Combination Of Ruxolitinib Research Articles

A Phase 1 Trial of Ruxolitinib, Lenalidomide and Methylprednisolone for Patients with Relapsed/Refractory Multiple Myeloma (MM)

Introduction Ruxolitinib (RUX) is an FDA-approved oral, selective inhibitor of Janus kinase (JAK) 1/2 for the treatment of patients with polycythemia vera who have had an inadequate response to or are intolerant of hydroxyurea or intermediate or high-risk myelofibrosis (MF). Preclinical studies from our laboratory have demonstrated that RUX in combination with the immunomodulatory agent lenalidomide (LEN) and dexamethasone shows marked anti-myeloma effects both in vitro and in vivo. Furthermore, MUC1 (Mucin 1) is responsible for LEN resistance in MM cells, and RUX blocks its expression in multiple myeloma (MM) cells. Thus, RUX may restore sensitivity to LEN. RUX also downregulates PD-L1 and PD-L2 expression on MM cells and reduces tumor stimulatory M2 macrophage polarization in MM bone marrow. Therefore, a phase 1 trial was conducted to determine the safety and efficacy of RUX in combination with LEN and the steroid methylprednisolone (MP) for relapsed/refractory (RR) MM patients who had previously been treated with LEN/steroids and a proteasome inhibitor (PI) and showed progressive disease at study entry. Methods A traditional 3+3 dose escalation design was used to enroll subjects in four cohorts with planned total enrollment to be 49 patients. Subjects received RUX twice daily continuously, LEN daily on d1-21 of a 28-d cycle and MP orally every other day. In DL0, patients received RUX 5 mg, LEN 5 mg, and MP 40 mg. In DL+1 and +2, both doses of LEN and MP remained unchanged and RUX was escalated to 10 and 15 mg, respectively. DL+3 escalated LEN to 10 mg with MP unchanged and RUX at 15 mg. Primary endpoints were safety, clinical benefit rate (CBR) and overall response rate (ORR). Results As of March 1, 2019, 43 patients were enrolled, and 40 were evaluable for efficacy. The median age was 65 years (range, 46-81), and 25 (58%) were male. Patients received a median of 6 prior treatments including LEN and steroids to which they were all refractory. No DLTs occurred, and DL+3 was expanded. Among all 40 evaluable patients, the CBR and ORR were 47% and 37%, respectively (1 CR, 4 VGPR, 10 PR and 4 MR), and 16 and 5 patients showed SD and PD. Notably, all 19 patients achieving > MR were refractory to LEN (i.e. progressed while on or within 8 weeks of last dosage). The median PFS for all evaluable patients was 4 months. G3/4 AEs included anemia (16%), sepsis (14%), lymphocytopenia (14%), pneumonia (12%), neutropenia (12%) and hypokalaemia (12%). Most common SAEs included sepsis (14%) and pneumonia (12%). Conclusions This phase 1 trial demonstrates for the first time that a JAK inhibitor, RUX, can overcome refractoriness to LEN and steroids for RRMM patients. This all oral regimen was well tolerated, and reversible Grade 3/4 cytopenias occurred in only a small minority of patients. These promising results are leading to expansion of the current clinical trial to 78 patients, and represent a potential novel therapeutic approach for treating MM. Disclosures Berenson: Takeda: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Amag: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Amag: Consultancy, Speakers Bureau; Sanofi: Consultancy; Amgen: Consultancy, Speakers Bureau; Sanofi: Consultancy; OncoTracker: Equity Ownership, Other: Officer; OncoTracker: Equity Ownership, Other: Officer; Takeda: Consultancy, Speakers Bureau; Incyte Corporation.: Consultancy, Research Funding; Incyte Corporation.: Consultancy, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding. Swift:Bristol Mayers Squib: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Jansen: Consultancy, Honoraria. Eades:Celgene: Other: Stock. Boccia:Genentech: Speakers Bureau; DSI: Speakers Bureau; AMAG: Consultancy; AstraZeneca: Speakers Bureau; Amgen: Speakers Bureau; Celgene: Speakers Bureau. OffLabel Disclosure: The goal of this clinical trial is to establish ruxolitinib in combination with lenalidomide and methylprednisolone as the therapy for relapse/refractory multiple myeloma patients.

Stratification of Responders and Non-Responders in the Reach-1 Trial Based on Serum Proteomic Analysis

Acute graft versus host disease (aGVHD) is a serious and potentially life-threatening condition that can develop in patients receiving hematopoietic stem cell transplantation (HSCT). Acute GVHD is characterized by increased levels of inflammatory mediators and signaling through the Janus Kinases (JAKs), leading to tissue and organ damage. Ruxolitinib, an oral JAK1/JAK2 inhibitor, is the first FDA-approved treatment for steroid refractory aGVHD. The current study evaluated proteomic signatures from participants in the REACH-1 clinical trial to identify those individuals which have an increased probability for success when treated with ruxolitinib in combination with corticosteroids. Plasma was collected for 42 participants enrolled in the REACH-1 clinical trial (NCT02953678) prior to and at designated times following treatment. Broad proteomic analysis of more than 1000 proteins was conducted using the OLINK proximity extension assay. Participants were separated into responders (complete responders, very good partial responders, partial responders) (n=36) or non-responders (mixed responders, progressive disease) (n=6) based on their clinical response at Day 28 of treatment. Baseline differences in day 28 responders versus non-responders were compared using t-tests. Pharmacodynamics changes within responders and non-responders were assessed using paired t-tests. Significance of statistical tests was conferred at p<0.05. Broad proteomic analysis of plasma identified a total of 145 differentially expressed proteins (p<0.05) between the responders and non-responders at baseline. Thirty-five proteins were elevated and 110 proteins were lower in responders compared to non-responders. At baseline, IL-8, IL-6, and IL-24 were among the most significantly down-regulated while SCF was one of the most significantly up-regulated in responders compared to non-responders. Pharmacodynamic analyses revealed 493 significantly modulated proteins in responders and 92 in non-responders. IL2-RA was among the most significantly down-regulated from baseline to day 28 in both responders and non-responders. This study suggests that proteomic characterization has the potential to stratify responders and non-responders to ruxolitinib and corticosteroid treatment in steroid refractory aGVHD. Additionally, this study demonstrated robust pharmacodynamic and correlative changes in responders following treatment with ruxolitinib and corticosteroids suggesting that defining a responder population could enrich for patients predisposed to positive therapeutic response; however, this should be prospectively validated in additional studies. Disclosures Owens: Incyte Corporation: Employment, Equity Ownership. Pratta:Incyte Research Institute: Employment. Liu:Incyte: Employment, Equity Ownership. Arbushites:Incyte: Employment. Tian:Incyte: Employment, Equity Ownership. Howell:Incyte: Employment.

A Phase I-II Study of Ruxolitinib (INCB18424) for Patients with Chronic Myeloid Leukemia with Minimal Residual Disease While on Therapy with Imatinib

A Phase I-II Study of Ruxolitinib (INCB18424) for Patients with Chronic Myeloid Leukemia with Minimal Residual Disease While on Therapy with Imatinib

Myeloid-Lineage Enhancers Drive Oncogene Synergy and Represent a Novel Therapeutic Target in CSF3R-CEBPA Mutant AML

Myeloid-Lineage Enhancers Drive Oncogene Synergy and Represent a Novel Therapeutic Target in CSF3R-CEBPA Mutant AML

Evaluation of Tagraxofusp (SL-401) Alone and in Combination with Ruxolitinib for the Treatment of Myeloproliferative Neoplasms

Background: The introduction of the JAK1/2 inhibitor Ruxolitinib has resulted in significant benefits for patients with Myelofibrosis (MF) and Polycythemia Vera, including reduction of splenomegaly and improvement in symptom burden. However, Ruxolitinib has limited ability to alter the natural history and biology of disease in myeloproliferative neoplasms (MPNs). More importantly, patients often lose response to ruxolitinib or suffer disease progression despite therapy with ruxolitinib. These observations have prompted efforts to introduce novel therapeutic approaches and devise novel combinatorial treatment strategies to improve the outcomes of patients with MPNs. CD123 (interleukin-3 receptor-a; IL-3R-a) has been identified as a therapeutic target in several myeloid malignancies. CD123 is expressed in a variety of myeloid malignancies, including AML, myelodysplastic syndrome (MDS) and CMML. Further, Tagraxofusp (ELZONRIS®, SL-401), a targeted therapy directed to CD123 comprised of recombinant IL-3 fused to a truncated diphtheria toxin payload, was recently FDA approved for the treatment of blastic plasmacytoid dendritic cell neoplasm (BPDCN). In an ongoing Phase 1/2 trial, Tagraxofusp has demonstrated single agent clinical activity, with a predictable and manageable safety profile, in patients with relapsed/refractory MF. Thus, Tagraxofusp appears to have activity in MF. However, the utility of Tagraxofusp in more advanced forms of MPN (such as accelerated phase MPN), as well as the utility of combination Ruxolitinib and Tagraxofusp, have not been evaluated to date. To address these questions, we first evaluated CD123 expression using flow cytometry analysis of peripheral blood samples from patients with MF with progression to accelerated-phase (>10%) or blast-phase (>20%) disease. CD123 expression was generally noted to be higher than that observed in normal control samples, by mean florescence intensity (Figure 1A). We next sought to determine the effect of treatment with Tagraxofusp alone and in combination with Ruxolitinib in leukemia cell lines and primary patient samples. We performed cell viability assays using the JAK2V617F mutant cell line UKE1. We first determined the IC50 of Tagraxofusp in UKE1 cells (range 2.95-3.57nM). Using this data, we then tested the impact of the addition of Tagraxofusp to Ruxolitinib on UKE1 cell viability using a fixed concentration of Tagraxofusp (5nM). The IC50 of range of single agent Ruxolitinib was 44.42-70.93nM. However, the addition of Tagraxofusp to Ruxolitinib resulted in a decrease of the IC50 range to 11.72-21.6nM, indicating an effect of combination therapy (Figure 1B). We then determined the impact of Tagraxofusp both alone and in combination with Ruxolitinib using primary patient MPN peripheral blood mononuclear cells in methylcellulose. Patient characteristics are described in Table 1. In most samples, CD123 expression was confirmed. In all samples studied, Tagraxofusp was able to significantly reduce colony formation when compared to vehicle, at a dose range of 2.5nM to 20nM. Notably, this includes two samples (151, 455) from patients with accelerated-phase disease. As well, Tagraxofusp demonstrated activity across genotypes, including in cases with TP53 and ASXL1 mutations. A reduction in colony formation in samples treated with combination Ruxolitinib and Tagraxofusp beyond that observed with either agent alone was observed in several cases (Figure 1C). Conclusions: Current therapeutic options for patients with MF beyond Ruxolitinib are limited. This is particularly the case for patients with progression to accelerated and blast-phase MPN. Here, we demonstrate that CD123 expression is evident in many such cases. Further, therapeutic targeting of CD123 using Tagraxofusp either alone or in combination with Ruxolitinib has activity in primary patient samples, including those in accelerated-phase and with high molecular risk profiles. These data thus support further testing of Tagraxofusp in MPNs, and in advanced MPNs in particular. Disclosures Roshal: Auron Therapeutics: Equity Ownership, Other: Provision of services; Physicians' Education Resource: Other: Provision of services; Celgene: Other: Provision of Services. Chen:Stemline Therapeutics: Employment, Equity Ownership. Brooks:Stemline Therapeutics: Employment, Equity Ownership, Patents & Royalties. Levine:Imago Biosciences: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy; C4 Therapeutics: Membership on an entity's Board of Directors or advisory committees; Isoplexis: Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy; Prelude Therapeutics: Research Funding; Celgene: Consultancy, Research Funding; Loxo: Membership on an entity's Board of Directors or advisory committees; Qiagen: Membership on an entity's Board of Directors or advisory committees; Lilly: Honoraria; Amgen: Honoraria; Roche: Consultancy, Research Funding. Rampal:Constellation, Incyte, and Stemline Therapeutics: Research Funding; Agios, Apexx, Blueprint Medicines, Celgene, Constellation, and Jazz: Consultancy.

COMBINATION THERAPY FOR MYELOFIBROSIS

Introduction.Ruxolitinib presents itself as a drug for the pathogenetic treatment of myelofibrosis (MF). New drugs have recently been developed for the treatment of MF. A search for optimal combinations of these drugs with ruxolitinib appears to be a logical approach to the development of MF therapy.Aim.To summarize data on the use of ruxolitinib in combination with various drugs approved or currently being studied in terms of their applicability for MF treatment.General findings.The review analyses data in publications retrieved from the PubMed and Elibrary.ru databases, including clinical cases, original research papers and reviews. We discuss preliminary results of clinical trials of various rational combination therapies, which have demonstrated a high efficacy for the forms of the disease untreatable with ruxolithinib monotherapy, e.g. bone marrow fibrosis and anemia. Combinations of ruxolithinib with azacytidine, panobinostat and α-interferon have shown the most promising results.

A Phase 1 Trial of Ruxolitinib, Lenalidomide and Methylprednisolone for Patients with Relapsed/Refractory Multiple Myeloma (MM)

Preclinical studies from our laboratory have demonstrated that ruxolitinib (RUX) in combination with lenalidomide (LEN) and dexamethasone shows marked anti-myeloma effects both in vitro and in vivo. Furthermore, MUC1 is responsible for LEN resistance in MM cells, and RUX blocks its expression in MM cells. Thus, RUX may restore sensitivity to LEN. Therefore, a Phase 1 trial was conducted to determine the safety and efficacy of RUX in combination with LEN and methylprednisolone (MP) for relapsed/refractory (RR) MM patients (pts) who had previously been treated with LEN/steroids and a proteasome inhibitor (PI) and showed progressive disease at study entry.

Autophagy inhibition potentiates ruxolitinib-induced apoptosis in JAK2V617F cells.

JAK2V617F can mimic growth factor signaling, leading to PI3K/AKT/mTOR activation and inhibition of autophagy. We hypothesized that selective inhibition of JAK1/2 by ruxolitinib could induce autophagy and limit drug efficacy in myeloproliferative neoplasms (MPN). Therefore, we investigated the effects of ruxolitinib treatment on autophagy-related genes and cellular processes, to determine the potential benefit of autophagy inhibitors plus ruxolitinib in JAK2V617F cells, and to verify the frequency and clinical impact of autophagy-related gene mutations in patients with MPNs. In SET2 JAK2V617F cells, ruxolitinib treatment induced autophagy and modulated 26 out of 79 autophagy-related genes. Ruxolitinib treatment reduced the expressions of important autophagy regulators, including mTOR/p70S6K/4EBP1 and the STAT/BCL2 axis, in a dose- and time-dependent manner. Pharmacological inhibition of autophagy was able to significantly suppress ruxolitinib-induced autophagy and increased ruxolitinib-induced apoptosis. Mutations in autophagy-related genes were found in 15.5% of MPN patients and were associated with increased age and a trend towards worse survival. In conclusion, ruxolitinib induces autophagy in JAK2V617F cells, potentially by modulation of mTOR-, STAT- and BCL2-mediated signaling. This may lead to inhibition of apoptosis. Our results suggest that the combination of ruxolitinib with pharmacological inhibitors of autophagy, such as chloroquine, may be a promising strategy to treat patients with JAK2V617F-mutated MPNs.

Abstract 3113: Regulation of TOR complex 1 by the BRAFV600EMutant determines response and development of resistance to MEK inhibition by trametinib in glioma models

Abstract Pediatric Low-Grade glioma (PLGG) is the most common brain tumor in children. Current treatment protocols, particularly those involving high dose radiation therapy are associated with neurocognitive and neuroendocrine dysfunction. Genomic studies have revealed that PLGG are characterized by activation of the MAPK cascade. Recently, the value of selumetinib, an allosteric inhibitor of MEK1/2 has been demonstrated in PLGG. However, drug resistance will inevitably limit the efficacy. Trametinib is a more potent MEK1/2 inhibitor with better brain penetration than selumetinib. Here we have attempted to identify the mechanism/s of the resistance to trametinib that PLGG developes, and to explore combination treatments that may retard or prevent emergence of trametinib resistance in animal models. In BT-40 (childhood anaplastic astrocytoma with BRAFV600E mutation) xenografts, trametinib caused complete tumor regressions, followed by tumor regrowth at the end of treatment. Trametinib treatment rapidly induced pSTAT3(Y705), that was blocked by the JAK1/2 inhibitor, ruxolitinib. Agaist BT-40 xenografts, ruxolitinib slightly enhanced the antitumor response to trametinib. The combination of trametinib with rapamycin was more active in each xenograft line than either single agent alone and in both subcutaneous and intracranial BT-40 models. In BT-40 xenografts, resistance to trametinib was consistently induced within 3 or 4 6-week cycles of treatment similar to that for the trametinib + ruxolitinib combination. In contrast, resistance to combined trametinib and rapamycin was not developed. Rapamycin prevented emergence of trametinib resistance, but did not reverse resistance to trametinib, once acquired. Inhibition of MAPK signaling by trametinib was similar in parental and trametinib-resistant BT-40 xenografts, however, trametinib reistant tumor cells failed to undergo apoptosis. Cells freshly isolated from trametinib resistant BT-40 xenografts had a higher apoptotic threshhold, whereas cells isolated from BT-40 xenografts after 3 cycles of trametinib + rapamycin, remained equally sensitive to parental BT-40 cells, as determined by BH3 profiling. This study reveals a potential new therapeutic use of rapamycin, preventing emergence of resistance to trametinib. Potentially, addition of rapamycin to MEK inhibitor therapy children with BRAF-driven low-grade glioma may be of value. Citation Format: Fuyang Li. Regulation of TOR complex 1 by the BRAFV600EMutant determines response and development of resistance to MEK inhibition by trametinib in glioma models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3113.

Cotargeting the JAK/STAT signaling pathway and histone deacetylase by ruxolitinib and vorinostat elicits synergistic effects against myeloproliferative neoplasms.

The majority of patients with Philadelphia-negative myeloproliferative neoplasms (MPNs) harbor a gain of function mutation V617F in Janus kinase (JAK) 2. Although JAK2 inhibitors such as ruxolitinib have been shown to be clinically efficacious, the hematological toxicity and eventual drug resistance limit its use as monotherapy. Other gene mutations or dysregulation correlated with the disease phenotype and prognosis have been found to contribute to the complexity and heterogeneity of MPNs, giving rise to an increasing demand for combination therapies. Here, we combine ruxolitinib and the histone deacetylase inhibitor vorinostat as a rational combination strategy for MPNs. We tested the combination of ruxolitinib and vorinostat in cells with the JAK2V617F mutation, such as HEL cells, c-Kit+ cells from JAK2V617F transgenic mice and bone marrow mononuclear cells (BMMNCs) from patients with MPN. Our results showed significant synergistic effects of this combination strategy. Cotreatment with ruxolitinib and vorinostat synergistically induced apoptosis, cell cycle arrest and inhibition of the colony-forming capacity of HEL cells by attenuating the JAK/signal transducer and activator of transcription (STAT) and protein kinase-B (AKT) signaling pathways. In particular, cotreatment with ruxolitinib and vorinostat prevented the formation of large colonies of colony-forming unit-granulocyte/erythroid/macrophage/megakaryocytes (CFU-GEMMs) and colony-forming unit-granulocyte/macrophages (CFU-GMs) derived from the BMMNCs of patients with MPN. Taken together, these data provided preclinical evidence that the combination of ruxolitinib and vorinostat is a potential dual-target therapy for patients with MPN.

PS1467 EARLY RESULTS OF A PHASE II STUDY OF COMBINED RUXOLITINIB AND THALIDOMIDE IN PATIENTS WITH MYELOFIBROSIS

Background:Among the most frequent and challenging hematologic manifestations of myelofibrosis (MF) are anemia and thrombocytopenia, the presence of which portends an adverse outcome. Few effective modalities to address these cytopenias exist, particularly thrombocytopenia. Further, although Ruxolitinib (RUX) has demonstrated significant clinical efficacy in MF patients, RUX frequently results in anemia and thrombocytopenia. Thalidomide (THAL) is an immunomodulatory agent which has demonstrated demonstrated improvements in anemia and thrombocytopenia in patients with MF.Aims:We sought to examine whether the combination of RUX and THAL could result in improvement in both disease‐ and therapy‐related cytopenias, as well as improve overall disease response in patients with MF.Methods:We conducted a multicenter two stage phase II trial designed to assess the effect of RUX and THAL combination in subjects with myelofibrosis (NCT03069326). Patients taking RUX at the time of enrollment must have had less than PR per IWG‐MRT/ELN 2013 criteria. Patients must have been taking RUX for a minimum of 3 months. Treatment‐naïve patients received single‐agent RUX for 3 months (run‐in phase) per label, and went on to combination therapy if they achieved less then a PR. Each cycle of therapy was 28 days. Response assessment was evaluated according to the IWG‐MRT/ELN 2013 criteria. Platelet response criteria (in patients with baseline thrombocytopenia) included: Major response (≥75% increase in platelet count), Intermediate Response (50–74% increase) and Minor Response (25–49% increase). Adverse events were assessed using the NCI CTCAE v. 4.0. The primary endpoint was the proportion of treated subjects that achieved a response by IWG‐MRT criteria and by platelet response criteria.Results:A total of 25 patients are planned to be accrued. At the time of this writing, 24 have been accrued. The median age was 70 years (43–85). 9 patients had received prior therapies. 11 patients enrolled to the run‐in phase. 16 patients had received red blood cell transfusions prior to study enrollment. A significant increase in platelet count was observed by cycle 3 of therapy compared to baseline (Figure 1A, P < 0.05). An increase in Hgb was observed over successive cycles of combination therapy (Figure 1B). 12 of 21 accrued patients were evaluable for response assessment at the time of abstract submission. The overall response rate in these patients was 58.3% (7/12 patients). Four of 12 (33.3%) evaluable patients had stable disease. 1 patient progressed to accelerated phase. Clinical Improvement (anemia response, spleen response, or symptom response) occurred in 5 patients. Major platelet response was observed in 6 patients with baseline thrombocytopenia (Table 1). Grade 3/4 non‐hematologic adverse events regardless of attribution included; limb edema, diverticulitis, hypertension, syncope, and a thromboembolic event (one patient each).Summary/Conclusion:The combination of THAL and RUX has demonstrated a promising efficacy signal in this initial analysis of an ongoing phase II study, and appears to be well tolerated. Reductions in spleen size, symptom burden, and improvements in hemoglobin and platelet count were observed. Improvement in platelet count is particularly important given the lack of treatment modalities for thrombocytopenia in this patient population. These data indicate a potential role for this regimen in patients with cytopenias and/or persistent disease manifestations while on RUX. Updated data on duration of response and overall response rate in all accrued patients will be presented.image

S1608 RUXOLITINIB PLUS POMALIDOMIDE IN MYELOFIBROSIS WITH ANEMIA: RESULTS FROM THE MPNSG‐0212 COMBINATION TRIAL (NCT01644110)

Background:Anemia is one clinically relevant symptom in patients (pts) with myelofibrosis (MF) which is not being addressed by treatment with ruxolitinib (RUX). Single treatment with pomalidomide (POM) improved cytopenia in 14% (POM 0.5 mg QD) and 29% (POM 2 mg QD) of MF pts in our previous MPNSG‐0109 trial.Aims:Therefore, we sought to investigate the combination of RUX plus POM in MF with anemia.Methods:MPNSG‐0212 (NCT01644110) is a multicenter, open‐label, single‐arm phase‐Ib/II trial with a target population of 90 pts in a two‐stage design. Pts 1–40 (cohort 1 [co1]) are treated with RUX (10 mg BID) plus low‐dose POM (0.5 mg QD), while pts 41–90 (cohort 2 [co2]) receive a step‐wise dose increase of POM after 3 and 6 cycles (0.5 ‐> 1 ‐> 2 mg QD). Primary endpoints are safety of the combination therapy and anemia response after 12 28‐day cycles (according to IWG‐MRT and RBC transfusion independency [RBC‐TI] criteria). Main inclusion criterion is MF with anemia (Hb <10 g/dL and/or RBC‐TD). Pts suitable for allogeneic transplantation and pts with low platelets (<100/nL) are excluded.Results:Data from 59 pts were available for this analysis. Baseline characteristics were as following: Median age 72 yrs (range 49–84), 53% had prior treatment (RUX in 22%, POM in 4%), median Hb level was 8.5 g/dL (range 5.4–11.7), 27% fulfilled the RBC‐TD criterion, median spleen size was 17.8 cm (range 12.6–36), 80% had constitutional symptoms, 93% were intermediate‐2 (64%) or high‐risk (29%) according to DIPSS, and 55% had ≥1 high molecular risk mutation (ASXL1, SRSF2, EZH2, and/or IDH1/2). Median number of treatment cycles was 12 (range 2–59) in co1 and 11 (range 1–16) in co2. 414 adverse events (AE) were recorded (mostly °I/II). Number or severity of AE were not increased in co2. Most common AE (°I/II) were anemia (34% of pts) and fatigue (29%) in the first weeks of treatment as well as musculoskeletal cramps (25%). Regarding serious AE (SAE), n = 77 were recorded in 64% of pts. No fatal (S)AE occurred in co2. Most common SAE were pneumonia (12%), leukemic transformation (10%), and worsening of general condition (7%). Interruption/termination of RUX and/or POM was rare in co1 and co2. In co1, 18/40 pts (45%) continued treatment beyond cycle 12 because of objective anemia response (7/40, 18%: CI‐Hb [Hb increase ≥2 g/dL] n = 5, PR and RBC‐TI n = 1 each) or stable disease in combination with clinical benefit (CB, 11/40, 28%) defined as: Hb increase ≥1 g/dL and/or doubling of RBC transfusion intervals [n = 4] or improvement of fatigue and/or overall quality of life >25% according to MPN‐SAF [n = 7]. Notably, 16 pts of co1 (40%) were on treatment for more than 24 cycles, and mean Hb increased continuously from 8.7 g/dl at baseline to 9.8 g/dL at end of cycle 18 and sustained thereafter at 9.7 g/dL until end of cycle 30 (Figure 1). In co2, 6/19 pts (31%) reached cycle 12 and continued treatment afterwards: 1/6 (17%) experienced RBC‐TI, whereas 5 had CB; 16/19 pts (84%) were still on treatment at the time of the analysis with 10/16 pts (62%) not having reached cycle 12 yet. Increase of the POM dose to 1 mg QD after 3 cycles and 2 mg QD after 6 cycles was feasible in 94% and 69% of pts, respectively.Summary/Conclusion:Combination treatment of RUX and POM is safe and feasible in pts with poor‐risk MF and resulted in an objective anemia response rate of 18% with RUX plus low‐dose POM in co1. Notably, 40% of pts showed a long‐lasting stabilization of their disease with sustained improvement of Hb and quality of life. Updated results on more than 70 pts will be presented.image

A phase I trial of ruxolitinib, lenalidomide, and methylprednisolone for patients with relapsed/refractory multiple myeloma (MM).

8048 Background: Preclinical studies from our laboratory have demonstrated that ruxolitinib (RUX) in combination with lenalidomide (LEN) and dexamethasone shows marked anti-myeloma effects both in vitro and in vivo. Furthermore, MUC1 is responsible for LEN resistance in MM cells, and RUX blocks its expression in MM cells. Thus, RUX may restore sensitivity to LEN. Therefore, a phase 1 trial was conducted to determine the safety and efficacy of RUX in combination with LEN and methylprednisolone (MP) for relapsed/refractory (RR) MM patients (pts) who had previously been treated with LEN/steroids and a proteasome inhibitor (PI) and showed progressive disease at study entry. Methods: A traditional 3+3 dose escalation design was used to enroll subjects in four cohorts with planned total enrollment to be 49 pts. Subjects received RUX twice daily continuously, LEN daily on d1-21 of a 28-d cycle and MP orally every other day. In DL0, pts received RUX 5 mg, LEN 5 mg, and MP 40 mg. In DL+1 and +2, both doses of LEN and MP remained unchanged and RUX was escalated to 10 and 15 mg, respectively. DL+3 escalated LEN to 10 mg with MP unchanged and RUX at 15 mg. Primary endpoints were safety, clinical benefit rate (CBR) and overall response rate (ORR). Results: As of September 1, 2018, 36 pts were enrolled, and 32 were evaluable for efficacy. The median age was 66 years (range, 46-81), and 21 (58%) were male. Pts received a median of 6 prior treatments including LEN and steroids to which they were all refractory and a proteasome inhibitor. No DLTs occurred, and DL+3 was expanded. Among evaluable pts, the CBR and ORR were 47% and 41%, respectively (1 CR, 2 VGPR, 10 PR and 2 MR), and 14 and 3 pts showed SD and PD. All 15 responding pts were refractory to LEN. G3 AEs included anemia (17%), neutropenia (14%), sepsis (14%), lymphocytopenia (11%), thrombocytopenia (11%), and pneumonia (11%). Most common SAEs included sepsis (14%) and pneumonia (11%). Conclusions: This Ph 1 trial demonstrates for the first time that a JAK inhibitor, RUX, can overcome refractoriness to LEN and steroids for RR MM pts. These promising results are leading to expansion of the current clinical trial to 78 pts, and represents a novel therapeutic approach for treating MM. Clinical trial information: NCT03110822.

Adding hydroxyurea in combination with ruxolitinib improves clinical responses in hyperproliferative forms of myelofibrosis.

Ruxolitinib, an orally bioavailable and selective inhibitor of Janus kinase 1 (JAK1) and JAK2, significantly reduces splenomegaly and disease‐related symptoms in patients with myelofibrosis (MF). However, no clear survival benefit has been demonstrated, which may in part reflect suboptimal drug exposure related to lower dosages needed to minimize hematological toxicity, specifically cytopenias. Furthermore, the optimal management of specific conditions such as leukocytosis or thrombocytosis in patients under ruxolitinib therapy is still undefined. In these cases, combining ruxolitinib with a cytoreductive agent like hydroxyurea might improve hematological response. This observational multi‐center study enrolled 20 adult patients with intermediate‐ or high‐risk primary MF, post‐ polycythemia vera MF, or postessential thrombocythemia MF with hyperproliferative manifestations of the disease and WBC and/or platelet counts not controlled by ruxolitinib therapy. The patients received treatment with a combination of ruxolitinib and hydroxyurea. A clinical response of any type was obtained in 8 patients (40%) during ruxolitinib monotherapy and in 17 patients (85%) during ruxolitinib‐hydroxyurea combination (P = 0.003). After a median duration of 12.4 months of combination therapy, 16/20 patients had a hematological response; 14/17 patients who had started combination therapy to control WBC count and 2/3 who started in order to reduce platelets count. The number of patients requiring ruxolitinib dosage reduction or discontinuations was lower during combination therapy and, at the end of follow‐up the median ruxolitinib dose was increased in 50% of patients. In conclusion, the combination of hydroxyurea with ruxolitinib yielded a high clinical response rate and increased ruxolitinib exposure in patients with hyperproliferative forms of MF.

Ruxolitinib in Combination With Venetoclax for the Treatment of Relapsed/Refractory Acute Myeloid Leukemia

Ruxolitinib in Combination With Venetoclax for the Treatment of Relapsed/Refractory Acute Myeloid Leukemia

Ruxolitinib in Combination with Corticosteroids for the Treatment of Steroid-Refractory Acute Graft-Vs-Host Disease: Results from the Phase 2 REACH1 Trial

Introduction Acute graft-vs-host disease (aGVHD) is a serious complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Less than 50% of patients (pts) achieve sustained responses with first-line corticosteroid (CS) treatment. Retrospective studies demonstrated clinical benefit with the Janus kinase (JAK)1/JAK2 inhibitor ruxolitinib (RUX) in pts with steroid-refractory (SR) aGVHD. Objectives To present updated results from REACH1 (NCT02953678), a phase 2 trial evaluating RUX plus CS in SR aGVHD. Methods REACH1 was a single-arm, open-label, multicenter study. Eligible pts were aged ≥12 years and developed grade II–IV SR aGVHD following allo-HSCT from any donor source for hematologic malignancies. SR aGVHD was defined as GVHD that progressed after 3 days or had not improved after 7 days of primary treatment with methylprednisolone ≥2 mg/kg/d (or equivalent), development of GVHD in another organ after receiving ≥1 mg/kg/d methylprednisolone for skin or skin plus upper gastrointestinal GVHD, or inability to tolerate CS taper. Pts received RUX 5 mg twice daily (BID), with optional increase to 10 mg BID in the absence of cytopenias. The primary endpoint was Day 28 overall response rate (ORR), and the key secondary endpoint was 6-month duration of response (DOR). ORR was defined as the proportion of patients demonstrating a complete response (CR), very good partial response, or partial response. Results The study enrolled 71 pts. Median age was 58 years, and 49.3% were male. Treatment was ongoing in 11 pts (15.5%) at data cutoff (2 Jul 2018). At Day 28, ORR was 54.9% (CR, 26.8%). Responses were observed irrespective of aGVHD grade and SR criteria (Figure 1). Best ORR at any time during treatment was 73.2% (CR, 56.3%). Median (range) time to response was 7 (6–49) days. Median DOR with minimum 6 months follow-up was 345 days for both Day 28 responders (Figure 2) and for pts who had a best overall response at any time during treatment . Four pts (5.6%) had malignancy relapse. Nonrelapse mortality at 6 months was 44.4%. Median overall survival had not been reached for Day 28 responders (Figure 3). The most frequently reported hematologic treatment-emergent adverse events (TEAEs) were anemia (64.8%), thrombocytopenia (62.0%), and neutropenia (47.9%). Cytomegalovirus infection (12.7%), sepsis (12.7%), and bacteremia (9.9%) were the most frequently reported infections. Fatal RUX-related TEAEs were sepsis and pulmonary hemorrhage (1 pt each) and were attributed to both RUX and CS. Conclusion In this first prospective trial of RUX in SR aGVHD, ORR was 54.9% by Day 28 and 73.2% at any time during treatment. Responses were rapid and durable. The AE profile was consistent with expectations for RUX and pts with SR aGVHD. RUX represents a promising therapeutic strategy.

JAK/STAT inhibition with ruxolitinib enhances oncolytic virotherapy in non-small cell lung cancer models.

The concept of using viruses to treat cancer has now shown proof of concept in several recent clinical trials, leading to the first FDA approval of virotherapy for melanoma last year. Vesicular stomatitis virus (VSV) is a promising oncolytic virus that has inhibitory effects on a number of cancer types including non-small cell lung cancer. One of the major mechanisms of resistance to VSV infection is the type I interferon (IFN) response, leading to the development of VSV expressing IFNβ which will lead to resistance of viral replication in normal cells which have intact IFN signaling but allow replication in cancer cells with defective IFNβ signaling. However, some cancer cells have intact or partially intact IFN signaling pathways leading to resistance to virotherapy. Here we utilized JAK/STAT inhibitor, ruxolitinib, in combination with VSV-IFNβ to see if inhibition of JAK/STAT signaling will enhance VSV-IFNβ therapy for lung cancer. We used five human and two murine NSCLC cell lines in vitro, and the combination treatment was assayed for cytotoxicity. We performed western blots on treated cells to see the effects of ruxolitinib on JAK/STAT signaling and PDL-1 expression in treated cells. Finally, the combination of VSV-IFNβ and ruxolitinib was tested in an immune competent murine model of NSCLC. Ruxolitinib enhanced virotherapy in resistant and sensitive NSCLC cells. The addition of ruxolitinib inhibited STAT1 phosphorylation and to a lesser extent STAT3 phosphorylation. Ruxolitinib treatment prevented NSCLC cells from enhancing PDL-1 expression in response to virotherapy. Combination ruxolitinib and VSV-IFNβ therapy resulted in a trend toward improved survival of mice without substantially effecting PDL-1 levels or levels of immune infiltration into the tumor. These results support further clinical evaluation of the combination of JAK/STAT inhibition with virotherapy.

Safety and efficacy of combined ruxolitinib and decitabine in accelerated and blast-phase myeloproliferative neoplasms

AbstractMyeloproliferative neoplasms (MPN), including polycythemia vera, essential thrombocythemia, and primary myelofibrosis, have a propensity to evolve into accelerated and blast-phase disease (MPN-AP/BP), carrying a dismal prognosis. Conventional antileukemia therapy has limited efficacy in this setting. Thus, MPN-AP/BP is an urgent unmet clinical need. Modest responses to hypomethylating agents and single-agent ruxolitinib have been reported. More recently, combination of ruxolitinib and decitabine has demonstrated synergistic in vitro activity in human and murine systems. These observations led us to conduct a phase 1 study to explore the safety of combined decitabine and dose-escalated ruxolitinib in patients with MPN-AP/BP. A total of 21 patients were accrued to this multicenter study. Ruxolitinib was administered at doses of 10, 15, 25, or 50 mg twice daily in combination with decitabine (20 mg/m2 per day for 5 days) in 28-day cycles. The maximum tolerated dose was not reached. The most common reasons for study discontinuation were toxicity/adverse events (37%) and disease progression (21%). Fourteen patients died during study treatment period or follow-up. The median overall survival for patients on study was 7.9 months (95% confidence interval, 4.1-not reached). Among evaluable patients, the overall response rate by protocol-defined criteria (complete remission with incomplete count recovery + partial remission) was 9/17 (53%) and by intention-to-treat analysis was 9/21 (42.9%). The combination of decitabine and ruxolitinib was generally well tolerated by patients with MPN-AP/BP and demonstrates potentially promising clinical activity. A phase 2 trial evaluating the efficacy of this combination regimen is ongoing within the Myeloproliferative Disorder Research Consortium.

Ruxolitinib in combination with prednisone and nilotinib exhibit synergistic effects in human cells lines and primary cells from myeloproliferative neoplasms.

Ruxolitinib is the front-line non-palliative treatment for myelofibrosis (MF). However, a significant number of patients lose or present suboptimal response, are resistant or have unacceptable toxicity. In an attempt to improve response and avoid the adverse effects of this drug, we evaluated the combination of 17 drugs with ruxolitinib in ex vivo models of peripheral blood mononuclear cells from MF patients and cell lines. We found that the combination ruxolitinib and nilotinib had a synergistic effect against MF cells (ΔEC50 nilotinib, −21.6%). Moreover, the addition of prednisone to combined ruxolitinib/nilotinib improved the synergistic effect in all MF samples studied. We evaluated the molecular mechanisms of combined ruxolitinib/nilotinib/prednisone and observed inhibition of JAK/STAT (STAT5, 69.2+11.8% inhibition) and MAPK (ERK, 29.4+4.5% inhibition) signaling pathways. Furthermore, we found that the triple therapy combination inhibited collagen protein and COL1A1 gene expression in human bone marrow mesenchymal cells. Taken together, we provide evidence that combined ruxolitinib/nilotinib/prednisone is a potential therapy for MF, possibly through the anti-fibrotic effect of nilotinib, the immunomodulatory effect of ruxolitinib and prednisone, and the anti-proliferative effect of ruxolitinib. This combination will be further investigated in a phase Ib/II clinical trial in MF.

Combination Therapy Using Ruxolitinib and Oncolytic HSV Renders Resistant MPNSTs Susceptible to Virotherapy.

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft-tissue sarcomas resistant to most cancer treatments. Surgical resection remains the primary treatment, but this is often incomplete, ultimately resulting in high mortality and morbidity rates. There has been a resurgence of interest in oncolytic virotherapy because of encouraging preclinical and clinical trial results. Oncolytic herpes simplex virus (oHSV) selectively replicates in cancer cells, lysing the cell and inducing antitumor immunity. We previously showed that basal interferon (IFN) signaling increases interferon-stimulated gene (ISG) expression, restricting viral replication in almost 50% of MPNSTs. The FDA-approved drug ruxolitinib (RUX) temporarily resets this constitutively active STAT signaling and renders the tumor cells susceptible to oHSV infection in cell culture. In the studies described here, we translated our in vitro results into a syngeneic MPNST tumor model. Consistent with our previous results, murine MPNSTs exhibit a similar IFN- and ISG-mediated oHSV-resistance mechanism, and virotherapy alone provides no antitumor benefit in vivo However, pretreatment of mice with ruxolitinib reduced ISG expression, making the tumors susceptible to oHSV infection. Ruxolitinib pretreatment improved viral replication and altered the oHSV-induced immune-mediated response. Our results showed that this combination therapy increased CD8+ T-cell activation in the tumor microenvironment and that this population was indispensable for the antitumor benefit that follows from the combination of RUX and oHSV. These data suggest that JAK inhibition prior to oncolytic virus treatment augments both oHSV replication and the immunotherapeutic efficacy of oncolytic herpes virotherapy.