On November 4, 2018, we entered into a license agreement with REGENXBIO to obtain rights to an exclusive worldwide license (subject to certain non-exclusive rights previously granted for MPS IIIA), with rights to sublicense, to REGENXBIO’s NAV AAV9 vector for the development and commercialization of gene therapies for the treatment of MPS IIIA, MPS IIIB, CLN1 Disease and CLN3 Disease. In return for these rights, REGENXBIO will receive a guaranteed $20 million upfront payment, $10 million of which was paid on signing of the agreement on November 4, 2018 and $10 million of which will be paid by November 4, 2019. In addition, REGENXBIO will receive a total of  $100 million in annual fees, payable upon the second through sixth anniversaries of the agreement, $20 million of which is guaranteed. REGENXBIO is also eligible to receive potential commercial milestone payments of up to $60 million as well as low double-digit royalties on net sales of products incorporating the licensed intellectual property. The license is amortized over the life of the patent of 8 years.

 

On August 3, 2016, we announced that we entered into an agreement (the “EB Agreement”) with EB Research Partnership (“EBRP”) and Epidermolysis Bullosa Medical Research Foundation (“EBMRF”) to collaborate on gene therapy treatments for EB. The EB Agreement became effective August 3, 2016, on the execution of two licensing agreements with The Board of Trustees of Leland Stanford Junior University (“Stanford”). We also entered into a license with Stanford for the AAV-based gene therapy EB-201 (AAV DJ COL7A1) technology, and

 preclinical development and clinical trials of a gene therapy treatment for EB based upon such in-licensed technology. EB-201 (AAV DJ COL7A1) is a preclinical candidate targeting a novel, AAV-mediated gene editing and delivery approach (known as homologous recombination) to correct gene mutations in skin cells (keratinocytes) for patients with RDEB. The licenses are amortized over the life of the license of 20 years.

 

On May 15, 2015, we acquired Abeona Therapeutics LLC, which had an exclusive license through Nationwide Children’s Hospital to the AB-101 and AB-102 patent portfolios for developing treatments for patients with Sanfilippo Syndrome Type A and Type B. The license is amortized over the life of the license of 20 years.

 

On September 22, 2014, we entered into an exclusive, worldwide, licensing agreement with Plasma Technologies LLC (“

”) to obtain rights to utilize and to sub-license to other pharmaceuticals firms its patented methods for the extraction of therapeutic biologics from human plasma. The license was to be amortized over the life of the patent of 11 years. Under the terms of the licensing agreement, as amended on January 23, 2015, we paid a license fee of $1 million in cash. In December 2017, the agreement was terminated and the technology was returned to

.

Licensed technology consists of the following:

 

 

The aggregate estimated amortization expense for intangible assets remaining as of December 31, 2018 is as follows (in thousands):

 

Amortization on licensed technology was $1,186,000, $534,000 and $677,000 for the years ended December 31, 2018, 2017 and 2016, respectively.