RELATED PARTY TRANSACTIONS	3 Months Ended
Mar. 31, 2019
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	In October 2014, we entered into an agreement (the “Office Agreement”) with Fortress Biotech, Inc. (“FBIO”) to occupy approximately 45% of the 24,000 square feet of New York City office space leased by FBIO, which is now our corporate headquarters. The Office Agreement requires us to pay our respective share of the average annual rent and other costs of the 15-year lease. We approximate an average annual rental obligation of $1.1 million under the Office Agreement. We began to occupy this new space in April 2016, with rental payments beginning in the third quarter of 2016. During the three months ended March 31, 2019, we recognized a lease liability of $9.4 million, with a corresponding Right of Use (ROU) asset of $7.9 million based on the present value of the remaining lease payments for all of our leased office spaces, the majority of which is comprised of our New York City office space. Mr. Weiss, our Executive Chairman and CEO, is also Executive Vice Chairman of FBIO. Under the Office Agreement, we agreed to pay FBIO our portion of the build out costs, which have been allocated to us at the 45% rate mentioned above. The allocated build-out costs have been recorded in Leasehold Interest, net on the Company’s consolidated balance sheets and will be amortized over the 15-year term of the Office Agreement. After an initial commitment period of the 45% rate for a period of three (3) years, we and FBIO will determine actual office space utilization annually and if our utilization differs from the amount we have been billed, we will either receive credits or be assessed incremental utilization charges. Also in connection with this lease, in October 2014 we pledged $0.6 million to secure a line of credit as a security deposit for the Office Agreement, which has been recorded as restricted cash in the accompanying consolidated balance sheets. Additional collateral of $0.6 million was pledged in April 2018 to increase the letter of credit for the office space. In July 2015, we entered into a Shared Services Agreement (the “Shared Services Agreement”) with FBIO to share the cost of certain services such as facilities use, personnel costs and other overhead and administrative costs. This Shared Services Agreement requires us to pay our respective share of services utilized. In connection with the Shared Services Agreement, we incurred expenses of approximately $0.2 million and $0.4 million for shared services for the three months ended March 31, 2019 and 2018, respectively, primarily related to shared personnel. In March 2015, we entered into a Global Collaboration Agreement (“Collaboration Agreement”) with Checkpoint for the development and commercialization of anti-PD-L1 and anti-GITR antibody research programs in the field of hematological malignancies. We incurred expenses of approximately $0.3 million and zero for the three months ended March 31, 2019 and 2018, related mainly to manufacturing costs of PD-L1. The relevant expenses are recorded in other research and development in the accompanying condensed consolidated statement of operations.

RELATED PARTY TRANSACTIONS

3 Months Ended

Mar. 31, 2019

In October 2014, we entered into an agreement (the “Office Agreement”) with Fortress Biotech, Inc. (“FBIO”) to occupy approximately 45% of the 24,000 square feet of New York City office space leased by FBIO, which is now our corporate headquarters. The Office Agreement requires us to pay our respective share of the average annual rent and other costs of the 15-year lease. We approximate an average annual rental obligation of $1.1 million under the Office Agreement. We began to occupy this new space in April 2016, with rental payments beginning in the third quarter of 2016. During the three months ended March 31, 2019, we recognized a lease liability of $9.4 million, with a corresponding Right of Use (ROU) asset of $7.9 million based on the present value of the remaining lease payments for all of our leased office spaces, the majority of which is comprised of our New York City office space. Mr. Weiss, our Executive Chairman and CEO, is also Executive Vice Chairman of FBIO.

Under the Office Agreement, we agreed to pay FBIO our portion of the build out costs, which have been allocated to us at the 45% rate mentioned above. The allocated build-out costs have been recorded in Leasehold Interest, net on the Company’s consolidated balance sheets and will be amortized over the 15-year term of the Office Agreement. After an initial commitment period of the 45% rate for a period of three (3) years, we and FBIO will determine actual office space utilization annually and if our utilization differs from the amount we have been billed, we will either receive credits or be assessed incremental utilization charges. Also in connection with this lease, in October 2014 we pledged $0.6 million to secure a line of credit as a security deposit for the Office Agreement, which has been recorded as restricted cash in the accompanying consolidated balance sheets. Additional collateral of $0.6 million was pledged in April 2018 to increase the letter of credit for the office space.

In July 2015, we entered into a Shared Services Agreement (the “Shared Services Agreement”) with FBIO to share the cost of certain services such as facilities use, personnel costs and other overhead and administrative costs. This Shared Services Agreement requires us to pay our respective share of services utilized. In connection with the Shared Services Agreement, we incurred expenses of approximately $0.2 million and $0.4 million for shared services for the three months ended March 31, 2019 and 2018, respectively, primarily related to shared personnel.

In March 2015, we entered into a Global Collaboration Agreement (“Collaboration Agreement”) with Checkpoint for the development and commercialization of anti-PD-L1 and anti-GITR antibody research programs in the field of hematological malignancies. We incurred expenses of approximately $0.3 million and zero for the three months ended March 31, 2019 and 2018, related mainly to manufacturing costs of PD-L1. The relevant expenses are recorded in other research and development in the accompanying condensed consolidated statement of operations.