Commitments and Contingencies	9 Months Ended
Sep. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	5. Commitments and Contingencies Concentrations of Credit Risk Bank accounts in the United States are insured by the Federal Deposit Insurance Corporation (“FDIC”) up to $250,000. The Company’s cash accounts significantly exceed FDIC limits. Indemnifications As permitted under Delaware law, the Company indemnifies its officers, directors, and employees for certain events and occurrences while the officer, or director is, or was, serving at the Company’s request in such capacity. License to Patented Technology In December 2017, the Company entered into an exclusive license agreement with the Department of Health and Human Services (“DHHS”). Under the agreement, the DHHS granted the Company an exclusive, sublicensable, worldwide license to certain patent rights under which the Company may develop and commercialize pharmaceutical and biological compositions comprising Gram-negative bacteria for the topical treatment of dermatological diseases and conditions (the “DHHS License”). Under the DHHS License, the Company is obligated to meet certain development benchmarks within certain time periods. If the Company is unable to meet any of these development benchmarks, the DHHS could terminate the license. In addition, the DHHS may terminate or modify the DHHS License in the event of a material breach or upon certain insolvency events that remain uncured following a 90 day written notice of such material breach or insolvency event. The DHHS also has the right to require the Company to grant mandatory sublicenses to patent rights licensed from the DHHS to product candidates covered by other DHHS licenses under certain specified circumstances, including if it is necessary to meet health and safety needs or to meet requirements for public use as specified by federal regulations that the Company is not reasonably satisfying. Under the DHHS License, as amended in May 2020, the Company was obligated to pay the DHHS a minimum annual payment of $20,000 for 2020, which increased to $100,000 beginning January 1, 2021. The Company is required to reimburse the DHHS for certain patent-related expenses and may also be obligated to make payments to the DHHS based upon achieving specified development and regulatory milestones for the first licensed product. Such development milestone payments are the completion of patient enrollment in a phase 3 clinical trial and the completion of a phase 3 clinical trial demonstrating a statistically significant efficacy benefit. The regulatory milestones are the receipt of the first FDA approval and the first non-USA regulatory agency approval. In addition, to the extent licensed products are approved for commercial sale, the Company is also obligated to pay the DHHS royalties based on net sales of licensed products sold by the Company and if applicable, its sublicensees. No milestones have been met as of September 30, 2021. The Company incurred $25,000 and $5,000 in minimum royalty expenses for the three months ended September 30, 2021 and 2020, and $75,000 and $25,000 for the nine months ended September 30, 2021 and 2020, respectively. Lease Agreements In April 2019, the Company entered into a lease agreement for certain office and laboratory space in Torrance, California. The lease agreement is cancellable by the Company at any time with a 30-day notice. In June 2021, the Company entered into a lease agreement for additional office space at a separate location for an initial lease of 6 months after which the lease term will be month-to-month. Total rent expense for all locations for the three and nine months ended September 30, 2021 was $9,000 and $0, respectively. Rent expense for the nine months ended September 30, 2021 included a credit of $9,000 due to a refund for operating expenses from a previous Tocagen facility. Total rent expense for three and nine months ended September 30, 2020 was $5,000 and $19,000, respectively. Clinical Supply Agreements The Company has entered into various agreements with CMOs for the manufacture of clinical trial materials and CROs for clinical trial services. These agreements provide the terms and conditions under which the CMOs and CROs will formulate, fill, inspect, package, label and test the Company’s drug product candidate, FB-401. Remaining commitment costs of $493.3 thousand have been recorded in research and developments expenses for the 3 months ended September 30, 2021 and have been included in accrued liabilities in the condensed balance sheet as of September 30, 2021 after termination notices had been sent out to the vendors for these agreements as a result of the FB-401 clinical trial not meeting its primary endpoint.

Commitments and Contingencies

9 Months Ended

Sep. 30, 2021

Commitments And Contingencies Disclosure [Abstract]

5. Commitments and Contingencies

Concentrations of Credit Risk

Bank accounts in the United States are insured by the Federal Deposit Insurance Corporation (“FDIC”) up to $250,000. The Company’s cash accounts significantly exceed FDIC limits.

Indemnifications

As permitted under Delaware law, the Company indemnifies its officers, directors, and employees for certain events and occurrences while the officer, or director is, or was, serving at the Company’s request in such capacity.

License to Patented Technology

In December 2017, the Company entered into an exclusive license agreement with the Department of Health and Human Services (“DHHS”). Under the agreement, the DHHS granted the Company an exclusive, sublicensable, worldwide license to certain patent rights under which the Company may develop and commercialize pharmaceutical and biological compositions comprising Gram-negative bacteria for the topical treatment of dermatological diseases and conditions (the “DHHS License”). Under the DHHS License, the Company is obligated to meet certain development benchmarks within certain time periods. If the Company is unable to meet any of these development benchmarks, the DHHS could terminate the license. In addition, the DHHS may terminate or modify the DHHS License in the event of a material breach or upon certain insolvency events that remain uncured following a 90 day written notice of such material breach or insolvency event. The DHHS also has the right to require the Company to grant mandatory sublicenses to patent rights licensed from the DHHS to product candidates covered by other DHHS licenses under certain specified circumstances, including if it is necessary to meet health and safety needs or to meet requirements for public use as specified by federal regulations that the Company is not reasonably satisfying.

Under the DHHS License, as amended in May 2020, the Company was obligated to pay the DHHS a minimum annual payment of $20,000 for 2020, which increased to $100,000 beginning January 1, 2021. The Company is required to reimburse the DHHS for certain patent-related expenses and may also be obligated to make payments to the DHHS based upon achieving specified development and regulatory milestones for the first licensed product. Such development milestone payments are the completion of patient enrollment in a phase 3 clinical trial and the completion of a phase 3 clinical trial demonstrating a statistically significant efficacy benefit. The regulatory milestones are the receipt of the first FDA approval and the first non-USA regulatory agency approval. In addition, to the extent licensed products are approved for commercial sale, the Company is also obligated to pay the DHHS

royalties based on net sales of licensed products sold by the Company and if applicable, its sublicensees. No milestones have been met as of September 30, 2021.

The Company incurred $25,000 and $5,000 in minimum royalty expenses for the three months ended September 30, 2021 and 2020, and $75,000 and $25,000 for the nine months ended September 30, 2021 and 2020, respectively.

Lease Agreements

In April 2019, the Company entered into a lease agreement for certain office and laboratory space in Torrance, California. The lease agreement is cancellable by the Company at any time with a 30-day notice. In June 2021, the Company entered into a lease agreement for additional office space at a separate location for an initial lease of 6 months after which the lease term will be month-to-month. Total rent expense for all locations for the three and nine months ended September 30, 2021 was $9,000 and $0, respectively. Rent expense for the nine months ended September 30, 2021 included a credit of $9,000 due to a refund for operating expenses from a previous Tocagen facility. Total rent expense for three and nine months ended September 30, 2020 was $5,000 and $19,000, respectively.

Clinical Supply Agreements

The Company has entered into various agreements with CMOs for the manufacture of clinical trial materials and CROs for clinical trial services. These agreements provide the terms and conditions under which the CMOs and CROs will formulate, fill, inspect, package, label and test the Company’s drug product candidate, FB-401. Remaining commitment costs of $493.3 thousand have been recorded in research and developments expenses for the 3 months ended September 30, 2021 and have been included in accrued liabilities in the condensed balance sheet as of September 30, 2021 after termination notices had been sent out to the vendors for these agreements as a result of the FB-401 clinical trial not meeting its primary endpoint.