Yttrium-90 anti-CD25 BEAM conditioning for autologous hematopoietic cell transplantation in Peripheral T-cell lymphoma.

ABSTRACT: Peripheral T-cell lymphomas (PTCLs) have a poor prognosis with current treatments. High-dose chemotherapy followed by autologous hematopoietic cell transplant (AHCT) is used as a consolidation strategy after achieving clinical remission with first-line therapy, as well as in chemotherapy-sensitive relapse if allogeneic transplant is not an option. CD25 is a targetable protein often highly expressed in PTCLs. In this phase 1 clinical trial, we tested the addition of ß-emitting 90yttrium (90Y)-labeled chimeric anti-CD25 basiliximab (aTac) to BEAM (carmustine, etoposide, cytarabine, and melphalan) as conditioning for AHCT for patients with PTCL. Twenty-three AHCT-eligible patients were enrolled, and 20 received therapeutic 90Y-aTac-BEAM AHCT. Radiation doses of 0.4, 0.5, and 0.6 mCi/kg were tested. With no observed dose-limiting toxicities, 0.6 mCi/kg was deemed the recommended phase 2 dose. The most prevalent adverse effect, grade 2 mucositis, was experienced by 80% of patients. As of this report, 6 (30%) of the treated patients had died, 5 due to progressive disease and 1 due to multiple organ failure (median time of death, 17 months [range, 9-21]) after AHCT. Median follow-up was 24 months (range, 9-26) overall and 24 months (range, 13-26) for surviving patients. For patients who received therapeutic 90Y-aTac-BEAM AHCT, the 2-year progression-free and overall survival were 59% (95% confidence interval [CI], 34-77) and 68% (95% CI, 42-84), respectively. 90Y-aTac-BEAM appears to be safe as an AHCT conditioning regimen for PTCL, with no increased toxicity over the toxicities historically seen with BEAM alone in this patient population. This trial was registered at www.ClinicalTrials.gov as #NCT02342782.

Consolidation with First and Second Allogeneic Transplants in Adults with Relapsed/Refractory B-ALL Following Response to CD19CAR T Cell Therapy.

CD19-targeted chimeric antigen receptor T cell (CAR-T) therapy has led to unprecedented rates of complete remission (CR) in children and adults with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL), yet the majority of adults relapse after initial response. One proposed method to extend the durability of remission in adults following response to CAR-T therapy is consolidation with allogeneic hematopoietic cell transplantation (alloHCT). Considering the limited published data for the utility of post CAR-T therapy consolidative alloHCT in r/r B-ALL, especially data related to patients receiving a second alloHCT, we sought to describe outcomes of patients with r/r B-ALL at our institution who received their first or second alloHCT following response to CAR-T therapy. We performed a retrospective analysis of adult patients with r/r B-ALL who responded to either investigational or standard of care (SOC) CD19-targeted CAR-T therapy and underwent consolidation with alloHCT while in CR without interim therapy. We identified 45 patients, of whom 26 (58%) and 19 (42%) received their first and second alloHCT as consolidation post CAR-T therapy, respectively. The median age was 31 years (range: 19-67) and 31 (69%) patients were Hispanic. Ph-like was the most common genetic subtype and comprised over half of cases (53%; n = 24). The median number of prior therapies pre-transplant was 5 (range: 2-7), and disease status at the time of alloHCT was CR1, CR2 or ≥CR3 in 7 (16%), 22 (49%) and 16 (35%) patients, respectively. The median time from CAR-T therapy until alloHCT was 93 (range: 42-262) days. The conditioning regimen was radiation-based myeloablative (MAC) in 22 (49%) patients. With a median follow-up of 2.47 years (range: 0.13-6.93), 2-year overall survival (OS), relapse free survival (RFS), cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) were 57.3% (95% CI: 0.432-0.760), 56.2% (95% CI: 0.562-0.745), 23.3% (95% CI: 0.13-0.42), and 20.4% (95% CI: 0.109-0.384), respectively. Two-year OS (52% vs. 68%, P = .641), RFS (54% vs. 59%, P = .820), CIR (33.5% vs. 8.5%, P = .104), and NRM (12.5% vs. 32.2%, P = .120) were not significantly different between patients who underwent their first vs. second transplant, respectively. In univariate analysis, only Ph-like genotype was associated with inferior RFS (P = .03). AlloHCT post CAR-T response is associated with a relatively low early mortality rate and encouraging survival results in high-risk adults with r/r B-ALL, extending to the second alloHCT for fit and eligible patients.

Brentuximab Vedotin Plus Ibrutinib in Relapsed and Refractory Hodgkin Lymphoma.

INTRODUCTION: Brentuximab vedotin (BV) is an antibody-drug conjugate that delivers monomethyl auristatin E (MMAE) to CD30+ cells and is safe and effective in relapsed/refractory (r/r) Hodgkin lymphoma (HL). Although most patients respond to BV, only a minority will obtain a complete response (CR), and almost all patients eventually progress. Ibrutinib is a Bruton's tyrosine kinase (BTK) inhibitor highly active in multiple subtypes of non-Hodgkin lymphoma; limited data exist regarding its use in HL. It irreversibly inhibits interleukin-2-inducible kinase (ITK) with Th1 based immune responses. As we previously observed preclinical synergy between ibrutinib and BV, we hypothesized ibrutinib may enhance the antitumor activity of BV in HL. We designed and conducted a phase II trial of ibrutinib plus BV in patients with R/R HL, and herein report the final primary analysis of safety and efficacy. METHODS: This was a multicenter phase II trial with a lead-in cohort in patients with r/r HL. Eligibility criteria included age ≥ 15 years with r/r HL after at least one prior line of therapy. Treatment consisted of 1.8 mg/kg BV intravenously every 3 weeks and ibrutinib 560 mg PO daily (420 mg PO daily in the lead-in cohort). Prior BV was allowed if patients were not refractory. The primary endpoint was the CR rate according to Lugano 2014. Secondary endpoints included toxicities, overall response rate (ORR), and duration of response (DOR). RESULTS: The 39 patients were enrolled onto the study, of which 67% were male; the median age was 33 (range: 17-71). 38% had extranodal disease at baseline, 51% had advanced stage disease, 51% were refractory to the prior therapy, and 21% had prior BV. Of 36 patients who were evaluable for response, the CR rate was 33% and ORR 64%; median DOR was 25.5 months. Thirteen patients proceeded to autologous transplant and 3 patients proceeded to allogeneic transplant for consolidation after response. The most common adverse events were nausea (67%), peripheral neuropathy (62%), diarrhea (59%), fatigue (46%), thrombocytopenia (46%), headache (41%), rash (41%), elevated ALT (38%), anemia (36%), vomiting (36%), abdominal pain (33%), fever (33%), and hypertension (33%). Six patients experienced unacceptable toxicity, defined as Gr 3/4 non-hematologic toxicity or non-resolving Gr 3/4 hematologic toxicity including one patient who died of multiorgan failure from suspected COVID-19 infection during cycle 1. DISCUSSION: The combination of BV and ibrutinib was active in r/r HL; however, given significant toxicity, it cannot be recommended for future development.

Phase 1 Study of Bortezomib, Fludarabine, and Melphalan, With or Without Total Marrow Irradiation, as Allogeneic Hematopoietic Stem Cell Transplant Conditioning for High-risk or Relapsed/Refractory Multiple Myeloma.

OBJECTIVE: We conducted a phase 1 study of a conditioning regimen with or without total marrow irradiation (TMI) before allogeneic hematopoietic stem cell transplantation for patients with high-risk or refractory multiple myeloma. METHODS: Eighteen patients were enrolled on one of 2 strata. Patients with no prior radiation received TMI (900 cGy), fludarabine (FLU), and melphalan (MEL) conditioning, with bortezomib added in the second cohort (stratum I). Patients with prior radiation received FLU, MEL, and bortezomib, without TMI (stratum II). RESULTS: Eight patients were enrolled in the TMI arm (stratum I). One of 3 patients in cohort 1 experienced dose-limiting toxicity (DLT), which led to the expansion to 3 more patients with no DLT. Cohort 2 enrolled only 2 patients due to low accrual, with bortezomib, added at 0.5 mg/m 2 ; neither experienced DLT. Nine patients were enrolled in the non-TMI arm (stratum II). Three patients were enrolled in cohort 1 (bortezomib 0.5 mg/m 2 ) and none experienced DLT. Three were enrolled in cohort 2 (bortezomib 0.7 mg/m 2 ), and 1 experienced DLT; therefore, the cohort expanded to 3 more patients. One more patient experienced DLT. Median overall survival on strata I and II was 44.5 months (95% CI: 1.73-not reached) and 21.6 months (95% CI: 4.1-72.7), respectively. Median progression-free survival on strata I and II was 18.1 months (95% CI: 1.73-not reached) and 8.9 months (95% CI: 2.7-24.4), respectively. CONCLUSION: TMI 900 cGy, FLU, and MEL are considered feasible as conditioning for allogeneic stem cell transplantation and may warrant further investigation due to favorable response rates and survival.

Treatment of relapsed or refractory FLT-3 acute myelogenous leukemia with a triplet regimen of hypomethylating agent, venetoclax, and gilteritinib.

Relapsed or refractory (R/R) acute myeloid leukemia (AML) with FMS-like tyrosine kinase 3 (FLT3) mutations remains a difficult and hard to treat entity. Gilteritinib is a potent oral FLT-3 inhibitor that improves overall survival in R/R AML, but studies are limited in combining gilteritinib with a hypomethylating agent and venetoclax treatment backbone (HMA-VEN-GILT). Here we report our experience with HMA-VEN-GILT for 22 R/R FLT3 AML patients. HMA-VEN-GILT yielded an ORR of 77.3% (17/22), CR 4.5% (1/22), CRi 13.6% (3/22), MLFS 59.1% (13/22). Median follow-up was 10.4 months with a relapse rate of 29.4% (5/17), median time to relapse of 69 days (range 35-298 days), 6-month overall survival of 84%, and median OS of 10.1 months. Additionally, 36.4% (8/22) of patients proceeded to hematopoietic stem cell transplant. In conclusion, HMA-VEN-GILT for the treatment of R/R FLT3 AML is feasible and can be used as a bridge to allogeneic transplantation.

A phase 1 trial of 8-chloro-adenosine in relapsed/refractory acute myeloid leukemia: An evaluation of safety and pharmacokinetics.

BACKGROUND: This study evaluated the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of 8-chloro-adenosine (8-Cl-Ado) in patients with relapsed/refractory acute myeloid leukemia (AML). METHODS: 8-Cl-Ado was administered daily for 5 days; the starting dose was 100 mg/m2 , the highest dose tested was 800 mg/m2 . The end points were toxicity, disease response, and PK/PD measurements. RESULTS: The predominant nonhematologic toxicity was cardiac with grade ≥3 toxicity. Plasma PK in all patients suggested heterogeneity among patients, yet, some dose-dependency for the accumulation of 8-Cl-Ado. Two 8-Cl-Ado metabolites accumulated at similar levels to 8-Cl-Ado. Cellular PK in eight patients indicated accumulation of 8-Cl-ATP, which was associated with AML blast cytoreduction in peripheral blood. The authors determined the RP2D of 8-Cl-Ado to be 400 mg/m2 . CONCLUSIONS: Given the cardiac adverse events observed, patients require monitoring for arrhythmias and QT interval during infusion. Although peripheral blood cytoreduction was observed, responses were transient, suggesting combination strategies will be required.

Bendamustine lymphodepletion is a well-tolerated alternative to fludarabine and cyclophosphamide lymphodepletion for axicabtagene ciloleucel therapy for aggressive B-cell lymphoma.

Fludarabine/cyclophosphamide (Flu/Cy) is established for lymphodepletion (LD) prior to standard-of-care CAR T-cell therapy for lymphoma. There is ongoing need to test alternative LD regimens to preserve efficacy, improve safety, and address challenges including the recent national fludarabine shortage. We retrospectively evaluated outcomes among patients with relapsed/refractory aggressive B-cell lymphoma who received bendamustine (n = 27) or Flu/Cy (n = 42) LD before axicabtagene ciloleucel (axi-cel) at our institution. The median change in absolute lymphocyte count from pre-LD to time of axi-cel infusion was -0.6×109 /L in bendamustine cohort and -0.7×109 /L in Flu/Cy cohort. The best overall response/complete response rates were 77.8% (95% CI: 57.7%-91.4%)/48.1% (95% CI: 28.7%-68.1%) among bendamustine cohort and 81.0% (95% CI: 65.9%-91.4%)/50.0% (95% CI: 34.2%-65.8%) among Flu/Cy cohort. Six-month progression-free survival were 43.8% (95% CI: 24.7%-61.3%) and 55.6% (95% CI: 39.0%-69.3%) in bendamustine and Flu/Cy cohorts, while 6-month overall survival were 81.5% (95% CI: 61.1%-91.8%) and 90.4% (95% CI: 76.4%-96.3%), respectively. Relative to Flu/Cy-treated patients, bendamustine-treated patients did not show an increase in hazards associated with experiencing progression/relapse/death (aHR:1.4 [95% CI: 0.7-2.8]; p = .32) or death (aHR:1.6 [95% CI: 0.5-5.6]; p = .46), after adjusting for baseline number of prior therapies and refractory disease. Any grade/grade ≥3 CRS were observed in 89%/3.7% and 86%/4.8% among bendamustine and Flu/Cy cohorts, while any grade ICANS/grade ≥3 ICANS were observed in 30%/19% and 55%/31% respectively. While more Flu/Cy-treated patients experienced grade ≥3 neutropenia compared with bendamustine-treated patients (100% vs. 68%), grade ≥3 infectious complications were comparable (24% vs. 19% respectively). More patients received bendamustine LD and axi-cel as outpatient than Flu/Cy cohort, without increased toxicities and with shorter median inpatient stays. In conclusion, we observed comparable efficacy and lower any grade ICANS among patients receiving bendamustine relative to Flu/Cy LD, followed by axi-cel.

Results of a Phase II Trial of Allogeneic Hematopoietic Stem Cell Transplantation Using 90Y-Ibritumomab Tiuxetan (Zevalin) in Combination With Fludarabine and Melphalan in Patients With High-Risk B-Cell Non-Hodgkin's Lymphoma.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (alloHCT) is potentially curative for relapsed/refractory (r/r) B-cell non-Hodgkin's lymphoma (B-cell NHL). However, relapse remains a major cause of treatment failure, especially in patients with either positron emission tomography (PET)-positive and/or chemoresistant disease prior to alloHCT. 90Y-ibritumomab tiuxetan (Zevalin) is a radiolabeled anti-CD20 antibody which is a safe and effective therapy in multiple histologic subtypes of B-cell NHL and has also been incorporated in both autologous HCT (autoHCT) and alloHCT conditioning regimens. OBJECTIVES: The purpose of this study was to evaluate the efficacy and confirm the safety of the radiolabeled anti-CD20 antibody ibritumomab tiuxetan (Zevalin) combined with the reduced intensity conditioning (RIC) regimen of fludarabine and melphalan (Flu/Mel) in patients with high-risk B-cell NHL. STUDY DESIGN: We conducted a phase II trial (NCT00577278) of Zevalin with Flu/Mel in patients with high-risk B-cell NHL. We enrolled 41 patients from October 2007 to April 2014, all of whom had either a fully matched sibling or 8/8 or 7/8 matched unrelated donor (MUD). Patients received 111In-Zevalin (5.0 mCi) on day -21 pre-HCT, followed by 90Y-Zevalin (0.4 mCi/kg) on day -14. Fludarabine (25 mg/m2 daily) was given from days -9 to -5 and melphalan (140 mg/m2) was administered on day -4. All patients received rituximab 250 mg/m2 on day +8 and an additional dose on either day +1 or -21 depending on the baseline rituximab level. Patients with a low rituximab level were given rituximab on days -21 and -15. All patients received tacrolimus/sirolimus (T/S) with or without methotrexate (MTX) for graft-versus-host disease (GVHD) prophylaxis starting on day -3, and stem cells were infused on day 0. RESULTS: The 2-year overall survival (OS) and progression-free survival (PFS) for all patients were 63% and 61%, respectively. The incidence of relapse at 2 years was 20%. Nonrelapse mortality (NRM) at day +100 and 1 year were 5% and 12%, respectively. The overall cumulative incidence of grade II-IV and III-IV acute GVHD (aGVHD) were 44% and 15%, respectively. Extensive chronic GVHD (cGVHD) occurred in 44% of patients. On univariate analysis, histology (diffuse large B cell lymphoma (DLBCL) vs. others) was negatively predictive for OS (P = .0013) and PFS (P = .0004), while histology (DLBCL vs. others, P = .0128) predicted for relapse. PET positivity pre-HCT did not correlate with any of the efficacy endpoints. CONCLUSION: Addition of Zevalin to Flu/Mel is safe and effective in high-risk NHL and met the prespecific endpoint. Results were suboptimal in patients with DLBCL.

Leflunomide Confers Rapid Recovery from COVID-19 and is Coupled with Temporal Immunologic Changes.

Background: Vaccines for SARS-CoV-2 have been considerably effective in reducing rates of infection and severe COVID-19. However, many patients, especially those who are immunocompromised due to cancer or other factors, as well as individuals who are unable to receive vaccines or are in resource-poor countries, will continue to be at risk for COVID-19. We describe clinical, therapeutic, and immunologic correlatives in two patients with cancer and severe COVID-19 who were treated with leflunomide after failing to respond to standard-of-care comprising remdesivir and dexamethasone. Both patients had breast cancer and were on therapy for the malignancy. Methods: The protocol is designed with the primary objective to assess the safety and tolerability of leflunomide in treating severe COVID-19 in patients with cancer. Leflunomide dosing consisted of a loading dose of 100 mg daily for the first three days, followed by daily dosing, at the assigned dose level (Dose Level 1: 40 mg, Dose Level -1, 20 mg; Dose Level 2, 60 mg), for an additional 11 days. At defined intervals, serial monitoring of blood samples for toxicity, pharmacokinetics, and immunologic correlative studies were performed, as well as nasopharyngeal swabs for PCR analysis of SARS-CoV-2. Results: Preclinically, leflunomide impaired viral RNA replication, and clinically, it led to a rapid improvement in the two patients discussed herein. Both patients completely recovered, with minimal toxicities; all adverse events experienced were considered unrelated to leflunomide. Single-cell mass-cytometry analysis showed that leflunomide increased levels of CD8+ cytotoxic and terminal effector T cells and decreased naïve and memory B cells. Conclusions: With ongoing COVID-19 transmission and occurrence of breakthrough infections in vaccinated individuals, including patients with cancer, therapeutic agents that target both the virus and host inflammatory response would be helpful despite the availability of currently approved anti-viral agents. Furthermore, from an access to care perspective, especially in resource-limited areas, an inexpensive, readily available, effective drug with existing safety data in humans is relevant in the real-world setting.

A Practical Guide to Relugolix: Early Experience With Oral Androgen Deprivation Therapy.

BACKGROUND: Relugolix is the newest form of androgen deprivation therapy (ADT) approved for prostate cancer. However, as an oral drug, several real-world concerns exist, particularly medication compliance, safety with other androgen receptor-targeted agents, and financial burden to patients. METHODS: A single institution retrospective chart review was conducted evaluating all patients who were prescribed relugolix for any prostate cancer indication from January 1, 2021 to January 31, 2022. Demographic data, cardiac risk factors, concomitant therapy usage, and PSA/testosterone levels, were abstracted from the chart review. Adverse effects were obtained by examining progress notes. Compliance was assessed by clinic notes as well as prescription fills by specialty pharmacy records. The reasons patients did not fill or discontinued the medication were noted. RESULTS: Hundred and one patients were prescribed relugolix, and 91 patients consented to research. Seventy-one (78%) patients filled the prescription to relugolix, with a median follow-up of 5 months. Prescription fill data were available for 45 (63%) patients, with 94% of days covered. The most commonly reported reason not to fill was cost at 50%. Sixty-six (93%) patients reported never missing a dose. PSA levels were available in 71 (100%) patients with 69 (97%) showing stable or improved PSA. Testosterone levels were available in 61 (86%) of patients, which showed 61 (100%) stable or successful castration. Twenty-four (34%) patients used relugolix in combination. No new major safety signals were seen in combination therapy. Nineteen (27%) patients had switched to another form of ADT. Fifteen of these (79%) felt similar or better on relugolix therapy. CONCLUSIONS: Compliance with relugolix seemed acceptable. No major new safety signals were seen, even in combination. Among patients who switched therapy, most tolerated relugolix similarly or better than the previous form of ADT. The cost was a major reason for patients not initiating and for discontinuing therapy.

Favorable Activity and Safety Profile of Memory-Enriched CD19-Targeted Chimeric Antigen Receptor T-Cell Therapy in Adults with High-Risk Relapsed/Refractory ALL.

PURPOSE: A phase I/II study evaluating the safety and activity of memory-enriched CD19-directed chimeric antigen receptor (CD19-CAR) T cells in adults with relapsed/refractory B-cell acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: In phase I, we tested sequentially two cell populations for CAR transduction: (i) central memory (Tcm) or (ii) naïve, stem, and central memory (Tn/mem) T cells. The study employed an activity constrained for toxicity design to determine the recommended phase II dose (RP2D), which was tested in phase II. RESULTS: The Tcm cohort was closed early due to lack of activity. The 200 ×106 Tn/mem-derived CD19-CAR T-cell dose was found to be safe and active, and was declared the RP2D. At RP2D, 58 participants underwent leukapheresis and 46 received CD19-CAR T cells. Median age for treated participants was 38 years (range, 22-72). Twenty-nine (63%) participants had relapsed post-allogeneic hematopoietic cell transplantation (alloHCT), 18 (39%) had Philadelphia-like (Ph-like) genotype, and 16 (35%) had extramedullary disease (EMD) at lymphodepletion (LD). Three (7%) participants had grade 3 cytokine release syndrome (CRS), and none had grade ≥ 4 CRS. Eight (17%) participants had grade ≥ 3 neurotoxicity, including one fatal cerebral edema. Forty (87%) patients achieved complete remission (CR)/CR with incomplete hematologic recovery, 2 (4%) progressed, and 4 (9%) were unevaluable for response. Among 42 response-evaluable participants, 16/17 with Ph-like ALL and 13/15 with EMD at LD responded. Twenty-one (53%) responders underwent alloHCT consolidation, which was associated with improved relapse-free survival (adjusted HR = 0.16; 95% confidence interval, 0.05-0.48; P = 0.001). CONCLUSIONS: Tn/mem-derived CD19-CAR T cells were safe and active, including in Ph-like ALL and EMD. See related commentary by El Marabti and Abdel-Wahab, p. 694.

Total marrow irradiation (TMI): Addressing an unmet need in hematopoietic cell transplantation - a single institution experience review.

Purpose: TMI utilizes IMRT to deliver organ sparing targeted radiotherapy in patients undergoing hematopoietic cell transplantation (HCT). TMI addresses an unmet need, specifically patients with refractory or relapsed (R/R) hematologic malignancies who have poor outcomes with standard HCT regimens and where attempts to improve outcomes by adding or dose escalating TBI are not possible due to increased toxicities. Over 500 patients have received TMI at this center. This review summarizes this experience including planning and delivery, clinical results, and future directions. Methods: Patients were treated on prospective allogeneic HCT trials using helical tomographic or VMAT IMRT delivery. Target structures included the bone/marrow only (TMI), or the addition of lymph nodes, and spleen (total marrow and lymphoid irradiation, TMLI). Total dose ranged from 12 to 20 Gy at 1.5-2.0 Gy fractions twice daily. Results: Trials demonstrate engraftment in all patients and a low incidence of radiation related toxicities and extramedullary relapses. In R/R acute leukemia TMLI 20 Gy, etoposide, and cyclophosphamide (Cy) results in a 1-year non-relapse mortality (NRM) rate of 6% and 2-year overall survival (OS) of 48%; TMLI 12 Gy added to fludarabine (flu) and melphalan (mel) in older patients (≥ 60 years old) results in a NRM rate of 33% comparable to flu/mel alone, and 5-year OS of 42%; and TMLI 20 Gy/flu/Cy and post-transplant Cy (PTCy) in haplo-identical HCT results in a 2-year NRM rate of 13% and 1-year OS of 83%. In AML in complete remission, TMLI 20 Gy and PTCy results in 2-year NRM, OS, and GVHD free/relapse-free survival (GRFS) rates of 0%, 86·7%, and 59.3%, respectively. Conclusion: TMI/TMLI shows significant promise, low NRM rates, the ability to offer myeloablative radiation containing regimens to older patients, the ability to dose escalate, and response and survival rates that compare favorably to published results. Collaboration between radiation oncology and hematology is key to successful implementation. TMI/TMLI represents a paradigm shift from TBI towards novel strategies to integrate a safer and more effective target-specific radiation therapy into HCT conditioning beyond what is possible with TBI and will help expand and redefine the role of radiotherapy in HCT.

Total marrow and lymphoid irradiation as conditioning in haploidentical transplant with posttransplant cyclophosphamide.

Posttransplant cyclophosphamide (PTCy) platform has shown low rates of graft-versus-host disease (GVHD) and nonrelapse mortality (NRM) after haploidentical hematopoietic cell transplantation (HaploHCT). However, because of the limited disease control, relapse rate remains a major cause of treatment failure in high-risk patients. Total marrow and lymphoid irradiation (TMLI) allows for delivery of high radiation to bone marrow and other targeted structures, without increasing off-target radiation exposure and toxicity to end organs. In this phase 1 trial, 31 patients with high-risk and/or active primary refractory leukemias or myelodysplastic syndrome underwent peripheral blood stem cell HaploHCT with TMLI, fludarabine, and cyclophosphamide as the conditioning regimen. Radiation dose was escalated in increments of 200 cGy (1200-2000 cGy). GVHD prophylaxis was PTCy with tacrolimus/mycophenolate mofetil. Grade 2 toxicities by the Bearman scale were mucositis (n = 1), hepatic (n = 3), gastrointestinal (n = 5), and cardiac (n = 2). One patient (1800 cGy) experienced grade 3 pulmonary toxicity (dose-limiting toxicity). At a follow-up duration of 23.9 months for the whole cohort; 2-year NRM was 13%. Cumulative incidence of day 100 grade 2 to 4 and 3 to 4 acute GVHD was 52% and 6%, respectively. Chronic GVHD at 2 years was 35%. For patients treated with 2000 cGy, with a median follow-up duration of 12.3 months, 1-year relapse/progression, progression-free survival, and overall survival rates were 17%, 74%, and 83%, respectively. In conclusion, HaploHCT-TMLI with PTCy was safe and feasible in our high-risk patient population with promising outcomes.

Phase I trial of daily subcutaneous SPL-108 injections in combination with paclitaxel in patients with platinum resistant CD44+ advanced ovarian epithelial cancer.

OBJECTIVE: Preclinical evidence and early clinical trials have demonstrated the activity of SPL-108, a targeted agent that inhibits CD44 mediated induction of multidrug resistance specifically to paclitaxel and platinum agents. We conducted a phase I, open label, dose escalation study of the safety and tolerability of the combination of SPL-108 with weekly paclitaxel in patients with platinum resistant CD44+ ovarian, primary peritoneal, or fallopian tube cancer. METHODS: Patients with platinum resistant histologically proven epithelial ovarian, primary peritoneal, or fallopian tube cancers and measurable disease according to RECIST (Response Evaluation Criteria in Solid Tumours) version 1.1 were selected. Tumors were tested for CD44 expression for eligibility, defined as strong (+++) or moderate (++) staining in ≥20% of the tumor tissue or diffuse + staining. Patients were treated with daily and then twice daily SPL-108 subcutaneous injections and weekly intravenous paclitaxel on days 1, 8, and 15 of a 28 day cycle. Endpoints included safety, determination of maximum tolerated dose, and efficacy. Tumors underwent comprehensive genomic profiling, and cell lines and western blotting were used to study markers of response. RESULTS: We screened 16 patients, and 14 were enrolled based on CD44+ expression. A total of 86% of patients had high grade serous tumors and all had received multiple prior therapies. There were no grade 4-5 toxicities. One patient had grade 3 peripheral sensory neuropathy attributed to paclitaxel and one patient developed presumed colonic perforation attributed to the study drug. No dose reductions or treatment discontinuations were required. All patients tolerated the maximum planned dose; no maximum tolerated dose was reached. Overall response rate was 36%; 5 (36%) patients had partial response and 5 (36%) patients had stable disease. CONCLUSIONS: The combination of SPL-108 with weekly paclitaxel was safe and well tolerated. Encouraging antitumor activity was observed, with 72% of patients deriving a clinical benefit. TRIAL REGISTRATION: NCT03078400.

Total Marrow and Lymphoid Irradiation with Post-Transplantation Cyclophosphamide for Patients with AML in Remission.

Graft-versus-host disease (GVHD) has remained the main cause of post-transplantation mortality and morbidity after allogeneic hematopoietic cell transplantation (alloHCT), adding significant economic burden and affecting quality of life. It would be desirable to reduce the rate of GVHD among patients in complete remission (CR) without increasing the risk of relapse. In this study, we have tested a novel conditioning regimen of total marrow and lymphoid irradiation (TMLI) at 2000 cGy, together with post-transplantation cyclophosphamide (PTCy) for patients with acute myeloid leukemia in first or second CR, to attenuate the risk of chronic GVHD by using PTCy, while using escalated targeted radiation conditioning before allografting to offset the possible increased risk of relapse. The primary objective was to evaluate the safety/feasibility of combining a TMLI transplantation conditioning regimen with a PTCy-based GVHD prophylaxis strategy, through the assessment of adverse events in terms of type, frequency, severity, attribution, time course, duration, and complications, including acute GVHD, infection, and delayed neutrophil/platelet engraftment. Secondary objectives included estimation of non-relapse mortality (NRM), overall survival (OS), relapse-free survival, acute and chronic GVHD, and GVHD-relapse-free survival (GRFS). A patient safety lead-in was first conducted to ensure there were no unexpected toxicities and was expanded on the basis of lack of dose-limiting toxicities. The patient safety lead-in segment followed 3 + 3 dose expansion/(de-)escalation rules based on observed toxicity through day 30; the starting dose of TMLI was 2000 cGy, and a de-escalation to 1800 cGy was considered. After the safety lead-in segment, an expansion cohort of up to 12 additional patients was to be studied. TMLI was administered on days -4 to 0, delivered in 200 cGy fractions twice daily. The radiation dose delivered to the liver and brain was kept at 1200 cGy. Cyclophosphamide was given on days 3 and 4 after alloHCT, 50 mg/kg each day for GVHD prevention; tacrolimus was given until day 90 and then tapered. Among 18 patients with a median age of 40 years (range 19-56), the highest grade toxicities were grade 2 Bearman bladder toxicity and stomatitis. No grade 3 or 4 Bearman toxicities or toxicity-related deaths were observed. The cumulative incidence of acute GVHD grade 2 to 4 and moderate-to-severe chronic GVHD were 11.1% and 11.9%, respectively. At a median follow up of 24.5 months, two-year estimates of OS and relapse-free survival were 86.7% and 83.3%, respectively. Disease relapse at 2 years was 16.7%. The estimates of NRM at 2 years was 0%. The GVHD/GRFS rate at 2 years was 59.3% (95% confidence interval, 28.8-80.3). This chemotherapy-free conditioning regimen, together with PTCy and tacrolimus, is safe, with no NRM. Preliminary results suggest an improved GRFS rate.

Response-adapted anti-PD-1-based salvage therapy for Hodgkin lymphoma with nivolumab alone or in combination with ICE.

This phase 2 trial evaluated PET-adapted nivolumab alone or in combination with ifosfamide, carboplatin, and etoposide (NICE) as first salvage therapy and bridge to autologous hematopoietic cell transplantation (AHCT) in relapsed/refractory (RR) classical Hodgkin lymphoma (cHL). Patients with RR cHL received 240 mg nivolumab every 2 weeks for up to 6 cycles (C). Patients in complete response (CR) after C6 proceeded to AHCT, whereas patients with progressive disease at any point or not in CR after C6 received NICE for 2 cycles. The primary endpoint was CR rate per the 2014 Lugano classification at completion of protocol therapy. Forty-three patients were evaluable for toxicity; 42 were evaluable for response. Thirty-four patients received nivolumab alone, and 9 patients received nivolumab+NICE. No unexpected toxicities were observed after nivolumab or NICE. After nivolumab, the overall response rate (ORR) was 81%, and the CR rate was 71%. Among 9 patients who received NICE, all responded, with 8 (89%) achieving CR. At the end of protocol therapy, the ORR and CR rates were 93% and 91%. Thirty-three patients were bridged directly to AHCT, including 26 after Nivo alone. The 2-year progression-free survival (PFS) and overall survival in all treated patients (n = 43) were 72% and 95%, respectively. Among 33 patients who bridged directly to AHCT, the 2-year PFS was 94% (95% CI: 78-98). PET-adapted sequential salvage therapy with nivolumab/nivolumab+NICE was well tolerated and effective, resulting in a high CR rate and bridging most patients to AHCT without chemotherapy. This trial was registered at www.clinicaltrials.gov #NCT03016871.

Expression of immune checkpoint molecules programmed death protein 1, programmed death-ligand 1 and inducible T-cell co-stimulator in mycosis fungoides and Sézary syndrome: association with disease stage and clinical outcome.

BACKGROUND: The relationship between immune checkpoint status and disease outcome is a major focus of research in cutaneous T-cell lymphoma (CTCL), a disfiguring neoplastic dermatological disorder. Mycosis fungoides (MF) and Sézary syndrome (SS) are the two most common types of CTCL. OBJECTIVES: The aim was to evaluate the immune checkpoint markers programmed death protein 1 (PD1), inducible T-cell co-stimulator (ICOS) and programmed death-ligand 1 (PD-L1) in skin biopsies from patients with CTCL relative to disease stage and overall survival. METHODS: This consecutive case series enrolled 47 patients: 57% had stage IA-IIA disease and 43% had stage IIB-IVA2 disease (including seven with SS). RESULTS: PD1, PD-L1 and ICOS expression was seen in all biopsies. Notably, PD-L1 was predominantly expressed on histiocytes/macrophages, but focal expression on CTCL cells was seen. High expression of either ICOS or PD-L1 was associated with advanced-stage disease (P = 0·007 for both) and with the appearance of large-cell transformation (LCT), a histopathological feature associated with a poor prognosis (ICOS: P = 0·02; PD-L1: P = 0·002). PD1 expression was not significantly associated with disease stage (P = 0·12) or LCT (P = 0·49), but expression was high in SS biopsies. A high combined checkpoint marker score (PD1, PD-L1 and ICOS) was associated with advanced-stage disease (P = 0·001), LCT (P = 0·021) and lower overall survival (P = 0·014). CONCLUSIONS: These findings demonstrate the existence of a complex immunoregulatory microenvironment in CTCL and support the development of immunotherapies targeting ICOS and PD-L1 in advanced disease.

Off-the-shelf, steroid-resistant, IL13Rα2-specific CAR T cells for treatment of glioblastoma.

BACKGROUND: Wide-spread application of chimeric antigen receptor (CAR) T cell therapy for cancer is limited by the current use of autologous CAR T cells necessitating the manufacture of individualized therapeutic products for each patient. To address this challenge, we have generated an off-the-shelf, allogeneic CAR T cell product for the treatment of glioblastoma (GBM), and present here the feasibility, safety, and therapeutic potential of this approach. METHODS: We generated for clinical use a healthy-donor derived IL13Rα2-targeted CAR+ (IL13-zetakine+) cytolytic T-lymphocyte (CTL) product genetically engineered using zinc finger nucleases (ZFNs) to permanently disrupt the glucocorticoid receptor (GR) (GRm13Z40-2) and endow resistance to glucocorticoid treatment. In a phase I safety and feasibility trial we evaluated these allogeneic GRm13Z40-2 T cells in combination with intracranial administration of recombinant human IL-2 (rhIL-2; aldesleukin) in six patients with unresectable recurrent GBM that were maintained on systemic dexamethasone (4-12 mg/day). RESULTS: The GRm13Z40-2 product displayed dexamethasone-resistant effector activity without evidence for in vitro alloreactivity. Intracranial administration of GRm13Z40-2 in four doses of 108 cells over a two-week period with aldesleukin (9 infusions ranging from 2500-5000 IU) was well tolerated, with indications of transient tumor reduction and/or tumor necrosis at the site of T cell infusion in four of the six treated research subjects. Antibody reactivity against GRm13Z40-2 cells was detected in the serum of only one of the four tested subjects. CONCLUSIONS: This first-in-human experience establishes a foundation for future adoptive therapy studies using off-the-shelf, zinc-finger modified, and/or glucocorticoid resistant CAR T cells.

Peritransplantation ruxolitinib administration is safe and effective in patients with myelofibrosis: a pilot open-label study.

We report results of our prospective pilot trial evaluating safety/feasibility of peritransplantation ruxolitinib for myelofibrosis treatment. Primary objectives were to determine safety and maximum tolerated dose (MTD) of ruxolitinib. Ruxolitinib was administered at 2 dose levels (DLs) of 5 and 10 mg twice daily, with fludarabine/melphalan conditioning regimen and tacrolimus/sirolimus graft-versus-host disease (GVHD) prophylaxis. We enrolled 6 and 12 patients at DL1 and DL2, respectively. Median age at transplantation was 65 years (range, 25-73). Per Dynamic International Prognostic Scoring System, 4 patients were high and 14 intermediate risk. Peripheral blood stem cells were graft source from matched sibling (n = 5) or unrelated (n = 13) donor. At each DL, 1 patient developed dose-limiting toxicities (DLTs): grade 3 cardiac and gastrointestinal with grade 4 pulmonary DLTs in DL1, and grade 3 kidney injury in DL2. All patients achieved engraftment. Grade 2 to 4 and 3 to 4 acute GVHD cumulative incidence was 17% (95% confidence interval [CI], 6-47) and 11% (95% CI, 3-41), respectively. Cumulative incidence of 1-year chronic GVHD was 42% (95% CI, 24-74). With 22.6-month (range, 6.2-25.8) median follow-up in surviving patients, 1-year overall and progression-free survival were 77% (95% CI, 50-91) and 71% (95% CI, 44-87), respectively. Causes of death (n = 4) were cardiac arrest, GVHD, respiratory failure, and refractory GVHD of liver. Our results show peritransplantation ruxolitinib is safe and well tolerated at MTD of 10 mg twice daily and associated with dose-dependent pharmacokinetic and cytokine profile. Early efficacy data are highly promising in high-risk older patients with myelofibrosis. This trial was registered at www.clinicaltrials.gov as #NCT02917096.