(MENAFN Editorial) SEATTLE, Jan. 08, 2018 (GLOBE NEWSWIRE) -- Aptevo Therapeutics Inc. (Nasdaq:), a biotechnology company focused on developing novel oncology and hematology therapeutics, today announced that it has commenced patient dosing in a Phase 2 clinical evaluation of otlertuzumab in a new indication – peripheral T-cell lymphoma (PTCL). Otlertuzumab is a monospecific antibody targeting CD37 that was built on Aptevo's ADAPTIR™ modular protein therapeutic platform.

'Clinical proof-of-concept data from a randomized Phase 2 study demonstrated the efficacy and tolerability of otlertuzumab with bendamustine in relapsed chronic lymphocytic lymphoma (CLL). In this study there was a significant increase in median progression free survival, from approximately 10 to 16 months in patients receiving the combination of otlertuzumab and bendamustine,' said Scott Stromatt, M.D., Senior Vice President and Chief Medical Officer for Aptevo. 'We were intrigued by recent reports in the literature showing that CD37 appears to be overexpressed in various T-cell lymphomas, suggesting a potential role for otlertuzumab in the treatment of T-cell malignancies. If the proof-of-concept clinical data in CLL translate to PTCL, this could open up a promising new market opportunity for otlertuzumab in the treatment of T-cell malignancies where there is a significant need for safe and effective new treatments.'

The Phase 2 study is an open-label, proof-of-concept evaluation of the safety and efficacy of otlertuzumab in combination with bendamustine in patients with relapsed or refractory peripheral T-cell lymphomas (PTCL). Up to 24 patients will be enrolled in the study. The primary endpoint is response rate, evaluable by the 2017 International Working Group consensus response evaluation criteria in lymphoma (RECIL 2017).

About Otlertuzumab
Otlertuzumab is a monospecific antibody targeting CD37 that was built on Aptevo's ADAPTIR modular protein therapeutic platform. CD37 is a member of the tetraspanin superfamily of molecules and is expressed on the surface of normal and transformed B cells, and also recently discovered to be present on the surface of T-cell lymphomas.

About PTCL
According to the Lymphoma Research Foundation, peripheral T-cell lymphoma (PTCL) consists of a group of rare and typically aggressive Non-Hodgkin lymphomas (NHLs) that develop from mature T-cells. Most T-cell lymphomas (a type of blood cancer) are classified as PTCLs. Treatment options for relapsed and refractory PTCL are limited, with only two approved drugs on the market, FOLOTYN and ISTODAX, with worldwide sales of approximately $50 million and $80 million, respectively.

ADAPTIR Clinical and Preclinical Portfolio:

APVO414 – a bispecific ADAPTIR candidate, currently in Phase 1 development, targeting prostate specific membrane antigen (PSMA), an enzyme that is expressed on the surface of prostate cancer cells, and, CD3, a component of the T cell receptor complex expressed on all T cells. APVO414 redirects T cells to specifically kill PSMA expressing tumors and is being developed for metastatic castration-resistant prostate cancer, which is advanced prostate cancer that has spread to other organs and no longer responds to hormone blocking therapies.

Otlertuzumab – a monospecific ADAPTIR candidate currently in Phase 2 development for the treatment of peripheral T-cell lymphoma (PTCL). Otlertuzumab has been studied in over 250 patients with CLL or indolent NHL. A previous Phase 2 clinical study evaluating otlertuzumab for the treatment of relapsed chronic lymphocytic leukemia (CLL) have shown that otlertuzumab in combination with bendamustine, compared to bendamustine alone, demonstrated a significant increase in median progression free survival for the combination, from approximately 10 to 16 months.

APVO436 – a bispecific ADAPTIR candidate currently in preclinical development targeting CD123, a cell surface receptor highly expressed on several hematological malignancies and CD3, a component of the T cell receptor. APVO436 engages T cells to initiate killing of tumor cells.

ALG.APV-527 – a bispecific antibody candidate, partnered with Alligator Bioscience, featuring a novel mechanism of action designed to simultaneously target 4-1BB (CD137) and 5T4, a tumor antigen widely overexpressed in a number of different types of cancer. 4-1BB, a costimulatory receptor on T cells, is known to enhance the immune response to cancer through activation of tumor-specific T cells and is believed to be a promising target for new immunotherapeutic approaches. ALG.APV-527 could potentially have utility in the treatment of a broad spectrum of cancers over-expressing the tumor antigen, including breast, cervical, non-small-cell-lung, prostate, renal, gastric, colorectal and bladder cancers.

APVO210 – a bispecific ADAPTIR preclinical candidate with a novel mechanism of action based on targeted cytokine delivery. APVO210 is composed of a humanized anti-CD86 antibody fused with a modified form of IL-10 that specifically induces IL-10 signaling on antigen presenting cells, but not on lymphoid populations. APVO210 functions by suppressing immune responses and inducing certain tolerogenic responses and therefore may have potential benefit for the treatment of autoimmune and inflammatory diseases.

ROR1 Bispecific – a proof-of-concept bispecific candidate targeting ROR1, an antigen found on several solid tumors and hematologic, or blood-related malignancies. Initial preclinical data demonstrate redirected T cell killing of tumors expressing ROR1 in vitro and in vivo in animal models.

About Aptevo Therapeutics Inc.

Aptevo Therapeutics Inc. is a clinical-stage biotechnology company focused on novel oncology and hematology therapeutics to meaningfully improve patients' lives. Aptevo has a commercial product, IXINITY® coagulation factor IX (recombinant), approved and marketed in the United States for the treatment of Hemophilia B, and a versatile core technology – the ADAPTIR™ modular protein technology platform capable of generating highly-differentiated bispecific antibodies with unique mechanisms of action to treat cancer and autoimmune diseases. Aptevo has two ADAPTIR antibody candidates currently in clinical development and a broad pipeline of novel investigational-stage bispecific antibody candidates focused in immuno-oncology and autoimmune disease and inflammation. For more information, please visit

Safe Harbor Statement

This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Any statements, other than statements of historical fact, including, without limitation, statements regarding potential milestone payments, Aptevo's outlook, financial performance or financial condition, Aptevo's technology and related pipeline, collaboration and partnership opportunities, commercial portfolio, and any other statements containing the words 'believes,' 'expects,' 'anticipates,' 'intends,' 'plans,' 'forecasts,' 'estimates,' 'will' and similar expressions are forward-looking statements. These forward-looking statements are based on Aptevo's current intentions, beliefs and expectations regarding future events. Aptevo cannot guarantee that any forward-looking statement will be accurate. Investors should realize that if underlying assumptions prove inaccurate or unknown risks or uncertainties materialize, actual results could differ materially from Aptevo's expectations. Investors are, therefore, cautioned not to place undue reliance on any forward-looking statement. Any forward-looking statement speaks only as of the date of this press release, and, except as required by law, Aptevo does not undertake to update any forward-looking statement to reflect new information, events or circumstances.

There are a number of important factors that could cause Aptevo's actual results to differ materially from those indicated by such forward-looking statements, including a deterioration in Aptevo's business or prospects; adverse developments in research and development; adverse developments in the U.S. or global capital markets, credit markets or economies generally; and changes in regulatory, social and political conditions. Additional risks and factors that may affect results are set forth in Aptevo's filings with the Securities and Exchange Commission, including its most recent Annual Report on Form 10-K, as filed on March 31, 2017, and its subsequent reports on Form 10-Q and current reports on Form 8-K. The foregoing sets forth many, but not all, of the factors that could cause actual results to differ from Aptevo's expectations in any forward-looking statement.

Source:

Aptevo Therapeutics
Stacey Jurchison
Senior Director, Investor Relations and Corporate Communications
206-859-6628

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