Fishkin, Paul A. S.

Abstract Background: MCL is a B-cell non-Hodgkin lymphoma for which auto-HCT is often employed in first CR, based on non-randomized phase 2 trials, and a randomized trial (Dreyling et al, Blood 2005) conducted before the advent of more effective induction and maintenance regimens. The TRIANGLE trial (Dreyling et al, Lancet 2024) suggested that auto-HCT may not add benefit to more effective induction and maintenance regimens containing high-dose cytarabine, rituximab and BTK inhibitors. E4151 explored whether auto-HCT benefits pts achieving deep first remission, as measured by a highly sensitive immunoglobulin high throughput sequencing minimal residual disease (MRD) assay. Methods: EA4151 is a four arm trial conducted through the U.S. National Clinical Trials Network (NCTN) and Blood and Marrow Transplant Clinical Trials Network (BMT-CTN). Pts with MCL between the ages of 18 and 70 and in first remission were eligible. After induction, pts underwent PET/CT, bone marrow biopsy, and the clonoSEQ® MRD assay from peripheral blood. Pts in CR with uMRD at 1 in 10-6 sensitivity (uMRD6) were randomized 1:1 to Arm A (auto-HCT + 3 years of maintenance rituximab [MR]) or Arm B (3 years of MR alone), stratified by MIPI-c score and intensive vs non-intensive induction. Pts with either MRD-positive (MRD+) CR or MRD-indeterminate CR (Arm C and Arm D, respsectively) both received auto-HCT + 3 years of MR. Pts who were MRD+ pre-transplant had MRD repeated at day 100. Primary endpoint was to compare overall survival (OS) in Arms A and B, with secondary endpoints including progression-free survival (PFS). Primary analysis population included all randomized pts. As some pts refused their assigned treatment (N=65 [25.3%] for arm A and N=2 [0.8%] for arm B), a “treated as assigned” analysis was also performed. Stratified logrank test was used to compare survival distributions. P-values are two-sided. Results: From Aug 2017 to July 2024, 650 pts were assigned to a treatment arm with 257, 259, 49, and 85 pts enrolled on Arms A, B, C, and D, respectively. Pts were 79% male and 92% white race. Median age was 60 years (range 27-70). MIPI-c was low/low-intermediate (LI) in 63% and high/ high-intermediate (HI) in 37%. Induction was intensive (defined as high-dose cytarabine-containing) in 73% and non-intensive in 27%. A BTK inhibitor was given during induction in 7.2% of pts, and during maintenance in 0.3% of pts. The third pre-planned interim analysis was based on data as of 7/15/24, with median follow up of 2.7 years. The futility boundary was an OS hazard ratio (HR) of 0.984 for Arm A vs B. The estimated OS HR for Arm A vs B in all randomized (n=516) and pts treated as assigned (n=375) were 1.11 (CI 0.71-1.74, p=0.66) and 1.00 (CI 0.58-1.74, p=0.99), respectively and crossed the futility boundary. The 3 year (yr) OS for Arms A and B were 82.1% and 82.7% in all randomized pts, and 86.2% and 84.8% in pts treated as assigned. The estimated PFS HR for Arm A vs B in all randomized and pts treated as assigned were 1.05 (CI 0.71-1.56, p=0.79) and 0.95 (CI 0.59-1.54, p=0.84), respectively. The 3 yr PFS for Arms A and B were 76.6% and 77.4% in all randomized pts, and 81.5% and 80.4% in pts treated as assigned. For Arm C, 3 yr OS and PFS were 81.9% (CI 69.6-96.4%) and 76.9% (CI 64.4-91.7%), respectively. For Arm D, 3 yr OS and PFS were 85.1% (CI 76.0%-95.4%) and 73.4% (62.7-85.9%), respectively. For the MIPI-c low/LI group, 3 yr OS was 84.6% vs 85.7% for Arm A vs B (p=0.96), while in the MIPI-c high/HI group, 3 yr OS was 77.4% vs 77.6% for Arm A vs B (p=0.71). For the intensive induction group, 3 yr OS was 83.0% vs 86.2% for Arm A vs B (p=0.30), while in the non-intensive induction group, 3 yr OS was 79.5% vs 72.8% for Arm A vs B (p=0.48). Exploratory analysis of MRD+ pts (Arm C) showed that pts who converted to uMRD6 post auto-HCT (n=17) had 3 yr OS of 100% and PFS of 100%, whereas those who remained MRD+ (n=13) post auto-HCT had 3 yr OS of 63.6% and PFS of 48.8%. Causes of death (COD) in Arm A were 4.7% lymphoma, 5.1% COVID-19, and 5.0% other/unknown. COD in Arm B were 3.5% lymphoma, 6.6% COVID-19, and 4.6% other/unknown. In Sept 2024, the DSMC recommended termination of accrual and release of trial findings based on these results. Conclusion: In this interim analysis, in the era of highly effective induction and maintenance regimens, MCL pts in first CR with uMRD6 did not benefit from consolidative auto-HCT. Pts who remain MRD+ after induction may benefit from auto-HCT. Longer follow-up will be important to confirm these findings.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. In 2003, the Eastern Cooperative Oncology Group initiated a randomized phase III clinical trial (E4402) comparing two different rituximab dosing strategies for patients with previously untreated low–tumor burden follicular lymphoma. Rituximab-responsive patients (n = 299) were randomly assigned to either a retreatment rituximab (RR) strategy or a maintenance rituximab (MR) strategy. Each dosing strategy was continued until treatment failure. The primary end point of the study was time to treatment failure (TTF). In the original report, there was no difference in TTF between the two dosing strategies. Here, we report on the long-term outcomes for secondary end points of time to first cytotoxic therapy, duration of response, and overall survival (OS). At 7 years, 83% of MR patients had not required first chemotherapy compared with 63% of RR patients (hazard ratio, 2.37 [95% CI, 1.5 to 3.76]). At 7 years, 71% of MR remained in their first remission compared with 37% of RR patients. Despite the improved first remission length with MR, there was no difference in OS at 10 years (83% v 84%). With mature long-term data, we confirm that prolonged maintenance rituximab does not confer an OS advantage in low–tumor burden follicular lymphoma.

Abstract BACKGROUND: E4402 was a randomized phase III study comparing two different rituximab dosing strategies for patients with previously untreated, low tumor burden follicular lymphoma (FL). The primary endpoint was time to treatment failure. The initial publication (Kahl, JCO 2014) demonstrated that a retreatment strategy utilized less drug and produced comparable time to treatment failure compared to a maintenance strategy. Here we provide long term follow up results, focusing on response duration, time to first cytotoxic therapy, overall survival, and risk of histologic transformation. METHODS: Eligible patients had untreated, low tumor burden (GELF criteria) FL. Patients received R 375 mg/m 2 weekly x 4 and responders were randomized to maintenance rituximab (MR) (single dose R q 3 months) or retreatment rituximab (RR) (R weekly x 4 doses at disease progression). Each strategy was continued until treatment failure. The primary endpoint, time to treatment failure, was defined as progression within 6 months of last R, no response to R retreatment, initiation of alternative therapy, or inability to complete protocol therapy. Secondary endpoints included time to first cytotoxic therapy, quality of life and safety. The ECOG Data Monitoring Committee recommended release of study results at a planned interim analysis in September 2011 and patients and providers were notified of results. Time to treatment failure data collection halted with release of the results but limited data collection on time to first cytotoxic therapy, response duration, and risk of histologic transformation continued. INITITIAL RESULTS: From 11/03 to 9/08, 384 patients with FL were enrolled. Complete or partial response was achieved in 289 patients (71%), who were then randomized to MR (n=146) or RR (n=143). Demographic features were similar in the two arms: median age 59 years; ECOG PS 0-1 in all patients, and FLIPI low-risk (14.9 vs. 16.4%), intermediate-risk (46.3 vs. 42.9%) and high-risk (38.8 vs. 40.7%) for MR vs. RR, respectively. At initial publication, with a median follow-up of 3.8 years, the time to treatment failure was 3.9 years for MR vs. 3.6 years for RR (p=NS). LONG TERM FOLLOW UP RESULTS: Immunoglobulin levels and risks for serious infections/late complications in MR patients will be updated at the annual meeting. For the endpoint of time to first cytotoxic therapy, the median follow up is 8.7 years. At 7 years, 83% of MR and 63% of RR remained free from first cytotoxic therapy (HR 2.37; 95% CI 1.50 - 3.76) [Figure 1]. For the endpoint of response duration, the median follow up is 12.1 years. At 10 years, 66% of the MR patients remained in their 1 st remission compared to 30% of the RR patients who remained in their 1 st remission [Figure 2]. The median response duration for RR patients receiving a single 4-week course of rituximab was 3.25 years. There was no difference in the overall survival at 10 years, 84% for MR vs. 83% for RR. There was a trend towards a lower risk of histologic transformation for patients receiving MR (n = 4) compared to RR (n = 11) (p = 0.11). CONCLUSIONS: With long term follow up, the RESORT data indicates that in previously untreated, low tumor burden, follicular lymphoma, MR was superior to RR for delaying time to first cytotoxic therapy and for response duration, with a trend towards reducing the risk of histologic transformation. MR did not improve the overall survival. The original publication concluded that the time to treatment failure is similar between the two dosing strategies. Due to study design, time to treatment failure could not be analyzed in this long term follow up analysis. Compared to the historical benchmark of 3 years median time to first cytotoxic therapy when watch and wait is utilized, single agent rituximab, administered by either dosing strategy, was highly effective at delaying the time to first cytotoxic therapy. Figure 1 Figure 1. Disclosures Kahl: AbbVie, Adaptive, ADCT, AstraZeneca, Bayer, BeiGene, Bristol-Myers Squibb, Celgene, Genentech, Incyte, Janssen, Karyopharm, Kite, MEI, Pharmacyclics, Roche, TG Therapeutics, and Teva: Consultancy; AbbVie, Acerta, ADCT, AstraZeneca, BeiGene, Genentech: Research Funding. Habermann: Incyte: Other: Scientific Advisory Board; Tess Therapeutics: Other: Data Monitoring Committee; Seagen: Other: Data Monitoring Committee; Morphosys: Other: Scientific Advisory Board; Loxo Oncology: Other: Scientific Advisory Board; Eli Lilly & Co.,: Other: Scientific Advisor. Schuster: Abbvie: Consultancy, Research Funding; Acerta Pharma: Consultancy; AstraZeneca: Consultancy; Adaptive Biotechnologies: Research Funding; BeiGene: Consultancy; Celgene: Consultancy, Honoraria, Research Funding; DTRM: Research Funding; Genetech: Consultancy, Research Funding; Roche: Consultancy, Research Funding; Incyte: Research Funding; Juno Theraputics: Consultancy, Research Funding; Loxo Oncology: Consultancy; Merck: Research Funding; Nordic Nanovector: Consultancy; Novartis: Consultancy, Honoraria, Patents & Royalties, Research Funding; Pharmaclcyclics: Research Funding; Tessa Theraputics: Consultancy; TG Theraputics: Research Funding. Fenske: TG Therapeutics: Consultancy, Speakers Bureau; Servier Pharmaceuticals: Consultancy; Seattle Genetics: Speakers Bureau; Sanofi: Speakers Bureau; Pharmacyclics: Consultancy; MorphoSys: Consultancy; Kite (Gilead): Speakers Bureau; KaryoPharm: Consultancy; CSL Therapeutics: Consultancy; Bristol-Myers Squibb: Speakers Bureau; Biogen: Consultancy; Beigene: Consultancy; AstraZeneca: Speakers Bureau; ADC Therapeutics: Consultancy; Adaptive Biotechnologies: Consultancy; AbbVie: Consultancy.

17505 Background: A previous trial of 2-CDA as a single agent for therapy of mantle cell lymphoma demonstrated this agent to be efficacious with an overall response rate of 81% (31% complete responses) (Blood 1999 Nov 15; 94:660a). A phase II study of the addition of rituximab to 2-CDA was conducted by the North Central Cancer Treatment Group based on improved outcomes achieved by the addition of rituximab to other regimens active in MCL. Methods: This one-stage phase II study was designed to determine the complete response (CR) or complete response/unconfirmed (CRu) rate. Central pathology confirmation of cyclin D1 positive mantle cell lymphoma was required. No previous therapy for lymphoma was allowed, with the exception of splenectomy. The shedule was rituximab 375 mg/m2 IV day 1; 2-CDA 5 mg/m2/d IV days 1–5 of a 4-week cycle. After 2 of the first 6 patients developed grade 4 neutropenia, subsequent patients received either pegfilgrastim or filgrastim support. Patients received 2–6 cycles of therapy, depending on response. Patients were required to achieve at least a PR after 2 cycles of therapy to continue on protocol therapy. Results: Patient characteristics of all 29 eligible pts: median age: 70 (range: 41–86); 21 male, 8 female; PS 0 (55.2%), PS 1 (41.4%), PS 2 (3.5%); stage II (6.9%), stage III (3.5%), stage IV (89.7%); prior splenectomy (20.7%). The only grade 4 adverse event occurring more than once was neutropenia (20.7%). One patient died of cerebral ischemia in the setting of pneumonia without neutropenia. Response has been determined in 26 pts with 50.0% (95% CI: 30.0–70.0%) achieving a CR, none of whom have relapsed to date. Three patients progressed early at 17, 45, and 46 days, two of whom have died, and a fourth relapsed day 222. 10 pts (34.0%) went on to receive further therapy off study, 5 in less than a PR after 2 cycles, 2 in PR after study therapy, and 1 who went off study for a rash. At last contact, 26 (89.7%) were alive (median follow-up 10.7 months; range: 1–28). Conclusions: Rituximab and cladribine were well tolerated for the treatment of MCL in a group including elderly patients. The response rate may have been underestimated due to the study design, which required at least a PR after 2 cycles to continue therapy. Despite this, 50% achieved a complete remission. [Table: see text]

LBA9006 Purpose: Many patients who receive EGFR inhibitors develop an acneiform rash, and anecdotal reports suggest tetracycline is effective in treating it. To our knowledge, however, no rigorous trials have ever been published to substantiate this approach. This double- blinded, placebo-controlled trial was conducted to assess the role of tetracycline in preventing EGFR inhibitor-induced rash and/or reducing its severity. Methods: 61 patients were randomly assigned to tetracycline 500 mg orally twice a day×4 weeks versus an identical, similarly prescribed placebo. Eligibility criteria required all patients to have begun an EGFR inhibitor </= 7 days prior with no rash at study entry. Patients were to be followed for 8 weeks. Physician assessments of rash incidence, severity, and adverse events, occurred at 4 and 8 weeks. Patients completed a weekly rash diary, quality of life questionnaire (SKINDEX-16), and EGFR inhibitor compliance questionnaire. Thirty patients per group provides 90% power to detect a difference in rash incidence (the primary endpoint) of 40% between groups and of rejecting the null hypothesis of equal proportions with a type I error of 5% (2-sided). Results: Treatment arms were balanced on baseline characteristics, drop out rates, and rates of discontinuation of the EGFR inhibitor. Rash incidence was comparable across arms. Physicians reported that 16 tetracycline-treated patients (70%) and 22 placebo-exposed patients (76%) developed a rash (p=0.61). However, tetracycline appears to have lessened rash severity. By week 4, physician-reported grade 2 rash occurred in 17% of tetracycline-treated patients (n=4) and 55% of placebo- exposed patients (n=16); (p=0.04). Tetracycline-treated patients reported better scores on certain quality of life parameters (SKINDEX-16), such as skin burning or stinging, skin irritation, and being bothered by a persistence/recurrence of a skin condition. Adverse events were comparable across arms. Conclusion: Tetracycline did not prevent EGFR inhibitor-induced rashes. However, diminished rash severity and improved quality of life suggest this antibiotic merits further study. No significant financial relationships to disclose.

Abstract Background: A previous trial of 2-CDA as a single agent for therapy of mantle cell lymphoma demonstrated this agent to be efficacious with an overall response rate of 81% (31% complete responses) (Blood 1999 Nov 15; 94:660a). A phase II study of the addition of rituximab to 2-CDA was conducted by the North Central Cancer Treatment Group based on improved outcomes achieved by the addition of rituximab to other regimens active in MCL. Methods: This one-stage phase II study was designed to determine the complete response (CR) or complete response/unconfirmed (CRu) rate. Central pathology confirmation of cyclin D1 positive mantle cell lymphoma was required. No previous therapy for lymphoma was allowed, with the exception of splenectomy. The schedule was rituximab 375 mg/m2 IV day 1; 2-CDA 5 mg/m2/d IV days 1–5 of a 4-week cycle. After 2 of the first 6 patients developed grade 4 neutropenia, subsequent patients received either pegfilgrastim or filgrastim support. Patients received 2–6 cycles of therapy, depending on response. Patients were required to achieve at least a PR after 2 cycles of therapy to continue on protocol therapy. Results: Patient characteristics of all 29 eligible pts: median age: 70 (range: 41–86); 21 male, 8 female; PS 0 (55.2%), PS 1 (41.4%), PS 2 (3.5%); stage II (6.9%), stage III (3.5%), stage IV (89.7%); prior splenectomy (20.7%). The only grade 4 adverse events occurring more than once were neutropenia (24.1%) and leucopenia (6.9%). One patient died of cerebral ischemia in the setting of pneumonia without neutropenia. Fifteen (51.7%; 95% CI: 32.5–70.6%) pts achieved a CR; only one has relapsed to date (665 days after starting therapy). Four additional pts achieved a PR. Ten pts have progressed with 4 pts progressing early at 17, 45, 46, and 71 days (two of whom have died). Ten pts (34.0%) went on to receive further therapy off study, 5 in less than a PR after 2 cycles, 2 in PR after study therapy, and 1 who went off study for a rash. Fourteen pts (48.3%) have progressed or gone on to receive additional therapy off study. At last contact, 26 (89.7%) were alive (median follow-up 14.3 months; range: 6–34). One year survival rate is 89.3% (95% CI: 78.5–100). Conclusions: Rituximab and cladribine were well tolerated for the treatment of MCL in a group of elderly patients. The response rate may have been underestimated due to the study design, which required at least a PR after 2 cycles to continue therapy. Despite this, 52% achieved a complete remission. Complete remissions attained with this regimen appear to be durable, with a single relapse to date among 15 patients achieving CR.

Abstract Abstract 3661 Objective: We conducted this trial to determine the maximum tolerated dose (MTD) and schedule of temsirolimus added to an established regimen comprised of rituximab and cladribine for the initial treatment of mantle cell lymphoma and to generate preliminary information on the toxicity and efficacy of this combination. Methods: A standard phase I cohort of 3 study design was utilized. MTD was defined as the dose level below the lowest dose that induces dose-limiting toxicity (DLT) in at least one-third of patients (at least 2 of a maximum of 6 new patients). DLT was defined as grade 4 ANC (<500) for ≥5 days, grade 4 ANC (<500) associated with fever (>100.5 F) and/or active infection, PLT <25,000, grade 4 infection, or ≥grade 3 non-hematologic toxicity during the first cycle of therapy as per NCI Common Terminology Criteria for Adverse Events v3.0. The fixed doses of rituximab and cladribine were 375 mg/m2 IV day 1 and 5 mg/m2/d IV days 1–5 of a 28 day cycle, respectively, as previously published. There were 5 planned temsirolimus IV dose levels: 15 mg day 1; 25 mg day 1; 25 mg days 1 and 15; 25 mg days 1,8 and 15; and 25 mg days 1,8,15, and 22. The fifth dose level is as previously published in combination with rituximab. Results: A total of 17 patients were treated: 3 each at dose levels 1–4 and 5 at dose level 5 (25 mg temsirolimus days 1,8,15, and 22). The median age was 75 years (52–86). There were 11 males and 6 females. At presentation 88% had stage IV disease, and 94% had extranodal disease. MIPI scores were low in 6% (1 patient), intermediate in 59% (10 patients), and high in 35% (6 patients). There was a single DLT recorded at dose level 3 based on the initial DLT criteria, though this cytokine release syndrome was clearly rituximab related, and occurred prior to the first dose of temsirolimus. Five patients were treated at the highest planned temsirolimus dose level (25 mg days 1,8,15, and 22) with no DLT observed. No further dose escalation was planned, and this level was determined to be tolerated, though higher levels may be tolerable. All patients were evaluable for adverse events. Hematologic toxicity was frequent, with grade 3 anemia in 12% of patients, grade 3 thrombocytopenia in 35%, grade 4 thrombocytopenia in 30%, grade 4 lymphopenia in 47%, grade 3 neutropenia in 24%, and grade 4 neutropenia in 18% of patients. There were 3 thrombotic episodes, 2 of which were attributed to therapy, and 3 episodes of pneumonitis. The overall response rate was 94% with 53% CR and 41% PR. The median progression free survival was 18.7 months. Conclusions: Temsirolimus 25 mg IV weekly may be safely added to rituximab and cladribine at 375 mg/m2 IV day 1 and 5 mg/m2/d IV days 1–5 of a 28 day cycle, respectively. This regimen had promising preliminary activity in an elderly cohort of patients with mantle cell lymphoma. Disclosures: Off Label Use: Temsirolimus for mantle cell lymphoma.

PurposeFulvestrant is an antiestrogen that leads to estrogen receptor degradation and has demonstrated efficacy in breast cancer patients who have had disease recurrence or progression after tamoxifen. This study was designed to examine the efficacy and toxicity of fulvestrant in patients with disease progression on a third-generation aromatase inhibitor (AI).Patients and MethodsA one-stage phase II trial was conducted in postmenopausal women with measurable disease by Response Evaluation Criteria in Solid Tumors criteria who experienced disease progression after treatment with a third-generation AI and, at most, one additional hormonal agent. Tumors must have been estrogen receptor and/or progesterone receptor positive. The primary end point was objective response rate, and secondary end points were time to disease progression, survival, duration of response, and toxicity.ResultsEighty patients were enrolled, and three were ineligible. Characteristics of the 77 eligible patients included median age of 68 years, performance score of 0 or 1 in 91% of patients, visceral dominant disease in 88% of patients, two prior hormonal treatments in 73% of patients, and prior chemotherapy for metastatic disease in 32% of patients. Eleven patients (14.3%) achieved a partial response, and 16 patients (20.8%) had stable disease for at least 6 months, for a clinical benefit rate of 35%. Antitumor activity seemed to be higher in women with prior treatment with AI alone compared with women whose prior treatment also included tamoxifen. Median time to progression was 3 months, and median survival time was 20.2 months. Fulvestrant was well tolerated.ConclusionFulvestrant is a well-tolerated treatment and has efficacy against breast cancers that have progressed after therapy with a third-generation AI.