What changed in this filing

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Item 2. Management’s Discussion and Analysis

2025-11-13 compared with 2025-08-12 · 110 added, 125 removed, 224 unchanged (51% of the section changed)

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We are a clinical-stage biopharmaceutical company focused on identifying and developing novel treatments for rare diseases and diseases caused by MDR bacterial infections with high unmet need.

Our most advanced clinical-stage product candidate, tebipenem HBr, is in Phase 3 development, with the potential to be the first broad-spectrum oral carbapenem to treat adult patients with cUTIs, including pyelonephritis, caused by certain microorganisms.

In May 2025, we and GSK announced that the pivotal Phase 3 PIVOT-PO trial evaluating tebipenem HBr met its primary endpoint and had stopped early for efficacy.

The other program in our pipeline is SPR720, a product candidate for first-line treatment of nontuberculous mycobacterial (“NTM”) pulmonary disease (“NTM-PD”).

In October 2024, we announced that results from a planned interim analysis of our Phase 2a clinical trial for SPR720 demonstrated the oral agent did not meet its primary endpoint and we elected to suspend development of SPR720 in its oral formulation.

We are currently determining next steps for SPR720.

Additionally, in March 2025, following a reprioritization of our programs, we announced that we are no longer pursuing a Phase 2 clinical trial for SPR206, which was previously included in our pipeline.

Our clinical-stage product candidate, tebipenem HBr, has completed a Phase 3 trial with the potential to be the first broad-spectrum oral carbapenem to treat adult patients with cUTIs, including pyelonephritis, caused by certain microorganisms.

In May 2025, we and GSK announced that the pivotal Phase 3 PIVOT-PO trial evaluating tebipenem HBr met its primary endpoint and was stopped early for efficacy.

Results from the Phase 3 PIVOT-PO trial were featured in a late breaking oral presentation on October 20, 2025, at IDWeek in Atlanta, GA.

GSK plans to submit the data from the trial as part of an FDA filing during the fourth quarter of 2025.

In March 2025, following a reprioritization of our programs, we announced that we were no longer pursuing a Phase 2 clinical trial for SPR206 and we have now ceased further development of the program.

Additionally, in November 2025, we announced that we ceased development of SPR720, a product candidate for first-line treatment of NTM-PD.

Following the termination of our earlier stage programs, we remain focused on completing our obligations under the GSK License Agreement and other corporate activities.

We have experienced mostly net losses and significant cash outflows from cash used in operating activities since our inception.

Our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of one or more of our product candidates.

As of June 30, 2025, we had an accumulated deficit of $475.2 million, and cash and cash equivalents of $31.2 million.

Our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of tebipenem HBr, or any product candidate we may develop in the future.

As of September 30, 2025, we had an accumulated deficit of $482.6 million, and cash and cash equivalents of $48.6 million.

We expect to continue to incur significant expenses and operating losses for at least the next year.

Based on our cash and cash equivalents as of June 30, 2025, together with earned and non-contingent development milestone payments from GSK, including the final payment under the GSK License Agreement of $23.8 million received in the third quarter of 2025, and the decrease in clinical expense as a result of the PIVOT-PO Phase 3 trial for tebipenem HBr stopping early for efficacy following positive interim analysis results, we believe that our cash runway will be sufficient to fund our operating expenses and required capital expenditures into 2028.

Based on our cash and cash equivalents as of September 30, 2025 and the decrease in clinical expense as a result of the completion of the PIVOT-PO Phase 3 trial for tebipenem HBr and the decision to cease development of SPR720, we believe that our cash runway will be sufficient to fund our operating expenses and required capital expenditures into 2028.

During this period, we plan to prioritize finalizing the Phase 3 clinical trial activities for tebipenem HBr under our GSK License Agreement.

Beyond this point, or in the event we change our current operating plan, we will need substantial additional funding to support our continuing operations and pursue our growth strategy.

Beyond this point, or in the event we change our current operating plan, we will need additional funding to support our continuing operations and explore our growth strategy.

Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through a combination of equity offerings, debt financings, government funding arrangements, collaborations, strategic alliances and marketing, distribution or licensing arrangements.

If we are not able to secure adequate additional funding, we plan to make further reductions in spending.

If we are not able to secure adequate additional funding, we will have to make further reductions in spending.

In that event, we may have to delay, scale back, or eliminate some or all of our planned development activities.

The actions necessary to reduce spending under this plan at a level that mitigates the factors described above is not considered probable, as defined in the accounting standards and therefore, the full extent to which management may extend our funds through these actions may not be considered in management’s assessment of our ability to continue as a going concern.

The actions necessary to reduce spending under this plan at a level that mitigates the factors described above are not considered probable, as defined in the accounting standards and therefore, the full extent to which management may extend our funds through these actions may not be considered in management’s assessment of our ability to continue as a going concern.

We will not generate revenue from product sales unless and until we successfully complete clinical development and obtain regulatory approval for our product candidates.

If we obtain regulatory approval for any of our product candidates and do not enter into a commercialization partnership, we expect to incur significant expenses related to developing our internal commercialization capability to support product sales, marketing and distribution.

If we obtain regulatory approval for any of our future product candidates and do not enter into a commercialization partnership, we expect to incur significant expenses related to developing our internal commercialization capability to support product sales, marketing and distribution.

Further, we expect to incur additional costs associated with our continued operation as a public company.

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Recent Developments

Nasdaq Deficiency Letter and Regained Compliance

On February 25, 2025, we received a deficiency letter from the Listing Qualifications Department of the Nasdaq Stock Market LLC informing us that we were not in compliance with the continued listing requirements of the Nasdaq GS because the bid price for our common stock had closed below $1.00 per share for 30 consecutive business days.

On June 12, 2025, we received a letter from the Listing Qualifications Department informing us that we had regained compliance with the bid price requirement and the matter is now closed.

Management Transitions and Board Composition

In January 2025, the independent directors of our Board of Directors approved the following actions as a matter of corporate governance best practices and to enable us to maintain focus on pursuing our business objectives pending resolution of a “Wells Notice” received from the Staff of the SEC, as further described in Part II, Item 1 “Legal Proceedings” of this Quarterly Report on Form 10-Q.

• The Board of Directors appointed director Frank Thomas to serve as the Chairman of the Board of Directors, stepping in for Ankit Mahadevia, M.D.

Shukla agreed to a paid administrative leave from his role as President and Chief Executive Officer.

During such leave, Mr.

Shukla remained an employee and continued to serve as a member of the Board of Directors.

• The Board of Directors appointed Esther Rajavelu, our then-current Chief Financial Officer, Chief Business Officer and Treasurer, to serve as Interim President and Chief Executive Officer during the term of Mr.

Shukla’s administrative leave.

The terms of Ms.

Rajavelu’s existing employment arrangement with the Company were amended to provide that she would receive additional cash compensation of $20,000 per month while she served as the Interim President and Chief Executive Officer, in addition to her role as Chief Financial Officer and Chief Business Officer.

Effective May 2, 2025, Ms.

Rajavelu was appointed as our President and Chief Executive Officer.

She continues to serve as our Chief Financial Officer and Treasurer.

In connection with the foregoing, Ms.

Rajavelu was nominated for election to serve as a member of our Board of Directors at our 2025 annual meeting of stockholders and was elected to the Board of Directors in June 2025.

In connection with the foregoing, we and Ms.

Rajavelu entered into an Amended and Restated Employment Agreement, dated April 28, 2025.

Shukla mutually decided to separate, effective May 2, 2025.

In connection with the foregoing, we and Mr.

Shukla entered into a Separation Agreement, dated April 28, 2025.

In addition, Mr.

Shukla stepped down from the Board of Directors, effective May 2, 2025.

For more information about the foregoing, please see our Current Report on Form 8-K filed with the SEC on April 28, 2025.

Tebipenem HBr

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The IDMC review did not identify any new safety concerns beyond what has been reported in other studies with tebipenem, with diarrhea and headache as the two most reported adverse events.

GSK plans to work with U.S.

regulatory authorities to include the data as part of a filing in the second half of 2025.

Full results will be submitted for presentation at an upcoming scientific meeting and for publication in a peer-reviewed journal.

Results from the Phase 3 PIVOT-PO trial were featured in a late breaking oral presentation on October 20, 2025, at IDWeek in Atlanta, GA.

GSK plans to submit the data from the trial as part of an FDA filing during the fourth quarter of 2025.

Remaining potential payments under the GSK License Agreement, which include milestones and royalties based on future regulatory events, commercial launch, and achievement of pre-specified sales thresholds, are as follows (in millions):

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Net annual sales greater than $1,000.0

*Under the terms of the GSK License Agreement, the maximum potential milestone amount was revised from $150.0 million after PIVOT-PO was stopped early for efficacy following completion of a pre-specified interim analysis of data from 1,690 patients enrolled in the trial, thereby reducing the overall cost of the trial to the Company;

the maximum potential milestone payment of $150.0 million was contingent upon the trial continuing to full enrollment, with 2,637 patients enrolled in the trial.

In addition to the milestones described above, GSK is obligated to pay royalties to the Company on annual net sales of GSK Licensed Products in the GSK Territory.

In addition to the milestones described above, GSK is obligated to pay royalties to us on annual net sales of GSK Licensed Products in the GSK Territory.

Such royalties are 1% for annual sales up to $750.0 million each year and range from high single-digit percentages on annual net sales above $750.0 million each year to low double-digit percentages on annual net sales above $1,000.0 million each year.

In March 2025, following a reprioritization of its programs, we announced that we are no longer pursuing a Phase 2 clinical trial for SPR206.

On April 4, 2025, NIAID informed us that it was canceling the five-year contract, awarded in May 2021, under the Agency’s Omnibus Broad Agency Announcement No.

In March 2025, following a reprioritization of our programs, we announced that we were no longer pursuing a Phase 2 clinical trial for SPR206 and had ceased further development of the program.

On April 4, 2025, the National Institute of Allergy and Infectious Diseases (“NIAID”) informed us that it was canceling the five-year contract, awarded in May 2021, under the Agency’s Omnibus Broad Agency Announcement No.

HHS-NIH-NIAID-BAA2020-1 award mechanism to support further development of SPR206, effective immediately, for its convenience.

In November 2025, we announced that we have ceased development of SPR720.

Components of Our Results of Operations

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To date, we have not generated any revenue from product sales.

If our development efforts for our product candidates are successful and result in regulatory approval, we may generate revenue in the future from product sales.

If our development efforts for our current and future product candidates are successful and result in regulatory approval, we may generate revenue in the future from product sales.

We cannot predict if, when, or to what extent we will generate revenue from the commercialization and sale of our product candidates.

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We also anticipate that we will continue to incur accounting, audit, legal, regulatory, compliance, infrastructure and director and officer insurance costs, as well as investor and public relations expenses associated with our continued operation as a public company.

Impairment Charges

During the third quarter of 2025, we evaluated our real estate lease in light of our new sublease agreements.

As a result of the evaluation, we recorded an impairment charge of $0.6 million associated with the right-of-use asset in the third quarter of 2025.

Restructuring

In light of our decision to suspend planned development activities for our oral SPR720 program and the strategic restructuring implemented in October 2024, we expect that our future expenses relating to development activities with respect to SPR720 will be substantially reduced as we determine next steps for SPR720.

In connection with our restructuring, we estimated that we would incur approximately $1.1 million of costs in connection with the reduction in workforce related to severance pay and other related termination benefits of which we incurred $0.9 million during the year ended December 31, 2024, $0.2 million during the quarter ended March 31, 2025, and less than $0.1 million during the quarter ended June 30, 2025.

We have incurred all of the costs associated with our workforce reduction as of June 30, 2025.

In October 2024, we implemented a strategic restructuring initiative and corresponding reduction in workforce.

We restructured our operations to reduce costs and reallocate resources in support of the development of tebipenem HBr and other corporate activities.

As of September 30, 2025, we had recognized $1.1 million in expense related to the October 2024 restructuring and do not expect to incur any further charges related to this restructuring.

Other Income (Expense)

Interest Income (Expense)

Interest income (expense) during the three and six months ended June 30, 2025 and 2024 consists of interest income related to the significant financing component related to the GSK License Agreement and interest earned on our cash equivalents, which are primarily invested in money market accounts, as well as interest earned on our investments in marketable securities.

Interest income (expense) during the three and nine months ended September 30, 2025 and 2024 consists of interest income related to the significant financing component related to the GSK License Agreement and interest earned on our cash equivalents, which are primarily invested in money market accounts, as well as interest earned on our investments in marketable securities.

Other Income (Expense), Net

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Results of Operations

Comparison of the Three Months Ended June 30, 2025 and 2024

The following table summarizes our results of operations for the three months ended June 30, 2025 and 2024 (in thousands):

Three Months Ended June 30,

Comparison of the Three Months Ended September 30, 2025 and 2024

The following tables summarize our results of operations for the three months ended September 30, 2025 and 2024 (in thousands):

Three Months Ended September 30,

Grant revenue

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General and administrative

Restructuring

Impairment charges

Total operating expenses

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Other income (expense), net

Total other income, net

Total other income (expense), net

Net loss before income taxes

Income tax benefit

Grant Revenue

Three Months Ended June 30,

Three Months Ended September 30,

BARDA Contract (Tebipenem HBr)

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Total grant revenue

Grant revenue recognized during the three months ended June 30, 2025 and 2024 consisted of the reimbursement of qualifying expenses incurred in connection with our various government awards.

The decrease in grant revenue during the three months ended June 30, 2025 was primarily due to a decrease of $1.7 million under our BARDA contract for tebipenem HBr, and a decrease of $0.1 million under our NIAID agreement relating to SPR206.

Grant revenue recognized during the three months ended September 30, 2025 and 2024 consisted of the reimbursement of qualifying expenses incurred in connection with our various government awards.

The decrease in grant revenue during the three months ended September 30, 2025 was primarily due to a decrease of $3.2 million under our BARDA contract for tebipenem HBr, and a decrease of $0.1 million under our NIAID agreement relating to SPR206.

Collaboration Revenue

Three Months Ended June 30,

Three Months Ended September 30,

GSK (Tebipenem HBr)

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Total collaboration revenue

During the three months ended June 30, 2025, we recognized $11.8 million in collaboration revenue related to our agreement with GSK and no revenue related to our agreement with Pfizer.

During the three months ended June 30, 2024, we recognized $5.9 million in collaboration revenue related to our agreement with GSK and $0.1 million in collaboration revenue related to our agreement with Pfizer.

The increase in revenue under the GSK License Agreement was directly related to the adjusted service period due to the pivotal Phase 3 PIVOT-PO trial stopping early for efficacy in the first half of 2025 following the pre-specified interim analysis.

During the three months ended September 30, 2025, we recognized $3.0 million in collaboration revenue related to our agreement with GSK and no revenue related to our agreement with Pfizer.

During the three months ended September 30, 2024, we recognized $7.8 million in collaboration revenue related to our agreement with GSK and $0.1 million in collaboration revenue related to our agreement with Pfizer.

The decrease in revenue under the GSK License Agreement was directly related to the adjusted service period due to the pivotal Phase 3 PIVOT-PO trial stopping early for efficacy in the first half of 2025 following the pre-specified interim analysis.

Research and Development Expenses

Three Months Ended June 30,

Three Months Ended September 30,

Direct research and development expenses by program:

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Total research and development expenses

Direct costs related to our tebipenem HBr program decreased by $7.6 million during the three months ended June 30, 2025, compared to the three months ended June 30, 2024, due to a decrease in clinical activities related to our pivotal Phase 3 PIVOT-PO trial, which met its primary endpoint and was stopped early for efficacy during the first half of 2025.

Direct costs related to our SPR720 program decreased by $4.5 million during the three months ended June 30, 2025, as compared to the three months ended June 30, 2024, due to decreased clinical activity during the period related to our Phase 2a clinical trial of SPR720, which completed enrollment in the second quarter of 2024.

Subsequently, in October 2024, we announced that we would suspend current development activities for SPR720 based on an interim analysis of the Phase 2a proof-of-concept study of SPR720 for the treatment of NTM-PD not meeting its primary endpoint.

Direct costs related to our SPR206 program decreased by $0.1 million during the three months ended June 30, 2025, primarily due to decreased preclinical activity.

In March 2025, following a reprioritization of our programs, we announced that we are no longer pursuing a planned Phase 2 clinical trial for SPR206.

The decrease in personnel-related costs of $0.8 million was primarily a result of increased retention program costs in our research and development functions offset by reduced headcount costs as a result of the previously announced restructuring in the fourth quarter of 2024.

Personnel-related costs for the three months ended June 30, 2025 and 2024 included stock-based compensation expense of $0.4 million and $0.7 million, respectively.

Direct costs related to our tebipenem HBr program decreased by $13.1 million during the three months ended September 30, 2025, compared to the three months ended September 30, 2024, due to a decrease in clinical activities related to our pivotal Phase 3 PIVOT-PO trial, which met its primary endpoint and was stopped early for efficacy during the first half of 2025.

Direct costs related to our SPR720 program decreased by $3.7 million during the three months ended September 30, 2025, as compared to the three months ended September 30, 2024, due to decreased clinical activity during the period related to our Phase 2a clinical trial of SPR720.

Subsequently, in November 2025, we announced that we ceased development of SPR720.

Direct costs related to our SPR206 program decreased by $0.2 million during the three months ended September 30, 2025, primarily due to decreased preclinical activity.

In March 2025, following a reprioritization of our programs, we announced that we ceased development of SPR206.

The decrease in personnel-related costs of $1.6 million was primarily a result of reduced headcount costs as a result of the restructuring in the fourth quarter of 2024.

Personnel-related costs for the three months ended September 30, 2025 and 2024 included stock-based compensation expense of $0.4 million and $0.7 million, respectively.

Facility-related and other costs primarily reflect costs related to supporting our research and development staff.

General and Administrative Expenses

Three Months Ended June 30,

Three Months Ended September 30,

Personnel related (including stock-based compensation)

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Total general and administrative expenses

The increase in personnel-related costs of $0.2 million was primarily a result of retention program costs in our general and administrative functions during the period, offsetting reduced headcount costs as a result of the previously announced restructuring in the fourth quarter of 2024.

Personnel-related costs for the three months ended June 30, 2025 and 2024 included stock-based compensation expense of $0.3 million and $1.4 million, respectively.

The increase in professional and consultant fees of $0.2 million was primarily due to an increase in legal and consulting expenses incurred in the three months ended June 30, 2025.

The decrease in personnel-related costs of $0.9 million was primarily a result of reduced headcount costs as a result of the restructuring in the fourth quarter of 2024.

Personnel-related costs for the three months ended September 30, 2025 and 2024 included stock-based compensation expense of $0.7 million and $1.5 million, respectively.

The decrease in professional and consultant fees of $0.2 million was primarily due to a decrease in legal and consulting expenses incurred in the three months ended September 30, 2025.

Facility-related and other costs primarily reflect costs related to supporting our general and administrative staff.

Impairment Charges

Impairment charges related to our right of use asset were $0.6 million for the three months ended September 30, 2025, compared to no charges for the three months ended September 30, 2024.

Other Income (Expense), Net

Other income (expense), net was $0.7 million for the three months ended June 30, 2025, compared to $1.2 million for the three months ended June 30, 2024.

Total other income for the three months ended June 30, 2025, included $0.7 million of interest income, of which $0.4 million related to the significant financing component recognized under the GSK License Agreement, offset by immaterial fluctuations in unrealized foreign currency.

Total other income for the three months ended June 30, 2024, included $1.2

million of interest income, of which $0.4 million related to the significant financing component recognized under the GSK License Agreement, offset by immaterial fluctuations in unrealized foreign currency.

Comparison of the Six Months Ended June 30, 2025 and 2024

The following table summarizes our results of operations for the six months ended June 30, 2025 and 2024 (in thousands):

Six Months Ended June 30,

Other income (expense), net was $0.5 million for the three months ended September 30, 2025, compared to $1.2 million for the three months ended September 30, 2024.

Total other income for the three months ended September 30, 2025, included $0.5 million of interest income, of which $0.2 million related to the significant financing component recognized under the GSK License Agreement, offset by immaterial fluctuations in unrealized foreign currency.

Total other income for the three months ended September 30, 2024, included $1.2 million of interest income, of which $0.4 million related to the significant financing component recognized under the GSK License Agreement, offset by immaterial fluctuations in unrealized foreign currency.

Comparison of the Nine Months Ended September 30, 2025 and 2024

The following tables summarize our results of operations for the nine months ended September 30, 2025 and 2024 (in thousands):

Nine Months Ended September 30,

Grant revenue

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General and administrative

Impairment charges

Restructuring

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Total other income, net

Net loss before income taxes

Income tax benefit

Grant Revenue

Six Months Ended June 30,

Nine Months Ended September 30,

BARDA Contract (Tebipenem HBr)

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Total grant revenue

Grant revenue recognized during the six months ended June 30, 2025 and 2024 consisted of the reimbursement of qualifying expenses incurred in connection with our various government awards.

The decrease in grant revenue during the six months ended June 30, 2025 was primarily due to a decrease of $5.9 million under our BARDA contract for tebipenem HBr, and a decrease of $0.2 million under our NIAID agreement relating to SPR206.

Grant revenue recognized during the nine months ended September 30, 2025 and 2024 consisted of the reimbursement of qualifying expenses incurred in connection with our various government awards.

The decrease in grant revenue during the nine months ended September 30, 2025 was primarily due to a decrease of $9.1 million under our BARDA contract for tebipenem HBr, and a decrease of $0.3 million under our NIAID agreement relating to SPR206.

Collaboration Revenue

Six Months Ended June 30,

Nine Months Ended September 30,

GSK (Tebipenem HBr)

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Total collaboration revenue

During the six months ended June 30, 2025, we recognized $16.9 million in collaboration revenue related to our agreement with GSK and under $0.1 million in collaboration revenue related to our agreement with Pfizer.

During the six months ended June 30, 2024, we recognized $10.0 million in collaboration revenue related to our agreement with GSK and $0.3 million in collaboration revenue related to our agreement with Pfizer.

During the nine months ended September 30, 2025, we recognized $19.9 million in collaboration revenue related to our agreement with GSK and less than $0.1 million in collaboration revenue related to our agreement with Pfizer.

During the nine months ended September 30, 2024, we recognized $17.7 million in collaboration revenue related to our agreement with GSK and $0.3 million in collaboration revenue related to our agreement with Pfizer.

Research and Development Expenses

Six Months Ended June 30,

Nine Months Ended September 30,

Direct research and development expenses by program:

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Total research and development expenses

Direct costs related to our tebipenem HBr program decreased by $6.7 million during the six months ended June 30, 2025, compared to the six months ended June 30, 2024, due to a decrease in clinical activities related to our pivotal Phase 3 PIVOT-PO trial which met its primary endpoint and was stopped early for efficacy during the first half of 2025.

Direct costs related to our SPR720 program decreased by $8.4 million during the six months ended June 30, 2025, as compared to the six months ended June 30, 2024, due to decreased clinical activity during the period related to our Phase 2a clinical trial of SPR720, which completed enrollment in the second quarter of 2024.

Direct costs related to our SPR206 program decreased by $0.3 million during the six months ended June 30, 2025, primarily due to decreased preclinical activity.

In March 2025, following a reprioritization of our programs, we announced that we are no longer pursuing a planned Phase 2 clinical trial for SPR206.

The decrease in personnel-related costs of $1.0 million was primarily a result of increased retention program costs in our research and development functions offset by reduced headcount costs as a result of the previously announced restructuring in the fourth quarter of 2024.

Personnel-related costs for the six months ended June 30, 2025 and 2024 included stock-based compensation expense of $0.9 million and $1.4 million, respectively.

Direct costs related to our tebipenem HBr program decreased by $19.6 million during the nine months ended September 30, 2025, compared to the nine months ended September 30, 2024, due to a decrease in clinical activities related to our pivotal Phase 3 PIVOT-PO trial which met its primary endpoint and was stopped early for efficacy during the first half of 2025.

Direct costs related to our SPR720 program decreased by $12.1 million during the nine months ended September 30, 2025, as compared to the nine months ended September 30, 2024, due to decreased clinical activity during the period related to our Phase 2a clinical trial of SPR720.

Subsequently, in November 2025, we announced that we ceased development of SPR720.

Direct costs related to our SPR206 program decreased by $0.5 million during the nine months ended September 30, 2025, primarily due to decreased preclinical activity.

In March 2025, following a reprioritization of our programs, we announced that we ceased development of SPR206.

The decrease in personnel-related costs of $2.6 million was primarily a result of reduced headcount costs as a result of the restructuring in the fourth quarter of 2024.

Personnel-related costs for the nine months ended September 30, 2025 and 2024 included stock-based compensation expense of $1.3 million and $2.1 million, respectively.

Facility-related and other costs primarily reflect costs related to supporting our research and development staff.

General and Administrative Expenses

Six Months Ended June 30,

Nine Months Ended September 30,

Personnel related (including stock-based compensation)

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Total general and administrative expenses

The increase in personnel-related costs of $1.0 million was primarily a result of retention bonus and executive severance expense in our general and administrative functions during the period offsetting reduced headcount costs as a result of the previously announced restructuring in the fourth quarter of 2024.

Personnel-related costs for the six months ended June 30, 2025 and 2024 included stock-based compensation expense of $1.3 million and $2.7 million, respectively.

The increase in professional and consultant fees of $0.4 million was primarily due to an increase in legal and consulting expenses incurred in the six months ended June 30, 2025.

The increase in personnel-related costs of $0.1 million was primarily a result of retention bonus and executive severance expense in our general and administrative functions during the period offsetting reduced headcount costs as a result of the restructuring in the fourth quarter of 2024.

Personnel-related costs for the nine months ended September 30, 2025 and 2024 included stock-based compensation expense of $2.0 million and $4.2 million, respectively.

The increase in professional and consultant fees of $0.3 million was primarily due to an increase in legal and consulting expenses incurred in the nine months ended September 30, 2025.

Facility-related and other costs primarily reflect costs related to supporting our general and administrative staff.

Impairment Charges

Impairment charges related to our right of use asset were $0.6 million for the nine months ended September 30, 2025, compared to no charges for the nine months ended September 30, 2024.

Other Income (Expense), Net

Total other income (expense), net was $1.6 million for the six months ended June 30, 2025, compared to $2.5 million for the six months ended June 30, 2024.

Total other income for the six months ended June 30, 2025, included $1.6 million of interest income, of which $0.7 million related to the significant financing component recognized under the GSK License Agreement, offset by immaterial fluctuations in unrealized foreign currency.

Total other income for the six months ended June 30, 2024, included $1.7 million of

interest income, of which $0.8 million related to the significant financing component recognized under the GSK License Agreement, offset by immaterial fluctuations in unrealized foreign currency.

Total other income (expense), net was $2.1 million for the nine months ended September 30, 2025, compared to $3.7 million for the nine months ended September 30, 2024.

Total other income for the nine months ended September 30, 2025, included $2.1 million of interest income, of which $0.9 million related to the significant financing component recognized under the GSK License Agreement, offset by immaterial fluctuations in unrealized foreign currency.

Total other income for the nine months ended September 30, 2024, included $3.7 million of interest income, of which $1.2 million related to the significant financing component recognized under the GSK License Agreement, offset by immaterial fluctuations in unrealized foreign currency.

Liquidity and Capital Resources

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Department of Defense, NIAID, CARB-X and BARDA, the GSK License Agreement and our license agreements with Everest and Pfizer.

We have not yet commercialized any of our product candidates and we may not generate revenue from sales of any product candidates.

We have not yet commercialized any product candidates and we may not generate revenue from sales of any product candidate.

To date, we have funded our operations with payments received under license and collaboration agreements and funding from government contracts, and from the proceeds of multiple common stock offerings.

As of June 30, 2025, we had cash and cash equivalents of $31.2 million.

In the third quarter of 2025, we received the final payment under the GSK License Agreement of $23.8 million.

As of September 30, 2025, we had cash and cash equivalents of $48.6 million.

We filed the 2024 Form S-3 on March 15, 2024, which became effective on March 22, 2024, and pursuant to which we registered for sale up to $300.0 million of any combination of our common stock, preferred stock, debt securities, warrants, rights and/or units from time to time and at prices and on terms that we may determine, including up to $75.0 million of our common stock available for issuance pursuant to the Sales Agreement with Cantor.

Under the Sales Agreement, Cantor may sell shares of our common stock by any method permitted by law deemed to be an “at-the-market” offering as defined in Rule 415 of the Securities Act, subject to the terms of the Sales Agreement.

During the three and six months ended June 30, 2025, we did not sell any shares of our common stock under the Sales Agreement.

The following table summarizes our sources and uses of cash for the six months ended June 30, 2025 and 2024 (in thousands):

Six Months Ended June 30,

During the three and nine months ended September 30, 2025, we did not sell any shares of our common stock under the Sales Agreement.

The following table summarizes our sources and uses of cash for the nine months ended September 30, 2025 and 2024 (in thousands):

Nine Months Ended September 30,

Cash used in operating activities

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Operating Activities

Net cash used in operating activities for the six months ended June 30, 2025, was $21.7 million, primarily resulting from our net loss of $15.6 million, adjusted for an increase to non-cash items of $2.8 million (primarily stock-based compensation).

Net cash used by changes in our operating assets and liabilities was $9.0 million and consisted primarily of a $24.9 million decrease in the collaboration receivable-related party, due to the receipt of the third installment payment from GSK (see Note 10), a $16.9 million decrease in deferred revenue, a $11.0 million decrease in accrued expenses, a $6.5 million decrease in accounts payable, a $0.6 million increase in prepaid expenses, a $0.6 million net increase in other receivables, and a $0.7 million decrease in operating lease liability.

Net cash used in operating activities for the six months ended June 30, 2024, was $12.8 million, primarily resulting from our net loss of $30.5 million, adjusted for an increase to non-cash items of $4.7 million (primarily stock-based compensation).

Net cash provided by changes in our operating assets and liabilities was $13.1 million and consisted primarily of a $21.4 million decrease in our related party collaboration receivable, due to the receipt of the first installment payment from GSK (see Note 10), a $10.2 million decrease in deferred revenue, a $3.2 million net decrease in receivables, a $1.3 million increase in accounts payable, an increase of $3.5 million in accrued expenses, and a $0.6 million decrease in operating lease liability.

Net cash used in operating activities for the nine months ended September 30, 2025, was $4.3 million, primarily resulting from our net loss of $22.9 million, adjusted for an increase to non-cash items of $4.7 million (primarily stock-based compensation).

Net cash provided by changes in our operating assets and liabilities was $13.9 million and consisted primarily of a $48.5 million decrease in the collaboration receivable-related party, due to the receipt of the third and fourth installment payments from GSK (see Note 11), a $20.0 million decrease in deferred revenue, a $9.9 million decrease in accrued expenses, a $5.9 million decrease in accounts payable, a $0.7 million increase in prepaid expenses and other assets, a $1.5 million net increase in other receivables, and a $0.9 million decrease in operating lease liability and other liabilities.

Net cash used in operating activities for the nine months ended September 30, 2024, was less than $0.1 million, primarily resulting from our net loss of $47.7 million, adjusted for an increase to non-cash items of $7.1 million (primarily stock-based compensation).

Net cash provided by changes in our operating assets and liabilities was $40.6 million and consisted primarily of a

$45.2 million decrease in our related party collaboration receivable, due to the receipt of the first and second installment payments from GSK (see Note 11), a $18.0 million decrease in deferred revenue, a $1.2 million net increase in receivables, a $4.7 million increase in accounts payable, a $2.4 million increase in prepaid expenses and other assets, an increase of $8.8 million in accrued expenses, and a $1.3 million decrease in operating lease liability and other liabilities.

Changes in accounts payable, accrued expenses and other current liabilities and prepaid expenses and other current assets in all periods were generally due to the advancement of our programs and the timing of vendor invoicing and payments.

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Investing Activities

We did not undertake any investing activities during the six months ended June 30, 2025 or 2024.

We did not undertake any investing activities during the nine months ended September 30, 2025 or 2024.

Financing Activities

We did not undertake any financing activities during the six months ended June 30, 2025 or 2024.

We did not undertake any financing activities during the nine months ended September 30, 2025 or 2024.

Funding Requirements

Our future use of operating cash and capital requirements, and the timing and amount thereof, will depend largely on:

• the timing and costs of our ongoing and planned clinical trials;

• the timing and costs of any ongoing and planned clinical trials;

• the initiation, progress, timing, costs and results of preclinical studies and clinical trials of our product candidates and potential new product candidates;

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• costs associated with litigation and any government investigation.

As of June 30, 2025, we had cash and cash equivalents of $31.2 million.

As of September 30, 2025, we had cash and cash equivalents of $48.6 million.

In accordance with ASU 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (Subtopic 205-40), we are required to evaluate whether there are conditions and events, considered in the aggregate, that raise substantial doubt about our ability to continue as a going concern from the issuance date of our financial statements.

Based on such cash and cash equivalents as of June 30, 2025, together with earned and non-contingent development milestone payments from GSK, including the final payment under the GSK License Agreement of $23.8 million received in the third quarter of 2025, and the decrease in clinical expense as a result of the PIVOT-PO Phase 3 trial for tebipenem HBr stopping early for efficacy following positive interim analysis results, we believe that our cash runway will enable us to fund our operating expenses and capital expenditure requirements for at least 12 months from the issuance of the financial statements included in this report and into 2028.

Based on such cash and cash equivalents as of September 30, 2025 and the decrease in clinical expense as a result of the completion of the PIVOT-PO Phase 3 trial for tebipenem HBr and the decision to cease development of SPR720, we believe that our cash runway will enable us to fund our operating expenses and required capital expenditure requirements for at least 12 months from the issuance of the financial statements included in this report and into 2028.

This timeline is subject to uncertainty as to the timing of future expenditures.

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In that event, we may have to delay, scale back, or eliminate some or all of our planned clinical trials, and research stage programs.

The actions necessary to reduce spending under this plan at a level that mitigates the factors described above are not

considered probable, as defined in the accounting standards and therefore, the full extent to which management may extend our funds through these actions may not be considered in management’s assessment of our ability to continue as a going concern.

We have based these estimates on assumptions that may prove to be wrong, and we could utilize our available capital resources sooner than we expect.

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If we raise additional funds through collaborations, strategic alliances or marketing, distribution or licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to us.

If our access to capital is restricted or associated borrowing costs increase as a result of developments in financial markets, our operations

and financial condition could be adversely impacted.

If our access to capital is restricted or associated borrowing costs increase as a result of developments in financial markets, our operations and financial condition could be adversely impacted.

If we are unable to raise additional funds through equity or debt financings or other arrangements when needed, we may be required to delay, limit, reduce or terminate our research, product development or future commercialization efforts or grant rights to develop and market product candidates that we would otherwise prefer to develop and market ourselves.

Contractual Obligations and Commitments

During the three and six months ended June 30, 2025, there have been no material changes to our contractual obligations and commitments from those described under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Contractual Obligations and Commitments” in our Annual Report on Form 10-K for the year ended December 31, 2024.

During the three and nine months ended September 30, 2025, there have been no material changes to our contractual obligations and commitments from those described under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Contractual Obligations and Commitments” in our Annual Report on Form 10-K for the year ended December 31, 2024.

Off-Balance Sheet Arrangements

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Quantitative and Qualitati ve Disclosures About Market Risk.

As of June 30, 2025, we had cash and cash equivalents of $31.2 million, consisting of cash and money market accounts.

As of September 30, 2025, we had cash and cash equivalents of $48.6 million, consisting of cash and money market accounts.

The primary objectives of our investment activities are to preserve principal, provide liquidity and maximize income without significantly increasing risk.

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Treasury interest rates.

We did not have any assets classified as marketable securities as of June 30, 2025.

We did not have any assets classified as marketable securities as of September 30, 2025.

As we incur research expenses in foreign countries, we face exposure to movements in foreign currency exchange rates, primarily the Euro, British Pound and Australian dollar against the U.S.

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Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-Q

Item 2. Management’s Discussion and Analysis