Note 8). On January 27, 2021, 406,250 Series 3 Warrants were exercised into 406,250 shares of common stock. Securities Purchase Agreement On January 13, 2021, the Company entered into a securities purchase agreement, pursuant to which the Company agreed to issue and sell, in a registered public offering an aggregate of 4,437,870 shares of common stock, par value $0.0001 per share, at an offering price of $3.38 per share for gross proceeds of approximately $15.0 million before deducting $1.4 million placement agent fee and related offering expenses. The offering closed on January 15, 2021. Note Purchase and Security Agreements On January 19, 2021, the Company entered into a note purchase agreement with Streeterville Capital, LLC (“Streeterville”), pursuant to which the Company issued a secured promissory note in the aggregate principal amount of $6.2 million for an aggregate purchase price of $6.0 million. The initial principal balance of the note includes $196,000 representing prepaid interest for the first twelve months and $25,000 to cover Investor’s transaction expenses. The Company will use the proceeds to fund development of the Company’s NP-300 (lechlemer) drug product candidate for the indication of the symptomatic relief of diarrhea from cholera and general corporate purposes, including the Company’s product pipeline activities. The note bears interest at 3.25% per annum and matures on January 20, 2025. Interest will be prepaid each 12 months at the beginning of the period. The Company also entered in a security agreement with Streeterville, pursuant to which Streeterville will receive a first priority security interest in all existing and future lechlemer technology, and the Company will agree, with certain exceptions, not to grant any lien on any of the collateral securing the note and not to grant any license under any of the intellectual property relating to such collateral. The grant of security interest under the security agreement will not be effective until such time the Company receives a required consent from a third party. In the event the Company sells a Tropical Disease Priority Review Voucher (“TDPRV”) Streeterville will be entitled to a maximum of 18% and a minimum of 1% of the gross proceeds received by the Company from the sale of the TDPRV. At any time following the occurrence of a Trial Failure, Streeterville, at its option, elect to increase the outstanding balance by multiplying the outstanding balance as of the date of the Trial Failure by 25% via written notice to the Company without accelerating the outstanding balance, in which event the outstanding balance shall be increased as of the date of the occurrence of the Trial Failure, but the outstanding balance shall not be immediately due and payable unless so declared by Streerville. “Trial Failure” means (a) the Company abandons the clinical trial with Lechlemer for an indication for the symptomatic relief of infectious diarrhea for cholera; (b) the Company fails to start the Phase 1 clinical trial of Lechlemer for the symptomatic relief of infectious diarrhea for cholera by July 1, 2022; or (c) the Company fails to meet all primary endpoints in the pivotal trials of Lechlemer for the symptomatic relief of infectious diarrhea for cholera with statistical significance. Pursuant to the Settlement, Termination, Asset Transfer and Transition Agreement, dated March 4, 2016, and amended May 10, 2016 (the “Settlement Agreement”), between the Company and Salix Pharmaceuticals, Inc. (“Salix”), the Company is required to enter into an intercreditor agreement with Salix for purposes of protecting the relative priority of Salix’s rights to payment and collection of amounts payable to Salix under the Settlement Agreement prior to the Company incurring any secured indebtedness (the “Intercreditor Obligation”). In connection with the Company’s issuance of a secured promissory note to a third party lender in January 2021, the Company requested that Salix waive its rights with respect to the Intercreditor Obligation. ATM Agreement During January and February 2021, the Company issued an aggregate of 2,009,554 shares under the ATM Agreement for total net proceeds of $5.5 million. As of February 18, 2021, all shares under the ATM Agreement have been issued. Royalty Purchase Agreement On March 8, 2021, the Company entered into a Purchase Agreement with Streeterville, pursuant to which the Company sold a royalty interest entitling Streeterville to $10.0 million and any interest, fees, and charges as royalty repayment amount for an aggregate purchase price of $5.0 million. Interest will accrue on the royalty repayment amount at a rate of 5% per annum, compounding quarterly, and will increase to 10% per annum, compounding quarterly on the 12-month anniversary of the closing date. The Company will be obligated to make minimum royalty payments on a monthly basis beginning at the earlier of (a) 36 months following the closing date or (b) 30 days following the satisfaction of all existing royalties to Streeterville, and its affiliates, but not earlier than 18 months following the closing date in an amount equal to the greater of (i) $250,000 beginning on the royalty payment start date and continuing until either the royalty repayment amount has been paid in full or the 6-month anniversary of the royalty payment start date, $400,000 beginning on the 6-month anniversary of the royalty payment start date and continuing until either the royalty repayment amount has been paid in full or the 12-month anniversary of the royalty payment start date, $600,000 beginning on the 12-month anniversary of the royalty payment start date and continuing until either the royalty repayment amount has been paid in full or the 18-month anniversary of the royalty payment start date, $750,000 beginning on the 18-month anniversary of the royalty payment start date and continuing until the royalty repayment amount has been paid in full, and (ii) 10% of the Company’s net sales on included products and 10% of worldwide revenues related to upfront licensing fees and milestone payments from licensees and/or distributors.

15. Subsequent Events

December 2019 PIPE Financing Warrants

During January 2021, an aggregate of 1,250,000 shares of common stock were issued upon the exercise of the December 2019 PIPE Financing Warrants for total proceeds of $975,000.

Exchange Note 2 3(a)(9) Exchange

On January 4, 2021, the Company issued 1,413,606 shares of common stock to CVP in exchange for a $1.8 million reduction in the outstanding balance of the secured promissory note, Exchange Note 2, held by CVP.

January 2021 Series 1 and Series Common Stock Purchase Warrants

During January 2021, an aggregate of 2,475,044 shares of common stock were issued upon the exercise of Series 1 and Series 2 Warrants for total proceeds of $1.2 million.

Series 3 Common Stock Purchase Warrant

On January 8, 2021, in accordance with the May 2020 Modification of the 2019 Bridge Note Warrants and Inducement Offer, an investor received 406,250 Series 3 Warrants for the exercise of 406,250 2019 Bridge Note Warrants on the same date (see Note 8). On January 27, 2021, 406,250 Series 3 Warrants were exercised into 406,250 shares of common stock.

Securities Purchase Agreement

On January 13, 2021, the Company entered into a securities purchase agreement, pursuant to which the Company agreed to issue and sell, in a registered public offering an aggregate of 4,437,870 shares of common stock, par value $0.0001 per share, at an offering price of $3.38 per share for gross proceeds of approximately $15.0 million before deducting $1.4 million placement agent fee and related offering expenses. The offering closed on
January 15, 2021.

Note Purchase and Security Agreements

On January 19, 2021, the Company entered into a note purchase agreement with Streeterville Capital, LLC (“Streeterville”), pursuant to which the Company issued a secured promissory note in the aggregate principal amount of $6.2 million for an aggregate purchase price of $6.0 million. The initial principal balance of the note includes $196,000 representing prepaid interest for the first twelve months and $25,000 to cover Investor’s transaction expenses. The Company will use the proceeds to fund development of the Company’s NP-300 (lechlemer) drug product candidate for the indication of the symptomatic relief of diarrhea from cholera and general corporate purposes, including the Company’s product pipeline activities. The note bears interest at 3.25% per annum and matures on January 20, 2025. Interest will be prepaid each 12 months at the beginning of the period.

The Company also entered in a security agreement with Streeterville, pursuant to which Streeterville will receive a first priority security interest in all existing and future lechlemer technology, and the Company will agree, with certain exceptions, not to grant any lien on any of the collateral securing the note and not to grant any license under any of the intellectual property relating to such collateral. The grant of security interest under the security agreement will not be effective until such time the Company receives a required consent from a third party.

In the event the Company sells a Tropical Disease Priority Review Voucher (“TDPRV”) Streeterville will be entitled to a maximum of 18% and a minimum of 1% of the gross proceeds received by the Company from the sale of the TDPRV.

At any time following the occurrence of a Trial Failure, Streeterville, at its option, elect to increase the outstanding balance by multiplying the outstanding balance as of the date of the Trial Failure by 25% via written notice to the Company without accelerating the outstanding balance, in which event the outstanding balance shall be increased as of the date of the occurrence of the Trial Failure, but the outstanding balance shall not be immediately due and payable unless so declared by Streerville. “Trial Failure” means (a) the Company abandons the clinical trial with Lechlemer for an indication for the symptomatic relief of infectious diarrhea for cholera; (b) the Company fails to start the Phase 1 clinical trial of Lechlemer for the symptomatic relief of infectious diarrhea for cholera by July 1, 2022; or (c) the Company fails to meet all primary endpoints in the pivotal trials of Lechlemer for the symptomatic relief of infectious diarrhea for cholera with statistical significance.

Pursuant to the Settlement, Termination, Asset Transfer and Transition Agreement, dated March 4, 2016, and amended May 10, 2016 (the “Settlement Agreement”), between the Company and Salix Pharmaceuticals, Inc. (“Salix”), the Company is required to enter into an intercreditor agreement with Salix for purposes of protecting the relative priority of Salix’s rights to payment and collection of amounts payable to Salix under the Settlement Agreement prior to the Company incurring any secured indebtedness (the “Intercreditor Obligation”). In connection with the Company’s issuance of a secured promissory note to a third party lender in January 2021, the Company requested that Salix waive its rights with respect to the Intercreditor Obligation.

ATM Agreement

During January and February 2021, the Company issued an aggregate of 2,009,554 shares under the ATM Agreement for total net proceeds of $5.5 million. As of February 18, 2021, all shares under the ATM Agreement have been issued.

Royalty Purchase Agreement

On March 8, 2021, the Company entered into a Purchase Agreement with Streeterville, pursuant to which the Company sold a royalty interest entitling Streeterville to $10.0 million and any interest, fees, and charges as royalty repayment amount for an aggregate purchase price of $5.0 million. Interest will accrue on the royalty repayment amount at a rate of 5% per annum, compounding quarterly, and will increase to 10% per annum, compounding quarterly on the 12-month anniversary of the closing date. The Company will be obligated to make minimum royalty payments on a monthly basis beginning at the earlier of (a) 36 months following the closing date or (b) 30 days following the satisfaction of all existing royalties to Streeterville, and its affiliates, but not earlier than 18 months following the closing date in an amount equal to the greater of (i) $250,000 beginning on the royalty payment start date and continuing until either the royalty repayment amount has been paid in full or the 6-month anniversary of the royalty payment start date, $400,000 beginning on the 6-month anniversary of the royalty payment start date and continuing until either the royalty repayment amount has been paid in full or the 12-month anniversary of the royalty payment start date, $600,000 beginning on the 12-month anniversary of the royalty payment start date and continuing until either the royalty repayment amount has been paid in full or the 18-month anniversary of the royalty payment start date, $750,000 beginning on the 18-month anniversary of the royalty payment start date and continuing until the royalty repayment amount has been paid in full, and (ii) 10% of the Company’s net sales on included products and 10% of worldwide revenues related to upfront licensing fees and milestone payments from licensees and/or distributors.