By Chris Wack


Spero Therapeutics shares were up 14% at $1.62 after the company received written agreement from the U.S. Food and Drug Administration, under a Special Protocol Assessment, on the design and size of its pivotal Phase 3 clinical trial of tebipenem HBr in patients with complicated urinary tract infection, including acute pyelonephritis.

The stock has more than doubled in the past 12 months.

The biopharmaceutical company designed tebipenem in collaboration with GSK to provide a clinical path to becoming the first oral carbapenem antibiotic for treatment of cUTI, if approved.

The primary efficacy endpoint of the trial will be overall response at the test-of-cure visit. The FDA has indicated that positive and persuasive results from the trial, along with previously completed studies, could be sufficient to support approval of tebipenem HBr as a treatment for cUTI, including pyelonephritis, for a limited use indication.

Spero is also eligible to receive milestone/royalty payments under the terms of its license agreement with GSK, conditional upon achievement of certain progression of milestones.

Spero could get up to an additional $120 million in development milestones as the Phase 3 clinical trial progresses; up to $150 million in potential commercial milestones based on first commercial sales; up to $225 million in potential sales-based milestones; and low-single digit to low-double digit tiered royalties on product sales of tebipenem HBr in all territories, except Japan and certain other Asian countries.


Write to Chris Wack at chris.wack@wsj.com


(END) Dow Jones Newswires

07-31-23 1244ET