On December 18, 2018, the Company agreed to make an investment of up to $5,000,000 in ILiAD Biotechnologies, LLC ("ILiAD"), a privately held development stage biotechnology company dedicated to the prevention of human disease caused by Bordetella pertussis with a current focus on its proprietary intranasal vaccine, BPZE1, for the prevention of pertussis (whooping cough). The investment by the Company is part of a financing of up to approximately $16,200,000 of Class C units of ILiAD, consisting of two tranches. The Company made an initial investment (tranche 1) at the December 18, 2018 closing of $2,500,000 to purchase 1,111,111 Class C units at $2.25 per unit and received five-year warrants to purchase 366,666 Class C units at an exercise price of $2.75 per unit.  In connection with its investment, the Company's Chairman and Chief Executive Officer obtained a seat on ILiAD's Board of Managers.  The Company incurred approximately $41,000 of advisory and legal expenses in conjunction with its equity investment in ILiAD which have been capitalized as a component of the equity investment carrying value at June 30, 2019.

In accordance with the Securities Purchase Agreement, dated December 18, 2018, the Company is obligated to invest an additional $2,500,000 (tranche 2) to purchase 943,396 Class C units at $2.65 per unit (and will also receive additional five-year warrants to purchase 311,320 Class C units at an exercise price of $3.50 per unit) contingent upon ILiAD receiving, on or before December 31, 2019, an "allowed-to-proceed" notification from the FDA for a Phase 2b clinical study. On May 2, 2019, ILiAD notified the Company that it had received an "allowed to proceed" notice from the FDA permitting ILiAD to advance to the Phase 2b clinical study of its BP2E1 vaccine. ILiAD elected to permit its Class C investors (including the Company) to bifurcate their tranche 2 commitments such that 40% would be currently due and 60% (additional $1,500,000 investment by the Company) would be due when ILiAD receives satisfactory safety data from the clinical study. On May 6, 2019, the Company satisfied its 40% commitment through an additional $1,000,000 investment by the Company in exchange for 377,358 Class C units at $2.65 per unit and received five-year warrants to purchase 124,528 Class C units at an exercise price of $3.50 per unit. At June 30, 2019, the Company owned approximately 8.4% of the outstanding units of ILiAD (on a non-fully diluted basis).

The Company's investment in ILiAD is accounted for as an equity method investment in accordance with ASC 323, Investments — Equity Method and Joint Ventures as the Company has the ability to exercise significant influence, but not control, over ILiAD. The Company's investment in ILiAD is measured at cost minus impairment, if any, plus or minus the Company's share of ILiAD's income or loss. The Company's proportionate share of the income or loss from its investment in ILiAD is recognized on a one-quarter lag. For the three and six months ended June 30, 2019, the Company recorded net (loss) from its equity investment in ILiAD totaling $(53,000) and $(149,000), respectively.

The difference between the Company's share of equity in ILiAD's net assets and the equity investment carrying value reported on the Company's condensed consolidated balance sheet at June 30, 2019 is due to an excess amount paid over the book value of the investment totaling approximately $3,392,000 which is accounted for as equity method goodwill.