License Agreements	12 Months Ended
Dec. 31, 2021
License Agreements [Abstract]
License Agreements	6. License Agreements License Agreement with the National Institutes of Health On June 28, 2018, the Company entered into a non-exclusive patent license agreement (the “NIH Agreement”) with a U.S. government entity, the National Institutes of Health, represented by National Institute of Allergy and Infectious Disease (“NIAID”). The NIH Agreement was amended in September 2018 and September 2020. Under the NIH Agreement, the Company obtained a non-exclusive, worldwide, royalty-bearing, sublicensable license under certain NIAID patent rights, and transfer of know-how and biological materials for use in adjuvanted or non-adjuvanted vaccines for the prevention, cure, or treatment of RSV and metapneumovirus infection in humans. Under the NIH Agreement, the Company is required to use commercially reasonable efforts to meet certain specified development, sales and regulatory milestones related to the licensed products within specified time periods. In consideration of the rights granted to the Company under the NIH Agreement, the Company paid a licensing fee upon execution of the NIH Agreement of $100,000, and will pay annual minimum royalty payments starting in the second year after the initial sale of each licensed product which can be credited against any earned royalties due for sales made in the year. There are milestone payments due upon the completion of certain development, regulatory, and commercial milestones for the licensed products in the future. The Company is obligated to pay aggregate potential milestone payments of up to $2.1 million with respect to future development and regulatory based milestones, and up to $6.5 million with respect to future sales milestones following commercialization. Additionally, the Company has agreed to pay a tiered royalty of a low single digit percentage on net sales of all products applicable to the license. Additional royalties would be due in connection with sublicenses. The Company’s royalty obligations continue for each licensed product for so long as licensed patent rights exist and have not expired, been revoked, lapsed, or held unenforceable. The NIH Agreement will terminate upon the last expiration of the patent rights or the Company may terminate the entirety of the agreement upon discontinuation of development or sales of licensed products and provision of written notice thereof to NIH. During the years ended December 31, 2021 and 2020, the Company paid $0.2 million and $0.1 million, respectively, in fees associated with the license, which were recorded as research and development expenses. License Agreements with University of Washington License Agreement with respect to RSV and Other Pathogens On June 29, 2018, the Company entered into an exclusive license agreement with an academic entity, University of Washington (the “UW 2018 Agreement”), for an exclusive license to covered intellectual property, a non-exclusive, worldwide license to use licensed know-how, and rights to sublicense for computationally designed nanoparticles and vaccines. The UW 2018 Agreement was amended in June 2019 and again in November 2020. The Company’s rights and obligations under the UW 2018 Agreement are subject to certain U.S. government rights, certain global access commitment rights for humanitarian purposes to BMGF, certain rights to Howard Hughes Medical Institute ("HHMI"), and certain other limited rights retained by University of Washington ("UW"). The Company issued 192,276 shares of common stock on August 1, 2018 in exchange for the UW 2018 Agreement’s exclusive license. The shares issued were recorded at their estimated fair value, which is de minimis, with the related expense classified as research and development in 2018. Under the UW 2018 Agreement, the Company is required to use commercially reasonable efforts to meet certain specified development, sales and regulatory milestones related to the licensed products within specified time periods. In consideration of the rights granted to the Company under the UW 2018 Agreement, the Company is required to pay an annual maintenance fee in the mid four figures starting in 2020. Additionally, the Company is required to pay minimum annual royalties following the first year after commercial sale of each licensed product. There are milestone payments due upon the completion of certain development, regulatory, and commercial milestones for licensed products in the future. The aggregate potential milestone payments for future development, regulatory, and sales-based milestones are $1.4 million per indication, up to a maximum of $6.8 million in total milestone payments. Additionally, the Company has agreed to pay a royalty of a low single digit percentage on net sales of all licensed products. Additional royalties would be due in connection with sublicenses and milestones. The Company’s royalty obligations continue for each licensed product for so long as licensed patent rights exist and have not expired, been revoked, lapsed, or held unenforceable. The UW 2018 Agreement will terminate when all licensed rights have been terminated and all obligations due to UW have been fulfilled, or the Company may terminate the entirety of the agreement upon written notice thereof to UW. On July 2, 2020, the Company entered into a non-exclusive license agreement with respect to specified intellectual property with options for exclusivity in North America and Europe subject to the performance of certain development milestones, with UW (the “UW 2020 Agreement”). Under the UW 2020 Agreement, the Company also received a non-exclusive, worldwide license to use specific know-how and rights to sublicense for computationally designed nanoparticles and vaccines. The UW 2020 Agreement was amended in August 2020 and subsequently in May 2021. The Company’s rights and obligations under the UW 2020 Agreement as amended are subject to certain U.S. government rights, certain global access commitment rights for humanitarian purposes to BMGF, certain rights to HHMI, and certain other limited rights retained by UW. Under the UW 2020 Agreement as amended, the Company is required to use commercially reasonable efforts to meet certain specified development, sales and regulatory milestones related to the licensed products within specified time periods. The Company has agreed to pay a royalty of a low single digit percentage on net sales of all products applicable to the license. However, the Company will not be required to pay royalties on net sales of any licensed product under the UW 2020 Agreement as amended if the Company is required to pay royalties on net sales under the UW 2018 Agreement. Additional royalties would be due in connection with sublicenses and milestones. The Company’s royalty obligations continue for each licensed product for so long as licensed patent rights exist and have not expired, been revoked, lapsed, or held unenforceable. The UW 2020 Agreement as amended will terminate when all licensed rights have been terminated and all obligations due to UW have been fulfilled, or the Company may terminate the entirety of the agreement upon written notice thereof to UW. During the years ended December 31, 2021 and 2020, the Company paid $0.2 million and $0.3 million respectively, in fees associated with the 2018 and 2020 Agreements. License Agreement with Respect to Influenza In September 2021, the Company entered into a license agreement with UW ("UW Flu License Agreement"). Pursuant to the UW Flu License Agreement, UW granted the Company a non-exclusive, worldwide, royalty-bearing, sublicensable (subject to certain restrictions) license under certain UW patents to make, use, sell, offer to sell, import, and otherwise exploit any product covered by the licensed patents ("Licensed Flu Products"), for the prophylactic and/or therapeutic treatment of influenza. UW also granted the Company a non-exclusive, worldwide license to use certain know-how related to the licensed patents. The licensed patents and know-how generally relate to computationally designed nanoparticles and vaccines based upon such designs, and relate to the Company's proprietary two-component virus-like-particle technology and nanoparticle-based influenza virus vaccines. As of March 2022, the UW Flu License Agreement is applicable to the Company's preclinical influenza program. The United States federal government and HHMI have similar rights under the UW Flu License Agreement and the UW License Agreement described above in “License Agreement with respect to RSV and Other Pathogens". The Company is obligated to use commercially reasonable efforts to commercialize Licensed Flu Products, and to initiate a clinical trial with respect to such Licensed Flu Products by a specified date in 2025. If the Company is unable to initiate a clinical trial by the specified date and cannot agree with UW to modify such obligation or do not cure by meeting such obligation, then UW may terminate the UW Flu License Agreement. Under the UW Flu License Agreement, the Company paid UW a one-time upfront license fee, and after September 2023 and for the remainder of the term of the UW Flu License Agreement, the Company is required to pay tiered minimum annual fees ranging from the mid four figures to the mid five figures, with such fees creditable against royalty payments. The Company is required to pay UW up to an aggregate of $350 thousand for payments related to development milestones and up to an aggregate of $6 million for payments related to commercial milestones based upon reaching certain cumulative net sales thresholds for all Licensed Flu Products. The Company is also required to pay UW a fixed low single digit percentage royalty on net sales of Licensed Flu Products by us and our sublicensees, subject to certain reductions if the Company is required to pay for third-party intellectual property rights in order to commercialize the Licensed Flu Products. The Company is not obligated to pay duplicate royalties on net sales of any Licensed Flu Products if the Company is already required to pay a royalty on such net sales under the UW License Agreement or the UW Option and License Agreement. The UW Flu License Agreement will remain in effect until all licensed patent rights have terminated and all obligations due to UW have been fulfilled. The last-to-expire licensed patent, if issued, is expected to expire in 2041, subject to any adjustment or extension of patent term that may be available. UW can terminate the UW Flu License Agreement if the Company breaches or fails to perform one of the material duties under the UW Flu License Agreement and are unable to remedy the default within an agreed upon time period that can be extended by UW. The Company can terminate the UW Flu License Agreement at will with prior written notice to UW. The Company can also terminate certain of its licensed rights through an amendment to the UW Flu License Agreement. During year ended December 31, 2021, the Company paid $0.1 million in fees associated with the UW Flu License Agreement. License Agreement with the University of Texas In June 2021, the Company entered into an exclusive patent license agreement with an academic entity, the University of Texas at Austin (the “UT Agreement”). Under the UT Agreement, the Company obtained an exclusive, worldwide, royalty-bearing, sublicensable license under certain patent rights, to use licensed know-how for prevention, cure, amelioration or treatment of respiratory disease caused by metapneumovirus infection in all vaccine fields, excluding mRNA-based vaccines. The Company is obligated to pay aggregate potential milestone payments of up to $0.8 million with respect to future development and regulatory based milestones, and up to $3.8 million with respect to future sales milestones following commercialization for each licensed product for so long as licensed patent rights exist and have not expired, been revoked, lapsed, or held unenforceable. The UT Agreement will terminate upon the last expiration of the patent rights or the Company may terminate the entirety of the agreement upon written notice thereof to the University of Texas at Austin. During year ended December 31, 2021, the Company paid a negligible amount in fees associated with the UT Agreement.

License Agreements

12 Months Ended

Dec. 31, 2021

6. License Agreements

License Agreement with the National Institutes of Health

On June 28, 2018, the Company entered into a non-exclusive patent license agreement (the “NIH Agreement”) with a U.S. government entity, the National Institutes of Health, represented by National Institute of Allergy and Infectious Disease (“NIAID”). The NIH Agreement was amended in September 2018 and September 2020. Under the NIH Agreement, the Company obtained a non-exclusive, worldwide, royalty-bearing, sublicensable license under certain NIAID patent rights, and transfer of know-how and biological materials for use in adjuvanted or non-adjuvanted vaccines for the prevention, cure, or treatment of RSV and metapneumovirus infection in humans.

Under the NIH Agreement, the Company is required to use commercially reasonable efforts to meet certain specified development, sales and regulatory milestones related to the licensed products within specified time periods. In consideration of the rights granted to the Company under the NIH Agreement, the Company paid a licensing fee upon execution of the NIH Agreement of $100,000, and will pay annual minimum royalty payments starting in the second year after the initial sale of each licensed product which can be credited against any earned royalties due for sales made in the year. There are milestone payments due upon the completion of certain development, regulatory, and commercial milestones for the licensed products in the future. The Company is obligated to pay aggregate potential milestone payments of up to $2.1 million with respect to future development and regulatory based milestones, and up to $6.5 million with respect to future sales milestones following commercialization. Additionally, the Company has agreed to pay a tiered royalty of a low single digit percentage on net sales of all products applicable to the license. Additional royalties would be due in connection with sublicenses. The Company’s royalty obligations continue for each licensed product for so long as licensed patent rights exist and have not expired, been revoked, lapsed, or held unenforceable.

The NIH Agreement will terminate upon the last expiration of the patent rights or the Company may terminate the entirety of the agreement upon discontinuation of development or sales of licensed products and provision of written notice thereof to NIH.

During the years ended December 31, 2021 and 2020, the Company paid $0.2 million and $0.1 million, respectively, in fees associated with the license, which were recorded as research and development expenses.

License Agreements with University of Washington

License Agreement with respect to RSV and Other Pathogens

On June 29, 2018, the Company entered into an exclusive license agreement with an academic entity, University of Washington (the “UW 2018 Agreement”), for an exclusive license to covered intellectual property, a non-exclusive, worldwide license to use licensed know-how, and rights to sublicense for computationally designed nanoparticles and vaccines. The UW 2018 Agreement was amended in June 2019 and again in November 2020. The Company’s rights and obligations under the UW 2018 Agreement are subject to certain U.S. government rights, certain global access commitment rights for humanitarian purposes to BMGF, certain rights to Howard Hughes Medical Institute ("HHMI"), and certain other limited rights retained by University of Washington ("UW").

The Company issued 192,276 shares of common stock on August 1, 2018 in exchange for the UW 2018 Agreement’s exclusive license. The shares issued were recorded at their estimated fair value, which is de minimis, with the related expense classified as research and development in 2018.

Under the UW 2018 Agreement, the Company is required to use commercially reasonable efforts to meet certain specified development, sales and regulatory milestones related to the licensed products within specified time periods. In consideration of the rights granted to the Company under the UW 2018 Agreement, the Company is required to pay an

annual maintenance fee in the mid four figures starting in 2020. Additionally, the Company is required to pay minimum annual royalties following the first year after commercial sale of each licensed product. There are milestone payments due upon the completion of certain development, regulatory, and commercial milestones for licensed products in the future. The aggregate potential milestone payments for future development, regulatory, and sales-based milestones are $1.4 million per indication, up to a maximum of $6.8 million in total milestone payments. Additionally, the Company has agreed to pay a royalty of a low single digit percentage on net sales of all licensed products. Additional royalties would be due in connection with sublicenses and milestones. The Company’s royalty obligations continue for each licensed product for so long as licensed patent rights exist and have not expired, been revoked, lapsed, or held unenforceable.

The UW 2018 Agreement will terminate when all licensed rights have been terminated and all obligations due to UW have been fulfilled, or the Company may terminate the entirety of the agreement upon written notice thereof to UW.

On July 2, 2020, the Company entered into a non-exclusive license agreement with respect to specified intellectual property with options for exclusivity in North America and Europe subject to the performance of certain development milestones, with UW (the “UW 2020 Agreement”). Under the UW 2020 Agreement, the Company also received a non-exclusive, worldwide license to use specific know-how and rights to sublicense for computationally designed nanoparticles and vaccines. The UW 2020 Agreement was amended in August 2020 and subsequently in May 2021. The Company’s rights and obligations under the UW 2020 Agreement as amended are subject to certain U.S. government rights, certain global access commitment rights for humanitarian purposes to BMGF, certain rights to HHMI, and certain other limited rights retained by UW.

Under the UW 2020 Agreement as amended, the Company is required to use commercially reasonable efforts to meet certain specified development, sales and regulatory milestones related to the licensed products within specified time periods. The Company has agreed to pay a royalty of a low single digit percentage on net sales of all products applicable to the license. However, the Company will not be required to pay royalties on net sales of any licensed product under the UW 2020 Agreement as amended if the Company is required to pay royalties on net sales under the UW 2018 Agreement. Additional royalties would be due in connection with sublicenses and milestones. The Company’s royalty obligations continue for each licensed product for so long as licensed patent rights exist and have not expired, been revoked, lapsed, or held unenforceable.

The UW 2020 Agreement as amended will terminate when all licensed rights have been terminated and all obligations due to UW have been fulfilled, or the Company may terminate the entirety of the agreement upon written notice thereof to UW.

During the years ended December 31, 2021 and 2020, the Company paid $0.2 million and $0.3 million respectively, in fees associated with the 2018 and 2020 Agreements.

License Agreement with Respect to Influenza

In September 2021, the Company entered into a license agreement with UW ("UW Flu License Agreement"). Pursuant to the UW Flu License Agreement, UW granted the Company a non-exclusive, worldwide, royalty-bearing, sublicensable (subject to certain restrictions) license under certain UW patents to make, use, sell, offer to sell, import, and otherwise exploit any product covered by the licensed patents ("Licensed Flu Products"), for the prophylactic and/or therapeutic treatment of influenza. UW also granted the Company a non-exclusive, worldwide license to use certain know-how related to the licensed patents. The licensed patents and know-how generally relate to computationally designed nanoparticles and vaccines based upon such designs, and relate to the Company's proprietary two-component virus-like-particle technology and nanoparticle-based influenza virus vaccines. As of March 2022, the UW Flu License Agreement is applicable to the Company's preclinical influenza program. The United States federal government and HHMI have similar rights under the UW Flu License Agreement and the UW License Agreement described above in “License Agreement with respect to RSV and Other Pathogens".

The Company is obligated to use commercially reasonable efforts to commercialize Licensed Flu Products, and to initiate a clinical trial with respect to such Licensed Flu Products by a specified date in 2025. If the Company is unable to initiate a clinical trial by the specified date and cannot agree with UW to modify such obligation or do not cure by meeting such obligation, then UW may terminate the UW Flu License Agreement.

Under the UW Flu License Agreement, the Company paid UW a one-time upfront license fee, and after September 2023 and for the remainder of the term of the UW Flu License Agreement, the Company is required to pay tiered minimum annual fees ranging from the mid four figures to the mid five figures, with such fees creditable against royalty payments. The Company is required to pay UW up to an aggregate of $350 thousand for payments related to development

milestones and up to an aggregate of $6 million for payments related to commercial milestones based upon reaching certain cumulative net sales thresholds for all Licensed Flu Products. The Company is also required to pay UW a fixed low single digit percentage royalty on net sales of Licensed Flu Products by us and our sublicensees, subject to certain reductions if the Company is required to pay for third-party intellectual property rights in order to commercialize the Licensed Flu Products. The Company is not obligated to pay duplicate royalties on net sales of any Licensed Flu Products if the Company is already required to pay a royalty on such net sales under the UW License Agreement or the UW Option and License Agreement.

The UW Flu License Agreement will remain in effect until all licensed patent rights have terminated and all obligations due to UW have been fulfilled. The last-to-expire licensed patent, if issued, is expected to expire in 2041, subject to any adjustment or extension of patent term that may be available. UW can terminate the UW Flu License Agreement if the Company breaches or fails to perform one of the material duties under the UW Flu License Agreement and are unable to remedy the default within an agreed upon time period that can be extended by UW. The Company can terminate the UW Flu License Agreement at will with prior written notice to UW. The Company can also terminate certain of its licensed rights through an amendment to the UW Flu License Agreement.

During year ended December 31, 2021, the Company paid $0.1 million in fees associated with the UW Flu License Agreement.

License Agreement with the University of Texas

In June 2021, the Company entered into an exclusive patent license agreement with an academic entity, the University of Texas at Austin (the “UT Agreement”). Under the UT Agreement, the Company obtained an exclusive, worldwide, royalty-bearing, sublicensable license under certain patent rights, to use licensed know-how for prevention, cure, amelioration or treatment of respiratory disease caused by metapneumovirus infection in all vaccine fields, excluding mRNA-based vaccines.

The Company is obligated to pay aggregate potential milestone payments of up to $0.8 million with respect to future development and regulatory based milestones, and up to $3.8 million with respect to future sales milestones following commercialization for each licensed product for so long as licensed patent rights exist and have not expired, been revoked, lapsed, or held unenforceable.

The UT Agreement will terminate upon the last expiration of the patent rights or the Company may terminate the entirety of the agreement upon written notice thereof to the University of Texas at Austin.

During year ended December 31, 2021, the Company paid a negligible amount in fees associated with the UT Agreement.