Spero Reports Preliminary Findings from Phase 1 Clinical Trial of SPR206 and Plans to Advance Program with Alliance Partners Everest Medicines and the Department of Defense

First indication of human safety and pharmacokinetic profiles for SPR206 supports advancement of program to clinical pharmacology studies planned to initiate in the second half of 2020


CAMBRIDGE, Mass., Jan. 13, 2020 (GLOBE NEWSWIRE) -- Spero Therapeutics, Inc. (Nasdaq: SPRO), a multi-asset clinical-stage biopharmaceutical company focused on identifying, developing and commercializing treatments in high unmet need areas involving multi-drug resistant (MDR) bacterial infections and rare diseases, today announced preliminary findings from its Phase 1 first-in-humans clinical trial of SPR206, an IV-administered product candidate being developed by Spero as an innovative option to treat MDR Gram-negative bacterial infections. 

Analysis of preliminary, blinded data from the Phase 1 double-blind, placebo-controlled single ascending dose (SAD) and multiple ascending dose (MAD) clinical trial in healthy adult volunteers suggests that SPR206 is well-tolerated at doses that are likely to be within a therapeutic range for target MDR Gram-negative bacterial infections and has a safety profile that Spero believes supports the further development of SPR206. The decision to continue development of SPR206 is also supported by data from nonclinical studies in which SPR206 demonstrated activity as a single agent against MDR and extensively drug resistant (XDR) bacterial strains, including isolates of Pseudomonas aeruginosaAcinetobacter baumannii and carbapenem-resistant Enterobacteriaceae, in both in vitro and in vivo models of infection.

“We are encouraged by the preliminary safety, tolerability and pharmacokinetic data collected for SPR206 in healthy volunteers and look forward to continuing the development of this novel compound in conjunction with our partners,” said Ankit Mahadevia, M.D., CEO of Spero Therapeutics.   “There exists an urgent need for safe and well-tolerated medicines with potent activity capable of treating the most serious Gram-negative infections experienced in the hospital setting. We believe SPR206 has the potential to meet this need and displace current sub-optimal options.”   

The Phase 1 clinical trial of SPR206 (Study SPR206-101) evaluated the safety, tolerability and pharmacokinetics of intravenously administered SPR206 at single doses ranging from 10 mg to 400 mg in seven SAD cohorts and repeat total daily doses ranging from 75 mg to 450 mg for seven  consecutive days and 300 mg for 14 consecutive days across five MAD cohorts. A total of 96 healthy volunteers were randomized to receive SPR206 or placebo. All reported adverse events were mild to moderate and there were no reported severe or serious adverse events. No evidence of nephrotoxicity was observed and there were no subjects with clinically significant changes in laboratory tests during the study.  Although the data remain blinded, an analysis of preliminary data indicates that SPR206 was well-tolerated at doses up to 100 mg administered three-times a day, a total of 300 mg daily, for 14 consecutive days.  Preliminary analyses of pharmacokinetic data across the cohorts indicates dose linearity and dose proportionality as well as mean plasma drug exposures of SPR206 that are concordant with preclinical models predictive for clinical efficacy against target Gram-negative pathogens.

Spero expects to receive a development milestone payment from its partner Everest Medicines upon delivery of the SPR206-101 SAD/MAD clinical study report (CSR) as specified under the regional collaboration launched in 2019 and expects to present final data from the Phase 1 clinical trial in the first half of 2020. In conjunction with Everest Medicines, and through its grant from the U.S. Department of Defense awarded in July 2019, Spero plans to conduct a Phase 1 bronchoalveolar lavage (BAL) clinical trial assessing the penetration of SPR206 into the pulmonary compartment in the second half of 2020 as well as initiate a renal impairment study of SPR206.  

About SPR206
SPR206 is designed to treat Gram-negative bacterial infections through the molecule’s interactions with the bacterium’s outer membrane. SPR206 is a direct acting IV-administered agent that has demonstrated potent broad-spectrum activity against Gram-negative bacteria, including organisms identified by the Centers for Disease Control and Prevention and the World Health Organization as urgent and serious threats to human health. SPR206 has been granted Qualified Infectious Disease Product (QIDP) designation by the U.S. Food and Drug Administration for the treatment of complicated urinary tract infections (cUTI) and hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia (HABP/VABP). Spero believes that its current intellectual property portfolio and pending patent applications for SPR206 will provide global protection, including China, the United States and Europe through 2039. 

SPR206 Research Support
Clinical research for the SPR206 program is funded by The U.S. Army Medical Research Acquisition Activity, 839 Chandler Street, Fort Detrick MD 217025014, which is the awarding and administering acquisition office. This work was supported by the Office of the Assistant Secretary of Defense for Health Affairs, through the Joint Warfighter Medical Research Program under Award No. W81XWH-19-1-0295.  Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the Department of Defense.

Non-clinical research for the SPR206 program is funded in part with Federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under Contract No. HHSN272201500014C.

Non-clinical research for the SPR206 program was funded in part by The U.S. Army Medical Research Acquisition Activity, 820 Chandler Street, Fort Detrick MD 21702-5014, which is the awarding and administering acquisition office. This work was supported in part by the Office of the Assistant Secretary of Defense for Health Affairs, through the Peer Reviewed Medical Research Program under Award No. W81XWH-16-2-0019. Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the Department of Defense.

About Spero
Spero Therapeutics, Inc. is a multi-asset, clinical-stage biopharmaceutical company focused on identifying, developing and commercializing novel treatments for multidrug-resistant (MDR) bacterial infections and rare diseases. 

Spero’s lead product candidate, Tebipenem HBr (tebipenem pivoxil hydrobromide; formerly SPR994), is designed to be the first oral carbapenem-class antibiotic for use in adults to treat MDR Gram-negative infections. 

Spero is also advancing SPR720, its novel oral therapy product candidate designed for the treatment of rare, orphan disease caused by pulmonary non-tuberculous mycobacterial (NTM) infections. 

Spero also has a platform technology known as its Potentiator Platform that it believes will enable it to develop drugs that will expand the spectrum and potency of existing antibiotics, including formerly inactive antibiotics, against Gram-negative bacteria. Spero’s potentiator product candidate, SPR206, is designed to treat MDR Gram-negative infections in the hospital setting. 

For more information, visit https://sperotherapeutics.com

Forward Looking Statements 
This press release may contain forward-looking statements. These statements include, but are not limited to, statements about Spero’s expectation that positive results from a single pivotal Phase 3 clinical trial of Tebipenem HBr and ancillary supportive studies to be conducted in parallel with the Phase 3 trial will support the approval of Tebipenem HBr; the design, initiation, timing, progress and results of Spero’s preclinical studies and clinical trials and its research and development programs, including the timing of Spero’s regulatory meeting with the FDA regarding SPR720, the timing of Spero’s IND submission with the FDA regarding SPR720, the commencement of Spero’s planned Phase 2a clinical trial of SPR720 and the commencement of Spero’s planned Phase 1 bronchoalveolar lavage (BAL) clinical trial assessing the penetration of SPR206 into the pulmonary compartment; management’s assessment of the results of such preclinical studies and clinical trials; the timing of clinical data, including the availability of pharmacokinetic data from the lead-in cohort in the Phase 3 clinical trial of Tebipenem HBr, final data from the Phase 1 clinical trial of SPR720 and final data from the Phase 1 clinical trial of SPR206; and Spero’s cash forecast and anticipated expenses, anticipated payments under Spero’s agreement with Everest Medicines, the sufficiency of its cash resources and the availability of additional non-dilutive funding from governmental agencies beyond any initially funded awards. In some cases, forward-looking statements can be identified by terms such as “may,” “will,” “should,” “expect,” “plan,” “aim,” “anticipate,” “could,” “intent,” “target,” “project,” “contemplate,” “believe,” “estimate,” “predict,” “potential” or “continue” or the negative of these terms or other similar expressions. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including whether the FDA will accept a single pivotal study for approval of Tebipenem HBr; whether results obtained in preclinical studies and clinical trials will be indicative of results obtained in future clinical trials; whether Spero’s product candidates will advance through the preclinical development and clinical trial process on a timely basis, or at all, taking into account the effects of possible regulatory delays, slower than anticipated patient enrollment, manufacturing challenges, clinical trial design and clinical outcomes; whether the results of such trials will warrant submission for approval from the U.S. Food and Drug Administration or equivalent foreign regulatory agencies; whether Spero will satisfy all of the pre-conditions to receipt of the development milestone payment under its agreement with Everest Medicines; whether Spero’s cash resources will be sufficient to fund its continuing operations for the periods and/or trials anticipated; and other factors discussed in the “Risk Factors” set forth in filings that Spero periodically makes with the U.S. Securities and Exchange Commission. The forward-looking statements included in this press release represent Spero’s views as of the date of this press release. Spero anticipates that subsequent events and developments will cause its views to change. However, while Spero may elect to update these forward-looking statements at some point in the future, it specifically disclaims any obligation to do so. These forward-looking statements should not be relied upon as representing Spero’s views as of any date subsequent to the date of this press release.

Spero Investor and Media Contact: 
Sharon Klahre 
Senior Director, Investor Relations 
857-242-1547 
IR@sperotherapeutics.com