Hypomethylating agent monotherapy in core binding factor acute myeloid leukemia: a French multicentric retrospective study.

Very few data are available about hypomethylating agent (HMA) efficiency in core binding factor acute myeloid leukemias (CBF-AML). Our main objective was to evaluate the efficacy and safety of HMA in the specific subset of CBF-AML. Here, we report the results of a multicenter retrospective French study about efficacy of HMA monotherapy, used frontline or for R/R CBF-AML. Forty-nine patients were included, and received a median of 5 courses of azacitidine (n = 46) or decitabine (n = 3). ORR was 49% for the whole cohort with a median time to response of 112 days. After a median follow-up of 72.3 months, median OS for the total cohort was 10.6 months. In multivariate analysis, hematological relapse of CBF-AML at HMA initiation was significantly associated with a poorer OS (HR: 2.13; 95%CI: 1.04-4.36; p = 0.038). Responders had a significantly improved OS (1-year OS: 75%) compared to non-responders (1-year OS: 15.3%; p < 0.0001). Hematological improvement occurred for respectively 28%, 33% and 48% for patients who were red blood cell or platelet transfusion-dependent, or who experienced grade 3/4 neutropenia at HMA initiation. Adverse events were consistent with the known safety profile of HMA. Our study highlights that HMA is a well-tolerated therapeutic option with moderate clinical activity for R/R CBF-AML and for patients who cannot handle intensive chemotherapy.

Arginine metabolism regulates human erythroid differentiation through hypusination of eIF5A.

Metabolic programs contribute to hematopoietic stem and progenitor cell (HSPC) fate, but it is not known whether the metabolic regulation of protein synthesis controls HSPC differentiation. Here, we show that SLC7A1/cationic amino acid transporter 1-dependent arginine uptake and its catabolism to the polyamine spermidine control human erythroid specification of HSPCs via the activation of the eukaryotic translation initiation factor 5A (eIF5A). eIF5A activity is dependent on its hypusination, a posttranslational modification resulting from the conjugation of the aminobutyl moiety of spermidine to lysine. Notably, attenuation of hypusine synthesis in erythroid progenitors, by the inhibition of deoxyhypusine synthase, abrogates erythropoiesis but not myeloid cell differentiation. Proteomic profiling reveals mitochondrial translation to be a critical target of hypusinated eIF5A, and accordingly, progenitors with decreased hypusine activity exhibit diminished oxidative phosphorylation. This affected pathway is critical for eIF5A-regulated erythropoiesis, as interventions augmenting mitochondrial function partially rescue human erythropoiesis under conditions of attenuated hypusination. Levels of mitochondrial ribosomal proteins (RPs) were especially sensitive to the loss of hypusine, and we find that the ineffective erythropoiesis linked to haploinsufficiency of RPS14 in chromosome 5q deletions in myelodysplastic syndrome is associated with a diminished pool of hypusinated eIF5A. Moreover, patients with RPL11-haploinsufficient Diamond-Blackfan anemia as well as CD34+ progenitors with downregulated RPL11 exhibit a markedly decreased hypusination in erythroid progenitors, concomitant with a loss of mitochondrial metabolism. Thus, eIF5A-dependent protein synthesis regulates human erythropoiesis, and our data reveal a novel role for RPs in controlling eIF5A hypusination in HSPCs, synchronizing mitochondrial metabolism with erythroid differentiation.

Retrospective, real-life study of venetoclax plus azacitidine or low-dose cytarabine in French patients with acute myeloid leukemia ineligible for intensive chemotherapy.

BACKGROUND: Recently, the combination of venetoclax plus a hypomethylating agent (HMA; azacitidine ordecitabine) or low-dose cytarabine (LDAC) showed promise in Phase III trials in previously untreated AML. In France at the time of this study, venetoclax was not yet approved for AML and there were therefore no formal usage recommendations. Here we report the first study in a French cohort that assessed venetoclax in combination with existing treatments for AML under real-life conditions. METHOD: This retrospective, real-life study collected data on venetoclax use and management in a French cohort with acute myeloid leukemia (AML) ineligible for intensive chemotherapy. RESULT: Of 118 patients, 81 were in second line/beyond (71.6% also hypomethylating agent [HMA]; 23.5% lowdose cytarabine [LDAC]) and 37 in first line. For venetoclax initiation, 57.3% underwent ramp up and 74.6% were hospitalized. Median venetoclax duration was 2.5 months (range 0.03-16.2). With all treatment lines and regimens, most common grade 3/4 adverse events were hematologic (overall 96.4% of patients) and infections (57.1%). Dosage adjustments for drug interactions and safety varied between centers. In second-line/beyond, median progression-free survival was 4.0 months (95% confidence interval [CI] 2.7-12.8) with venetoclax-HMA and 3.4 months (1.3-8.9) with venetoclax-LDAC; overall response rate was 51.9% and 41.2%, respectively. Thus, we showed that venetoclax-based treatment yields promising findings in patients with AML, but to address treatment complexity, practice harmonization is needed.

[Management of neurotoxicity following CAR-T cell therapy: Recommendations of the SFGM-TC]. / Prise en charge du syndrome de neurotoxicité associée au traitement par cellules CAR-T chez l'adulte et l'enfant : recommandations de la SFGM-TC.

The immune effector cell-associated syndrome (ICANS) has been described as the second most frequent specific complication following CAR-T cell therapy. The median time to the onset of neurological symptoms is five days after CAR-T infusion. ICANS can be concomitant to cytokine release syndrome but often follows the resolution of the latter. However, 10 % of patients experience delayed onset after 3 weeks of CAR-T cell infusion. The duration of symptoms is usually short, around five days if an early appropriate treatment is given. Symptoms are heterogeneous, ranging from mild symptoms quickly reversible (alterations of consciousness, deterioration in handwriting) to more serious forms with seizures or even a coma. The ICANS severity is currently based on the ASTCT score. The diagnosis of ICANS is clinical but EEG, MRI and lumbar punction can help ruling out alternative diagnoses. The first line treatment consists of high-dose corticosteroids. During the twelfth edition of practice harmonization workshops of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC), a working group focused its work on updating the SFGM-TC recommendations on the management of ICANS. In this review we discuss the management of ICANS and other neurological toxicities in patients undergoing of CAR-T cell therapy. These recommendations apply to commercial CAR-T cells, in order to guide strategies for the management neurological complications associated with this new therapeutic approach.

[Management of cytokine release syndrome and macrophage activation syndrome following CAR-T cell therapy: Guidelines from the SFGM-TC]. / Prise en charge du syndrome de relargage cytokinique et du syndrome d'activation macrophagique après traitement par CAR-T cells : recommandations de la SFGM-TC.

The use of chimeric antigen receptor T cells (CAR-T) has increased since their approval in the treatment of several relapsed/refractory B cell malignancies. The management of their specific toxicities, such as cytokine release syndrome (CRS), tends to be better understood and well-defined. During the twelfth edition of practice harmonization workshops of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC), a working group focused its work on the management of patients developing CRS following CAR-T cell therapy. A special chapter has been allocated to macrophage activation syndrome (MAS), a rare but life-threatening complication post-CAR-T. In addition to symptomatic measures and preemptive broad-spectrum antibiotics, immunomodulators such as tocilizumab and corticosteroids remain the corner stone for the treatment of CRS. Tocilizumab/corticosteroids-resistant CRS associated with haemophagocytosis markers (spleen and liver enlargement, hyperferritinaemia>10,000ng/mL, hypofibrinogenemia…) should direct the diagnosis towards an overlapping CRS/MAS. An adapted treatment will be based on high-dose IV anakinra and corticosteroids and chemotherapy with etoposide at late refractory stages. These complications and others delignate the need of close collaboration with an intensive care unit.

[Prevention and management of infections in patients undergoing CAR T-cell therapy: Recommendations of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Prise en charge prophylactique, thérapeutique des complications infectieuses et vaccination des patients traités par CAR-T cells : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

Infections occurring after CAR T-cells are a common complication. At the acute phase of treatment following CAR T-cell infusion, the exact incidence of infections is unknown given the overlapping symptoms with cytokine release syndrome. The risk factors for infection include the malignant underlying disease and its multiple treatments, and an immunosuppressive state induced by CAR-T cells themselves and the treatment of their complications. During the twelfth edition of practice harmonization workshops of the Francophone society of bone marrow transplantation and cellular therapy (SFGM-TC), a working group focused its work on the management of post-CAR infectious complications. In this review we discuss anti-infection prophylaxis and vaccination of patients undergoing CAR T-cell therapy as well as a special chapter for the specific case of COVID-19. These recommendations apply to commercial CAR-T cells, in order to guide strategies for the management and prevention of infectious complications associated with this new therapeutic approach.

[Complications other than infections, CRS and ICANS following CAR T-cells therapy: Recommendations of the Francophone Society of bone marrow transplantation and cell therapy (SFGM-TC)]. / Complications des cellules CAR-T autres que les infections, CRS et ICANS : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

CAR-T cells are an innovative treatment for an increasing number of patients, particularly since the extension of their indication to mantle lymphoma and multiple myeloma. Several complications of CAR T-cell therapy, that were first described as exceptional, have now been reported in series of patients, since its first clinical use in 2011. Among them, cardiac complications, delayed cytopenias, acute and chronic Graft versus Host Disease, and tumoral lysis syndrome are recognized as specific potent complications following CAR T-cells infusion. During the twelfth edition of practice harmonization workshops of the Francophone society of bone marrow transplantation and cellular therapy (SFGM-TC), a working group focused its work on the management of these complications with focuses the epidemiology, the physiopathology and the risk factors of these 4 side effects. Our recommendations apply to commercial CAR-T cells, in order to guide strategies for the management of complications associated with this new therapeutic approach.

Angiogenic factors could help us to define patients obtaining complete response with undetectable minimal residual disease in untreated CLL patients treated by FCR: results from the CLL2010FMP, a FILO study.

Angiogenesis is in a constant balance between pro and anti-angiogenic factors. Neoangiogenesis, implicated in metastatic spreading is characterized in solid cancers, but fairly new in chronic lymphocytic leukemia (CLL). We hypothesize that secretion of angiogenic factors could be correlated to the pathogenesis of CLL, and therefore predict the outcome of patients. We investigated concentrations of 22 cytokines and chemokines in 137 non-del 17p B-CLL patients, treated with a fludarabine-cyclophosphamide-rituximab (FCR)-based regimen. We constructed a biomarker index defining different risk groups based on lymphocyte count, the intensity of CD20 antigen on CD19+ cells, Ang-2, and PDGF-BB plasma concentrations at diagnosis. Four groups were defined, exhibiting specific molecular signatures and correlated with progression-free survival of patients. Our results suggest that we can determine at diagnosis of non-del 17p B-CLL patients, those with a very high probability of progression-free survival, independently of IGVH mutational status and residual disease at the end of treatment.

[National patient follow-up care logbook: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Carnet national de suivi post-allogreffe de l'adulte : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

In an attempt to harmonize clinical practices among francophone hematopoietic stem cell transplantation centers, the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) held its eleventh annual workshop series in September 2020 in Lille. This event brought together practitioners from across Europe. Our article discusses the updates and modifications for the 2021 version of the national patient follow-up care logbook.

Conventional chemotherapy for acute myeloid leukemia in older adults: Impact on nutritional, cognitive, and functional status.

OBJECTIVES: The impact of conventional treatment for acute myeloid leukemia (AML) on the nutritional, cognitive, and functional status of elderly patients is seldom studied. This assessment was performed in the context of the LAMSA 2007 trial. METHODS: The trial enrolled 424 patients with de novo AML. Among them, 316 benefited from geriatric assessment (GA) including nutritional, cognitive, and functional status and were scored according to Eastern Cooperative Oncology Group (ECOG) and sorror for the prediction of treatment toxicity, morbidity, and mortality. Patients were investigated at diagnosis for three times during follow-up. RESULTS: This study showed that AML and its treatment have no impact on cognitive (P = .554) nor functional status (P = .842 for Activity of Daily Living and P = .087 for Instrumental Activities of Daily Living). The nutritional status improved over time (P = .041). None of these three parameters at baseline, associated or not with ECOG and sorror scores, impacted survivals or toxicities. CONCLUSIONS: The cognitive, functional, and nutritional status had no impact in this cohort of fit elderly AML patients without unfavorable cytogenetics. The GA tools used provided no additional information compared with ECOG and sorror scores, to predict toxicity, morbidity, or mortality due to intensive chemotherapy.

Post-transplantation cyclophosphamide versus antithymocyte globulin in patients with acute myeloid leukemia undergoing allogeneic stem cell transplantation from HLA-identical sibling donors: A retrospective analysis from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

BACKGROUND: Graft-versus-host disease (GVHD) is a major complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Addition of antithymocyte globulin (ATG) or post-transplantation cyclophosphamide (PTCY) to standard immunosuppressive agents reduces GVHD in different donor settings. METHODS: We compared the outcomes of adults with acute myeloid leukemia undergoing allo-HSCT from HLA-identical sibling donors after the use of PTCY (n = 197) or ATG (n = 1913). RESULTS: Patients in the PTCY group were younger than those in the ATG group (median age, 47 vs 54 years; P < .01). Peripheral blood was the most frequently used stem cell source, being significantly more frequent in the ATG group than in the PTCY group (95% vs 70% P < .01). The conditioning regimen was more frequently myeloablative in the PTCY group than in the ATG group (59% vs 48%; P < .01). Time to neutrophil engraftment was shorter in the ATG group than in the PTCY group (17 vs 20 days; P < .01). No differences were observed according to the other transplantation outcomes, except for chronic GVHD of all grades and extensive chronic GVHD at 2 years, which were significantly lower in the ATG group compared with the PTCY group (P < .02). CONCLUSION: PTCY is feasible in an HLA-identical sibling setting, and despite similar outcomes, ATG may be associated with lower incidence of chronic GVHD.

A Retrospective Comparison of DLI and gDLI for Post-Transplant Treatment.

Donor lymphocyte infusion (DLI) is used to prevent or treat haematological malignancies relapse after allogeneic stem cell transplantation (allo-SCT). Recombinant human granulocyte colony-stimulated factor primed DLI (gDLI) is derived from frozen aliquots of the peripheral blood stem cell collection. We compared the efficacy and safety of gDLI and classical DLI after allo-SCT. We excluded haploidentical allo-SCT. Initial diseases were acute myeloblastic leukaemia (n = 45), myeloma (n = 38), acute lymphoblastic leukaemia (n = 20), non-Hodgkin lymphoma (n = 10), myelodysplasia (n = 8), Hodgkin lymphoma (n = 8), chronic lymphocytic leukaemia (n = 7), chronic myeloid leukaemia (n = 2) and osteomyelofibrosis (n = 1). Indications for DLI were relapse (n = 96) or pre-emptive treatment (n = 43). Sixty-eight patients had classical DLI and 71 had gDLI. The response rate was 38.2%, the 5-year progression-free survival (PFS) rate was 38% (29-48) and the 5-year overall survival (OS) rate was 37% (29-47). Graft versus host disease rate was 46.7% and 10.1% of patients died from toxicity. There were no differences between classical DLI and gDLI in terms of response (p = 0.28), 5-year PFS (p = 0.90), 5-year OS (p. 0.50), GvHD (p = 0.86), treated GvHD (p = 0.81) and cause of mortality (p. 0.14). In conclusion, this study points out no major effectiveness or toxicity of gDLI compared to classical DLI.

Fludarabine/busulfan versus fludarabine/total-body-irradiation (2 Gy) as conditioning prior to allogeneic stem cell transplantation in patients (≥60 years) with acute myelogenous leukemia: a study of the acute leukemia working party of the EBMT.

Nonmyeloablative (NMA) conditioning regimens facilitate allogeneic stem cell transplantation (alloSCT) in elderly patients and/or in those with comorbidities. The acute leukemia working party (ALWP) of the European Society for Blood and Marrow Transplantation (EBMT) compared the outcomes of patients ≥60 years with AML in first complete remission (CR1), that had received an alloSCT following NMA conditioning, i.e. either fludarabine/busulfan (FB2) or fludarabine/total-body-irradiation-2Gy (FluTBI2Gy). A total of 1088 patients were included (median age 65 years). Donors were matched siblings (MSD) and matched unrelated donors (MUD) in 47% and 53%, respectively. In vivo T-cell depletion (TCD) was applied to 79% and none (0%) of patients in the FB2 and FluTBI2Gy groups, respectively. In the MSD group we found a trend for less extensive cGVHD in patients receiving FB2 with in vivo TCD, HR: 0.49, p = 0.08, and in those without worse NRM, HR: 2.14, p = 0.04, and a trend for more total cGVHD, HR: 1.61, p = 0.09. Patients transplanted from MUDs had a significantly higher incidence of total cGVHD, extensive cGVHD and a worse GRFS with FluTBI2Gy in comparison to FB2, HR: 2.44; p < 0.0001; HR 4.59; p < 0.00001 and HR: 1.35; p = 0.03, respectively. No differences were observed with respect to LFS, OS, RI, NRM, and aGVHD.

Association of Occupational Pesticide Exposure With Immunochemotherapy Response and Survival Among Patients With Diffuse Large B-Cell Lymphoma.

Importance: Professional use of pesticides is a risk factor for non-Hodgkin lymphoma. The main biological mechanisms of pesticides and chemotherapy are genotoxicity and reactive oxygen species generation. Cellular adaptation among patients exposed to low doses of genotoxic and oxidative compounds might hinder chemotherapy efficiency in patients with lymphoma. Objective: To examine the association of occupational exposure to pesticides with immunochemotherapy response and survival among patients treated for diffuse large B-cell lymphoma. Design, Setting, and Participants: This retrospective cohort study assessed patients treated from July 1, 2010, to May 31, 2015, for diffuse large B-cell lymphoma, with a 2-year follow-up. The study took place at 6 university and nonuniversity hospitals in Languedoc-Roussillon, France. A total of 404 patients with newly diagnosed diffuse large B-cell lymphoma treated with anthracycline-based immunochemotherapy were included before the study began. Occupational history was reconstructed for 244 patients and analyzed with the PESTIPOP French job-exposure matrix to determine likelihood of occupational exposure to pesticides. Analysis of the data was performed from July 15, 2017, to July 15, 2018. Main Outcomes and Measures: Treatment failure (ie, partial response, stable disease, disease progression, or interruption for toxic effects) rate, 2-year event-free survival, and overall survival between exposed and nonexposed patients after adjustment for confounding factors. Results: A total of 244 patients (mean [SD] age, 61.3 [15.2] years; 153 [62.7%] male) had complete occupational data. Of these patients, 67 (27.4%) had occupational exposure to pesticides, with 38 exposed through agricultural occupations. Occupational exposure was not associated with clinical and biological characteristics at diagnosis. Occupationally exposed patients had a significantly higher treatment failure rate (22.4% vs 11.3%; P = .03; adjusted odds ratio [AOR] for confounding factors, 3.0; 95% CI, 1.3-6.9); this difference was higher among patients with exposing agricultural occupations compared with other patients (29.0% vs 11.7%; AOR, 5.1; 95% CI, 2.0-12.8). Two-year event-free survival was 70% in the occupationally exposed group vs 82% in the unexposed group (adjusted hazard ratio [AHR] for confounding factors, 2.2; 95% CI, 1.3-3.9). Among patients with exposing agricultural occupations compared with other patients, the difference was more pronounced (2-year event-free survival, 56% vs 83%; AHR, 3.5; 95% CI, 1.9-6.5). Similarly, 2-year overall survival was lower in the group of patients with exposing agricultural occupations compared with other patients (81% vs 92%; AHR, 3.9; 95% CI, 1.5-10.0). Conclusions and Relevance: This retrospective study showed that agricultural occupational exposure to pesticides was associated with treatment failure, event-free survival, and overall survival among patients with diffuse large B-cell lymphoma.

Infusion-related reactions to rituximab: frequency, mechanisms and predictors.

INTRODUCTION: Rituximab, an anti-CD20 monoclonal antibody (mAb), is indicated in the treatment of B-cell non-Hodgkin lymphomas, chronic lymphoid leukemia, and rheumatoid arthritis. The occurrence of infusion-related reactions (IRR), especially during the first infusion, is one of the main concerns of rituximab, otherwise well tolerated. Although IRR are usually mild to moderate, fatal evolutions have been reported. These reactions are not specific to rituximab and also observed with other compounds, including those recruiting effectors cells. Further studies are required to predict the frequency and severity of such reactions, to avoid life-threatening complications, especially in the first-in-human studies. Areas covered: This review reports data available to date on the occurrence of IRR induced by rituximab. Then, factors associated with IRR are described, with proposed pathogenic mechanisms of IRR. Finally, different methods to prevent and manage IRR are reported. Expert opinion: Various factors have been associated with the occurrence and severity of IRR. A predictive model of IRR is of importance to prevent life-threatening IRR or detrimental interruption of rituximab therapy. This model would combine parameters, such as the number of CD20 positive cells and NK cells (CD16 positive), together with the level of CD20 and CD16 expressions, and FCGR3Apolymorphism.

A safe and highly efficient tumor-targeted type I interferon immunotherapy depends on the tumor microenvironment.

Despite approval for the treatment of various malignancies, clinical application of cytokines such as type I interferon (IFN) is severely impeded by their systemic toxicity. AcTakines (Activity-on-Target cytokines) are optimized immunocytokines that, when injected in mice, only reveal their activity upon cell-specific impact. We here show that type I IFN-derived AcTaferon targeted to the tumor displays strong antitumor activity without any associated toxicity, in contrast with wild type IFN. Treatment with CD20-targeted AcTaferon of CD20+ lymphoma tumors or melanoma tumors engineered to be CD20+, drastically reduced tumor growth. This antitumor effect was completely lost in IFNAR- or Batf3-deficient mice, and depended on IFN signaling in conventional dendritic cells. Also the presence of, but not the IFN signaling in, CD8+ T lymphocytes was critical for proficient antitumor effects. When combined with immunogenic chemotherapy, low-dose TNF, or immune checkpoint blockade strategies such as anti-PDL1, anti-CTLA4 or anti-LAG3, complete tumor regressions and subsequent immunity (memory) were observed, still without any concomitant morbidity, again in sharp contrast with wild type IFN. Interestingly, the combination therapy of tumor-targeted AcTaferon with checkpoint inhibiting antibodies indicated its ability to convert nonresponding tumors into responders. Collectively, our findings demonstrate that AcTaferon targeted to tumor-specific surface markers may provide a safe and generic addition to cancer (immuno)therapies.

Early-onset invasive aspergillosis and other fungal infections in patients treated with ibrutinib.

Ibrutinib has revolutionized the management of chronic lymphocytic leukemia and is now being increasingly used. Although considered to be less immunosuppressive than conventional immunochemotherapy, the observation of a few cases of invasive fungal infections in patients treated with ibrutinib prompted us to conduct a retrospective survey. We identified 33 cases of invasive fungal infections in patients receiving ibrutinib alone or in combination. Invasive aspergillosis (IA) was overrepresented (27/33) and was associated with cerebral localizations in 40% of the cases. Remarkably, most cases of invasive fungal infections occurred with a median of 3 months after starting ibrutinib. In 18/33 cases, other conditions that could have contributed to decreased antifungal responses, such as corticosteroids, neutropenia, or combined immunochemotherapy, were present. These observations indicate that ibrutinib may be associated with early-onset invasive fungal infections, in particular IA with frequent cerebral involvement, and that patients on ibrutinib should be closely monitored in particular when other risk factors of fungal infections are present.

Delivering Type I Interferon to Dendritic Cells Empowers Tumor Eradication and Immune Combination Treatments.

An ideal generic cancer immunotherapy should mobilize the immune system to destroy tumor cells without harming healthy cells and remain active in case of recurrence. Furthermore, it should preferably not rely on tumor-specific surface markers, as these are only available in a limited set of malignancies. Despite approval for treatment of various cancers, clinical application of cytokines is still impeded by their multiple toxic side effects. Type I IFN has a long history in the treatment of cancer, but its multifaceted activity pattern and complex side effects prevent its clinical use. Here we develop AcTakines (Activity-on-Target cytokines), optimized (mutated) immunocytokines that are up to 1,000-fold more potent on target cells, allowing specific signaling in selected cell types only. Type I IFN-derived AcTaferon (AFN)-targeting Clec9A+ dendritic cells (DC) displayed strong antitumor activity in murine melanoma, breast carcinoma, and lymphoma models and against human lymphoma in humanized mice without any detectable toxic side effects. Combined with immune checkpoint blockade, chemotherapy, or low-dose TNF, complete tumor regression and long-lasting tumor immunity were observed, still without adverse effects. Our findings indicate that DC-targeted AFNs provide a novel class of highly efficient, safe, and broad-spectrum off-the-shelf cancer immunotherapeutics with no need for a tumor marker.Significance: Targeted type I interferon elicits powerful antitumor efficacy, similar to wild-type IFN, but without any toxic side effects. Cancer Res; 78(2); 463-74. ©2017 AACR.