Relapse has emerged as the most important cause of treatment failure after allogeneic hematopoietic stem cell transplantation (HSCT). To test the hypothesis that natural killer (NK) cells can ...decrease the risk of leukemia relapse, we initiated a phase 1 dose-escalation study of membrane-bound interleukin 21 (mbIL21) expanded donor NK cells infused before and after haploidentical HSCT for high-risk myeloid malignancies. The goals were to determine the safety, feasibility, and maximum tolerated dose. Patients received a melphalan-based reduced-intensity conditioning regimen and posttransplant cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis. NK cells were infused on days −2, +7, and +28 posttransplant. All NK expansions achieved the required cell number, and 11 of 13 patients enrolled received all 3 planned NK-cell doses (1 × 105/kg to 1 × 108/kg per dose). No infusional reactions or dose-limiting toxicities occurred. All patients engrafted with donor cells. Seven patients (54%) developed grade 1-2 acute GVHD (aGVHD), none developed grade 3-4 aGVHD or chronic GVHD, and a low incidence of viral complications was observed. One patient died of nonrelapse mortality; 1 patient relapsed. All others were alive and in remission at last follow-up (median, 14.7 months). NK-cell reconstitution was quantitatively, phenotypically, and functionally superior compared with a similar group of patients not receiving NK cells. In conclusion, this trial demonstrated production feasibility and safety of infusing high doses of ex vivo–expanded NK cells after haploidentical HSCT without adverse effects, increased GVHD, or higher mortality, and was associated with significantly improved NK-cell number and function, lower viral infections, and low relapse rate posttransplant.
•High doses of NK cells expanded ex vivo with mbIL21-expressing feeder cells can be safely infused posthaplotransplant.•Infusion of NK cells was associated with improved NK-cell function, low relapse, and incidence of viral infections.
In this phase I/II clinical trial, we investigated the safety and efficacy of high doses of mb-IL21 ex vivo expanded donor-derived NK cells to decrease relapse in 25 patients with myeloid ...malignancies receiving haploidentical stem-cell transplantation (HSCT). Three doses of donor NK cells (1 × 10
-1 × 10
cells/kg/dose) were administered on days -2, +7, and +28. Results were compared with an independent contemporaneously treated case-matched cohort of 160 patients from the CIBMTR database.After a median follow-up of 24 months, the 2-year relapse rate was 4% vs. 38% (p = 0.014), and disease-free survival (DFS) was 66% vs. 44% (p = 0.1) in the cases and controls, respectively. Only one relapse occurred in the study group, in a patient with the high level of donor-specific anti-HLA antibodies (DSA) presented before transplantation. The 2-year relapse and DFS in patients without DSA was 0% vs. 40% and 72% vs. 44%, respectively with HR for DFS in controls of 2.64 (p = 0.029). NK cells in recipient blood were increased at day +30 in a dose-dependent manner compared with historical controls, and had a proliferating, mature, highly cytotoxic, NKG2C+/KIR+ phenotype.Administration of donor-derived expanded NK cells after haploidentical transplantation was safe, associated with NK cell-dominant immune reconstitution early post-transplant, preserved T-cell reconstitution, and improved relapse and DFS. TRIAL REGISTRATION: NCT01904136 ( https://clinicaltrials.gov/ct2/show/NCT01904136 ).
Allogeneic SCT for older patients remains challenging at least in part due to graft-versus-host disease (GVHD) and higher non-relapse mortality (NRM). We conducted a prospective pilot study primarily ...for older patients undergoing matched unrelated donor (MUD) SCT using a reduced-intensity (RIC) melphalan-based conditioning and post-transplant cyclophosphamide (PTCy)-based GVHD prophylaxis with tacrolimus and mycophenolate mofetil. Twenty-two patients (median age 64, IQR 58, 66) underwent RIC MUD SCT for high-risk hematological malignancies including AML/MDS (73%), CML/MPD (18%), and other (10%). Two (9%) patients had early death; the rest (100%) engrafted. After a median follow-up of 17 months, 11 patients were alive and disease-free with an estimated 2-year progression-free (PFS) and overall (OS) survival of 48%. The cumulative incidences of grades 2-4 and 3-4 acute GVHD (aGVHD) at day + 100 and 2-years were 32 and 4%, and 59 and 24%, respectively. No cases of chronic GVHD (cGVHD) were noted. However, late acute GVHD was observed in 6 (27%) patients. In conclusion, RIC MUD SCT with melphalan-based conditioning and PTCy-based GVHD-based prophylaxis for older patients appears effective in controlling relapse. While cGVHD was not seen and early aGVHD appears controllable, a significant proportion developed late aGVHD responsible for higher NRM seen in these patients.
Natural killer (NK)‐cells have potent anti‐tumor effects, yet it remains unclear if they are effective for patients with relapsed acute myeloid leukemia (AML). In a phase I clinical trial, we treated ...12 patients (median age 60 years) with refractory AML (median 5 lines of prior therapy, median bone marrow blast count of 47%) with fludarabine/cytarabine followed by 6 infusions of NK‐cells expanded from haploidentical donors using K562 feeder cells expressing membrane‐bound IL21 and 4‐1BBL. Patients received 106–107/kg/dose. No toxicity or graft‐versus‐host disease (GVHD) was observed and MTD was not reached. Seven patients (58.3%) responded and achieved a complete remission (CR) with/without count recovery. Median time to best response was 48 days. Five responding patients proceeded to a haploidentical transplant from the same donor. After a median follow‐up of 52 months, 1‐year overall survival (OS) for the entire group was 41.7%, better for patients who responded with CR/CRi (57.14%), and for patients who responded and underwent transplantation (60%). Persistence and expansion of donor‐derived NK‐cells were identified in patients' blood, and serum IFNγ levels rose concurrently with NK cell infusions. A higher count‐functional inhibitory KIR was associated with higher likelihood of achieving CR/CRi. In conclusion, we observed a significant response to ex vivo expanded NK‐cell administration in refractory AML patients without adverse effects.
Swimmer plot of patients treated on clinical trial and CF‐iKIR scores.
Background: Disease relapse following allogeneic stem-cell transplantation remains unacceptably high and there is an urgent need for new therapies that decrease relapse rates and improve survival ...post-transplant. Natural killer (NK) cells have potent antitumor effects, particularly those expended with mb-IL21 from peripheral blood. Preliminary data from a phase-1 dose-escalation study of up to 1x108 NK cells/Kg/dose and multiple dosing yielded promising results and a favorable safety profile (Ciurea SO.Blood.2017;130:18657). This report presents long-term follow-up from a phase-1/2 clinical trial in patients with high-risk myeloid malignancies (AML/MDS/CML) (clinicaltrials.gov NCT01904136) and a comparison with CIBMTR controls.
Methods: Patients received conditioning with fludarabine 160 mg/m2, melphalan 140 mg/m2 and 2GyTBI, post-transplant cyclophosphamide-based GVHD prophylaxis and bone marrow graft from a haploidentical donor. Ex vivo expanded NK cells were generated from peripheral blood mononuclear cells of the same donor with a K562 feeder cells expressing mb-IL21 and 41BB and infused fresh on Day-2, and cryopreserved on Day+7 and +28 (up to Day+90). 1x108/Kg/dose was chosen for the phase 2 trial. An independent matched-pair analysis was done using controls from the CIBMTR database stratified by conditioning intensity.
Results: 24/26 patients treated to date were evaluable (one short follow-up and one excluded as ineligible). 80% (19/24) of patients received all 3 doses of NK cells. The median age was 45 years (range 18-59), median follow-up was 43.6 months (range 15.1-60.9). Thirteen patients (54%) were females. 5 patients had donor-specific anti-HLA antibodies (DSA). The median HCT-CI was 2 (range 0-8), 12 patients (50%) had HCT-CI>3. 17 patients (72%) had AML/MDS and 7 (28%) advanced CML. Of AML/MDS patients, 10 (59%) had high-risk cytogenetics, 7 (41%) had measurable residual disease, 9 (53%) had intermediate/adverse-risk ELN2017 and 5 (29.4%) had primary induction failure. No infusion reactions or significant adverse events were observed to date.
All patients (100%) achieved engraftment after a median of 19 days (range 14-42). The cumulative incidence (CI) of grade 2-4 aGVHD was 29.2% at Day100 and 41.7% at 1-year post-transplant. Only one patient developed severe grade 3-4 aGVHD and one patient had extensive cGVHD. Only one patient relapsed (a patient with DSA who did not receive desensitization prior to transplantation), 1-year CI of relapse was 5.9%. The CI of TRM at 1-year for patients without DSA was 21%. The median overall survival and progression-free survival (PFS) were not reached. The 1-year and 3-year PFS for all patients and patients without DSA was 70.8% and 66.1%, and 79% and 72.9% for patients without DSA, respectively (Figure 1). One-year and 3-years GRFS for all patients and patients without DSA was 70.8% and 66.1%, and 79% and 72.9%, respectively.
An independent matched-pair analysis (at least 1:1) was conducted by CIBMTR after the first 18 patients treated on study in 07/2018 with RIC (N=57) or MAC (N=61) controls. The relapse was 1/18 vs 25/57 for RIC (p=0.037) and 15/61 for MAC (p=0.07), while the 1-year PFS was 82% vs 49% for RIC and 64% for MAC (p=0.21) (Figure 1). Updated results of this analysis will be presented at the meeting.
Conclusions: Results from this long-term follow-up analysis confirm very low relapse rate and excellent GRFS after haploSCT for patients treated with high-doses of NK cells expanded with mbIL21 stimulation. A prospective multi-center phase 2 BMTCTN study will evaluate the safetly and efficacy of high doses of NK cells for the prevention of relapse in patents with AML/MDS receiving haploSCT.
Display omitted
Ciurea:Miltenyi: Research Funding; Kiadis Pharma: Membership on an entity's Board of Directors or advisory committees, Other: stock holder; MolMed: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees. Bashir:Kite: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; StemLine: Research Funding; Acrotech: Research Funding; Celgene: Research Funding; Imbrium: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Pasquini:Novartis: Research Funding; Kite Pharmaceuticals: Research Funding; BMS: Research Funding; Medigene: Consultancy; Amgen: Consultancy; Pfizer: Consultancy. Lee:Kiadis Pharma: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.
▪
Background: Disease relapse has emerged as the most common cause of treatment failure after transplantation. Natural killer (NK) cells have potent antitumor and antiviral effects. We hypothesized ...that multiple infusions of ex vivo expanded NK cells administered in early post-transplant will enhance graft-versus-leukemia (GVL) effect and began a phase 1/2 clinical trial in haploidentical transplant patients (clinicaltrials.gov NCT01904136).
Methods: Results from the phase 1 clinical trial were recently reported. The aim was to determine the maximum tolerated dose of ex vivo expanded NK cells with a K562 expressing mb-IL21 feeder cell system in patients with myeloid malignancies (AML/MDs/CML). Patients received conditioning with melphalan 140mg/m2, fludarabine 160mg/m2 and 2GyTBI, and GVHD prophylaxis with post-transplant cyclophosphamide, tacrolimus and mycophenolate. All patients had bone marrow graft. NK cells were generated from peripheral blood mononuclear cells of the same donor and infused fresh on Day -2, and cryopreserved on Day +7 and +28 (up to 90). Having an NK-cell alloreactive donor or certain KIR genotype was not a requirement to participate in this study, although these characteristics were evaluated in all patients. In the phase 1 study dose escalation patients received NK cells starting at 1x105 to 1x108/Kg/dose for 3 doses. No dose limiting toxicities were observed in the phase 1 study. 1x108/kg/dose was chosen for the phase 2 trial.
Results: Twenty patients were treated to date, 13 on the phase 1 study and 7 on the phase 2 part. The median age was 45 years (range 18-59), the median follow-up survivors was 16.5 months. Twelve patients (60%) were females. The median HCT-CI was 2 (range 0-8). Ten patients (50%) had AML (9 in CR1 and 1 beyond CR2), 3 (15%) had MDS (2 with induction failure, 1 untreated), and 7 (35%) had advanced CML (4 in CP2 after progression to blast-phase of which 2 in CNS, 1 in CP1, 1 clonal evolution). Of the patients with AML 4 patients with AML had poor-risk cytogenetics and 6 had intermediate with high-risk mutations except one (2 had FLT3, 2 had NRAS, 1 had ASXL1) and 3 patients had primary induction failure. Two MDS patients had complex cytogenetics and one diploid with high percent of bone marrow blasts. DRI was very high/high in 10 patients and intermediate/low in 10 patients. All patients received all 3 NK cell infusions as planned except one patient. Eight patients received the maximum dose of 1x108/kg/dose.
One patient had early death due to hemorrhage. Nineteen patients were evaluable for engraftment and all achieve primary engraftment after a median time of 19 days (range 16-42). Nine of 12 female patients (75%) had donor-specific anti-HLA antibodies. Chimerism was 100% donor in all patients except one who had mixed chimerism. The cumulative incidence (CI) of all aGVHD at Day100 and 1 year post-transplant was 26.1% and 48% (3 patients had late acute GVHD), exclusively grade 2 and exclusively GI tract. No grade 3 or grade 4 aGVHD, and no chronic GVHD was observed. Also, none of the patients developed liver GVHD. The CI of TRM at 1 and 2 years post-transplant was 5.6% and 16.7%, respectively. Only one patient relapsed to date for a CI of relapse at 1 and 2 years on 5.6%. The only patient who relapsed was an advanced FLT3+AML patient (beyond CR2) who received the lowest NK cells dose. None of the patients who received ≥1x105/kg dose relapsed. The median overall survival and progression-free survival (PFS) were not reached. The 1-year and 2-years PFS was 84.4% and 74%, respectively (Figure 1). Eight of 19 patients (42%) reactivated CMV and 4 patients (21%) had grade 1 transient BKV cystitis.
Conclusions: Multiple infusions of high doses of donor-derived ex vivo expanded NK cells with a K562 feeder cell system and mbIL-21 administered early post-transplant are safe and are associated with low relapse rate and low incidence of viral reactivation. A randomized trial is needed to confirm these results.
Display omitted
Oran:Celgene: Research Funding; AROG: Research Funding; Astex: Research Funding. Lee:Courier Therapeutics, Inc: Membership on an entity's Board of Directors or advisory committees; Cyto-Sen Therapeutics, Inc: Other: Founder, Vice President, Medical Director; Intellia Therapeutics, Inc: Consultancy; Miltenyi: Speakers Bureau.
Background: Disease relapse remains the most common cause of treatment failure after transplantation. To enhance anti-tumor effect of the graft we explored the use of high doses of donor-derived ex ...vivo expanded NK cells administered after haploidentical stem cell transplantation (HaploSCT) with the ultimate goal to decrease relapsed rate post-transplant.
Methods: We aimed to study safety and determine the maximum tolerated dose (MTD) of high doses of mbIL-21 ex vivo expanded NK cells in a phase I clinical trial (clinicaltrials.gov NCT01904136) administered post-transplant in patients with myeloid malignancies (AML, CML, MDS). We hypothesized that infusion of mature NK cells would compensate for the lower NK-cell numbers and poor function previously observed by our group in the first month post-transplant. Patients received conditioning with melphalan 140mg/m2, fludarabine 160mg/m2 and 2GyTBI, and GVHD prophylaxis with post-transplant cyclophosphamide, tacrolimus and mycophenolate (Gaballa S, et al. Cancer. 2016). All patients had a bone marrow graft. NK cells were generated from peripheral blood mononuclear cells of the same donor with infusions on Days -2, +7 and on/after +28. The first infusion was with fresh and the other two were with cryopreserved NK cells. Dose escalation was planned in cohorts of 2 patients starting at 1x105 to 1x109 NK cells/Kg. Having an NK-cell alloreactive donor or certain KIR genotype was not a requirement to participate in this study, although these characteristics were evaluated in all patients.
Results: Thirteen patients were enrolled. Eight patients had AML (7 in CR1, 4 with high-risk cytogenetics, 3 had primary induction failure AML and 3 had +minimal residual disease (MRD) at transplant, and one FLT3+ AML in CR2 with persistent MRD by flow cytometry), and 5 had CML (4 in second chronic phase, 2 with prior CNS disease, one had associated MDS with monosomy 7, and 2 who failed multiple TKIs). The median age was 41.5 years (range 18-60). Five patients were males and 8 females. The NK-cell dose escalation was as follows: 1x105/kg (N=2), 1x106/kg (N=3), 1x107/kg (N=3), 3x107/kg (N=2) and 1x108/kg (N=2). One patient was treated with 1x104/kg (Dose -1). All patients received the 3 planned infusions except one. Median purity of the NK-cell product was 98.98%. All patients achieved primary engraftment (100%) with 100% donor chimerism except one patient (who received 1x104/kg) who had secondary graft failure with concurrent parainfluenza pneumonia and died of treatment-related mortality (TRM). The median time to neutrophil and platelet engraftment was 18 and 26 days, respectively. Of 12 patients evaluable for aGVHD, the maximum grade was II in 7 patients. No grade III-IV aGVHD or cGVHD was observed. Only 5/12 patients had CMV reactivation (41.6% compared with 71% in retrospective data with the same treatment without NK cells), while none developed BK virus hemorrhagic cystitis. All patients (N=12) achieved remission with negative MRD after transplant. One patient treated NK cells at 1x105/kg/dose relapsed, received salvage treatment and was alive at last follow-up. All other patients are alive and in complete remission (N=11) after a median follow-up of 12.8 months (range 6-25.1). Compared with patients treated on a previous clinical trial with the same conditioning without NK cells (AML in CR1/2 and CML in CP), the patients who received NK cells had marked improvement in NK-cell function and cytotoxicity, as well as a significantly increase in INF gamma and TNF alpha production. A lower relapse rate and improved survival was observed compared with the retrospective cohort of patients treated without NK cells, although not statistically significant (p=0.21) (Figure 1).
Conclusions: Doses up to 3x108/kg total dose of mbIL-21 ex vivo expanded NK cells obtained from the same donor can be safely administered in the early post-transplant period after HaploSCT. This was the maximum feasible dose to be manufactured in the current system, while no toxicity or increase in GVHD was observed. Three infusions of 1x108 NK cells per kg will be administered in the phase II study
Display omitted
Ciurea:Spectrum Pharmaceuticals: Other: Advisory Board; Cyto-Sen Therapeutics: Equity Ownership. Lee:Sanofi: Consultancy; Cyto-Sen Therapeutics: Equity Ownership, Other: Board of Directors; Intellia Therapeutics: Other: Advisory Board; Courier Therapeutics: Other: Advisory Board; Intrexon: Consultancy, Patents & Royalties; Shire: Other: Advisory Board; Ziopharm: Consultancy, Patents & Royalties. Bashir:Spectrum: Consultancy; Celgene: Research Funding; Takeda: Research Funding; Takeda: Consultancy. Champlin:Intrexon: Equity Ownership, Patents & Royalties; Ziopharm Oncology: Equity Ownership, Patents & Royalties.
PDF
