Koenig, Patricia

Abstract BACKGROUND: DNA methyltransferase inhibition offers palliative benefit but does not alter disease biology. in chronic myelomonocytic leukemia (CMML, Merlevede J et al. Nat Comm 2016). This was conclusively demonstrated in the phase 3 DACOTA study, where decitabine did not improve event-free survival in comparison to hydroxyurea (median 12.1 versus 10.3 months, P=0.27) in advanced myeloproliferative CMML (MP-CMML). Hence, there is in urgent need to develop disease modifying therapies for this dismal condition. We and others have demonstrated a role for RAS mutations in MP-CMML through the activation of the KMT2A-PLK1 axis. Targeting of this axis using onvansertib, an inhibitor of PLK1, has demonstrated its pre-clinical efficacy in MP-CMML patient-derived organoid and xenograft models. (Carr RM et al. Nat Comm 2021). METHODS: We conducted a single center phase 1 study to assess the safety and efficacy of onvansertib in relapsed/refractory MP-CMML (NCT05549661). We used a Bayesian Optimal Interval (BOIN) study design to determine the maximum tolerated dose (MTD). The three dose cohorts included 6, 9 and 12 mg/m2 given orally from days 1 to 21 of each 28-day cycle. Key inclusion criteria included a WHO-defined diagnosis of MP-CMML with a white blood cell (WBC) count > 13,000/mm3 and adequate organ function (estimated GFR > 50 mL/min/m2). Response was evaluated per the MDS/MPN International Working Group Criteria (Savona et al. Blood 2015). Targeting efficacy was assessed by measuring phosphorylation of TCTP (a PLK1 substrate), specifically pTCTP/TCTP ratios by immunoblotting in peripheral blood mononuclear cell (PBMC) samples pre and post cycle 1 (Days 1, 7, 21) and end of cycle 3. Pharmacokinetic studies and translational correlative studies were conducted per protocol. RESULTS: Between April 2023 and July 2025, a total of 9 patients were enrolled. The median age at enrollment was 68 years (range: 60-83); all caucasian with 4 (44%) males. All patients had a diagnosis of CMML-1 with a median bone marrow (BM) blast percentage of 4 (0-9), median hemoglobin 10 (7.1-13.2) g/dL, median WBC count of 11.1 (3.1-72.7) x 109/L (4 patients had a WBC count < 13 x 109/L at enrollment due to hydroxyurea use but were confirmed to be MP-CMML at diagnosis), absolute monocyte count 2.1 (1.9-19.6) x 109/L, and platelet count of 36 (20-494) x 109/L. TET2 (89%), SRSF2 (78%), ASXL1 (56%), NRAS, KRAS and CBL (22% each) were the most frequent molecular abnormalities. Previous therapies included hydroxyurea (n=8) and decitabine (n=1). Four patients were enrolled at the 6mg/m2dose level, 2 at the 9 mg/m2 dose level and we currently have one patient at the 12 mg/m2 dose level. While there were 2 planned patients at the 6 mg/m2 dose level, due to a case of pericardial effusion that was possibly drug related, an additional two patients were enrolled at the same dose level, without any dose limiting toxicity (DLT). Targeting efficacy was confirmed by pTCTP immunoblotting in PBMC samples from 4 patients (6 and 9 mg/m2 dose levels) showing suppressed pTCTP/TCTP ratios. No confirmed DLT has been identified thus far, and no grade 3 or 4 toxicities attributable to the study drug have been reported. Possible or unrelated grade 3 adverse effects included infections (sepsis/cellulitis, n=2, 22%), acute kidney injury (n=1, 11%), pericardial effusion (n=1, 11%), and atrial fibrillation with rapid ventricular response (n=1, 11%). Median duration on therapy was 124 (range: 15-654) days with most common cause of study discontinuation being disease progression (33%). Response was assessed as per the MDS/MPN IWG criteria in patients who received at least 1 cycle (n=8) with 3 (38%) patients meeting criteria for either hematological or optimal marrow response. Specifically, there was one (14%) patient with >100% platelet response, one (14%) with normalization of WBC count (baseline WBC count >50 x 109/L), one (14%) optimal marrow response with BM blast% reduction from 8 to 2, facilitating candidacy for an allogeneic hematopoietic stem cell transplantation, and three patients (38%) remained as stable disease. CONCLUSION: In MP-CMML, PLK1 inhibition with onvansertib is relatively well tolerated and shows preliminary efficacy in approximately 40% of patients, with one patient having an optimal marrow response at the 9 mg/m2 dose. Future directions include a dose expansion phase and studying upfront combination with DNA methyltransferase inhibitors.

Abstract Introduction: Approximately 75% of myelofibrosis (MF) patients develop anemia during evolution of the disease process predicting decreased survival. Previous studies exploring the effect of danazol in the treatment of anemia in MF demonstrate responses in anemia of 30-55%. Ruxolitinib has demonstrated improvement in MF related splenomegaly, symptom burden, and even survival yet improvements in cytopenias are uncommon. We designed a phase II multicenter pilot study to evaluate the efficacy and tolerability of combination therapy with ruxolitinib and danazol in MF patients with anemia. Methods: This is a pre-planned interim analysis of a Simon optimum two-stage phase II trial designed to include a minimum of 10 and a maximum of 27 patients. Participants received ruxolitinib 10mg (plat >75 x10x9) BID or 5mg (plat <75 x10 x9) BID with danazol 200mg orally TID. Dose escalation was allowed after completion of 28 days for lack of response or for disease progression. Patients without progression were continued for 6 cycles at 56 days each. Treatment modifications were based on adverse events including thrombocytopenia, leukopenia, and elevation in creatinine and transaminases. Treatment responses were evaluated by the IWG-MRT response criteria (Blood 2013). Patient reported outcome questionnaires (MPN-SAF and EORTC QLQ-C30) were administered at baseline, prior to treatment cycles, and at study discontinuation. Results: Patients: Ten of the 12 evaluable patients enrolled (median age 70.5, range 57-78, M:F ratio 4:1) are included in this analysis. Eight patients had primary MF (PMF), 1 had post essential thrombocytosis (ET) MF, and 1 had post polycythemia vera (PV) MF. Jak2 V617F mutation was positive in 30%. At the time of enrollment 40% had received an erythrocyte transfusion in the last month and all were DIPSS Int-2 or higher. Median baseline hemoglobin was 9.0 g/dL (range 8.3 - 12.4). Median baseline platelet level was 172 x10 (9)/L (range 56 - 346). Most (90%) had received prior therapy and many were refractory to multiple lines of therapy prior to enrollment. Three (30%) patients had previously participated in a JAK inhibitor clinical trial. Tolerability: Among 6 patients who have completed treatment, median duration of treatment was 39 days (range 24-287) with treatment discontinuation due to progression of disease in 2 patients, allogeneic stem cell transplant in 1, alternative treatment in 1, unrelated adverse event (hyponatremia) in 1, and unrelated death (leukemic transformation with intracranial hemorrhage) in 1. Hematologic Grade 3 or > adverse events included anemia (60%), neutropenia (20%), and leukopenia (10%). Non-hematologic Grade 3 or > adverse events included electrolyte abnormalities (20%), edema (10%), infection (10%), and intracranial hemorrhage (10%). Efficacy: Treatment response per IWG-MRT response criteria included stable disease (SD) in 8/10 (80%), clinical improvement in 1/10 (10%), and progressive disease (PD) in 1 (10%). The median change in hemoglobin and platelet count from baseline was -0.05 g/dL (range -0.5 - 1.8) and 28.5 x10(9)/L (range -143 – 118) respectively, however 4/10 (40%) and 7/10 (70%) had improvement at some point during treatment in level of anemia and/or thrombocytopenia. The median follow-up time was 2 months (range 0.9-9.4). Among 6 patients with a baseline and at least one post-baseline MPN-SAF TSS, 2/6 (30%) of patients had at least a 10-point (clinically meaningful) improvement, with 1 of the 2 achieving the stricter 50% improvement from baseline. Responses might have been confounded due to impact of prior therapies. Conclusions: On interim analysis, ruxolitinib and danazol combination therapy demonstrates modest additional clinical benefit, however in a group of exceedingly high risk MF patients with significant anemia and prior single agent JAK inhibitor failures. Preliminary data suggests improvement in anemia and/or thrombocytopenia in some treated patients however only one clinical improvement per IWG-MRT criteria was observed. Combination therapy was well tolerated with no major incremental toxicity attributable to the addition of danazol. Maturation of data is needed to fully evaluate efficacy of ruxolitinib and danazol combination therapy prior to continuation of accrual. Disclosures Mascarenhas: Incyte Corporation: Consultancy, Research Funding; Novartis Pharmaceuticals Corporation: Research Funding. Reeder:Millennium, Celgene, Novartis: Research Funding. Tibes:Seattle Genetics, Inc.: Research Funding. Mesa:Incyte: Research Funding; Novartis: Consultancy; Gilead: Research Funding; Genentech: Research Funding; Promedior: Research Funding; Ns Pharma: Research Funding; Celgene: Research Funding; Lilly: Research Funding; Cti: Research Funding.

Abstract Introduction: Most myelofibrosis (MF) patients develop anemia during evolution of the disease process predicting decreased survival. Previous studies exploring the effect of danazol for the treatment of anemia in MF demonstrate responses in anemia. In prior randomized-controlled studies, ruxolitinib demonstrated improvements in splenomegaly, symptom burden, and even survival yet improvements in cytopenias were uncommon. We designed a phase II multicenter pilot study to evaluate the efficacy and tolerability of combination therapy with ruxolitinib and danazol in MF patients with anemia. Methods: This was a Simon optimum two-stage phase II trial. Eligible subjects received ruxolitinib, a JAK 1/JAK2 inhibitor, at 10mg (plat >75 x10x9) BID or 5mg (plat <75 x10 x9) BID) representing initial dose reduction for JAK inhibitor naïve patients to minimize cytopenias, in combination with tapered danazol up to 200mg orally TID. Dose escalation was allowed after completion of 28 days for lack of response or for disease progression. Pts without progression continued for 6 cycles at 56 days each. Treatment modifications were allowed for either medication based on emergent adverse events (AE). Treatment responses were evaluated every cycle by IWG-MRT criteria (Blood 2006). Patient reported outcome questionnaires (MPN-SAF, EORTC QLQ-C30) were administered at baseline, prior to treatment cycles, and at study discontinuation. Results: Patients: Fourteen pts enrolled (9 Mayo Arizona, 5 Mount Sinai). Median (Med) age 70.5 (range 43-78), M:F ratio 1.8:1. Ten primary MF, 2 post-essential thrombocythemia MF, and 2 post-polycythemia vera MF. JAK2 V617F positive in 42.9%. DIPSS Low in 1 pt, Int-1 in 1pt, Int-2 in 8 pts, High in 2 pts, and unknown in 2pts. Transfusion dependence in 35.7% at baseline. Med baseline hemoglobin (hgb) was 9.0 g/dL (R: 8.3 - 12.4), platelet (plt)157 x109/L (R:143 - 520). Thirteen pts received prior therapy, with 9 pts (64.2%) on a JAK inhibitor within 3 months of study entry. Tolerability: Nine pts (64.2%) ended active treatment, due to progression of disease in 2 pts (22.2%), adverse event (AE) in 2, pt preference in 2, stem cell transplant in 1, unrelated death in 1, and comorbidity in 1. Med duration of therapy: 91 days (range 24-287). AEs regardless of attrition included: hematologic grade 3 or >: anemia in 7 pts (50%), neutropenia in 2 (14.3%), leukopenia in 1 (7.1%), and thrombocytopenia in 2 (14.3%). Non-hematologic grade 3 or >: electrolyte abnormalities in 3 pts (21.4%), infection in 2 (14.3%), edema in 1(7.1%), hypertension in 1 (7.1%), and intracranial hemorrhage in 1 (7.1%). Efficacy: Of the 5 JAK inhibitor naïve pts, 4 had stable or increasing hgb levels with therapy despite new ruxolitinib therapy. Of the 9 pts on prior JAK inhibitor (5 ruxolitinib, 4 other), 5 (55.5%) and 7 (77.7%) patients had stable or increasing hgb or plt levels, respectively. See Table #1. Four pts (28.6%) had at least 50% improvement from baseline on MPN-SAF TSS (95% CI 8.4%-58.1%). Overall treatment response: (IWG-MRT) stable disease (SD) in 10 pts (71.4%), clinical improvement (CI) in 3 (21.4%) all of which were spleen responses, and progressive disease (PD) in 1 (7.1%). Trial was halted secondary to lack of anemia response. Table 1. Patient Specific Response Patient IWG-MRT Response: Study Cycles (N): Prior therapy (within 3 mo) Hemoglobin Response*: (initial, final g/dL) Platelet Response*: (initial, final 10(9)/L) Ruxolitinib 1 CI-Spleen 5 D (8.8, 7.6) S (221,212) 2 SD 4 D (10.3,7.9) S (54,46) 3 SD 2 S (8.8,8.9) S (82,101) 4 SD 3 I (8.9,9.8) S (441,458) 5 SD 3 S (9.6, 9.5) I (161, 231) JAK Inhibitor: 6 SD 5 Momelotinib S (9.0, 9.2) S (132,113) 7 SD 1 NS-018 D (8.3, 7.1) D (120,43) 8 SD 3 NS-018 D (10.1,9.0) D (138,111) 9 SD 2 LY2784544 S (8.7,9.1) S (56,21) Other: 10 CI-Spleen 9 Procrit I (10.5,11.9) S (153,198) 11 CI-Spleen 7 None I (8.9,10.2) D (338,133) 12 PD 1 Hydroxyurea S (12.4, 12.2) D (310, 82) 13 SD 1 Procrit D (10.1, 8.6) D (192, 71) 14 SD 1 Hydroxyurea S (9.1,8.9) D (346,119 *S=stable (Hgb +/- 0.5g/dL, Plt +/- 50x109, D=decreasing, I=increasing. Conclusions: Although overall well tolerated, the addition of danazol to ruxolitinib therapy has modest incremental efficacy by IWG-MRT criteria. Clinical improvement was observed in 21.4% of treated patients, however responses were limited to spleen reduction. The degree to which danazol may stabilize expected cytopenias is interesting and may require further investigation. Disclosures Hoffman: Promedior: Research Funding; Geron: Consultancy, Membership on an entity's Board of Directors or advisory committees; All Cells, LLC: Consultancy, Membership on an entity's Board of Directors or advisory committees. Mesa:Gilead: Research Funding; Genentech: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; CTI Biopharma: Research Funding; Pfizer: Research Funding; Promedior: Research Funding; NS Pharma: Research Funding; Incyte Corporation: Research Funding.

Abstract Abstract 1665 Poster Board I-691 Mantle cell lymphoma (MCL) is an aggressive, incurable B-cell malignancy that represents approximately 6% of lymphoma cases. Patients with MCL who relapse after conventional therapy or stem cell transplantation have a poor prognosis and are candidates for treatment with novel agents. The characteristic feature of MCL is overexpression of cyclin D1. Cyclin D1 is under the control of the phosphatidylinositol-3 kinase signal-transduction pathway and is downstream of the mammalian target of rapamycin kinase (mTOR). We have previously shown that temsirolimus (CCI-779), a dihydroester of the selective mTOR inhibitor rapamycin, is an active antitumor agent in MCL. In previous phase 2 trials of temsirolimus as a single agent, we observed a 40% overall response rate (ORR) with a median duration of response (DR) of 6 months in patients with relapsed or refractory disease (J Clin Oncol 23:5347-56, 2005; Cancer 113:508-514, 2008). Due to the fact that rituximab has improved the response rate and overall outcome of lymphoma patients when combined with chemotherapy, we tested the efficacy and toxicity of temsirolimus in combination with rituximab in patients with MCL. Eligible patients with confirmed relapsed or refractory MCL based on morphologic and phenotypic features received temsirolimus 25 mg intravenously every week and four weekly doses of rituximab with the first cycle and then one dose of rituximab every other cycle. Patients with a tumor response after six cycles were eligible to continue treatment for a total of 12 cycles or two cycles after complete remission, and were then observed without maintenance. Seventy-one patients were enrolled between May 2005 and March 2009. The median age was 67 years (range, 44 to 86 years), with 51 males and 20 females enrolled. Patients had received a median of two prior therapies (range, 1-9), 31% had received a prior stem cell transplant and 28% were rituximab refractory. The ORR was 48% (34/71 patients) with 20% (14/71) complete responses and 28% (20/71) partial responses. The median DR was 9.5 months (95% CI, 4.5 to 11.3 months). The median DR in the rituximab sensitive patients was 9.5 months (CI: 4.5-11.6) and 7.15 months (CI: 4.1-11.3) in the rituximab refractory patients (p= 0.73). While the combination was generally well tolerated, 12 patients experienced grade 4 toxicity and 2 patients died while on therapy – both from progressive disease. Hematologic toxicities were the most common, with 5 patients having grade 4 thrombocytopenia and 3 having grade 4 neutropenia. This study demonstrates that temsirolimus in combination with rituximab is well tolerated and has substantial antitumor activity in relapsed MCL. Further comparative studies of this combination in MCL are therefore warranted. Disclosures Witzig: Wyeth: Patents & Royalties.

AbstractThe combination of pomalidomide (POM) and dexamethasone (DEX) was evaluated for relapsed/refractory primary central nervous system lymphoma (PCNSL) and primary vitreoretinal lymphoma (PVRL) to determine the maximal tolerated dose (MTD) of POM as the primary objective, and overall response rate (ORR), progression-free survival (PFS), and safety profile as secondary objectives. A cohorts-of-3 study design was used with a dose-escalation schedule consisting of POM (3, 5, 7, or 10 mg) orally daily for 21 days every 28 days and DEX 40 mg orally every week. After 2 cycles, POM was continued alone until disease progression, intolerance, or subject withdrawal. Following MTD determination, the MTD cohort was expanded. Twenty-five of 29 patients with the median of 3 prior treatments were eligible for assessment as per international PCNSL collaborative group criteria. The MTD of POM was 5 mg daily for 21 days every 28 days. Whole-study ORR was 48% (12 of 25; 95% confidence interval [CI], 27.8%, 68.7%) with 6 complete response (CR), 2 complete response, unconfirmed (CRu), and 4 partial response (PR). MTD cohort ORR was 50% (8 of 16; 95% CI, 24.7%, 75.4%) with 5 CR, 1 CRu, and 2 PR. Median PFS was 5.3 months (whole study) and 9 months (for responders). One patient had pseudoprogression. Grade 3/4 hematologic toxicities included neutropenia (21%), anemia (8%), and thrombocytopenia (8%). Grade 3/4 nonhematologic toxicities included lung infection (12%), sepsis (4%), fatigue (8%), syncope (4%), dyspnea (4%), hypoxia (4%), respiratory failure (8%), and rash (4%). POM/DEX treatment is feasible with significant therapeutic activity against relapsed/refractory PCNSL and PVRL. This trial was registered at www.clinicaltrials.gov as #NCT01722305.

Abstract Purpose: The growth of non–Hodgkin lymphomas can be influenced by tumor–immune system interactions. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is a negative regulator of T-cell activation that serves to dampen antitumor immune responses. Blocking anti–CTLA-4 monoclonal antibodies improves host resistance to immunogenic tumors, and the anti–CTLA-4 antibody ipilimumab (MDX-010) has clinical activity against melanoma, prostate, and ovarian cancers. Experimental Design: We did a phase I trial of ipilimumab in patients with relapsed/refractory B-cell lymphoma to evaluate safety, immunologic activity, and potential clinical efficacy. Treatment consisted of ipilimumab at 3 mg/kg and then monthly at 1 mg/kg × 3 months (dose level 1), with subsequent escalation to 3 mg/kg monthly × 4 months (dose level 2). Results: Eighteen patients were treated, 12 at the lower dose level and 6 at the higher dose level. Ipilimumab was generally well tolerated, with common adverse events attributed to it, including diarrhea, headache, abdominal pain, anorexia, fatigue, neutropenia, and thrombocytopenia. Two patients had clinical responses; one patient with diffuse large B-cell lymphoma had an ongoing complete response (&gt;31 months), and one with follicular lymphoma had a partial response lasting 19 months. In 5 of 16 cases tested (31%), T-cell proliferation to recall antigens was significantly increased (&gt;2-fold) after ipilimumab therapy. Conclusions: Blockade of CTLA-4 signaling with the use of ipilimumab is well tolerated at the doses used and has antitumor activity in patients with B-cell lymphoma. Further evaluation of ipilimumab alone or in combination with other agents in B-cell lymphoma patients is therefore warranted. (Clin Cancer Res 2009;15(20):6446–53)