Exhibit 31.2

CERTIFICATIONS

I, Mark Guerin, certify that:

1. I have reviewed this Annual Report on Form 10-K/A of Onconova Therapeutics, Inc.; and

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report.

Dated: May 1, 2023

/s/ MARK GUERIN

Mark Guerin

Chief Operating Officer and Chief Financial Officer

(Principal Financial Officer)