Spero Therapeutics and Everest Medicines announced that they have entered into a collaboration to develop, manufacture and commercialize SPR206 in Greater China, South Korea and certain Southeast Asian countries, along with an exclusive option to rights to SPR741 in the territory. Spero, through certain of its wholly owned subsidiaries, has granted Everest an exclusive license to develop, manufacture, and commercialize SPR206 in the territory. Everest also has a 12-month exclusive option to rights to SPR741 in the territory.

A Joint Development Committee will be established between the companies to coordinate and review the development, manufacturing and commercialization plans with respect to SPR206 in the territory. Spero will receive an upfront payment of $2 million and is eligible to receive milestone payments of up to an additional $59.5 million upon achievement of specified clinical, regulatory and commercial milestones related to SPR206, of which Spero anticipates receiving at least $2 million in near-term milestones during 2019. Furthermore, Spero will be eligible to receive high single-digit to low double-digit royalties on any sales of SPR206 products in the territory following regulatory approval.

Everest will also pay Spero $1 million upfront fee for its exclusive 12-month option to rights to SPR741. SPR206 and SPR741, two intravenous (IV)-administered product candidates from Spero's Potentiator Platform, are being developed as innovative options to treat MDR Gram-negative bacterial infections. Based on microbiological and in vivo testing, Spero believes that SPR206 has the potential to offer a broad-spectrum of activity, including against extensively drug-resistant bacterial strains, together with improved safety and tolerability compared with other molecules in its class.

Spero initiated a phase 1 clinical trial of SPR206 in December 2018, designed as a double-blind, placebo-controlled, ascending dose, multi-cohort study in healthy subjects, and expects top-line data from this trial in the second half of 2019.