Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Other current assets	$ 1,519	$ 928
Prepaid Expenses [Member]
Other current assets	1,500	900
Prepaid Expenses [Member] | BP1002 in lymphoma, prexigebersen in AML and prexigebersen-A [Member]
Other current assets	1,000	600
Other Prepaid Expenses [Member] | BP1002 in lymphoma, prexigebersen in AML and prexigebersen-A [Member]
Prepaid insurance	400	$ 300
Prepaid expenses related to preclinical studies	$ 100