NKTR-255 is an interleukin-15 (IL-15) receptor agonist, which is currently being evaluated in a Phase 1 clinical study in patients with multiple myeloma (MM) and non-Hodgkin's lymphoma (
"The preclinical data being recognized at ASH demonstrate NKTR-255's promise in hematological malignancies through its potential to restore both NK cell and memory CD8 T cell compartments in patients," said Loui Madakamutil, Ph.D., Senior Vice President and Head of Discovery and Research at
Details of the preclinical data presentations at ASH are as follows and are available on the scientific section of Nektar's website at http://www.nektar.com/science/scientific-posters:
Abstract 2866: "Combination of NKTR-255, a polymer conjugated human IL-15, with CD19 CAR T cell immunotherapy in a preclinical lymphoma model," Chou, C., et al. (This study was conducted in collaboration with the
- Session: 625. Lymphoma: Pre-Clinical – Chemotherapy and Biologic Agents: Poster II
Sunday, December 8, 2019, 6:00 p.m.– 8:00 p.m. Eastern Standard Time
- CAR T cells treated with NKTR-255 demonstrate increased proliferation and survival both in vitro and in vivo which may in part be due to increased expression of bcl-2.
- Tumor bearing mice treated with NKTR-255 and CAR T cells have decreased tumor burden and increased survival compared to mice treated with CAR T cells alone.
- Tumor-bearing mice previously treated with NKTR-255 and CAR T cells are able to reject tumor re-challenge supporting persistence of functional CAR T cells.
Abstract 4398: "Restoring innate and adaptive immune repertoire in multiple myeloma for therapeutic application," Fernandez, R., et al. (This study was conducted in collaboration with Dr.
- Session: 652. Myeloma: Pathophysiology and Pre-Clinical Studies, Excluding Therapy: Poster III
Monday, December 9, 2019, 6:00 p.m.– 8:00 pm. Eastern Standard Time
- Multiple myeloma patients are known to experience impaired innate immunity and a decline in function of NK cells along with lower expression of activating receptors found on these cells.
- Treatment with NKTR-255 enhanced the number and function of both NK and CD8+ effector memory T cell populations in peripheral blood from healthy donors and MM patients in a dose dependent manner.
- NKTR-255 was also able to revert the inhibitory status of NK cells from MM patients and showed synergy with daratumumab and elotuzumab to significantly increase status of NK susceptibility of the MM cells.
- Findings suggest NKTR-255 delivers a significant impact on the activation of effector cell function to efficiently target MM cells.
Details of the Trials in
Abstract 4459: "A Phase 1, Open-Label, Multi-Center, Dose Escalation and Dose Expansion Study of NKTR-255 As a Single Agent in Relapsed or Refractory Hematologic Malignancies and in Combination with Daratumumab As a Salvage Regimen for Multiple Myeloma," Shah, N., et al.
- Session: 704. Immunotherapies: Poster III
Monday, December 9, 2019; 6:00 p.m.– 8:00 p.m. Eastern Standard Time
About the Phase 1 Study of NKTR-255 (NCT04136756)
NKTR-255 is currently being evaluated in an open-label Phase 1, dose escalation and dose expansion study in patients with select hematological malignancies (relapsed or refractory
NKTR-255 is an IL-15 receptor agonist designed to activate the IL-15 pathway and expand NK cells and promote the survival and expansion of memory CD8+ T cells without inducing suppressive regulatory T cells. Through optimal engagement of the IL-15Rα/IL-2Rβγ receptor complex, NKTR-255 enhances functional NK cell repopulation and formation of long-term immunological memory, which may lead to sustained anti-tumor immune response. NKTR-255 is uniquely designed to overcome the challenges of recombinant IL-15 and other IL-15 agonists, which are rapidly cleared from the body and have shown diminishing response to successive doses.1 Designed using Nektar's polymer conjugation technology to extend circulating half-life, NKTR-255 can be dosed every 14 or 21 days.
Cautionary Note Regarding Forward-Looking Statements
This press release contains forward-looking statements which can be identified by words such as: "promise," "potential," "design," "enhance," "may," "will" and similar references to future periods. Examples of forward-looking statements include, among others, statements we make regarding the expected benefits of NKTR-255 (both alone as a single agent as well as in combination with other agents, such as targeted antibodies), the ability to obtain useful data from the Phase 1 clinical study of NKTR-255, and the future clinical development plans for NKTR-255. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based only on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies, anticipated events and trends, and other future conditions. Because forward-looking statements relate to the future, they are subject to inherent uncertainties, risks and changes in circumstances that are difficult to predict and many of which are outside of our control. Our actual results may differ materially from those indicated in the forward-looking statements. Therefore, you should not rely on any of these forward-looking statements. Important factors that could cause our actual results to differ materially from those indicated in the forward-looking statements include, among others: (i) NKTR-255 is in early-stage clinical development and there are substantial risks that can unexpectedly occur for numerous reasons including negative safety and efficacy findings in the Phase 1 clinical study notwithstanding positive preclinical findings; (ii) clinical study outcomes, including the Phase 1 clinical study outcome of NKTR-255, remain very unpredictable and it is possible that a clinical study could fail due to efficacy, safety or other important clinical findings; (iii) the timing of the commencement or end of clinical trials and the availability of clinical data may be delayed or unsuccessful due to regulatory delays, slower than anticipated patient enrollment, manufacturing challenges, changing standards of care, evolving regulatory requirements, clinical trial design, clinical outcomes, and competitive factors; (iv) scientific discovery of new therapeutics is an inherently uncertain process and the future success of applying our technology platform to potential new drug candidates (such as NKTR-255) is therefore highly uncertain and unpredictable; (v) patents may not issue from our patent applications for NKTR-255, patents that have issued may not be enforceable, or additional intellectual property licenses from third parties may be required; and (vi) certain other important risks and uncertainties set forth in Nektar's Quarterly Report on Form 10-Q filed with the
1. Blood 2018
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