Spero Therapeutics, Inc. (NASDAQ:SPRO) Q4 2023 Earnings Conference Call March 13, 2024 4:30 PM ET Company Participants Michael Wood - Managing Director of LifeSci Advisors Sath Shukla - CEO Kamal Hamed - CMO Esther Rajavelu - CFO and Chief Business Officer Conference Call Participants Ritu Baral - TD Cowen Louise Chen - Cantor Operator Good afternoon and welcome to the Spero Therapeutics Full Year 2023 Financial Results Conference Call. At this time, all participants are in a listen-only mode. Following the ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ____to____ Commission file number 001-38266 SPERO THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 46-4590683 State or other juri ...

Spero Therapeutics, Inc. (NASDAQ:SPRO) Q3 2023 Earnings Conference Call November 13, 2023 4:30 PM ET Company Participants Ted Jenkins - Vice President, Investor Relations and Strategic Finance Sath Shukla - Chief Executive Officer Kamal Hamed - Chief Medical Officer Steve Dipalma - Interim Chief Financial Officer and Treasurer Conference Call Participants Louise Chen - Cantor Fitzgerald Boobalan Pachaiyappan - H.C. Wainwright Good afternoon and welcome to the Spero Therapeutics Third Quarter 2023 Financial ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38266 SPERO THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) | Delaware | 46-4590683 | | --- | --- ...

Spero Therapeutics, Inc. (NASDAQ:SPRO) Q2 2023 Earnings Conference Call August 10, 2023 4:30 PM ET Company Participants Ted Jenkins - Vice President, Investor Relations and Strategic Finance Sath Shukla - Chief Executive Officer Kamal Hamed - Chief Medical Officer Steve Dipalma - Interim Chief Financial Officer and Treasurer Conference Call Participants Louise Chen - Cantor Boobalan Pachaiyappan - H.C. Wainwright Ritu Baral - Cowen Operator Good afternoon and welcome to the Spero Therapeutics Second Quarter ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38266 SPERO THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) | Delaware | 46-4590683 | | --- | --- | | ...

Financial Data and Key Metrics Changes - Total revenues for Q1 2023 were $2.1 million, unchanged from Q1 2022 [27] - Net loss for Q1 2023 was $13.3 million or $0.25 per share, compared to a net loss of $32.8 million or $1.01 per share in Q1 2022 [43] - Research and development expenses decreased to $9 million in Q1 2023 from $17 million in Q1 2022, primarily due to lower costs related to the tebipenem HBr program and decreased clinical activity for the SPR206 program [28] - General and administrative expenses for Q1 2023 were $7.3 million, down from $15.3 million in the same period in 2022, mainly due to reduced personnel costs and professional fees [60] Business Line Data and Key Metrics Changes - The SPR720 program is advancing as planned, with a Phase 2 proof of concept trial currently enrolling at over 15 active sites, with top-line data expected in the first half of 2024 [24] - The tebipenem HBr program is being developed in partnership with GSK, with ongoing engagement with the FDA regarding a potential Special Protocol Assessment for a planned Phase 3 trial [26] Market Data and Key Metrics Changes - The company is focusing on the NTM-PD market, where there is a significant unmet need for effective treatments, particularly for frontline patients who often fail existing therapies [45][70] - The SPR720 program aims to address the needs of early-stage NTM patients, who represent 75% of the target population [45] Company Strategy and Development Direction - The company aims to create value through the advancement of its pipeline, supported by a strong management team, industry partnerships, and a solid balance sheet [23] - The strategy includes expanding the SPR720 development program into Japan, where NTM-PD has a higher prevalence [25] - The company is also focused on developing and validating patient-reported outcomes for NTM-PD to align with FDA guidance [39] Management's Comments on Operating Environment and Future Outlook - Management expressed confidence in the progress of their clinical programs and the potential for SPR720 to meet significant medical needs [23] - The company expects to provide updates on the Special Protocol Assessment agreement and trial design by mid-2023 [40] - The management highlighted the importance of the upcoming data from the ARIKAYCE study and its potential influence on the SPR720 development plan [71] Other Important Information - The company reported having $96.3 million in cash and cash equivalents as of March 31, 2023, which is expected to be sufficient to fund operations beyond 2024 [41] Q&A Session Summary Question: What are the competitive advantages of SPR720 and upcoming inflection points with GSK? - Management highlighted the unmet need in frontline NTM treatment and the potential of SPR720 to address this gap, with expected development milestones from GSK during the Phase 3 trial [61][46] Question: Can you provide updates on enrollment progress for SPR720? - Management reiterated that they are on track for trial data in the first half of 2024 and mentioned ongoing site openings [73] Question: Will the company consider adding a fatigue scale to the PRO development? - Management confirmed that fatigue will be assessed in studies, including the use of the PROMIS scale in the ongoing Phase 2a study [51]

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38266 SPERO THERAPEUTICS, INC. (Registrant's telephone number, including area code) Securities registered pursuant to Section 1 ...

Financial Data and Key Metrics Changes - Total revenues for Q4 2022 were $47.4 million, a significant increase from $2.7 million in Q4 2021, primarily due to $46.1 million in collaboration revenue from agreements with GSK and Pfizer [29] - Total revenue for the year ended December 31, 2022, was $53.5 million compared to $18.3 million for the year ended December 31, 2021, again driven by partnership collaboration revenue [30] - Net income for Q4 2022 was $26.8 million, while the full year net loss was $46.4 million, translating to a net income of $0.55 and a net loss of $1.23 per share, compared to net losses of $29.2 million and $89.8 million in Q4 2021 and the full year 2021, respectively [33] Business Line Data and Key Metrics Changes - The company is developing tebipenem HBr as a potential first oral carbapenem antibiotic for complicated urinary tract infections (cUTI), with an exclusive license agreement with GSK that includes a $66 million upfront payment and eligibility for up to $525 million in development and sales milestone payments [8][9] - SPR720 is being developed as a first-line treatment for nontuberculous mycobacterial pulmonary disease (NTM-PD), with a Phase IIa clinical trial initiated to establish proof of concept [20][22] Market Data and Key Metrics Changes - The target patient population for SPR720 consists of treatment-naive patients or those with nonrefractory disease, addressing a significant unmet need as there are currently no FDA-approved first-line therapies for NTM-PD [16][18] - The company aims to provide an at-home oral treatment for cUTI patients, potentially improving health outcomes and reducing costs for the healthcare system [13][14] Company Strategy and Development Direction - The company remains committed to developing a pipeline of medicines that address unmet needs with high commercial potential while emphasizing capital efficiency [7] - The partnership with GSK is seen as a strong foundation for advancing tebipenem HBr through the regulatory process, with expectations for commercialization by 2026 if successful [11][12] Management's Comments on Operating Environment and Future Outlook - Management expressed confidence in the cash runway, indicating that the current cash and equivalents, along with nondilutive funding commitments, will be sufficient to fund operations beyond 2024 [34] - The company anticipates providing updates on its engagement with the FDA regarding tebipenem HBr in the first half of the year, including details on clinical trial design and regulatory activities [11] Other Important Information - Restructuring expenses of $11.6 million were incurred in 2022, primarily due to severance and other employee costs, as well as contract termination fees [32] - The company has a strong balance sheet and is actively engaging with the FDA for its clinical trials [7][10] Q&A Session Summary Question: Will the cash balance take the company to the 720 Phase II readout? - Management confirmed that the cash balance is expected to be sufficient to cover expenses until the top-line data readout for SPR720 in the first half of 2024 [42] Question: If SPR720 is approved for NTM, where does the company expect to fit into the treatment paradigm? - Management indicated that SPR720 aims to be a first-line treatment for patients early in their disease journey, addressing a significant unmet need as current options often lead to discontinuation due to tolerability issues [40] Question: How should the company think about operating expenses relative to 2022? - Management noted that the operating expenses run rate is similar to the previous quarter, with expectations for an increase in R&D expenses as new programs are initiated, but these will be offset by milestone payments from partners [44][45]

Product Development and Regulatory Approval - The company currently has no products approved for sale and has invested a significant portion of its resources in the development of tebipenem HBr for treating bacterial infections causing cUTI[218]. - The timeline for obtaining FDA approval for tebipenem HBr may impact its commercialization attractiveness through the partnership with GSK[218]. - Clinical trials are expensive and can take many years to complete, with inherent uncertainties regarding outcomes[219]. - The company may face significant setbacks in clinical trials, even after promising results in earlier studies[220]. - Variability in safety and efficacy results can occur between different trials of the same product candidate due to various factors[222]. - Delays in patient enrollment for clinical trials could significantly increase development costs and slow down the approval process[228]. - The company may incur additional unplanned costs and face delays in obtaining marketing approval for its product candidates[225]. - Serious adverse events or undesirable side effects could lead to interruptions or halts in clinical trials, affecting regulatory approval[232]. - The company may need to abandon product development or limit it to specific uses if unexpected adverse events occur during trials[233]. - Regulatory authorities may impose additional requirements or withdraw approvals if serious adverse events are identified post-marketing[235]. - The lengthy review process and unpredictability of clinical trial results may result in failure to obtain regulatory approval, significantly harming the company's business and financial condition[358]. - The company has limited experience in filing applications for marketing approvals and relies on third-party contract research organizations for assistance[354]. - The FDA's approval policies and requirements for clinical data may change during the development of product candidates, impacting the approval process[355]. - The company has not obtained regulatory approval for any product candidate to date, and it is possible that none of its future candidates will receive approval[356]. - The company faces challenges in obtaining marketing approvals in international jurisdictions, which may delay or prevent the marketing of product candidates abroad[369]. - Regulatory approvals, if granted, will require ongoing compliance and could lead to significant additional expenses for the company[370]. - Marketing approvals may come with limitations on indicated uses and may require costly post-marketing testing and surveillance[371]. - The FDA imposes stringent regulations on post-approval marketing and promotion, and non-compliance could lead to enforcement actions[372]. Financial Condition and Capital Requirements - The company reported a net loss of $46.4 million for the year ended December 31, 2022, with no revenue generated from product sales since its inception in 2013[272]. - The company expects to incur significant expenses and increasing operating losses for the foreseeable future as it advances product candidates through preclinical and clinical development[274]. - The company believes its existing cash and cash equivalents will fund operating expenses for at least 12 months from the issuance of the financial statements, with a cash runway sufficient to extend beyond 2024[273][279]. - The company has a history of losses and anticipates substantial future losses, which could adversely affect stockholders' equity and working capital[276]. - The company may need to raise additional capital through equity or debt financings, collaborations, or grant funding to continue operations[273][278]. - The company has not maintained insurance for environmental liability or toxic tort claims, which may expose it to significant costs[260]. - The company has received an upfront payment of $66 million from GSK for securing rights to tebipenem HBr, with potential milestone payments totaling approximately $150 million for development milestones[316]. - The company is obligated to pay future milestone payments of up to $1 million upon achieving specified regulatory milestones for tebipenem HBr[315]. - As of December 31, 2022, the company had net operating loss carryforwards (NOLs) of $291.9 million federally, $282.9 million at the state level, and $4.6 million internationally[284]. - The federal NOLs of $73.0 million will expire between 2033 and 2037, while approximately $218.9 million can be carried forward indefinitely[284]. - The company filed a universal shelf registration statement with the SEC for the sale of up to $300.0 million in various securities, including $75.0 million of common stock available for issuance[281]. - The company may seek additional capital through public or private equity offerings, debt financings, collaborations, and government funding arrangements[282]. - The company has broad discretion in the use of cash reserves, which may not be applied effectively, risking financial losses and impacting stock price[407]. - The company does not anticipate paying any cash dividends in the foreseeable future, relying on capital appreciation for stockholder returns[413]. Market Competition and Commercialization Challenges - The company may face challenges in achieving market acceptance for its product candidates, which could adversely affect commercial success and revenue generation[236]. - Competition from major pharmaceutical and biotechnology companies is significant, with competitors potentially developing more effective or less costly products[243]. - Tebipenem HBr, if approved, may face competition from established therapies like Levaquin and Cipro, which could impact its market position[244]. - The company anticipates that some product candidates will be administered in hospital settings, where reimbursement challenges may affect adoption[249]. - Coverage and reimbursement from government programs and third-party payors are critical for the commercial success of outpatient products[250]. - The emergence of bacterial resistance to product candidates could significantly impact their revenue potential[252]. - The company aims to discover and develop a portfolio of therapeutics for drug-resistant infections, which is essential for its growth strategy[254]. - Product liability lawsuits could divert resources and limit commercialization efforts, posing a significant risk to the company[256]. Operational Risks and Compliance - The company is subject to numerous environmental, health, and safety laws, and non-compliance could result in substantial fines or penalties[259][261]. - The company faces risks related to cybersecurity threats that could disrupt product development programs and lead to liability[262][263]. - The COVID-19 pandemic has adversely impacted the company's operations, including preclinical studies and clinical trials, with ongoing monitoring of its effects[270][271]. - The company relies on third parties for conducting all nonclinical studies and clinical trials, which poses risks if these parties do not meet their obligations[300]. - The company may face significant competition in securing collaborations for product development and commercialization[293]. - The company is subject to audits by U.S. government agencies, and negative outcomes could impact its business operations[327]. - The company must register clinical trials and post results on ClinicalTrials.gov, with non-compliance potentially leading to fines and adverse publicity[1]. - The company faces potential civil and criminal penalties, including contract termination and fines, if audits reveal improper cost allocations or illegal activities[328]. - Changes in government contracting laws and regulations could adversely affect the company's ability to maintain existing contracts and secure new ones, impacting operational results[331]. - The company may lose profits and face suspension of payments if contracts are terminated due to violations of laws or regulations[332]. - The company is exposed to risks of misconduct by employees and third parties, which could lead to regulatory sanctions and harm its reputation[387]. - The company has undertaken internal restructuring activities that may disrupt its business and adversely affect its financial condition[394]. - The company is at risk of losing key executives, which could significantly harm its ability to implement its business strategy[393]. Intellectual Property and Legal Risks - The company’s intellectual property rights may be affected by government contracts, particularly those funded by BARDA, which could grant the government certain rights to patents[334]. - The company’s ability to protect its proprietary technology through patents is uncertain, with potential challenges from competitors leading to loss of competitive advantage[335]. - The patent application process is costly and time-consuming, and the company may not be able to secure necessary patent protections in a timely manner[335]. - The company may face litigation regarding its patents, which could be expensive and time-consuming, potentially affecting its competitive position[342]. - The company could be forced to cease development or commercialization of products if found to infringe third-party intellectual property rights[346]. - Claims of misappropriation of intellectual property by the company or its employees could lead to costly litigation and distract management[347]. - The company may struggle to enforce ownership of intellectual property if agreements with employees and contractors are not successfully executed[348]. Corporate Governance and Stockholder Matters - The company reduced its workforce from 146 full-time employees as of December 31, 2021, to 41 full-time employees by the end of Q2 2022 following a restructuring[392]. - The company received a deficiency letter from Nasdaq on August 8, 2022, due to the closing bid price of its common stock being below the $1.00 requirement for 30 consecutive trading days[400]. - The company regained compliance with the Nasdaq Bid Price Requirement on October 6, 2022, after the closing bid price was at least $1.00 per share for a minimum of 10 consecutive trading days[400]. - The company is subject to increased costs and compliance requirements as a public entity, impacting operational efficiency[409]. - The market value of the company's common stock held by non-affiliates must remain below $250 million to qualify as a smaller reporting company, affecting disclosure requirements[408]. - The company has issued a total of 3,215,000 shares of Series D Convertible Preferred Stock, convertible on a one-to-one basis into common stock[406]. - The exclusive forum provision in the corporate charter may limit stockholder rights in certain legal actions, creating uncertainty[416]. - Provisions in the corporate charter may hinder beneficial acquisitions and complicate management changes, potentially depressing stock price[414]. - The company has not declared or paid cash dividends historically, indicating a focus on reinvestment rather than shareholder payouts[413].