Nearing phase 3, resTORbio posts new data on infection drug 

ResTORbio has shared additional data from a phase 2b trial of RTB101 in patients with respiratory tract infections (RTIs). The analyses provide further evidence of the effect the TORC1 inhibitor has on the incidence of RTIs and urinary tract infections (UTIs) in high-risk elderly patients.

Boston-based resTORbio posted top-line data from the phase 2b earlier this year. That readout linked RTB101 to a statistically significant reduction in the percentage of patients with RTIs, triggering a big jump in resTORbio’s stock and emboldening the company to start preparations for a pivotal phase 3 program.  

Over the following weeks, during which time resTORbio’s stock fell back toward earth, the biotech dug into aspects of the data beyond the primary endpoint. ResTORbio has now shared the fruits of those analyses.

The analyses link RTB101 to statistically significant reductions in the incidence of RTIs with severe symptoms and rate of infections of any kind. The incidence of UTIs fell, too, although the decline only hit statistical significance among the cohort that received RTB101 twice a day.

The 10 mg once-daily regimen held its own against other endpoints, though. The difference in RTI and UTI outcomes is one of the topics that will occupy resTORbio in the months to come.

“It remains to be determined if the most efficacious RTB101 dose for preventing RTIs and UTIs differs because UTIs occur in a different organ system and are caused by different pathogens than RTIs. We continue to develop our clinical strategy for UTIs, including dose selection,” resTORbio Chief Medical Officer Joan Mannick, M.D., said in a statement.

The other, bigger task facing resTORbio is the phase 3 in RTIs. ResTORbio has chosen to move the 10 mg once-daily regimen forward in that patient population. An end-of-phase 2 meeting with the FDA is coming up. If all goes to plan, resTORbio will kick of its pivotal phase 3 program in the first half of next year.