Puretech Health : resTORbio Advances Immunotherapy Candidate for Aging-Related Conditions Following Recommendation from Independent Data Monitoring Committee

PureTech Health plc (LSE: PRTC), an advanced, clinical-stage biopharmaceutical company, announced today that resTORbio, Inc., an affiliate of PureTech Health, has begun dosing patients in the second part of a Phase 2b clinical study designed to assess the safety, tolerability and efficacy of resTORbio's lead programme in reducing respiratory tract infections (RTIs) in the elderly.

This final stage of the study was initiated following a unanimous recommendation to proceed by the independent data monitoring committee overseeing the clinical study.

resTORbio, Inc. is developing medicines to treat aging-related diseases and conditions by targeting a key pathway that regulates aging, with an initial focus on conditions caused by immunosenescence, the decline in immune function that occurs with age. resTORbio's lead programme is built upon two previous Phase 2a clinical studies, which demonstrated promising safety and efficacy results in almost 500 hundred elderly individuals.

Atul Pande, Chief Medical Officer of PureTech Health, said: 'The unanimous recommendation to move ahead following review of safety and efficacy data by the independent committee is a significant milestone for the programme. The lead indication, reducing the incidence of respiratory tract infections (RTIs) in elderly individuals, seeks to address a significant medical need and is the first of several indications that may be advanced in additional aging-related conditions.

The full text of the announcement from resTORbio is as follows:

resTORbio Advances to Part 2 of a Phase 2b Clinical Study of RTB101 Immunotherapy Following Unanimous Recommendation of Independent Data Monitoring Committee Overseeing the Study

BOSTON, Massachusetts, November 20, 2017- resTORbio, Inc., a clinical-stage biopharmaceutical company focused on the development and commercialisation of novel therapeutics for the treatment of aging-related diseases, today announced that an independent Data Monitoring Committee (DMC) has unanimously recommended advancing an ongoing Phase 2b clinical study to Part 2 of the study. The Phase 2b clinical study is a dose-range finding study of RTB101, an orally-administered TORC1 inhibitor, alone or in combination with everolimus as a first-in-class immunotherapy designed to enhance the ability of the aging immune system to fight infections. The Phase 2b clinical study is designed to assess the safety, tolerability and efficacy of 16 weeks of treatment with RTB101 alone or in combination with everolimus as compared to placebo in reducing the percentage of elderly individuals with respiratory tract infections (RTIs).

The independent DMC reviewed the safety and efficacy data from 179 elderly individuals from Part 1 of the randomised, multicentre, double-blinded, placebo-controlled Phase 2b clinical study and recommended moving forward to Part 2 of the study that is expected to enrol 424 elderly individuals to three active arms and a placebo arm. The clinical study is at least 80% powered to demonstrate a statistically significant difference in the percentage of individuals with one or more RTIs, assuming an effect size of 40% reduction.

'The unanimous recommendation by the independent DMC to continue the study following review of safety and efficacy from Part 1 of the study is a significant milestone for our programme. RTIs are the fifth leading cause of death in people age 85 and over and the seventh leading cause of death in people age 65 and over, and result in high healthcare burdens for the elderly and high healthcare costs for healthcare systems,' said Dr Joan Mannick, Chief Medical Officer of resTORbio.

About mTOR

Mechanistic target of rapamycin(mTOR) is a protein serine/threonine kinasethat regulates multiple cell functions, including cell growth and metabolism, via two complexes: TORC1 and TORC2. TORC1 inhibition has been found to have many beneficial effects on aging-related diseases and conditions, while TORC2 inhibition has been associated with adverse events including hyperglycaemia and hypercholesterolemia. The TORC1 inhibitor programme being developed by resTORbio may therefore have therapeutic potential to ameliorate multiple aging-related diseases with a favourable safety profile.

About resTORbio

resTORbio, Inc. is a clinical stage biopharmaceutical company focused on the development and commercialisation of novel therapeutics for the treatment of aging-related diseases. resTORbio's lead programme is targeting the target of rapamycin complex 1 (TORC1) pathway to treat aging-related diseases and conditions with an initial focus on conditions caused by immunosenescence, the decline in immune function that occurs during aging. resTORbio's lead product candidate, RTB101, is in a Phase 2b clinical trial to evaluate its potential in reducing the incidence of respiratory tract infections (RTI) in elderly subjects at increased risk of RTI-related morbidity and mortality. resTORbio's lead programme is supported by two Phase 2a clinical studies from which promising safety and efficacy signals were observed in almost 500 hundred elderly subjects. resTORbio is pursuing a pragmatic clinical development plan to address areas of key unmet medical need in the aging population. For more information, please visitwww.restorbio.com. resTORbio is an affiliate ofPureTech Health.

About PureTech Health

PureTech Health (PureTech Health plc, PRTC.L) is an advanced, clinical-stage biopharmaceutical company developing novel medicines targeting serious diseases that result from dysfunctions in the nervous, immune, and gastrointestinal systems (brain-immune-gut or the 'BIG' axis), which together represent the adaptive human systems. PureTech Health is at the forefront of understanding and addressing the biological processes and crosstalk associated with the BIG axis. By harnessing this emerging field of human biology, the Company is pioneering new categories of medicine with the potential to have great impact on people with serious diseases. PureTech Health is advancing a rich pipeline of innovative therapies that includes two pivotal stage programmemes, multiple human proof-of-concept studies and a number of early clinical and pre-clinical programmemes. PureTech's rich research and development pipeline has been advanced in collaboration with some of the world's leading scientific experts, who along with PureTech's team of biopharma pioneers, entrepreneurs and seasoned Board, identify, invent, and clinically de-risk new medicines. With this experienced team pursuing cutting edge science, PureTech Health is building the biopharma company of the future focused on improving and extending the lives of people with serious disease. For more information, visitwww.puretechhealth.comor connect with us on Twitter@puretechh.

Forward Looking Statement

This press release contains statements that are or may be forward-looking statements, including statements that relate to the company's future prospects, developments and strategies. The forward-looking statements are based on current expectations and are subject to known and unknown risks and uncertainties that could cause actual results, performance and achievements to differ materially from current expectations, including, but not limited to, those risks and uncertainties described in the risk factors included in the regulatory filings for PureTech Health plc. These forward-looking statements are based on assumptions regarding the present and future business strategies of the company and the environment in which it will operate in the future. Each forward-looking statement speaks only as at the date of this press release. Except as required by law and regulatory requirements, neither the company nor any other party intends to update or revise these forward-looking statements, whether as a result of new information, future events or otherwise.