Meet the Executive Team

For the Engage Therapeutics team, our dedication to the epilepsy community is personal. We are parents of children with epilepsy and epileptologists who are tired of feeling helpless when seizures strike. We are passionate about providing people with epilepsy and their families with a rescue treatment that will allow them to stop ongoing seizures.

Gregory T. Mayes

President, Chief Executive Officer and Founder

A biopharma leader with more than 20 years of experience in oncology, Greg became involved in the epilepsy community following his teenage son’s epilepsy diagnosis in 2014. Leveraging his drug development experience and deep roots in the pharmaceutical industry, Greg founded Engage Therapeutics in 2017 to develop what could be the U.S.’s first seizure rescue inhaler.

Greg previously served as President of Unigene Laboratories, Inc. and subsequently as Chief Operating Officer of Advaxis Immunotherapies, a New Jersey-based biotech company developing immuno-oncology therapies for patients with hard-to-treat cancers through its bacterial vector system, Lm Technology™. He played an integral role in the company’s growth, helping to secure more than $200 million in funding and negotiating partnerships with companies such as Amgen, AstraZeneca and Merck & Co., Inc.

A lawyer by training, Greg served as ImClone’s General Counsel and played a key role in managing multiple clinical and regulatory activities that led to the 2008 acquisition by Eli Lilly for $6.5 billion. Earlier in his career, Greg was responsible for providing legal advice to the AstraZeneca oncology franchise as senior counsel and he started his biopharma legal career at the national law firm of Morgan Lewis. Greg holds a Bachelor of Science degree from Syracuse University and a JD from Temple University School of Law.

Jouko Isojarvi MD, PhD

Executive Vice President, Chief Medical Officer and Founder

Jouko is a physician and clinical researcher with over 35 years of experience caring for patients with epilepsy. He has served as a researcher and investigator on numerous international clinical trials for antiepileptic drugs including a LAMICTAL® (lamotrigine), a well-known treatment for epilepsy.

Prior to launching Engage Therapeutics, Jouko was senior medical director at Lundbeck, where he was responsible for medical oversight and post approval development of epilepsy products including SABRIL® (vigabatrin) and ONFI® (clobazam). He oversaw the optimal and safe use of the drugs, working closely with advocacy groups including the Epilepsy Foundation.

Before his time at Lundbeck, Jouko served in leadership roles at UCB Pharma within the epilepsy team for the clinical development of VIMPAT® (lacosamide). He played a key role in designing, implementing and completing clinical trials for phases 3-4 and served as medical lead for the VIMPAT® (lacosamide) monotherapy programs for partial onset seizures in the United States and Europe. He was also the lead for the VIMPAT® (lacosamide) generalized tonic-clonic seizures program. Jouko also served as medical and clinical lead for the BRIVIACT® (brivaracetam) program in idiopathic generalized seizures. In his role at UCB he served as the medical expert in all interactions with U.S, and EU regulatory authorities.

Jouko has also served as head of the neurology group in clinical development at Jazz Pharmaceuticals, where he played an integral role in the development of JZP-8 (intranasal clonazepam) for acute repetitive seizures and JZP-4 (a lamotrigine-like compound) for partial onset seizures. At GlaxoSmithKline, Jouko was director in clinical development and medical affairs for LAMICTAL® (lamotrigine), where he was scientific and clinical lead. Jouko received his MD and PhD from the University of Oulu in Finland, where he served at the helm of the Epilepsy Research Group for nearly 10 years.

Mark Theeuwes

Senior Vice President and Chief Operating Officer

Mark is a healthcare executive with more than 15 years of experience. He has a wide range of focus within the rare diseases, urology, pain, primary care, infectious disease and dental industries. With his daughter’s diagnosis of epilepsy 13 years ago, Mark and his family have been involved within the epilepsy community by creating local awareness through work with the Epilepsy Foundation of Eastern PA.

Most recently, Mark served as Vice President of Sales, Trade and Commercial Operations at Egalet. As one of the first commercial employees, Mark was integral in establishing key functions within Trade, Commercial Operations and Sales Excellence at Egalet in order to lead the launch of three products within the company’s first two years. Prior to that, he was an Executive Director of Decision Support and member of the U.S. Commercial Leadership team at NPS until it was acquired by Shire plc in 2015. Before this role at NPS, Mark headed up Sales Operations at ViroPharma until it was acquired by Shire plc in 2014.

Mark started his career as a sales representative at Alza, which was acquired by Johnson & Johnson in 2001. Over the next 10 years, Mark held a number of sales, training, operations and analytics positions of increasing responsibility within the Johnson & Johnson family of companies.

Robert J. Small, RN, BSN

Vice President Clinical Operations

Rob is a registered nurse with over 20 years of experience in clinical project management of drug and device clinical trials. Rob’s clinical trial experience includes phase 1-4 projects in a wide range of therapeutic areas including neurology, oncology, cardiology, infectious disease, pulmonology, dermatology and ophthalmology.

Prior to joining Engage Therapeutics, Rob served as Sr. Director Clinical Operations at Soligenix Inc. in Princeton, New Jersey. He was also a founding member of INO Therapeutics and was part of the team responsible for the clinical trials and subsequent approval of inhaled nitric oxide for the treatment of persistent pulmonary hypertension in the newborn.