Financial Instruments

12 Months Ended

Dec. 31, 2019

Fair Value Measurements

We classify the inputs used to measure fair value into the following hierarchy:



Level 1	Unadjusted quoted prices in active markets for identical assets or liabilities.

Level 2	Unadjusted quoted prices in active markets for similar assets or liabilities, or unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are observable for the asset or liability.

Level 3	Unobservable inputs for the asset or liability.

At December 31, 2019, we had no financial assets or liabilities measured at fair value on a recurring basis.

The Healios Warrant that was issued in March 2018 was measured at fair value on a nonrecurring basis and is a Level 3 equity instrument under the hierarchy. Refer to Note F regarding its valuation.

Financing Arrangements

We lease office and laboratory space under operating leases. The lease for our corporate offices and laboratories began in 2000 and currently expires in March 2021, with options to renew annually through March 2024. Our rent is approximately $267,000 per year and our rental rate has not changed since the lease inception in 2000. We also lease office and laboratory space for our Belgian subsidiary, which expires in July 2021. Annual rent expense is approximately $190,000, subject to adjustments based on an inflationary index.

Aggregate rent expense for the years ended December 31, 2018 and 2017 recognized prior to the adoption of Topic 842 was approximately $493,000 and $477,000, respectively. Refer to Note J regarding our adoption of Topic 842 in January 2019 to account for our leases.