Seattle-based biotechnology company Aptevo Therapeutics reported positive data from an ongoing Phase Ib trial, attracting many investors, according to BioSpace.

The company reported the complete remission of acute myeloid leukemia (AML) in a patient who received its experimental therapy – APVO436, a bispecific CD3xCD123 ADAPTIR.

After this promising clinical update, Aptevo stock rose dramatically to more than 46% in premarket trading to $9.52 per share.

In the trial, the high-risk AML patient was treated with a combination of chemotherapy and APVO436. They achieved complete remission after just one cycle of therapy, without any evidence of overt toxicity, according to the company.

Taking the positive findings of the Phase Ib trial into consideration, Aptevo believes that its therapy has the potential to help AML patients achieve complete remissions.

The biotechnology company also said that its treatment might be associated with a low risk of cytokine release syndrome and an increased likelihood of responses, per BioSpace.

Marvin White, President and CEO of Aptevo, said full data from the trial is expected in the first half of 2022. The findings from the trial will determine its clinical strategy for the continued development of the experimental AML treatment.

Earlier this month, Hilario Ramos, Senior Director, Head of Immunobiology at Aptevo, talked about the company’s oncology therapy – APVO603 – at the Society for Immunology in Cancers (SITC) 2021 Annual Meeting.

Ramos said APV0603 is a differentiated bispecific antibody with the potential to leverage the benefits of 4-1BB and OX40 in a single agent, according to BioSapce.

He said the investigational AML treatment could improve treatment options by targeting responses specifically to sites of active inflammation and limiting on-target toxicity.

Ramos said at the SITC meeting, “The data presented here demonstrate that this combination has the potential to promote anti-tumor responses two-fold. First, by improving the fitness of exhausted effector CD8+ T cells. Second, by reducing the potential for activation of suppressive responses by T regulatory subsets.”

“This dual biological mechanism of action offers the potential for development of a compound that acts against both solid and hematologic tumors and in the presence of addition immunomodulatory treatments or modalities such as CAR T or adoptive immune cell therapies,” he added.