Benzinga | Nov 3, 2020 09:03AM EST

Aptevo Therapeutics Announces First Complete Remission Observed In Ongoing APVO436 Phase 1 Clinical Trial

First Complete Remission Observed in a Patient in Cohort 6

Dosing Continues in Cohort 7

SEATTLE, WA / ACCESSWIRE / November 3, 2020 / Aptevo Therapeutics Inc. (NASDAQ:APVO), a clinical-stage biotechnology company focused on developing novel immuno-oncology therapeutics based on its proprietary ADAPTIR(tm) platform, today provided an update on its ongoing APVO436 Phase 1 clinical trial.

APVO436 is a novel anti-CD123 x anti-CD3 targeted investigational bispecific antibody therapy being evaluated for the treatment of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), in a Phase 1/1b open-label, dose-escalation study evaluating the safety and pharmacokinetic profile.

Aptevo is pleased to announce that, based on preliminary data, a patient in cohort 6 of the clinical trial has shown complete remission.

In summary:

* Patient bone marrow blasts decreased from 29% at screen to 6% after the first cycle of treatment, and to 0% after the second cycle of treatment; and,

* The patient's platelet count and absolute neutrophil count (ANC) met complete remission criteria (CR).

"We are greatly encouraged by the complete remission in the patient in cohort 6, which is a wonderful outcome for them," said Marvin White, President and CEO of Aptevo Therapeutics. "We are now in a critical phase of the study, as pharmacokinetic modelling suggests that dosing in cohorts 5 through 8 is in a therapeutic range, which could result in potential clinical activity of the drug. We look forward to continuing the dose escalation and monitoring potential clinical responses as we advance through the upcoming dose cohorts," concluded Mr. White.

APVO436 was built on Aptevo's next generation proprietary ADAPTIR(tm) protein therapeutic platform. Focused on generating novel, targeted bispecific antibody-based immunotherapies for cancer the ADAPTIR(tm) platform offers key advantages over other bispecific formats, derived in part from the flexible and modular nature of the ADAPTIR(tm) structure.

Aptevo believes that its differentiated ADAPTIR(tm) bispecific technology platform has the potential to offer a more convenient and cost-effective solution compared to other immunotherapies such as CAR-T therapies. While CAR-T therapies have proven effective in generating robust and durable treatment responses, they remain challenging and expensive to manufacture and administer to patients. In contrast, bispecific technologies may represent a simpler, more competitive 'off-the-shelf' solution in the rapidly advancing field of cancer immunotherapy.