Shustov, Andrei R.

Introduction: Waldenström macroglobulinemia (WM)remains incurable with current therapies. Treatment options for patients beyond initial therapy are limited, underscoring the need for new agents with novel mechanisms of action. Iopofosine I 131 is a novel radiopharmaceutical composed of a lipid raft-targeting phospholipid ether covalently bound to 131I, a beta-emitting radioisotope. Herein, we report the results of the CLOVER-WaM study [NCT02952508] in patients with previously treated WM. Methods: Eligible WM patients had received >2 prior therapies and had symptomatic disease requiring therapy according to consensus recommendations for WM. Treatment consisted of 2 cycles of iopofosine I 131 administered at 15 mCi/m2 on days 1 and 15 of each 57-day cycle. Dose reduction to 10 mCi/m2 was allowed in the second cycle in patients with incomplete hematologic recovery or if the expected total dose exceeded 132 mCi. Supportive care with growth factors and transfusions was permitted per treating physician discretion. The primary endpoint was major response rate (MRR, defined as partial response or better) as determined by the modified VIth International Workshop on Waldenström Macroglobulinemia Response Criteria. Secondary endpoints included overall response rate (ORR), treatment-free survival (TFS), duration of response (DOR), and clinical benefit rate (CBR, defined as stable disease or better). Efficacy endpoints were assessed in the modified intent-to-treat (mITT) population, defined as all patients who received ≥60 mCi total administered dose of iopofosine I 131. MRR was analyzed with a 95% 2-sided confidence interval (CI) using the Clopper-Pearson interval method. In this population, MRR >20% was considered statistically significant. Time-dependent efficacy endpoints were analyzed using the Kaplan-Meier method. Safety was evaluated using CTCAE v4.03 in patients who received >1 dose of iopofosine I 131. The data cut-off for this analysis was May 31, 2024. Results: In 65 patients enrolled (safety population), the median age was 70 (range, 50-88) years; 48 (73.8%) were male, and 17 (26.2%) were female. Sixty-one (93.8%) were White, 1 (1.5%) was Black/African American, and 3 (4.6%) were other or unknown. Fifty-five patients met mITT criteria and were evaluable for efficacy. The median number of prior therapies was 4 (range, 2-15). Bruton's tyrosine kinase inhibitor (BTKi) exposure was noted in 39 (71%) patients, of whom 31 (56%) were BTKi-refractory. Sixteen (29%) patients had MYD88-wild type, and 5 (9%) had CXCR4-mutated disease. The MRR was 56.4% (95% CI, 42.3-69.7). ORR was 80%; among MYD88-wild type patients, ORR was 81%, and among post-BTKi patients, ORR was 72%. CBR was 98%. The median DOR and TFS were not reached at a median follow-up of 8.8 months, with an estimated 72% of responding patients remaining progression-free at 18 months. In the safety population, any-grade adverse events, regardless of causality, were reported in 57 (87%) patients. Grade 3 or higher treatment-emergent adverse events (TEAEs) occurring in >10% of patients included thrombocytopenia (80%), neutropenia (69.2%), anemia (44.6%), lymphopenia (13.8%), infections (12.3%), and febrile neutropenia (10.8%). Adverse event-related death occurred in 1 patient due to bacterial sepsis. Conclusion: Iopofosine I 131 demonstrated durable efficacy in previously treated WM patients, with no current standard of care therapy. The treatment was well-tolerated with a manageable toxicity profile across broad biologic and clinical subgroups, irrespective of risk stratification. Based on the results of this trial, iopofosine I 131 shows promise as a novel treatment for WM patients.

Abstract Background: The prognosis of patients with PTCL remains poor after standard CHOP therapy - the most commonly used combination regimen. Relapses occur in the majority of patients, and curability rates of the relapsed disease are very low. Hence, advances in front-line therapy of PTCL are long overdue. Pralatrexate, a second-generation antifolate, demonstrated a single agent activity in patients with relapsed and refractory PTCL with a response rate of 27%, including complete remissions in 11% of patients (O'Connor et al. J Clin Onc 2011). We conducted a Phase 1 multi-center dose-escalation study of pralatrexate in combination with standard CHOP (Fol-CHOP) in treatment-naïve PTCL patients. Objectives: The primary objective of the study was to determine the maximum tolerated dose (MTD) of pralatrexate when administered with a standard CHOP regimen to patients with newly diagnosed PTCL. The secondary objectives included safety, tolerability, efficacy and pharmacokinetics of pralatrexate in combination with CHOP (Fol-CHOP). Methods: In Part 1 of this 3+3 dose-escalation study, pralatrexate was administered at 10, 15, 20, 25, or 30 mg/m2 as an IV push on days 1 and 8 of a standard 21-day CHOP regimen (cyclophosphamide 750 mg/m2, doxorubicin 50 mg/m2, vincristine 1.4 mg/m2 [maximum 2 mg] on day 1 and oral prednisone 100 mg on days 1-5). In Part 2 of the study patients were treated at the MTD of pralatrexate established in Part 1, with standard CHOP. In both parts of the study patients were treated with up to 6 cycles of therapy, or until toxicity or disease progression. Patients received antimicrobial prophylaxis, myeloid growth factor support, and "leucovorin rescue" throughout 6 cycles of therapy. Dose-limiting toxicities (DLT) were considered during the 1st cycle of Fol-CHOP and included: Grade 4 infections, treatment-related non-hematological toxicity ≥Grade 3, platelet count < 25 X 109/L at any time, or ANC < 0.5 X 109/L for >7 days despite G-CSF administration. Responses were assessed by the investigator per the Revised Response Criteria for Malignant Lymphoma (Cheson 2007). Results: A total of 31 patients have been enrolled (19 in Part 1; 12 in Part 2). MTD was not reached and pralatrexate dose of 30 mg/m2 in combination with CHOP was selected for Part 2 of the study as predefined by the protocol. The majority of patients were male, White, with the median age of 66 yrs (range, 18-78) at the time of enrolment. PTCL diagnoses included: anaplastic large cell lymphoma, anaplastic lymphomakinase-negative (ALCL, ALK-, n=5), peripheral T-cell lymphoma, not-otherwise specified (PTCL-NOS, n=18), and angioimmunoblastic T-cell lymphoma (AITL, n=5). Fol-CHOP was generally well tolerated with median RDI of 98%. Common (≥ 30%) adverse events (AEs) of any grade were fatigue (n=23), constipation (n=20), nausea (n=16), mucositis (n=14), diarrhea (n=12), anemia (n=9), vomiting (n=10) and oral pain (n=10). Most common (≥ 10%) AEs ≥ grade 3 were anemia (n=6), fatigue (n=4) and neutrophil count decreas (n=5). The only Grade >3 treatment-related AEs (≥10%) was neutrophil count decrease (n=4). SAEs were observed in 13 patients, treatment related SAEs were anemia, febrile neutropenia, dehydration, mucositis and nausea. Five patients withdrew from study: 2 due to disease progression, 1 due to AE and 2 due lapse >28 days between doses. In the 27 patients avaluable for response, the investigator assessed objective response (OR) and complete response (CR) rates were 89% wand 67%, respectively. Conclusions: The combination of pralatrexate and CHOP was well tolerated in treatment-naive PTCL patients. MTD of pralatrexate was not reached, and the protocol-defined maximum dose of 30 mg/m2 on days 1 and 8 of a 21-day CHOP cycle was recomended for future studies. The observed OR and CR rates warrant further evaluation of this regimen in newly diagnosed PTCL patients. Disclosures Shustov: Celgene: Other: Publication assistance; Spectrum Pharmaceuticals: Consultancy, Research Funding. Bhat: Spectrum Pharmaceuticals: Employment. Reddy: Spectrum Pharmaceuticals: Employment.

Hepatosplenic T-cell lymphoma (HSTCL) is a rare subtype of T-cell lymphoma associated with an aggressive clinical course and a worse prognosis. HSTCL develops in the setting of chronic immune suppression or immune dysregulation in up to 20% of cases and is most often characterized by spleen, liver, and bone marrow involvement. Diagnosis and management of HSTCL pose significant challenges given the rarity of the disease along with the absence of lymphadenopathy and poor outcome with conventional chemotherapy regimens. These Guidelines Insights focus on the diagnosis and treatment of HSTCL as outlined in the NCCN Guidelines for T-Cell Lymphomas.

Mycosis fungoides (MF) is the most common subtype of cutaneous T-cell lymphoma (CTCL), and Sézary syndrome (SS) is a rare erythrodermic and leukemic subtype of CTCL characterized by significant blood involvement. Although early-stage disease can be effectively treated predominantly with skin-directed therapies, systemic therapy is often necessary for the treatment of advanced-stage disease. Systemic therapy options have evolved in recent years with the approval of novel agents such as romidepsin, brentuximab vedotin, and mogamulizumab. These NCCN Guidelines Insights discuss the diagnosis and management of MF and SS (with a focus on systemic therapy).

Abstract Background Peripheral T-cell lymphomas (PTCL) are a heterogeneous group of non-Hodgkin’s lymphomas (NHL) characterized by poor treatment outcomes with conventional chemotherapy, including CHOP [complete remission (CR) ∼40%]. Retrospective studies suggest that the incorporation of etoposide into chemotherapy regimens may improve outcomes compared to CHOP. In contrast, anthracyclines appear to have a limited role in PTCL, largely attributed to p-glycoprotein related resistance. Pralatrexate was the first drug approved for patients (pts) with relapsed PTCL, providing a rationale to evaluate it in the front-line setting. Herein, we evaluated the efficacy of a novel combination for the primary therapy of pts with PTCL whereby the anthracycline in CHOP backbone was replaced with etoposide (CEOP) alternating with pralatrexate (P). Methods Pts > 18 years (yrs) with PTCL stages II-IV with no prior therapy and adequate end organ function were eligible. Eligible histologies included, PTCL-NOS, AILT, ALCL (ALK positive pts only allowed if IPI >3). CEOP (Cycle A) was administered as: cyclophosphamide 750 mg/m2 IV d1, etoposide 100 mg/m2 IV d1-3 (or 100 mg/m2 IV d1 and 200 mg/m2 PO days 2-3), vincristine 2 mg IV day 1 and prednisone 100 mg/day X 5 alternating with P (cycle B) 30 mg/m2 IV d 15, 22 and 29 (with vitamin B12 and folate supplementation). Growth factors were used to support both cycles of therapy. Imaging to assess response was done after cycle 2B, 4B and 6B. Pts achieving a remission were eligible for consolidative autologous stem cell transplant (ASCT) after cycle 4B at physician discretion. The primary statistical aim was to improve the CR rate from 40 to 63% with CEOP-P and optional transplant. Secondary objectives included assessment of event free survival (EFS), overall survival (OS) and toxicity of the regimen. A two-stage Simon design (alpha=0.10, 90% power) tested the null hypothesis that the CR rate would be </= to 40%. For the first stage of 20 evaluable pts, the trial would be terminated if 8 or fewer pts experienced a CR after course 2B of chemotherapy. For the second stage, a total of 34 pts were required with at least 17 achieving a CR at the end of therapy to consider the regimen useful. Results 34 pts were enrolled and one withdrew consent before starting therapy, leaving 33 pts enrolled between 7/2011 and 1/2013. Characteristics are shown in Table 1. 27 pts received at least 2 cycles of therapy. 6 pts received only 1 cycle due to early disease progression in 4 and adverse events in 2. Grade 3-4 toxicities attributed to therapy included, anemia (27%), thrombocytopenia (12%), febrile neutropenia (18%), mucositis (18%), sepsis (15%), increased creatinine (12%) and liver transaminases (12%). At the end of stage 1, 10 of 20 pts (50%) achieved a CR; therefore accrual proceeded to stage 2. At the time of this initial analysis, the overall response rate is 70%. To date 15 pts (45%) have achieved a CR with two additional pts pending evaluation. Overall, the 1-yr EFS is 48% (95% CI 28-64), and 1-yr OS 70% (95% CI 47-84) (Figures 1 and 2). 6 pts (18%) to date (n=3 CR, n=2 PR and 1 with stable disease) have received consolidation with ASCT and all are in CR post-transplant. Pts who proceeded to ASCT were younger than the non-transplant cohort (median age 58 versus 64 yrs) with other clinical characteristics being similar. On exploratory bivariate analyses, age <60 yrs, absence of B symptoms, low IPI score (0,1), achieving a CR, and receiving a ASCT were associated with better EFS. Attaining a CR was the only factor associated with better OS and was highest in patients with low IPI (78%) and those with ALCL histology (75%). Conclusions CEOP-P met the pre-defined stage 1 response criteria. Longer follow-up is needed to assess the impact on the final CR rate and secondary objectives of EFS and OS. Defining optimal front line therapy in PTCL continues to be a challenge and an unmet need. Disclosures: Advani: Seattle Genetics: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Spectrum Pharmaceuticals: Research Funding. Off Label Use: Pralatrexate is currently only approved for relapsed/refractory PTCL. Lechowicz:Allos Therapeutics: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Millennium: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Seattle Genetics: Membership on an entity’s Board of Directors or advisory committees, Research Funding. Carson:Spectrum Pharmaceuticals: Honoraria, Research Funding, Speakers Bureau. Foss:merck: Research Funding; spectrum: Research Funding; eisai: Membership on an entity’s Board of Directors or advisory committees; millenium: Honoraria, Membership on an entity’s Board of Directors or advisory committees; celgene: Honoraria, Research Funding; seattle genetics: Research Funding. Horwitz:Celgene : Consultancy, Research Funding; Spectrum Pharamaceuticals: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Infinity Pharmaceuticals: Consultancy; Kyowa Hakko Kirn Pharma: Consultancy; Genzyme : Research Funding; Janssen: Research Funding; Millennium: Consultancy, Research Funding. Pro:Spectrum Pharmaceuticals: Honoraria. Pinter-Brown:Spectrum Pharmaceuticals: Consultancy, Honoraria. Smith:Micromet: Consultancy; Seattle Genetics: Consultancy; Celgene: Consultancy; Allos: Consultancy; Genentech: Consultancy; Onyx: Consultancy. Shustov:Spectrum Pharmaceuticals: Consultancy, Honoraria. Savage:Spectrum Pharmaceuticals: Research Funding. Vose:Spectrum Pharmaceuticals: Research Funding.

Abstract Background: Peripheral T-cell lymphomas (PTCL) are a heterogeneous group of mature T-cell and natural-killer-cell aggressive non-Hodgkin lymphomas associated with poor prognosis with current therapies. Numerous studies have reported poor survival for PTCL patients with a median Overall Survival (OS) shorter than 2 years and 5-year survival rates of <30%. Traditionally, patients with PTCL have been treated with a cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)-like first-line chemotherapeutic regimen. Unfortunately, the prognosis remains poor with most patients relapsing within 2 years. Thus, improved front line treatment strategies are needed. Pralatrexate (Folotyn) is a folate analogue metabolic inhibitor that was the first drug approved in the US for the treatment of patients with relapsed or refractory PTCL (R/R PTCL). Approval was based on results from the pivotal Phase 2 PROPEL study (O'Connor et al, JCO, 2011) of pralatrexate in R/R PTCL, in which pralatrexate monotherapy demonstrated a durable clinical benefit (objective response rate of 29%). Pralatrexate is administered intravenously (IV) at a dose of 30 mg/m2 weekly for 6 weeks of a 7-week treatment cycle. Since pralatrexate and each of the components of the CHOP regimen target different aspects of tumor cell growth and proliferation, there is a potential for synergistic anti-tumor effect, and limited additive toxicities. Objectives: The primary endpoint of the study is the determination of the MTD of pralatrexate in combination with CHOP (Fol-CHOP) in previously untreated PTCL patients. Secondary endpoints included safety, tolerability and ORR (complete response [CR] + partial response [PR]) and pharmacokinetics. Methods: In this study, patients with PTCL received CHOP in combination with pralatrexate, repeated every 3-weeks for up to 6 cycles. Part 1 of the study was to determine the Maximum Tolerated Dose (MTD) of the Fol-CHOP combination. Once the MTD was determined, an additional 10 patients were treated in the Expansion Phase (Part 2). The cohort schema followed a traditional "3+3" design. Pralatrexate was to be administered as 10, 15, 20, 25, or 30 mg/m2 IV push over 3 to 5 minutes on Days 1 and 8 of each cycle. The starting cohort was CHOP + 10 mg/m2 of pralatrexate. Patients received prophylaxis with acyclovir and sulfamethoxazole/trimethoprim during the study and primary prophylaxis with growth factor (filgrastim or pegfilgrastim) support. Dose-limiting toxicities (DLT) were considered during the 1st cycle and included: Severe infections, study treatment-related non-hematological toxicity Grade 3-4, platelet count < 25 X 109/L at any time or ANC < 0.5 X 109/L lasting more than 7 days despite G-CSF administration. Results: A total of 12 patients have been enrolled in Part 1 of the study at the time of abstract submission. Nine patients have completed Cycle 1 and no DLT was reported. Among these nine patients, three patients each were treated at CHOP + 10 mg/m2, 15 mg/m2 and 20 mg/m2 of pralatrexate. One patient (11%) treated with CHOP + 10 mg/m2 had one serious adverse event (SAE) of febrile neutropenia that was deemed unrelated to any study drug. Only four Grade 3 AEs (anemia, constipation, mucosal inflammation, and nausea) were reported, in one patient (11%). The enrollment into the study continues. Conclusions: These interim results demonstrate that the combination of pralatrexate with CHOP (Fol-CHOP) is well tolerated, with all components of CHOP as well as pralatrexate being given at close to or at standard doses. The rates of AEs are comparable to those typically reported with CHOP alone. The study is ongoing to confirm the MTD and to assess preliminary efficacy of the Fol-CHOP combination. Updated results will be presented at the meeting. Disclosures Oki: Novartis: Research Funding. Barta:Celgene, Merck, Seattle Genetics: Research Funding; Janssen: Honoraria, Speakers Bureau. Sharma:Spectrum Pharmaceuticals: Employment. Song:Spectrum Pharmaceuticals: Employment. Mourya:Spectrum Pharmaceuticals: Employment.

TPS7577 Background: Nivolumab (nivo) is a PD-1 immune checkpoint inhibitor that augments T-cell activation and host anti-tumor responses. PD-1 blockade has shown promise in B- and T-cell non-Hodgkin lymphoma (NHL),1 but many patients (pts) with NHL do not respond or progress after response. Combination therapy using anti-tumor agents with complementary mechanisms of action and low immunosuppressive impact may result in more frequent and durable responses. Brentuximab vedotin (BV) is an anti-CD30 antibody–drug conjugate that induces cell cycle arrest and apoptosis, with activity in a range of NHL tumors.2,3 Tumor cells undergoing BV-induced apoptosis have shown subsequent immune-mediated anti-tumor cytotoxicity.4 Therefore, nivo and BV may synergize if combined for relapsed/refractory (RR) NHL. Methods: CheckMate 436 (NCT02581631) is a phase 1–2, open-label, international, single-arm study evaluating nivo + BV for CD30-expressing RR NHL (study start: Dec 2015) in pts with RR diffuse large B-cell lymphoma, peripheral T-cell lymphoma (excluding anaplastic large cell lymphoma), and cutaneous T-cell lymphoma (mycosis fungoides/Sézary syndrome); cohorts with primary mediastinal B-cell lymphoma (PMBL) and mediastinal gray zone lymphoma were made eligible in Sept 2016. Pts with PMBL must be aged ≥15 y (≥18 y for other histologies). All pts must have CD30-expressing disease, defined by CD30 on ≥1% of tumor cells or tumor-infiltrating lymphocytes by immunohistochemistry. In the phase 1 component, 6 pts will receive nivo and BV until disease progression or unacceptable toxicity. In the phase 2 component, ~130 more pts across the 5 histologies will be enrolled and treated at the recommended dose. Primary endpoints: safety, tolerability, and investigator-assessed objective response rate; secondary endpoints: duration of response and complete response (CR), CR rate, and progression-free and overall survival. Accrual is ongoing. References: 1. Lesokhin A et al. JCO 2016;34:2698–704 2. Jacobsen E et al. Blood 2015;125:1394–402 3. Horwitz S et al. Blood 2014;123:3095–100 4. Gardai S et al. Cancer Res 2015;75(15 Suppl):2469 [abstract]. Clinical trial information: NCT02581631.

Summary Peripheral T‐cell lymphomas ( PTCL ) have suboptimal outcomes using conventional CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy. The anti‐folate pralatrexate, the first drug approved for patients with relapsed/refractory PTCL , provided a rationale to incorporate it into the front‐line setting. This phase 2 study evaluated a novel front‐line combination whereby cyclophosphamide, etoposide, vincristine and prednisone ( CEOP ) alternated with pralatrexate ( CEOP ‐P) in PTCL . Patients achieving a complete or partial remission ( CR / PR ) were eligible for consolidative stem cell transplantation ( SCT ) after 4 cycles. Thirty‐three stage II ‐ IV PTCL patients were treated: 21 PTCL ‐not otherwise specified (64%), 8 angioimmunoblastic T cell lymphoma (24%) and 4 anaplastic large cell lymphoma (12%). The majority (61%) had stage IV disease and 46% were International Prognostic Index high/intermediate or high risk. Grade 3–4 toxicities included anaemia (27%), thrombocytopenia (12%), febrile neutropenia (18%), mucositis (18%), sepsis (15%), increased creatinine (12%) and liver transaminases (12%). Seventeen patients (52%) achieved a CR . The 2‐year progression‐free survival and overall survial, were 39% (95% confidence interval 21–57) and 60% (95% confidence interval 39–76), respectively. Fifteen patients (45%) (12 CR ) received SCT and all remained in CR at a median follow‐up of 21·5 months. CEOP ‐P did not improve outcomes compared to historical data using CHOP . Defining optimal front line therapy in PTCL continues to be a challenge and an unmet need.