Security
Spero Therapeutics, Inc. Common Stock · SPRO
SPRONASDAQCommon stockCurrentCIK 1701108Updated Oct 29, 2026
Name history
Spero Therapeutics, LLC · through Mar 21, 2017
SPRO price & chart
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NASDAQ:SPRO on TradingView ↗About the company
Spero Therapeutics is a clinical-stage biopharmaceutical company focused on advancing next-generation medicines for patients with serious immune-mediated diseases. The company’s lead program, SP001, is a third-generation, Fc-silent anti-CD40L monoclonal antibody being advanced first in IgG4-related disease, with potential for development in additional immunological & inflammatory diseases. For more information, visit www.sperotx.com.
In the news
Spero Therapeutics Announces $105 Million Non-Recourse Non-Dilutive Financing Backed by a Portion of Utebzi Milestones & Royalties ↗
Recent filings
S-8 filing
Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements
Items 5.02
EFFECT filing
Entry into a Material Definitive Agreement · Other Events
Items 1.01, 8.01, 9.01
S-3 filing
Show 5 more recent filings
Results of Operations and Financial Condition
Items 2.02, 9.01
10-Q filing
Entry into a Material Definitive Agreement · Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement · Regulation FD Disclosure · Other Events
Items 1.01, 2.03, 7.01, 8.01, 9.01
4 filing
4 filing
Financials
FY 2025 · USDSource
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balance sheet · annual statements
| Line item | Q3 2025 | Q3 2024 | Q2 2026 | Q2 2025 | Q2 2024 | Q1 2026 | Q1 2025 | Q1 2024 | FY 2025 | FY 2024 | FY 2023 | FY 2022 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ASSETS | ||||||||||||
| AssetsUSD | 54,170,000Source | 135,161,000Source | 52,766,000Source | 62,119,000Source | 149,881,000Source | 59,021,000Source | 77,709,000Source | 167,703,000Source | 68,919,000Source | 110,543,000Source | 182,390,000Source | 124,802,000Source |
| Property, Plant and Equipment, NetUSD | — | 0Source | — | — | 0Source | — | — | 2,000Source | — | 0Source | 2,000Source | 368,000Source |
| Current assets: | ||||||||||||
| Cash and Cash Equivalents, at Carrying ValueUSD | 48,616,000Source | 76,290,000Source | 50,774,000Source | 31,194,000Source | 63,527,000Source | 56,129,000Source | 48,887,000Source | 82,271,000Source | 40,265,000Source | 52,889,000Source | 76,333,000Source | 109,107,000Source |
| Assets, CurrentUSD | 52,323,000Source | 131,627,000Source | 51,584,000Source | 59,402,000Source | 122,218,000Source | 57,612,000Source | 74,714,000Source | 140,154,000Source | 67,286,000Source | 107,276,000Source | 131,208,000Source | 113,570,000Source |
| Prepaid Expense and Other Assets, CurrentUSD | 1,248,000Source | 2,055,000Source | 785,000Source | 1,295,000Source | 3,196,000Source | 1,439,000Source | 1,548,000Source | 3,668,000Source | 1,634,000Source | 1,911,000Source | 4,178,000Source | 3,379,000Source |
| Operating Lease, Right-of-Use AssetUSD | 1,694,000Source | 3,381,000Source | 1,029,000Source | 2,564,000Source | 3,644,000Source | 1,256,000Source | 2,842,000Source | 3,902,000Source | 1,480,000Source | 3,114,000Source | 4,155,000Source | 5,124,000Source |
| Other Assets, NoncurrentUSD | 153,000Source | 153,000Source | 153,000Source | 153,000Source | 434,000Source | 153,000Source | 153,000Source | 434,000Source | 153,000Source | 153,000Source | 435,000Source | 5,740,000Source |
| LIABILITIES AND EQUITY | ||||||||||||
| LiabilitiesUSD | 27,676,000Source | 69,654,000Source | 8,562,000Source | 29,291,000Source | 69,381,000Source | 6,087,000Source | 43,895,000Source | 71,454,000Source | 9,898,000Source | 64,420,000Source | 75,496,000Source | 48,868,000Source |
| Stockholders’ equity: | ||||||||||||
| Preferred Stock, Value, IssuedUSD | 0Source | 0Source | 0Source | 0Source | 0Source | 0Source | 0Source | 0Source | 0Source | 0Source | 0Source | 0Source |
| Common Stock, Value, IssuedUSD | 56,000Source | 54,000Source | 58,000Source | 56,000Source | 54,000Source | 58,000Source | 56,000Source | 54,000Source | 56,000Source | 55,000Source | 53,000Source | 52,000Source |
| Retained Earnings (Accumulated Deficit)USD | -482,586,000Source | -438,750,000Source | -467,821,000Source | -475,204,000Source | -421,603,000Source | -458,269,000Source | -473,504,000Source | -403,741,000Source | -451,066,000Source | -459,638,000Source | -391,072,000Source | -413,878,000Source |
| Accumulated Other Comprehensive Income (Loss), Net of TaxUSD | — | — | — | — | — | — | — | — | — | — | 0Source | 0Source |
| Stockholders' Equity Attributable to ParentUSD | 26,494,000Source | 65,507,000Source | 44,204,000Source | 32,828,000Source | 80,500,000Source | 52,934,000Source | 33,814,000Source | 96,249,000Source | 59,021,000Source | 46,123,000Source | 106,894,000Source | 75,934,000Source |
| Additional Paid in Capital, Common StockUSD | 509,024,000Source | 504,203,000Source | 511,967,000Source | 507,976,000Source | 502,049,000Source | 511,145,000Source | 507,262,000Source | 499,936,000Source | 510,031,000Source | 505,706,000Source | 497,913,000Source | 489,760,000Source |
| Liabilities and EquityUSD | 54,170,000Source | 135,161,000Source | 52,766,000Source | 62,119,000Source | 149,881,000Source | 59,021,000Source | 77,709,000Source | 167,703,000Source | 68,919,000Source | 110,543,000Source | 182,390,000Source | 124,802,000Source |
| Current liabilities: | ||||||||||||
| Liabilities, CurrentUSD | 13,649,000Source | 49,096,000Source | 8,428,000Source | 14,945,000Source | 45,633,000Source | 5,489,000Source | 29,155,000Source | 41,821,000Source | 8,868,000Source | 49,074,000Source | 37,153,000Source | 21,649,000Source |
| Operating Lease, Liability, CurrentUSD | 1,899,000Source | 1,739,000Source | 2,000,000Source | 1,844,000Source | 1,732,000Source | 1,967,000Source | 1,795,000Source | 1,725,000Source | 1,956,000Source | 1,746,000Source | 1,718,000Source | 1,690,000Source |
| Accounts Payable, CurrentUSD | 1,395,000Source | 6,090,000Source | 155,000Source | 780,000Source | 2,696,000Source | 217,000Source | 1,765,000Source | 3,066,000Source | 693,000Source | 7,306,000Source | 1,378,000Source | 617,000Source |
| Operating Lease, Liability, NoncurrentUSD | 1,452,000Source | 2,883,000Source | 43,000Source | 1,771,000Source | 3,206,000Source | 507,000Source | 2,165,000Source | 3,519,000Source | 939,000Source | 2,551,000Source | 3,825,000Source | 4,957,000Source |
| Additional Financial Items | ||||||||||||
| Deferred Revenue, CurrentUSD | 0Source | 788,000Source | — | 0Source | 3,663,000Source | — | 0Source | 2,868,000Source | 0Source | 368,000Source | 2,132,000Source | 10,369,000Source |
| Deferred Revenue, NoncurrentUSD | 12,575,000Source | 11,850,000Source | — | 12,575,000Source | 9,040,000Source | — | 12,575,000Source | 9,948,000Source | 0Source | 12,219,000Source | 10,825,000Source | 22,166,000Source |
| Deferred Tax Liabilities, NetUSD | — | — | — | — | — | — | — | — | 388,000Source | — | — | — |
cash flow · annual statements
| Line item | Q4 2025 | Q4 2024 | Q3 2025 | Q3 2024 | Q2 2026 | Q2 2025 | Q1 2026 | Q1 2025 | FY 2025 | FY 2024 | FY 2023 | FY 2022 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cash flows from operating activities: | ||||||||||||
| Net Income (Loss), Including Portion Attributable to Noncontrolling InterestUSD | — | — | -7,382,000Source | -17,147,000Source | -9,552,000Source | -1,700,000Source | -7,203,000Source | -13,866,000Source | 8,572,000Source | -68,566,000Source | 22,806,000Source | -46,415,000Source |
| Adjustments to reconcile net income to net cash provided by operating activities: | ||||||||||||
| Depreciation, Depletion and AmortizationUSD | — | — | — | — | — | — | — | — | 0Source | 2,000Source | 367,000Source | 869,000Source |
| Share-based Payment Arrangement, Noncash ExpenseUSD | — | — | 1,048,000Source | 2,154,000Source | 822,000Source | 714,000Source | 1,114,000Source | 1,556,000Source | 4,325,000Source | 7,793,000Source | 7,932,000Source | 9,123,000Source |
| Changes in operating assets and liabilities: | ||||||||||||
| Increase (Decrease) in Accounts PayableUSD | — | — | — | — | — | — | -476,000Source | -5,541,000Source | -6,613,000Source | 5,928,000Source | 761,000Source | -484,000Source |
| Deferred Income Tax Expense (Benefit)USD | — | — | — | — | — | — | — | — | — | 0Source | 0Source | — |
| Net Cash Provided by (Used in) Operating ActivitiesUSD | — | — | — | — | — | — | 15,864,000Source | -4,002,000Source | -12,624,000Source | -23,444,000Source | -32,995,000Source | -7,731,000Source |
| Cash flows from investing activities: | ||||||||||||
| Net Cash Provided by (Used in) Investing ActivitiesUSD | — | — | — | — | — | — | — | — | — | — | 0Source | 33,807,000Source |
| Cash flows from financing activities: | ||||||||||||
| Net Cash Provided by (Used in) Financing ActivitiesUSD | — | — | — | — | — | — | — | — | — | 0Source | 221,000Source | -29,553,000Source |
| Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate EffectUSD | — | — | — | — | — | — | 15,864,000Source | -4,002,000Source | -12,624,000Source | -23,444,000Source | -32,774,000Source | -3,477,000Source |
| Additional Financial Items | ||||||||||||
| Share-based Payment Arrangement, ExpenseUSD | — | — | — | — | — | — | — | — | — | — | 100,000Source | 1,000,000Source |
| Derivative, Gain (Loss) on Derivative, NetUSD | — | — | — | — | — | — | — | — | — | — | 0Source | 917,000Source |
| Foreign Currency Transaction Gain (Loss), before TaxUSD | — | — | — | — | — | — | — | — | — | — | 0Source | -10,000Source |
| Gain (Loss) on Sale of DerivativesUSD | — | — | — | — | — | — | — | — | — | — | 0Source | 917,000Source |
| Gain (Loss) on Extinguishment of DebtUSD | — | — | — | — | — | — | — | — | — | — | 0Source | -3,581,000Source |
| General and Administrative ExpenseUSD | — | — | 4,174,000Source | 5,198,000Source | 6,492,000Source | 5,878,000Source | 4,887,000Source | 6,824,000Source | 21,176,000Source | 23,704,000Source | 25,554,000Source | 36,483,000Source |
| Income Tax Expense (Benefit)USD | — | — | 0Source | 290,000Source | — | — | — | — | 261,000Source | 0Source | 2,598,000Source | 0Source |
| Investment Income, InterestUSD | — | — | 532,000Source | 1,182,000Source | 377,000Source | 740,000Source | 336,000Source | 864,000Source | 2,512,000Source | 4,735,000Source | 3,937,000Source | 1,106,000Source |
| Net Income (Loss) Attributable to ParentUSD | — | — | -7,382,000Source | -17,147,000Source | -9,552,000Source | -1,700,000Source | -7,203,000Source | -13,866,000Source | 8,572,000Source | -68,566,000Source | — | — |
| Net Income (Loss) Available to Common Stockholders, BasicUSD | — | — | — | -17,147,000Source | — | — | — | — | — | — | — | 46,415,000Source |
| Nonoperating Income (Expense)USD | — | — | 534,000Source | 1,156,000Source | 374,000Source | 744,000Source | 335,000Source | 865,000Source | 2,519,000Source | 4,795,000Source | 3,923,000Source | -4,218,000Source |
| Operating ExpensesUSD | — | — | 13,358,000Source | 32,062,000Source | 9,926,000Source | 16,633,000Source | 7,796,000Source | 20,605,000Source | 60,488,000Source | 121,338,000Source | 82,300,000Source | 95,706,000Source |
| Other Nonoperating Income (Expense)USD | — | — | 2,000Source | -26,000Source | -3,000Source | 4,000Source | -1,000Source | 1,000Source | 7,000Source | 60,000Source | -14,000Source | -55,000Source |
| Proceeds from Issuance of Common StockUSD | — | — | — | — | — | — | — | — | — | 0Source | — | — |
| Proceeds from Stock Options ExercisedUSD | — | — | — | — | — | — | — | — | — | — | 0Source | 420,000Source |
| Restructuring CostsUSD | — | — | — | — | — | — | — | — | 1,100,000Source | — | — | — |
income statement · annual statements
| Line item | Q4 2025 | Q4 2024 | Q3 2025 | Q3 2024 | Q2 2026 | Q2 2025 | Q1 2026 | Q1 2025 | FY 2025 | FY 2024 | FY 2023 | FY 2022 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Total RevenueUSD | — | — | 0Source | 13,469,000Source | 0Source | 0Source | 0Source | 5,874,000Source | 66,802,000Source | 47,977,000Source | 103,781,000Source | 48,579,000Source |
| Operating Income (Loss)USD | — | — | -7,916,000Source | -18,593,000Source | -9,926,000Source | -2,444,000Source | -7,538,000Source | -14,731,000Source | 6,314,000Source | -73,361,000Source | 21,481,000Source | -42,197,000Source |
| Other Nonoperating Income (Expense)USD | — | — | 2,000Source | -26,000Source | -3,000Source | 4,000Source | -1,000Source | 1,000Source | 7,000Source | 60,000Source | -14,000Source | -55,000Source |
| Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling InterestUSD | — | — | — | — | — | — | — | — | 8,833,000Source | -68,566,000Source | 25,404,000Source | -46,415,000Source |
| Income Tax Expense (Benefit)USD | — | — | 0Source | 290,000Source | — | — | — | — | 261,000Source | 0Source | 2,598,000Source | 0Source |
| Net Income (Loss) Attributable to ParentUSD | — | — | -7,382,000Source | -17,147,000Source | -9,552,000Source | -1,700,000Source | -7,203,000Source | -13,866,000Source | 8,572,000Source | -68,566,000Source | — | — |
| Earnings Per Share, BasicUSD per share | — | — | -0.13Source | -0.32Source | -0.16Source | -0.03Source | -0.13Source | -0.25Source | 0.15Source | -1.27Source | 0.43Source | -1.23Source |
| Earnings Per Share, DilutedUSD per share | — | — | -0.13Source | -0.32Source | -0.16Source | -0.03Source | -0.13Source | -0.25Source | 0.15Source | -1.27Source | 0.43Source | -1.23Source |
| Weighted Average Number of Shares Outstanding, Basicshares | — | — | 56,280,844Source | 54,124,862Source | 57,968,608Source | 56,026,767Source | 57,281,570Source | 55,376,188Source | 56,020,363Source | 54,037,917Source | 52,703,467Source | 37,585,075Source |
| Weighted Average Number of Shares Outstanding, Dilutedshares | — | — | 56,280,844Source | 54,124,862Source | 57,968,608Source | 56,026,767Source | 57,281,570Source | 55,376,188Source | 59,039,225Source | 54,037,917Source | 52,989,030Source | 37,585,075Source |
| Additional Financial Items | ||||||||||||
| Current Income Tax Expense (Benefit)USD | — | — | — | — | — | — | — | — | 261,000Source | 0Source | 2,598,000Source | — |
| Foreign Currency Transaction Gain (Loss), before TaxUSD | — | — | — | — | — | — | — | — | — | — | 0Source | -10,000Source |
| General and Administrative ExpenseUSD | — | — | 4,174,000Source | 5,198,000Source | 6,492,000Source | 5,878,000Source | 4,887,000Source | 6,824,000Source | 21,176,000Source | 23,704,000Source | 25,554,000Source | 36,483,000Source |
| Income (Loss) from Continuing Operations before Income Taxes, DomesticUSD | — | — | — | — | — | — | — | — | 8,833,000Source | -68,566,000Source | 25,404,000Source | -46,249,000Source |
| Investment Income, InterestUSD | — | — | 532,000Source | 1,182,000Source | 377,000Source | 740,000Source | 336,000Source | 864,000Source | 2,512,000Source | 4,735,000Source | 3,937,000Source | 1,106,000Source |
| Net Income (Loss) Available to Common Stockholders, BasicUSD | — | — | — | -17,147,000Source | — | — | — | — | — | — | — | 46,415,000Source |
| Nonoperating Income (Expense)USD | — | — | 534,000Source | 1,156,000Source | 374,000Source | 744,000Source | 335,000Source | 865,000Source | 2,519,000Source | 4,795,000Source | 3,923,000Source | -4,218,000Source |
| Operating ExpensesUSD | — | — | 13,358,000Source | 32,062,000Source | 9,926,000Source | 16,633,000Source | 7,796,000Source | 20,605,000Source | 60,488,000Source | 121,338,000Source | 82,300,000Source | 95,706,000Source |
| Research and Development ExpenseUSD | — | — | 8,597,000Source | 26,864,000Source | 3,434,000Source | 10,672,000Source | 2,909,000Source | 13,606,000Source | 38,467,000Source | 96,757,000Source | 51,440,000Source | 47,593,000Source |
| Restructuring CostsUSD | — | — | — | — | — | — | — | — | 1,100,000Source | — | — | — |
Offerings
Registration 333-298641
Filing attachments
d12478dex991.htm · S-8 · 2026-10-28
Exhibit 99.1 SPERO THERAPEUTICS, INC. Amended and Restated 2019 Inducement Equity Incentive Plan (As Amended and Restated on September 25, 2026) DEFINITIONS. Unless otherwise specified or unless the context otherwise requires, the following terms, as used in this Spero Therapeutics, Inc. 2019 Inducement Equity Incentive Plan, have the following meanings: Administrator means the Board of Directors, unless it has delegated power to act on its behalf to the Committee, in which case the term…
Read attachment ↗d48582dex410.htm · S-3 · 2026-08-28
Exhibit 4.10 SPERO THERAPEUTICS, INC. and Trustee INDENTURE Dated as of _______________ SUBORDINATED DEBT SECURITIES CROSS-REFERENCE TABLE 1 Section of Trust Indenture Act Section of Indenture of 1939, as amended ──────────────────────────────────────────────────── 310(a) 6.09 310(b) 6.086.10 310(c) Inapplicable 311(a) …
Read attachment ↗d48582dex411.htm · S-3 · 2026-08-28
Exhibit 4.11 Form of Senior Note (FACE OF SECURITY) [Each Global Security shall bear substantially the following legend: UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR SECURITIES IN DEFINITIVE REGISTERED FORM, THIS SECURITY MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF …
Read attachment ↗d48582dex412.htm · S-3 · 2026-08-28
Exhibit 4.12 Form of Subordinated Note (FACE OF SECURITY) [Each Global Security shall bear substantially the following legend: UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR SECURITIES IN DEFINITIVE REGISTERED FORM, THIS SECURITY MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMIN…
Read attachment ↗d48582dex49.htm · S-3 · 2026-08-28
Exhibit 4.9 SPERO THERAPEUTICS, INC. and Trustee INDENTURE Dated as of _______________ SENIOR DEBT SECURITIES CROSS-REFERENCE TABLE1 Section of Section of Trust Indenture Act Indenture of 1939, as amended ───────────────────────────────────────── 310(a) 6.09 310(b) 6.08 6.10 310(c) Inapplicable 311(a) 6.13 311(b) 6.13 311(c) …
Read attachment ↗d69249dex991.htm · 8-K · 2026-08-12
EX-99.1 2 d69249dex991.htm EX-99.1 EX-99.1 Exhibit 99.1 Spero Therapeutics Announces Second Quarter 2026 Operating Results and Provides Business Update Entered an exclusive license agreement with Innovent Biologics for SP001, a Phase 2-ready, third-generation anti-CD40L antibody for immune-mediated diseases U.S. Food and Drug Administration approved Utebzi™ (tebipenem pivoxil), the first and only oral carbapenem antibiotic for adults with complicated urinary tract infections (cUTIs…
Read attachment ↗