UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | |------------------------------------------------------------|--------------------- ...

AACR Annual Meeting April 2019 – Abstract Number LB-199 Dosing Period (QW) Cmax (Dose 4) 11.4 mg/ml 63.4 mg/ml 256.4 mg/ml Clearance (Dose 4) 4.9 ml/hr/kg 4.0 ml/hr/kg 3.7 ml/hr/kg Half life (Dose 1) 63 hr (range 31.6 to 88.3) 74 hr (range 52 to 99.5) 73.4 hr (range 60.9 to 91) Half life (Dose 4) 26.4 hr (range <1 to 80.7) 18.8 hr (range <1 to 85.4) 37.7 hr (range 1.5 to 108) G r o u p 2 G r o u p 3 G r o u p 4 APVO436, a Bispecific anti-CD123 x anti-CD3 ADAPTIR™ Molecule for Redirected T-cell Cytotoxicity ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2018 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-37746 APTEVO THERAPEUTICS INC. (Exact name of Registrant as specified in its Charter) Delaware 81-1567056 (State or other jurisdictio ...