Our lead program selectively inhibits the activity of a protein complex called target of rapamycin complex 1, or TORC1, an evolutionarily conserved pathway that contributes to the decline in function of multiple aging organ systems. Our lead product candidate is a TORC1 inhibitor called RTB101.
We are developing RTB101 alone and in combination with other TORC1 inhibitors for multiple aging-related diseases. In addition to developing our TORC1 product candidates, we are building a pipeline of products targeting multiple mechanisms underlying the biology of aging.
RTB101 inhibits the phosphorylation of multiple targets downstream of TORC1. Inhibition of TORC1 has been observed to extend lifespan and healthspan in aging preclinical species and to improve the function of multiple organ systems, including immune, neurologic and cardiac function, suggesting potential benefits in several aging-related diseases.
We currently have two ongoing RTB101 clinical programs, a Phase 3 program in clinically symptomatic respiratory illness, and a Phase 1b/2a program in Parkinson’s disease. We expect to develop RTB101 for additional indications in other aging-related diseases.
About Clinically Symptomatic Respiratory Illness (CSRI)
The reduced ability of the aging immune system to effectively detect and fight infectious pathogens results in increased susceptibility of older adults to respiratory tract infections (RTIs), which, in turn negatively impacts their overall health and quality of life. There is a significant unmet medical need for an innovative therapy to reduce the burden of illness associated with respiratory tract infections, or clinically symptomatic respiratory illness (CSRI):
The large and growing population of older adults is particularly susceptible to morbidity and mortality from RTIs. In the United States, RTIs are the second leading cause of hospitalizations in people age 85 and over and the fourth leading cause of hospitalizations in people age 65 and over.
The majority of RTIs are caused by viruses, most of which lack approved therapies, leaving physicians with few treatment options. Even if vaccinated, older adults are less likely to develop sufficient protective immunity against influenza and pneumococcal infections due to age-related decrease in immune function with age.
Antibiotics, which are ineffective against viruses, are often prescribed indiscriminately to treat RTIs, which may cause side effects related to antibiotic use and contribute to the growing global problem of antibiotic resistance.
RTIs contribute to high healthcare burden and costs. At least 80% of hospitalizations for asthma exacerbations and 11% of hospitalizations for congestive heart failure exacerbations are associated with RTIs. Even colds, which are usually mild in younger adults, often progress to more serious lower-respiratory tract infections in older adults. In addition, the risk of a having a cardiovascular event such as a heart attack or stroke increases 3-fold when people have an upper RTI (common cold).
The collective results from our Phase 2a and Phase 2b clinical trials that enrolled more than 900 people age 65 years and older suggest that RTB101 10 mg once daily, if successfully developed and approved, may improve the function of the aging immune system and reduce the incidence of clinically symptomatic respiratory illness in older adults. PROTECTOR 1, the first Phase 3 clinical trial, completed enrollment of 1,024 patients in July 2019. PROTECTOR 2, the second Phase 3 clinical trial, is planned to begin in the northern hemisphere in the fourth quarter of 2019 and is expected to enroll approximately 1,600 patients. Based on our current enrollment expectations for the Phase 3 program, top-line data are expected by early Q1 2020 for PROTECTOR 1 and in mid-2020 for PROTECTOR 2.
About Parkinson’s Disease
The incidence of PD increases rapidly in people 60 years of age and older, with a mean age at diagnosis of 70.5 years. In PD, neurodegeneration is thought to be caused, at least in part, by the accumulation of aggregates of a protein called alpha-synuclein that are toxic to neurons in the brain. Patients with PD develop shaking, rigidity, slowness of movement and difficulty walking.
Selective and broad inhibition of TORC1 has been shown to ameliorate neurodegenerative disease in several preclinical studies, including models of PD. TORC1 inhibition with RTB101 in combination with sirolimus, another TORC1 inhibitor, may provide a therapeutic benefit to PD patients by potentially inducing autophagy to clear the toxic alpha-synuclein aggregates in neurons.