which we agreed to pay MSK to provide research services over a period of three years related to the intellectual property licensed under the SADA License Agreement. For three months ended June 30, 2021 and 2020, we incurred research and development expenses of $947,000 and $929,000, respectively, under these agreements. For six months ended June 30, 2021 and 2020, we incurred research and development expenses of $1,895,000 and $1,978,000, respectively, under these agreements.
Lease Agreements
In July 2019, the Company entered a development, manufacturing and supply agreement with SpectronRx in South Bend, Indiana, to secure access to clinical and commercial scale radiolabeling capacity for omburtamab. Under the terms of the agreement, SpectronRx has agreed to establish a manufacturing unit designated for the Company within its existing facilities, at which both clinical and commercial supply of radiolabeled omburtamab can be produced. Since the Company possesses the right to substantially all the economic benefits and directs the use of the production area, the Company accounts for the payments related to the access to the manufacturing space under ASC 842 as an operating lease. The term of the lease is two years from the commencement date of August 31, 2020. Upon the lease commencement date, we recorded $3,617,000 as right of use asset and $2,679,000 as lease liability with the difference of $938,000 resulting from certain prepayments and other costs incurred. The company pays equal monthly installments of approximately $117,000 per month in additional access fees through September 2022 resulting in total payments of $1,631,000 remaining under the agreement. There are no renewal options in this agreement.
In February 2019, the Company entered into a lease agreement in connection with its 4,548 square feet laboratory in New Jersey. In December 2019, we expanded the space with an additional 235 square feet. The term of the lease is three years from the date the Company occupied the premises, with an option to extend for an additional two years which the Company expects to exercise and has included in the determination of the related lease liability. Fixed rent payable under the lease is approximately $144,000 per annum and is payable in equal monthly installments of approximately $12,000.
In January 2018, the Company entered into a lease agreement in connection with its corporate headquarters in New York. The term of the lease is five years from the date the Company began to occupy the premises. Fixed rent payable under the lease is approximately $384,000 per annum and is payable in equal monthly installments of approximately $32,000, which are recognized on a straight-line basis.
Additionally, the Company entered a three-year lease agreement for the lease of certain office space in Denmark in February 2018, as amended in November 2018 and February 2019. The lease is payable in monthly installments of approximately $19,000, which are recognized on a straight-line basis.
Total operating lease costs were $646,000 and $173,000 for the three months ended June 30, 2021 and 2020, respectively, and $1,291,000 and $347,000 for the six months ended June 30, 2021 and 2020, respectively.
For the three months ended June 30, 2021, the operating lease expenses were recorded as $587,000 in research and development expense and $59,000 in general and administrative expense. For the three months ended June 30, 2020, the expenses were recorded as $124,000 in research and development expense and $49,000 in general and administrative expense. For the six months ended June 30, 2021, the expenses were recorded as $1,174,000 in research and development expense and $117,000 in general and administrative expense. For the six months ended June 30, 2020, the expenses were recorded as $247,000 in research and development expense and $100,000 in general and administrative expense.
Cash paid for amounts included in the measurement of lease liabilities for the three and six months ended June 30, 2021 was $549,000 and $1,093,000, respectively, and cash paid for amounts included in the measurement of lease liabilities for the three and six months ended June 30, 2020 was $205,000 and $393,000, respectively. These payments were included in net cash used in operating activities in the Company’s Consolidated Statements of Cash Flows.