Eileen J. Ennis

Eileen J. Ennis
McNeill Baur PLLC
125 Cambridge Park Drive
Suite 301
Cambridge, MA 02140*

Experienced in clinical development to marketed products, Eileen builds a patent strategy aligned with her clients' business needs

Eileen J. Ennis joins the firm with over 15-years experience as a patent attorney working in-house for mid-size pharmaceutical companies. She brings a thorough understanding of the business considerations that factor into in-house counsel decision-making. 

Eileen’s prosecution experience consists of global patent portfolios related to small molecule, peptide, and liposomal drugs.  She has prosecuted various types of patent applications such as active pharmaceutical ingredients, salts, polymorphs, formulations, and methods of treatment.

Eileen has conducted many due diligence evaluations in the oncology and rare disease space (e.g., small molecule, peptides, conjugates, and complex formulations), and her diligence work has ranged from early-stage research to candidates in clinical development and marketed products.  This work involved review of patent and regulatory exclusivity positions to determine loss of exclusivity, freedom to operate analysis, and review of intellectual property provisions in agreements. 

Eileen has also collaborated with European counsel on European oppositions and complex Supplementary Protection Certificate applications and has attended opposition hearings. 

While at Yale, Eileen conducted research focused on peptide synthesis and synthesis of macrocyclic scaffolds such as calixarene and porphyrin scaffolds, and their applications in oncology. Prior to joining McNeill Baur PLLC, Eileen was a Director of Intellectual Property at Ipsen Bioscience.


Select Publications

 “Structure-activity studies on a library of potent calix[4]arene-based PDGF antagonists that inhibit PDGF-stimulated PDGFR tyrosine phosphorylation,” Organic & Biomolecular Chemistry, 4(12):2376-86, (2006) (coauthor)

Inhibiting angiogenesis and tumorigenesis by a synthetic molecule that blocks binding of both VEGF and PDGF to their receptors,” Oncogene, 4701-4709, (2005) (coauthor)



District of Columbia

US Patent and Trademark Office 


*Not admitted in MA 



University of Florida, Levin College of Law,

JD, 2006


Yale University,

MS, Organic Chemistry, 2002


Creighton University,

BS, Chemistry/German, 2000



Current Leadership Roles

Chairperson, Activities and Public Relations Committee, Boston Intellectual Property Law Association