Spero Therapeutics Announces First Quarter 2026 Operating Results and Provides Business Update
Rhea-AI Summary
Spero Therapeutics (Nasdaq: SPRO) reported first quarter 2026 results and a business update. The NDA for tebipenem HBr for cUTI, including pyelonephritis, is under FDA review with a PDUFA date of June 18, 2026.
Q1 2026 net loss was $7.2 million (vs. $13.9 million in Q1 2025), or $0.13 diluted net loss per share (vs. $0.25). Revenue was $0.3 million (vs. $5.9 million). R&D expenses fell to $2.9 million and G&A to $4.9 million. Cash and equivalents were $56.1 million, and Spero reiterates cash runway guidance into 2028.
AI-generated analysis. Not financial advice.
Positive
- Tebipenem HBr NDA under FDA review with June 18, 2026 PDUFA
- Phase 3 PIVOT-PO trial stopped early for efficacy in 2025
- Q1 2026 net loss reduced to $7.2 million from $13.9 million
- Q1 2026 R&D expenses down to $2.9 million from $13.6 million
- Q1 2026 G&A expenses down to $4.9 million from $6.8 million
- Cash and equivalents $56.1 million; runway guidance maintained into 2028
Negative
- Q1 2026 revenue declined to $0.3 million from $5.9 million
- Company remains loss-making with $7.2 million Q1 2026 net loss
News Market Reaction – SPRO
On the day this news was published, SPRO gained 13.11%, reflecting a significant positive market reaction. Argus tracked a peak move of +8.5% during that session. Our momentum scanner triggered 17 alerts that day, indicating notable trading interest and price volatility. This price movement added approximately $18M to the company's valuation, bringing the market cap to $158.94M at that time. Trading volume was very high at 3.2x the daily average, suggesting strong buying interest.
Data tracked by StockTitan Argus on the day of publication.
Key Figures
Market Reality Check
Peers on Argus
Momentum scanner shows only ARMP in action, moving down, while other biotech peers show mixed standalone moves (e.g., MGNX and ZNTL up, ATOS down). This points to stock-specific drivers for SPRO rather than a unified sector trend.
Previous Earnings Reports
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Mar 26 | Q4 2025 results | Positive | -1.7% | Reported 2025 net income, higher revenue and reiterated tebipenem HBr PDUFA date. |
| Nov 13 | Q3 2025 results | Positive | -1.2% | Phase 3 PIVOT-PO success and planned FDA submission, with reduced net loss. |
| Aug 12 | Q2 2025 results | Negative | -18.0% | Trial success but program suspension and prior trial failure weighed on outlook. |
| May 13 | Q1 2025 results | Negative | -5.8% | Higher net loss, lower revenue and reminder of suspended SPR720 program. |
| Mar 27 | FY 2024 results | Negative | -10.9% | Large annual loss, steep revenue drop and discontinuation of pipeline programs. |
Earnings-related releases have historically skewed negative for SPRO, with an average move of -7.52% and 3 of 5 past earnings events seeing price moves aligned with generally cautious or negative fundamentals.
Over the last five earnings cycles, Spero’s story has centered on tebipenem HBr and a shift toward this single lead asset. Earlier results highlighted Phase 3 success, NDA resubmission, and an FDA PDUFA date of June 18, 2026, alongside shrinking losses and extended cash runway into 2028. Despite operational progress and milestones, shares often traded lower on earnings days, especially when updates included program discontinuations or weaker revenue trends.
Historical Comparison
Across the last five earnings releases, SPRO’s average move was about -7.52%, with shares often reacting negatively even when tebipenem HBr progress and cash runway extensions were highlighted.
Earnings updates show a progression from planning a Phase 3 interim analysis in 2024, to PIVOT-PO meeting efficacy endpoints in 2025, and then to NDA resubmission and an FDA PDUFA date of June 18, 2026, while Spero streamlines around tebipenem HBr and extends cash runway into 2028.
Market Pulse Summary
The stock surged +13.1% in the session following this news. A strong positive reaction aligns with ongoing progress around tebipenem HBr and Spero’s strengthened balance sheet. Earnings have previously averaged moves of about -7.52% on results days, so any sharp upside would contrast with that pattern. Investors may still weigh concentration risk in a single lead asset and prior pipeline cuts, which could limit how long momentum persisted after initial enthusiasm.
Key Terms
new drug application (nda) regulatory
pdufa regulatory
cUTI medical
pyelonephritis medical
phase 3 medical
carbapenem medical
clinicaltrials.gov technical
AI-generated analysis. Not financial advice.
- New Drug Application (NDA) for tebipenem HBr for complicated urinary tract infections (cUTI), including pyelonephritis, is under review at the FDA, with PDUFA date of June 18, 2026
- Spero maintains its cash runway guidance into 2028
CAMBRIDGE, Mass., May 13, 2026 (GLOBE NEWSWIRE) -- Spero Therapeutics, Inc. (Nasdaq: SPRO), a clinical-stage biopharmaceutical company focused on identifying and developing novel treatments for rare diseases and diseases with high unmet need, today announced financial results for the first quarter ended March 31, 2026, and provided a business update.
“We continue to make solid progress on the tebipenem HBr program alongside our licensing partner, GSK, as we prepare for the FDA’s decision expected in June,” said Esther Rajavelu, President and CEO of Spero Therapeutics. “With GSK's leadership in anti-infectives, tebipenem HBr, if approved, has the potential to meaningfully improve treatment options for cUTI patients. Looking ahead, we are positioning the company for the next phase by advancing other corporate activities, including exploring opportunities to grow our portfolio of clinical-stage product candidates.”
Program Update
Tebipenem HBr
Tebipenem HBr is an investigational oral carbapenem antibiotic being developed for the treatment of cUTI, including pyelonephritis, to provide an effective oral therapeutic alternative to IV carbapenems. Spero granted GSK an exclusive license to commercialize tebipenem HBr in all territories, except certain Asian territories where Meiji holds development and commercialization rights.
- In February 2026, GSK announced that the U.S. Food and Drug Association (FDA) set the Prescription Drug User Fee Act (PDUFA) date to complete the review of the tebipenem HBr NDA as June 18, 2026. The NDA was submitted by GSK in December 2025, supported by results from the Phase 3 PIVOT-PO trial. The trial was stopped early for efficacy in May 2025, demonstrating non-inferiority of tebipenem HBr compared to intravenous imipenem-cilastatin in hospitalized patients with cUTI, including pyelonephritis, based on the overall response (composite of clinical cure plus microbiological eradication of the bacteria causing the infection) at the test of cure visit.
- The safety and tolerability profile of tebipenem HBr in PIVOT-PO was consistent with results reported in other studies with tebipenem and in line with that of the carbapenem antibiotic class. The most frequently reported adverse events were diarrhea and headache; these events were all mild or moderate and non-serious.
- For more information on the PIVOT-PO trial, please refer to ClinicalTrials.gov ID NCT06059846.
First Quarter 2026 Financial Results
- Spero reported a net loss of
$7.2 million for the first quarter of 2026 compared to a net loss of$13.9 million for the first quarter of 2025, or a diluted net loss per share of common stock of$0.13 and$0.25 , respectively. - Total revenue for the first quarter of 2026 was
$0.3 million , compared to total revenue of$5.9 million for the first quarter of 2025. - Research and development expenses for the first quarter of 2026 were
$2.9 million , compared to$13.6 million of research and development expenses for the same period in 2025. The decrease was a result of decreased clinical activities related to our pivotal Phase 3 clinical trial of tebipenem HBr, which was stopped early for efficacy during the first half of 2025, and a decrease in personnel-related costs. - General and administrative expenses for the first quarter of 2026 were
$4.9 million , compared to$6.8 million of general and administrative expenses for the same period in 2025. The decrease was a result of decreased legal and personnel-related costs. - As of March 31, 2026, cash and cash equivalents were
$56.1 million . - Spero maintains its cash runway guidance into 2028.
For further details on Spero’s financials, refer to Spero’s Quarterly Report on Form 10-Q, filed with the U.S. Securities and Exchange Commission (SEC) today.
Government Agency Research Support
The views expressed in this press release are those of the authors and may not reflect the official policy or position of the Department of the Army, Department of Defense, or the U.S. Government.
Tebipenem HBr Research Support
Select tebipenem HBr studies have been funded in part with federal funds from the Department of Health and Human Services; Administration for Strategic Preparedness and Response; and Biomedical Advanced Research and Development Authority, under contract number HHSO100201800015C.
About Spero Therapeutics
Spero Therapeutics, headquartered in Cambridge, Massachusetts, is a clinical-stage biopharmaceutical company focused on identifying and developing novel treatments for rare diseases and diseases with high unmet need. For more information, visit www.sperotherapeutics.com.
Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding the potential for tebipenem HBr to meaningfully improve treatment options for cUTI patients, if approved; the anticipated PDUFA date set by the FDA as June 18, 2026; Spero’s exploration of opportunities to expand its portfolio of clinical stage product candidates; the potential of tebipenem HBr to be the first oral carbapenem antibiotic for US patients with cUTI, including pyelonephritis, and to set a new standard of care; the potential receipt of milestone payments under Spero’s license and collaboration agreements; Spero’s estimation that its cash and cash equivalents as of March 31, 2026 will be sufficient to fund operations into 2028; and the potential benefits of any of Spero’s current or future product candidates in treating patients. In some cases, forward-looking statements may be identified by terms such as “may,” “will,” “should,” “expect,” “plan,” “aim,” “anticipate,” “could,” “intent,” “target,” “project,” “contemplate,” “believe,” “estimate,” “predict,” “potential” or “continue,” the negative of these terms or other similar expressions. Any forward-looking statements in this press release are based on management’s current expectations and beliefs and are subject to a number of important risks, uncertainties and other factors that may cause actual results to differ materially from those indicated by such forward looking statements, including whether the FDA will ultimately approve tebipenem HBr and, if so, the timing of any such approval, taking into account the effects of possible regulatory delays; whether the FDA will require any additional clinical data or place labeling restrictions on the use of tebipenem HBr that would delay approval and/or reduce the commercial prospects of tebipenem HBr; whether a successful commercial launch can be achieved and market acceptance of tebipenem HBr can be established; Spero’s reliance on third parties to manufacture, develop, and commercialize its product candidates, if approved; Spero’s reliance on GSK, pursuant to the exclusive GSK License Agreement, to advance development of tebipenem HBr and GSK’s right thereunder to determine, in its sole discretion, whether to further develop and commercialize tebipenem HBr; Spero’s need for additional funding; Spero’s ability to retain key personnel; whether Spero’s cash resources will be sufficient to fund its continuing operations for the periods anticipated; and other factors discussed in the “Risk Factors” set forth in filings that Spero periodically makes with the SEC. The forward-looking statements included in this press release represent Spero’s views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date. Except as required by law, Spero explicitly disclaims any obligation to update any forward-looking statements.
Investor Relations Contact:
Shai Biran, PhD
Spero Therapeutics
IR@Sperotherapeutics.com
Media Inquiries:
media@sperotherapeutics.com
-- Tables –
| Condensed Consolidated Balance Sheet Data | |||||||||
| (in thousands) | |||||||||
| (unaudited) | |||||||||
| March 31, | December 31, | ||||||||
| 2026 | 2025 | $ Change | |||||||
| Cash and cash equivalents | $ | 56,129 | $ | 40,265 | $ | 15,864 | |||
| Other assets | 2,892 | 28,654 | (25,762 | ) | |||||
| Total assets | $ | 59,021 | $ | 68,919 | $ | (9,898 | ) | ||
| Total liabilities | 6,087 | 9,898 | (3,811 | ) | |||||
| Total stockholder's equity | 52,934 | 59,021 | (6,087 | ) | |||||
| Total liabilities and stockholders' equity | $ | 59,021 | $ | 68,919 | $ | (9,898 | ) | ||
| Spero Therapeutics, Inc. | |||||||||||
| Condensed Consolidated Statements of Operations | |||||||||||
| (in thousands, except share and per share data) | |||||||||||
| (unaudited) | |||||||||||
| Three Months Ended March 31, | |||||||||||
| 2026 | 2025 | $ Change | |||||||||
| Revenues: | |||||||||||
| Grant revenue | $ | — | $ | 763 | $ | (763 | ) | ||||
| Collaboration revenue - related party | 258 | 5,099 | (4,841 | ) | |||||||
| Collaboration revenue | — | 12 | (12 | ) | |||||||
| Total revenues | 258 | 5,874 | (5,616 | ) | |||||||
| Operating expenses: | |||||||||||
| Research and development | 2,909 | 13,606 | (10,697 | ) | |||||||
| General and administrative | 4,887 | 6,824 | (1,937 | ) | |||||||
| Restructuring | — | 175 | (175 | ) | |||||||
| Total operating expenses | 7,796 | 20,605 | (12,809 | ) | |||||||
| Loss from operations | (7,538 | ) | (14,731 | ) | 7,193 | ||||||
| Other income (expense) | 335 | 865 | (530 | ) | |||||||
| Net loss | $ | (7,203 | ) | $ | (13,866 | ) | $ | 6,663 | |||
| Net loss per share attributable to common shareholders per share, basic and diluted | $ | (0.13 | ) | $ | (0.25 | ) | $ | 0.12 | |||
| Weighted average shares outstanding, basic and diluted: | 57,281,570 | 55,376,188 | 1,905,382 | ||||||||
