Highest-materiality recent filing
Spero enters $100M ATM facility with Jefferies, terminates Cantor ATM
Sale Agreement with Jefferies LLC enables up to $100M of common stock in at-the-market offerings once S-3 is effective.
Spero Q2 net loss widens to $9.6M; FDA approves Utebzi, $105M financing extends runway
Net loss of $9.6M ($0.16 diluted EPS) vs $1.7M loss ($0.03) in Q2 2025.
Spero in-licenses SP001 anti-CD40L antibody from Innovent, secures $105M non-dilutive financing
In-licensed SP001 (anti-CD40L) from Innovent; Spero gets ex-China rights. Upfront $35M, milestones up to ~$1.05B, tiered royalties high single to mid-teen %.
Spero shareholders approve doubling authorized shares to 240M and 2026 equity plan
Authorized common shares increased from 120M to 240M via certificate of amendment filed June 23, 2026.
FDA approves Spero Therapeutics' Utebzi, first oral carbapenem for cUTIs
Utebzi (tebipenem pivoxil) approved June 17, 2026 for complicated UTIs in adults with limited oral alternatives.
Spero posts Q1 net loss of $7.2M; tebipenem HBr PDUFA date June 18, 2026
Net loss of $7.2M ($0.13 diluted EPS) vs $13.9M loss ($0.25 EPS) in Q1 2025.
Spero posts Q4 net income $31.5M; tebipenem HBr PDUFA set for June 18, 2026
Q4 2025 net income $31.5M (vs $20.9M loss); diluted EPS $0.53.
Director resigns; SEC concludes investigation with no enforcement action
Ankit Mahadevia, MD resigned from board effective Jan 30, 2026 due to other professional commitments; no dispute with company.
GSK files NDA resubmission for tebipenem HBr; Spero to receive $25M milestone in Q1 2026
GSK resubmitted NDA to FDA for oral carbapenem tebipenem HBr for cUTI/pyelonephritis.
Spero Therapeutics Q3 net loss narrows to $7.4M; GSK plans FDA filing for tebipenem HBr in Q4 2025
Net loss of $7.4M ($0.13 EPS) vs $17.1M ($0.32 EPS) in Q3 2024; revenue $5.4M, down from $13.5M.
Spero reports Q2 results and tebipenem Phase 3 success; plans FDA filing in 2H 2025
Q2 2025 net loss $1.7M ($0.03/share) vs $17.9M ($0.33) in Q2 2024; revenue $14.2M up from $10.2M.
Stockholders approved amendment to 2017 Plan increasing authorized shares by 3,000,000.
Spero/GSK Phase 3 PIVOT-PO trial for tebipenem HBr meets primary endpoint, stops early for efficacy
Tebipenem HBr met non-inferiority vs IV imipenem-cilastatin in 1,690 cUTI patients; IDMC recommended early stop.
Spero Q1 loss $13.9M, revenue $5.9M; appoints new CEO, tebipenem trial interim on track
Net loss $13.9M ($0.25/share) vs $12.7M loss in Q1 2024; revenue $5.9M down from $9.3M.
Esther Rajavelu named Spero CEO effective May 2; former CEO Sath Shukla departs
Esther Rajavelu appointed President and CEO effective May 2, 2025; nominated for board election at annual meeting.
Spero posts Q4 net loss of $20.9M; revenue down 80% YoY; pipeline setbacks and SEC Wells Notice
Net loss of $20.9M in Q4 2024 vs net income of $51.2M in Q4 2023; diluted EPS loss of $(0.38).
Nasdaq notified Spero on Feb 25, 2025 that its stock closed below $1.00 for 30 consecutive trading days.
Spero Therapeutics receives SEC Wells Notice; CEO placed on paid administrative leave
SEC staff preliminarily recommends enforcement action over 2022 disclosures on tebipenem HBr commercialization.
Spero Q3 net loss widens to $17.1M; SPR720 halted after Phase 2a miss
Q3 net loss of $17.1M ($0.32 EPS) vs $3.2M loss a year ago; revenue fell 47% to $13.5M.
SPR720 Phase 2a interim analysis did not meet primary endpoint; 3 cases of reversible grade 3 hepatotoxicity at 1,000 mg dose.
Filed an updated investor presentation dated September 9, 2024, under Regulation FD.
Spero Therapeutics Q2 net loss $17.9M; CMO departs; SPR720 data expected 4Q 2024
Net loss $17.9M ($0.33/share) vs $11.9M loss ($0.23) in Q2 2023; revenue $10.2M up from $2.7M.
Spero Therapeutics shareholders approve 3M share increase for 2017 stock plan
Stockholders approved amendment to 2017 Stock Incentive Plan, adding 3,000,000 authorized shares.
Spero Therapeutics Q1 net loss $12.7M; SPR720 Phase 2a data expected 2H 2024
Net loss $12.7M ($0.24/share) vs $13.3M ($0.25/share) in Q1 2023; revenue $9.3M up from $2.1M.
Spero Therapeutics sets 2024 Annual Meeting for May 29, 2024 (online)
Annual Meeting on May 29, 2024, will be held entirely online via virtual format.
Spero Therapeutics reports Q4 2023 net income of $51.2M; SPR720 topline data expected 2H 2024
Q4 2023 net income of $51.2M ($0.96 diluted EPS) vs $26.8M in Q4 2022; full-year net income of $22.8M ($0.43 diluted EPS).
Spero Therapeutics Chief Legal Officer Tamara Joseph to depart March 6, 2024
Tamara Joseph, Chief Legal Officer and Corporate Secretary, is leaving effective March 6, 2024 to pursue other interests.
Spero Therapeutics files updated investor presentation; no specific new material details provided
Company updated its corporate investor presentation on January 8, 2024.
Preliminary cash and cash equivalents of $76.3M as of Dec 31, 2023 (unaudited).
Spero starts Phase 3 PIVOT-PO trial of tebipenem HBr; $95M milestone payable over two years from GSK
First patient first visit for Phase 3 PIVOT-PO trial (cUTI/AP) targeting ~2,648 patients.
Spero Q3 net loss $3.2M, revenue $25.5M on $30M GSK milestone; FDA SPA for Phase 3 tebipenem HBr
Net loss $3.2M ($0.06/shr) vs $11.7M loss ($0.33/shr) YoY; revenue $25.5M vs $2.0M YoY driven by $23.2M GSK collaboration revenue.
Spero Therapeutics appoints Esther Rajavelu as CFO and CBO effective Nov 6
Esther Rajavelu appointed CFO and Chief Business Officer; assumes principal financial officer role after Q3 10-Q filing.
Spero Therapeutics corrects 8-K: charter amendment was not approved; files Certificate of Correction
Amendment No. 1 to 8-K discloses tabulation error in October 5 annual meeting vote.
Spero Therapeutics stockholders approve 2.5M share increase to 2017 Plan and charter amendments
Stockholders approved amendment to 2017 Stock Incentive Plan, increasing authorized shares by 2,500,000.
Spero reports Q2 loss $11.9M; FDA SPA for tebipenem HBr P3 trial
Net loss $11.9M ($0.23/sh) vs $28.7M ($0.87) in Q2 2022; revenue $2.7M.
FDA agrees to SPA for Spero's Phase 3 tebipenem HBr trial; $30M milestone due from GSK
FDA granted Special Protocol Assessment (SPA) for pivotal Phase 3 PIVOT-PO trial of oral tebipenem HBr vs IV imipenem in cUTI/acute pyelonephritis.
Spero Therapeutics appoints Sath Shukla as CEO, Mahadevia becomes Chairman
CEO Ankit Mahadevia steps down effective Aug 1, 2023; becomes Chairman of the Board.
Net loss of $13.3M ($0.25 per share) in Q1 2023, compared to net loss of $32.8M ($1.01 per share) in Q1 2022.
Spero Therapeutics reports Q4 net income of $26.8M; GSK deal provides $66M upfront
Q4 2022 net income $26.8M ($0.55 EPS) vs net loss $29.2M in Q4 2021; full-year net loss $46.4M ($1.23 loss per share).
Spero Therapeutics names Timothy Keutzer Chief Operating Officer effective Feb 1, 2023
Timothy Keutzer, previously Chief Development Officer, appointed COO effective February 1, 2023.
Spero reports preliminary cash of ~$109M as of Dec 31, 2022; updates investor presentation
Preliminary cash, cash equivalents and marketable securities of ~$109M as of Dec 31, 2022 (unaudited, subject to change).
Net loss $11.7M ($0.33/shr) vs $22.5M ($0.70/shr) in Q3 2021; revenue $2M down from $3.1M.
Spero Therapeutics closes exclusive license agreement with GSK for tebipenem HBr
Received $66 million upfront payment from GSK under the exclusive license agreement.
Spero licenses tebipenem HBr to GSK for $66M upfront, up to $525M milestones plus tiered royalties
GSK gets exclusive license to develop and commercialize oral carbapenem antibiotic tebipenem HBr outside Japan and certain Asian countries.
Spero Therapeutics stockholders approve 2M share increase to 2017 Stock Incentive Plan
Stockholders approved amendment to 2017 Stock Incentive Plan, increasing authorized shares by 2,000,000 (total 4,608,374 for new awards).
FDA indicated positive results from one additional Phase 3 trial, plus confirmatory nonclinical evidence, could support approval.
Net loss $28.7M ($0.87/share) vs $18.6M ($0.63/share) in Q2 2021; revenue $2.0M down from $5.1M.
Spero Therapeutics grants CEO $254K cash + $508K RSU, CFO $168K cash + $336K RSU retention awards
CEO Ankit Mahadevia receives $254K cash bonus (Nov 30, 2022) and up to $508K in stock based on performance criteria.
FDA rejects Spero's tebipenem HBr NDA for cUTI; additional clinical study required
Received Complete Response Letter on June 27, 2022 for tebipenem HBr oral tablets cUTI NDA.
Spero pays $54.5M to terminate HCR revenue interest agreement, regains Tebi asset rights
Cash payment of $54.5M (exact $54,484,895) on June 7, 2022 to terminate HCR financing agreement and release all liens.
On April 28, 2025, Spero Therapeutics, Inc. (the “Company”) announced that effective as of May 2, 2025 (the “Effective Date”), Esther Rajavelu will serve as the Company’s President and Chief Executive Officer.
Tamara Joseph, the Chief Legal Officer and Corporate Secretary of Spero Therapeutics, Inc. (the “Company”), is stepping down from that position to pursue other interests, effective as of March 6, 2024 (the “Effective Date”).
On October 30, 2023, the Board of Directors (the “Board”) of Spero Therapeutics, Inc. (the “Company”) appointed Esther Rajavelu as the Company’s Chief Financial Officer and Chief Business Officer.
Ankit Mahadevia, M.D., the Company’s Chief Executive Officer and President, determined to step down from that role, effective as of August 1, 2023
Satyavrat Shukla, the Company’s current Chief Financial Officer and Treasurer, was appointed by the Board to serve as Chief Executive Officer and President of the Company and as a member of the Board
Stephen J. DiPalma to be the Company’s Interim Chief Financial Officer and Treasurer to succeed Mr. Shukla
Dr. Mahadevia will serve as a consultant to the Company and will continue to serve as a member of the Company’s Board of Directors (the “Board”) and will assume the role of Chairman of the Board
On January 30, 2023, the Board of Directors (the “Board”) of Spero Therapeutics, Inc. (the “Company”) appointed Timothy Keutzer as the Company’s Chief Operating Officer, effective as of February 1, 2023
Chief Operating Officer Effective as of July 2, 2022 (the "Effective Date"), Cristina Larkin will separate from the Company as its Chief Operating Officer pursuant to the Restructuring.
Chief Medical Officer Effective as of the Effective Date, David Melnick, M.D. will separate from the Company as its Chief Medical Officer pursuant to the Restructuring.
On October 11, 2021, Jean-François Formela, M.D. notified the Board of Directors (the “Board”) of Spero Therapeutics, Inc. (the “Company”) of his resignation from the Board and the Compensation Committee and Nominating and Corporate Governance Committee of the Board, effective as of October 11, 2021.
On October 11, 2021, the Board, upon the recommendation of the Nominating and Corporate Governance Committee of the Board, appointed Kathleen Tregoning to the Board, effective as of October 11, 2021, to fill the vacancy created by Dr. Formela’s resignation.
Max materiality 0.90 · Median 0.70 · Most common event other_material