Consolidative Radiotherapy for Residual PET-Avid Disease on Day +30 Post CAR T-Cell Therapy in Non-Hodgkin Lymphoma

PURPOSE/OBJECTIVE(S)

Up to30% of non-Hodgkin lymphoma (NHL) patients achieve a partial response (PR) to anti-CD19 Chimeric Antigen Receptor T-cell Therapy (CART) on day +30. Most PR patients relapse and only 30% achieve spontaneous complete response (CR) without additional therapies. This study is the first to report on the role of consolidative radiotherapy (cRT) for PR PET-avid disease on day +30 post-CART in NHL.

MATERIALS/METHODS

Aretrospective review across 3 institutions from 2018 to 2022 identified 60 patients with B-cell NHL who received CART and achieved PR (Deauville 4-5) with <5 PET-avid disease sites on day +30. Progression-free survival (PFS) was defined from CART infusion to any disease progression. Overall survival (OS) was defined from CART infusion to death. Local relapse-free survival (LRFS), calculated based on the total number of PR sites, was defined from CART infusion to local relapse (LR) in the PR site identified on day +30. cRT was defined as comprehensive (compRT) - treated all PR PET-avid sites - or focal (focRT).

RESULTS

Followingday +30 PET scan, 45 PR patients were observed and 15 received cRT. Only one patient received consolidative systemic therapy and belonged to the cRT group. Prior to CART, bridging RT was given to 13 patients (9 in observation group and 4 in cRT group). There were no significant differences in the pre-CART and day +30 baseline characteristics, including the median size and SUVmax of the PR sites, between the two groups. However, the median number of PR sites on day +30 was higher in the cRT group (2 [range 1-3] vs 1 [range 1-3], p = 0.003). The median equivalent 2 Gy dose was 39.1 (Interquartile range 36.8-41) Gy, and the most common cRT regimen was 37.5 Gy in 15 fractions. The median follow-up was 21 months. Among the observed patients, 15 (33%) achieved spontaneous CR, and 27 (60%) experienced disease progression with all relapses involving the initial PR sites. Among patients who received cRT, 10 (67%) achieved CR, and 3 (20%) had disease progression with no relapses in the radiated PR sites. None of the 10 cRT patients achieving CR relapsed or required subsequent therapies. The 2-year PFS was 80% and 37% (p = 0.012) and the 2-year OS was 78% and 43% (p = 0.12) in the cRT and observation groups, respectively. Patients consolidated with compRT (n = 12) had superior 2-year PFS (92% vs 37%, p = 0.003) and 2-year OS (86% vs 43%, p = 0.048) compared to observed or focRT patients (n = 48). There were no grade 3+ RT-related toxicities. A total of 90 PR sites were identified; 64 were observed and 26 received cRT. Fourteen (22%) observed PR sites achieved spontaneous sustained CR and 42 (66%) experienced LR. Twenty-four (92%) PR sites consolidated with cRT achieved sustained CR and none experienced LR. The 2-year LRFS was 100% in the cRT sites and 31% in the observed sites (p<0.001).

CONCLUSION

NHL patients who achieve PR by PET to CART are at high risk of local progression. cRT for residual PET-avid disease on day +30 post-CART appears to alter the pattern of relapse and improve LRFS and PFS.

The Role of Radiation Therapy in the Management of Gray Zone Lymphoma

PURPOSE/OBJECTIVE(S)

Gray zone lymphoma (GZL) is a relatively rare disease predominantly affecting young adults with purportedly poor outcomes with current treatment approaches. The role of radiation therapy (RT) in the management of GZL is not well established. This is the largest study to report on the outcomes of GZL patients treated with and without RT.

MATERIALS/METHODS

A retrospective review of 30 patients with GZL treated across 3 institutions from 2009 to 2021 was performed. Event-free survival (EFS) was defined from initiation of frontline chemotherapy (CHT) to disease progression/relapse, initiation of salvage therapy, or death. Local control (LC) was defined from RT start date to in-field recurrence.

RESULTS

The median age was 32 (range: 18-86) years, and 16 (53%) patients had early stage (I-II) disease. Bulky mediastinal disease was present in 63% of patients, and the median tumor diameter was 10 (range: 1.5-18) cm. Patients received ABVD (20%), RCHOP (33%), or REPOCH (47%) as frontline CHT. Among 25 patients with interim PET/CT scan, there were 6 rapid early responders and 14 slow early responders (SER), with 2-year EFS of 33% and 24%, respectively (p = 0.13). After the completion of CHT, 15 (50%) patients achieved complete response (CR) and 10 (33%) achieved partial response (PR), with 2-year EFS of 46% and 10%, respectively (p = 0.004). RT was given to 9 patients in CR (n = 3) or in PR (n = 6). The median RT dose was 36 (30.6-48.6) Gy, at 1.8-2 Gy/fraction. Those receiving RT had bulkier disease at diagnosis (p = 0.049) and lower rates of CR following CHT (p = 0.03). After RT, 3/6 (50%) PR patients converted to CR. At a median follow-up of 4 years, the 2-year EFS was 26% for all patients, 33% for RT and 23% for noRT (p = 0.44). Among patients who did not receive upfront RT and experienced progression (n = 17), 16 (94%) relapsed in pre-existing sites. The 5-year OS was 80% for all patients, 88% for RT and 78% for no RT (p = 0.63). Patients who achieved PR to CHT and received RT had better 2-year EFS (17% vs 0%, p = 0.007) compared to patients who did not receive RT. Similarly, patients with SER who received RT had superior 2-year EFS (33% vs 13%, p = 0.038). Patients with bulky mediastinal disease had a 2-year EFS of 43% with RT and 11% without RT (p = 0.08). After 1st line treatment, 22 (73%) patients relapsed and 18 were successfully salvaged with a sustained CR. The most common salvage regimen involved high dose CHT followed by hematopoietic cell transplantation (HCT) (n = 15). RT was given for 7 patients in the relapsed/refractory setting (consolidative peri-HCT n = 4; definitive salvage n = 3) and 5 (71%) achieved a sustained CR. Among the 16 patients who received RT in the upfront (n = 9) or salvage (n = 7) setting, 3 patients experienced in-field recurrence translating to 2-year LC of 79%.

CONCLUSION

GZL patients have high risk of relapse and maximal upfront combined modality therapy should be considered. RT provides good local control and improves EFS particularly for SER, PR, and bulky mediastinal disease.

Report of consensus panel 7 from the 11th international workshop on Waldenström macroglobulinemia on priorities for novel clinical trials

Recent advances in the understanding of Waldenström macroglobulinemia (WM) biology have impacted the development of effective novel agents and improved our knowledge of how the genomic background of WM may influence selection of therapy. Consensus Panel 7 (CP7) of the 11th International Workshop on WM was convened to examine the current generation of completed and ongoing clinical trials involving novel agents, consider updated data on WM genomics, and make recommendations on the design and prioritization of future clinical trials. CP7 considers limited duration and novel-novel agent combinations to be the priority for the next generation of clinical trials. Evaluation of MYD88, CXCR4 and TP53 at baseline in the context of clinical trials is crucial. The common chemoimmunotherapy backbones, bendamustine-rituximab (BR) and dexamethasone, rituximab and cyclophosphamide (DRC), may be considered standard-of-care for the frontline comparative studies. Key unanswered questions include the definition of frailty in WM; the importance of attaining a very good partial response or better (≥VGPR), within stipulated time frame, in determining survival outcomes; and the optimal treatment of WM populations with special needs.

Coinhibition of the deubiquitinating enzymes, USP14 and UCHL5, with VLX1570 is lethal to ibrutinib- or bortezomib-resistant Waldenstrom macroglobulinemia tumor cells

The survival of Waldenstrom macroglobulinemia (WM) tumor cells hinges on aberrant B-cell receptor (BCR) and MYD88 signaling. WM cells upregulate the proteasome function to sustain the BCR-driven growth while maintaining homeostasis. Clinically, two treatment strategies are used to disrupt these complementary yet mutually exclusive WM survival pathways via ibrutinib (targets BTK/MYD88 node) and bortezomib (targets 20 S proteasome). Despite the success of both agents, WM patients eventually become refractory to treatment, highlighting the adaptive plasticity of WM cells and underscoring the need for development of new therapeutics. Here we provide a comprehensive preclinical report on the anti-WM activity of VLX1570, a novel small-molecule inhibitor of the deubiquitinating enzymes (DUBs), ubiquitin-specific protease 14 (USP14) and ubiquitin carboxyl-terminal hydrolase isozyme L5 (UCHL5). Both DUBs reside in the 19 S proteasome cap and their inhibition by VLX1570 results in rapid and tumor-specific apoptosis in bortezomib- or ibrutinib-resistant WM cells. Notably, treatment of WM cells with VLX1570 downregulated BCR-associated elements BTK, MYD88, NFATC, NF-κB and CXCR4, the latter whose dysregulated function is linked to ibrutinib resistance. VLX1570 administered to WM-xenografted mice resulted in decreased tumor burden and prolonged survival (P=0.0008) compared with vehicle-treated mice. Overall, our report demonstrates significant value in targeting USP14/UCHL5 with VLX1570 in drug-resistant WM and carries a high potential for clinical translation.

Whole-exome analysis reveals novel somatic genomic alterations associated with outcome in immunochemotherapy-treated diffuse large B-cell lymphoma

Lack of remission or early relapse remains a major clinical issue in diffuse large B-cell lymphoma (DLBCL), with 30% of patients failing standard of care. Although clinical factors and molecular signatures can partially predict DLBCL outcome, additional information is needed to identify high-risk patients, particularly biologic factors that might ultimately be amenable to intervention. Using whole-exome sequencing data from 51 newly diagnosed and immunochemotherapy-treated DLBCL patients, we evaluated the association of somatic genomic alterations with patient outcome, defined as failure to achieve event-free survival at 24 months after diagnosis (EFS24). We identified 16 genes with mutations, 374 with copy number gains and 151 with copy number losses that were associated with failure to achieve EFS24 (P<0.05). Except for FOXO1 and CIITA, known driver mutations did not correlate with EFS24. Gene losses were localized to 6q21-6q24.2, and gains to 3q13.12-3q29, 11q23.1-11q23.3 and 19q13.12-19q13.43. Globally, the number of gains was highly associated with poor outcome (P=7.4 × 10⁻¹²) and when combined with FOXO1 mutations identified 77% of cases that failed to achieve EFS24. One gene (SLC22A16) at 6q21, a doxorubicin transporter, was lost in 54% of EFS24 failures and our findings suggest it functions as a doxorubicin transporter in DLBCL cells.

A meta-analysis of Hodgkin lymphoma reveals 19p13.3 TCF3 as a novel susceptibility locus

Recent genome-wide association studies (GWAS) of Hodgkin lymphoma (HL) have identified associations with genetic variation at both HLA and non-HLA loci; however, much of heritable HL susceptibility remains unexplained. Here we perform a meta-analysis of three HL GWAS totaling 1,816 cases and 7,877 controls followed by replication in an independent set of 1,281 cases and 3,218 controls to find novel risk loci. We identify a novel variant at 19p13.3 associated with HL (rs1860661; odds ratio (OR)=0.81, 95% confidence interval (95% CI) = 0.76-0.86, P(combined) = 3.5 × 10(-10)), located in intron 2 of TCF3 (also known as E2A), a regulator of B- and T-cell lineage commitment known to be involved in HL pathogenesis. This meta-analysis also notes associations between previously published loci at 2p16, 5q31, 6p31, 8q24 and 10p14 and HL subtypes. We conclude that our data suggest a link between the 19p13.3 locus, including TCF3, and HL risk.

Activation of TAK1 by MYD88 L265P drives malignant B-cell Growth in non-Hodgkin lymphoma

Massively parallel sequencing analyses have revealed a common mutation within the MYD88 gene (MYD88_L265P) occurring at high frequencies in many non-Hodgkin lymphomas (NHLs) including the rare lymphoplasmacytic lymphoma, Waldenström's macroglobulinemia (WM). Using whole-exome sequencing, Sanger sequencing and allele-specific PCR, we validate the initial studies and detect the MYD88_L265P mutation in the tumor genome of 97% of WM patients analyzed (n=39). Due to the high frequency of MYD88 mutation in WM and other NHL, and its known effects on malignant B-cell survival, therapeutic targeting of MYD88 signaling pathways may be clinically useful. However, we are lacking a thorough characterization of the role of intermediary signaling proteins on the biology of MYD88_L265P-expressing B cells. We report here that MYD88_L265P signaling is constitutively active in both WM and diffuse large B-cell lymphoma cells leading to heightened MYD88_L265P, IRAK and TRAF6 oligomerization and NF-κB activation. Furthermore, we have identified the signaling protein, TAK1, to be an essential mediator of MYD88_L265P-driven signaling, cellular proliferation and cytokine secretion in malignant B cells. Our studies highlight the biological significance of MYD88_L265P in NHL and reveal TAK1 inhibition to be a potential therapeutic strategy for the treatment of WM and other diseases characterized by MYD88_L265P.

Bowel perforation in intestinal lymphoma: incidence and clinical features

BACKGROUND

Perforation is a serious life-threatening complication of lymphomas involving the gastrointestinal (GI) tract. Although some perforations occur as the initial presentation of GI lymphoma, others occur after initiation of chemotherapy. To define the location and timing of perforation, a single-center study was carried out of all patients with GI lymphoma.

PATIENTS AND METHODS

Between 1975 and 2012, 1062 patients were identified with biopsy-proven GI involvement with lymphoma. A retrospective chart review was undertaken to identify patients with gut perforation and to determine their clinicopathologic features.

RESULTS

Nine percent (92 of 1062) of patients developed a perforation, of which 55% (51 of 92) occurred after chemotherapy. The median day of perforation after initiation of chemotherapy was 46 days (mean, 83 days; range, 2-298) and 44% of perforations occurred within the first 4 weeks of treatment. Diffuse large B-cell lymphoma (DLBCL) was the most common lymphoma associated with perforation (59%, 55 of 92). Compared with indolent B-cell lymphomas, the risk of perforation was higher with aggressive B-cell lymphomas (hazard ratio, HR = 6.31, P < 0.0001) or T-cell/other types (HR = 12.40, P < 0.0001). The small intestine was the most common site of perforation (59%).

CONCLUSION

Perforation remains a significant complication of GI lymphomas and is more frequently associated with aggressive than indolent lymphomas. Supported in part by University of Iowa/Mayo Clinic SPORE CA97274 and the Predolin Foundation.

Denileukin diftitox in combination with rituximab for previously untreated follicular B-cell non-Hodgkin's lymphoma

Follicular lymphoma exhibits intratumoral infiltration by non-malignant T lymphocytes inluding CD4+CD25+ regulatory T (T_reg) cells. We combined denileukin diftitox with rituximab in previously untreated, advanced-stage follicular lymphoma patients anticipating that denileukin diftitox would deplete CD25+ T_reg cells while rituximab would deplete malignant B-cells. Patients received rituximab 375 mg/m2 weekly for 4 weeks and denileukin diftitox 18 mcg/kg/day for 5 days every 3 weeks for 4 cycles; neither agent was given as maintenance therapy. Between August 2008 and March 2010, 24 patients were enrolled. One patient died before treatment was given and was not included in the analysis. Eleven of 23 patients (48%; 95% CI: 27–69%) responded; 2 (9%) had complete responses and 9 (39%) had partial responses. The progression-free rate at 2 years was 55% (95%CI: 37–82%). Thirteen patients (57%) experienced grade ≥3 adverse events and 1 patient (4%) died. In correlative studies, soluble CD25 and the number of CD25+ T-cells decreased after treatment, however there was a compensatory increase in IL-15 and IP-10. We conclude that while the addition of denileukin diftitox to rituximab decreased the number of CD25+ T-cells, denileukin diftitox contributed to the toxicity of the combination without an improvement in response rate or time to progression.

Lenalidomide can be safely combined with R-CHOP (R2CHOP) in the initial chemotherapy for aggressive B-cell lymphomas: phase I study

Lenalidomide was shown to have significant single-agent activity in relapsed aggressive non-Hodgkin's lymphoma (NHL). We conducted a phase I trial to establish the maximum tolerated dose of lenalidomide that could be combined with R-CHOP (rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisone). Eligible patients were adults with newly diagnosed, untreated CD20 positive diffuse large cell or follicular grade III NHL. Patients received oral lenalidomide on days 1-10 with standard dose R-CHOP every 21 days. All patients received pegfilgrastim on day 2 of the cycle and aspirin prophylaxis. The lenalidomide dose levels tested were 15, 20 and 25 mg. A total of 24 patients were enrolled. The median age was 65 (35-82) years and 54% were over 60 years. Three patients received 15 mg, 3 received 20 mg and 18 received 25 mg of lenalidomide. No dose limiting toxicity was found, and 25 mg on days 1-10 is the recommended dose for phase II. The incidence of grade IV neutropenia and thrombocytopenia was 67% and 21%, respectively. Febrile neutropenia was rare (4%) and there were no toxic deaths. The overall response rate was 100% with a complete response rate of 77%. Lenalidomide at the dose of 25 mg/day administered on days 1 to 10 of 21-day cycle can be safely combined with R-CHOP in the initial chemotherapy of aggressive B-cell lymphoma.

MicroRNA expression in tumor cells from Waldenstrom's macroglobulinemia reflects both their normal and malignant cell counterparts

MicroRNAs (miRNAs) are involved in the regulation of many cellular processes including hematopoiesis, with the aberrant expression of differentiation-stage specific miRNA associated with lymphomagenesis. miRNA profiling has been essential for understanding the underlying biology of many hematological malignancies; however the miRNA signature of the diverse tumor clone associated with Waldenstrom's macroglobulinemia (WM), consisting of B lymphocytes, plasmacytes and lymphoplasmacytic cells, has not been characterized. We have investigated the expression of over 13 000 known and candidate miRNAs in both CD19(+) and CD138(+) WM tumor cells, as well as in their malignant and non-malignant counterparts. Although neither CD19(+) nor CD138(+) WM cells were defined by a distinct miRNA profile, the combination of all WM cells revealed a unique miRNA transcriptome characterized by the dysregulation of many miRNAs previously identified as crucial for normal B-cell lineage differentiation. Specifically, miRNA-9(*)/152/182 were underexpressed in WM, whereas the expression of miRNA-21/125b/181a/193b/223/363 were notably increased (analysis of variance; P<0.0001). Future studies focusing on the effects of these dysregulated miRNAs will provide further insight into the mechanisms responsible for the pathogenesis of WM.

The absolute monocyte and lymphocyte prognostic score predicts survival and identifies high-risk patients in diffuse large-B-cell lymphoma

Despite the use of modern immunochemotherapy regimens, almost 50% of patients with diffuse large-B-cell lymphoma will relapse. Current prognostic models, including the International Prognostic Index, incorporate patient and tumor characteristics. In contrast, recent observations show that variables related to host adaptive immunity and the tumor microenvironment are significant prognostic variables in non-Hodgkin lymphoma. Therefore, we retrospectively examined the absolute monocyte and lymphocyte counts as prognostic variables in a cohort of 366 diffuse large-B-cell lymphoma patients who were treated between 1993 and 2007 and followed at a single institution. The absolute monocyte and lymphocyte counts in univariate analysis predicted progression-free and overall survival when analyzed as continuous and dichotomized variables. On multivariate analysis performed with factors included in the IPI, the absolute monocyte and lymphocyte counts remained independent predictors of progression-free and overall survival. Therefore, the absolute monocyte and lymphocyte counts were combined to generate a prognostic score that identified patients with an especially poor overall survival. This prognostic score was independent of the IPI and added to its ability to identify high-risk patients.

A phase II trial of the oral mTOR inhibitor everolimus in relapsed aggressive lymphoma

The phosphatidylinositol 3-kinase signal transduction pathway members are often activated in tumor samples from patients with non-Hodgkin's lymphoma (NHL). Everolimus is an oral agent that targets the raptor mammalian target of rapamycin (mTORC1). The goal of this trial was to learn the antitumor activity and toxicity of single-agent everolimus in patients with relapsed/refractory aggressive NHL. Patients received everolimus 10 mg PO daily. Response was assessed after two and six cycles, and then every three cycles until progression. A total of 77 patients with a median age of 70 years were enrolled. Patients had received a median of three previous therapies and 32% had undergone previous transplant. The overall response rate (ORR) was 30% (95% confidence interval: 20-41%), with 20 patients achieving a partial remission and 3 a complete remission unconfirmed. The ORR in diffuse large B cell was 30% (14/47), 32% (6/19) in mantle cell and 38% (3/8) in follicular grade 3. The median duration of response was 5.7 months. Grade 3 or 4 anemia, neutropenia and thrombocytopenia occurred in 14, 18 and 38% of patients, respectively. Everolimus has single-agent activity in relapsed/refractory aggressive NHL and provides proof-of-concept that targeting the mTOR pathway is clinically relevant.

A Phase 1b/2 trial of mapatumumab in patients with relapsed/refractory non-Hodgkin's lymphoma

Background:

We conducted a multicentre Phase 1b/2 trial to evaluate the safety and efficacy of mapatumumab, a fully human agonistic monoclonal antibody to the tumour necrosis factor-related apoptosis-inducing ligand receptor 1 (TRAIL-R1) in patients with relapsed non-Hodgkin's lymphoma (NHL).

Methods:

Forty patients with relapsed or refractory NHL were treated with either 3 or 10 mg kg⁻¹ mapatumumab every 21 days. In the absence of disease progression or prohibitive toxicity, patients received a maximum of six doses.

Results:

Mapatumumab was well tolerated, with no patients experiencing drug-related hepatic or other dose-limiting toxicity. Three patients with follicular lymphoma (FL) experienced clinical responses, including two with a complete response and one with a partial response. Immunohistochemistry staining of the TRAIL-R1 suggested that strong staining in tumour specimens did not appear to be a requirement for mapatumumab activity in FL.

Conclusions:

Mapatumumab is safe and has promising clinical activity in patients with FL.

Low risk of symptomatic venous thromboembolic events during growth factor administration for PBSC mobilization

The use of erythropoietic agents has been associated with an increased risk of venous thromboembolic events (VTEs), especially in patients with underlying malignancies. However, it is not known whether there is an increased risk of VTE associated with granulocyte growth factors. We reviewed 621 patients undergoing PBSC mobilization using granulocyte growth factors, alone or in combination with CY. Patients with a diagnosis of AL amyloidosis (AL: 114; 18%), multiple myeloma (MM: 278; 44%) Hodgkin lymphoma (HL: 20; 3%) or non-Hodgkin lymphoma (NHL: 209; 33%) were included. Symptomatic VTE occurred in six (0.97%) patients: two AL, two MM and two NHL. Of the six patients, two had pulmonary embolism, one developed deep vein thrombosis and three developed symptomatic catheter related thrombosis. Two patients with AL had heparin-induced thrombocytopenia and thrombosis. We found a low incidence of VTE among patients undergoing PBSC mobilization.

Low risk for symptomatic venous thromboembolic events (vte) during cytokine administration for peripheral blood stem cell mobilization

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Background: Erythropoiesis-stimulating agents are known to increase the risk for VTE events, especially in patients with underlying malignancies. However, there is a paucity of information on other hematopoietic growth factors such as granulocyte colony-stimulating factor (GSCF) granulocyte-macrophage colony stimulating factor (GM-CSF) AMD 3001 and risk for VTE. Methods: Between January 2000 and October 2008, a total of 631 patients underwent peripheral blood stem cell mobilization (PBSCM) using either GCSF, GMCSF, cyclophosphamide, AMD 3100, or with any of the above combination. We included only patients with a diagnosis of AL amyloidosis (AL), multiple myeloma (MM) Hodgkin's lymphoma (HL) and non Hodgkin's lymphoma (NHL). Patients’ demographic details and diagnosis of VTE were collected from electronic medical records. Results: Of the 631 patients who underwent PBSCM the median age of the patients was 57 years (range 17–77). 448 patients (71%) received single agent GCSF, 82 (13%) received combination of GMCSF and cyclophosphamide, 52 (8%) received cyclophosphamide and GCSF, 30 patients received a combination of GMCSF and GCSF, 10 (1.5%) patients received GCSF and AMD 3100. Of the 631 patients, 278 (44%) MM, 209 (33%) NHL, 114 (18%) AL, and 20 (3%) had HL. We found 7 (1.1%) patients with symptomatic VTE occurring between administration of growth factors and stem cell transplant. The median duration from the administration of growth factors to detection of VTE was 5 days (range 1–30). Two AL,3 MM and 2 NHL. Of the 7 patients, 2 patients had pulmonary embolism and 1 patient developed deep vein thrombosis. Two patients with AL developed heparin induced thrombocytopenia (HIT). The remaining 4 patients developed symptomatic catheter related thrombosis. Only 1 patient had past history of VTE. Of the 7 patients, 5 received GCSF alone, 1 received GMCSF, and cyclophosphamide, 1 received GCSF and cyclophosphamide. Of the 4 patients who developed catheter related thrombosis, catheter was removed in 2 patients. None of the patients developed VTE related morality. Conclusions: The risk for symptomatic VTE during PBSCM is low. HIT should be considered as a possible cause for VTE in patients undergoing PBSCM.

No significant financial relationships to disclose.

Excessive false-positive errors in single-arm phase II trials: A simulation-based analysis

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Background: The use of randomized phase II designs with an experimental arm and a standard-treatment control arm (R2PII) instead of a conventional single-arm design is clearly increasing in oncology. In practice, sample size, related cost issues, the belief that historical controls are adequate, and the use of a standard-treatment control arm in a phase II setting are frequently raised objections to R2PII trials. As the expense and complexity of definitive phase III trials increase, the ability of phase II trials to provide reliable and accurate results is critical. Methods: We investigated the ability of single arm vs R2PII trials to provide accurate conclusions by modeling variability in historical controls, patient outcome drifts independent of the tested therapy, and patient selection effects. Simulations compared R2PII and single-arm designs with binary endpoints under realistic parameters (e.g. alpha = beta = 0.10, historical control success rate = 20%, target success rate = 40%). Results: In the absence of variability in historical controls, estimated false positive and negative rates in both designs mirror the designated specifications. However, even in the presence of a modest drift effect in the population (mean 5% absolute shift in true control success rate), the false positive rate in single-arm designs is inflated two to three fold (to 20%-30%), while the R2PII retains the desired error rates. Greater confidence in historical controls in the single-arm design corrects only a small portion of the deviations. Increasing the sample size in each trial inflates the false positive error rate further to as much as 50%. Varying several sets of parameters gave similar results. Conclusions: In the presence of variability in historical controls, patient drift and/or selection effects, the false positive error rate of a single arm design is unacceptably high. In contrast, the R2PII design is reliable and robust despite the complexities in patient outcome drift and selection effects, and variability in historical control success rates. Given the rapid improvements in outcomes of many tumor types, the R2PII design should be the preferred method to evaluate novel agents in oncology in spite of the associated costs and the use of a reference control arm.

No significant financial relationships to disclose.

A role for IFN-lambda1 in multiple myeloma B cell growth

Multiple myeloma (MM) is a progressive disease that results from dysregulated proliferation of plasma cells. Although, causative factors such as genetic events and altered expression of anti-apoptotic factors have been described in a number of patients, the mechanistic details that drive myeloma development and continued growth of malignant cells remain largely undefined. Numerous growth factors, including interleukin (IL)-6, Insulin-like growth factor-1 and IL-10 have been shown to promote growth of MM cells suggesting a significant role for cytokines in this disease. Interferon (IFN)-lambda1 is a new member of the Class II cytokine family that, similar to IFN-alpha, has been shown to mediate viral immunity. In light of data supporting a role for cytokines in myeloma, we investigated the significance of IFN-lambda1 on myeloma cell biology. Our studies show for the first time that myeloma cells bind to soluble IFN-lambda1, and that IFN-lambda1 induces myeloma cell growth and protects against dexamethasone-induced cell death. Our data also show that IFN-lambda1 induces phosphorylation of STAT1, STAT3 and Erk. Taken together, our results suggest that IFN-lambda1 may regulate myeloma cell biology and could prove to be therapeutically important.

Phase II trial of the oral mTOR inhibitor everolimus (RAD001) for patients with relapsed or refractory lymphoma

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Background: mTOR inhibition with intravenous temsirolimus (Wyeth Pharmaceuticals) has been associated with responses in mantle cell lymphoma (J Clin Oncol 23;5347, 2005) as well as other lymphomas (Blood 108 (11) 2483; 2006). This phase II study tested the oral mTOR inhibitor everolimus (RAD001, Novartis Pharmaceuticals) in three simultaneous two-stage phase II lymphoma studies - aggressive (group 1), indolent (group 2), or uncommon (group 3). The goals were to learn the toxicity profile and to assess the anti-tumor response. Planned interim analysis for groups 1 and 3 have been completed and are the subject of this report. Methods: Patients (pts) received 10 mg PO daily for each 28 day cycle (up to 12) and restaged after 2, 6, and 12 cycles. The primary endpoint is the confirmed response rate, including CR, CRu or PR. 12 pts were enrolled in stage 1 of each study. At least 1 success in 12 is required to proceed to stage 2, to a total of 37 pts. Overall, the treatment will be considered promising if 4 or more successes are observed in all 37 pts in each group. Results: The median age of the 12 pts in group 1 was 68.5 yrs (range: 53–80), with a median of 3 (range, 1–15) prior therapies. Four pts had a prior stem cell transplant (SCT). Pts completed a median of 7 (range, 1–12) cycles of therapy. 6 confirmed responses have been achieved (1 CR, 5 PR), meeting the overall criteria for promising results in this study. Common grade 3 adverse events (AEs) include thrombocytopenia (3 pts) and anemia (2 pts). For group 3, the median age was 49 yrs (range, 27–78), with a median of 7 (range, 1–13) prior therapies and 6 pts had a prior SCT. Pts have completed a median of 6.5 cycles (range, 1–11). 5 confirmed responses have been achieved (5 PR), meeting the criteria for this regimen to be considered promising. Of these 5 patients, 3 had HD, 1 T-cell NHL, and 1 had macroglobulinemia. Common grade 3 AEs include anemia (3 pts) and thrombocytopenia (2 pts). No grade 4 AEs were reported. Conclusions: Oral everolimus has activity in a spectrum of lymphomas with acceptable toxicity. The responses observed in both group 1 and group 3 met the criteria to continue accrual. These results provide the rationale for additional studies with this novel class of agents and to integrate mTOR inhibitors into salvage treatment regimens.

No significant financial relationships to disclose.

Early lymphocyte recovery after autologous stem cell transplantation predicts superior survival in mantle-cell lymphoma

Autologous stem cell transplantation (ASCT) is an effective treatment strategy for mantle-cell lymphoma (MCL) demonstrating significantly prolonged progression-free survival (PFS) when compared to interferon-alpha maintenance therapy of patients in first remission. The study of absolute lymphocyte count at day 15 (ALC-15) after ASCT as a prognostic factor in non-Hodgkin lymphoma (NHL) included different lymphoma subtypes. The relationship of ALC-15 after ASCT in MCL has not been specifically addressed. We evaluated the impact of ALC-15 recovery on survival of MCL patients undergoing ASCT. We studied 42 consecutive MCL patients who underwent ASCT at the Mayo Clinic in Rochester from 1993 to 2005. ALC-15 threshold was set at 500 cells/microl. The median follow-up after ASCT was 25 months (range, 2-106 months). The median overall survival (OS) and PFS times were significantly better for the 24 patients who achieved an ALC-15 >or=500 cells/microl compared with 18 patients with ALC-15 <500 cells/microl (not reached vs 30 months, P<0.01 and not reached vs 16 months, P<0.0006, respectively). Multivariate analysis demonstrated ALC-15 to be an independent prognostic factor for OS and PFS. The ALC-15 >or=500 cells/microl is associated with a significantly improved clinical outcome following ASCT in MCL.

Autologous hematopoietic stem cell transplantation for older patients with relapsed non-Hodgkin's lymphoma

To evaluate autologous stem cell transplant (ASCT) in older patients with intermediate grade non-Hodgkin's lymphoma (NHL), the Mayo Clinic Rochester BMT database was reviewed for all patients 60 years of age and older who received ASCT for NHL between September 1995 and February 2003. Factors evaluated included treatment-related mortality (TRM), event-free survival (EFS) and overall survival (OS). Ninety-three patients were identified, including twenty-four (26%) over the age of 70 years. Treatment-related mortality (5.4%) was not significantly different when compared to a younger cohort (2.2%). At a median follow-up of 14 months (0.6-87.6 months), the estimated median survival is 25 months (95% confidence interval (CI) 12-38) in the older group compared to 56 months (95% CI 37-75) (P=0.037) in the younger group. The estimated 4-year EFS was 38% for the older group compared to 42% in the younger cohort (P=0.1). By multivariate analysis, the only factor found to influence survival in the older group was age-adjusted International Prognostic Index at relapse, 0-1 better than 2-3 (P=0.03). Autologous stem-cell transplant can be safely performed in patients 60 years or older with chemotherapy sensitive relapsed or first partial remission NHL. The outcome may not be different from that of younger patients in terms of TRM and EFS.

Anti-tumor activity of mTOR inhibitor temsirolimus for relapsed mantle cell lymphoma: A phase II trial in the North Central Cancer Treatment Group

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Background: Mantle Cell Lymphoma (MCL) is characterized by t(11;14) resulting in over expression of cyclin D1, a member of the phosphatidylinosital 3-kinase (PI3K) pathway. Temsirolimus is a novel inhibitor of the mammalian target of rapamycin (mTOR) kinase. Previous studies with weekly temsirolimus at a dose of 250mg demonstrated a 38% overall response rate in 35 patients (JCO 23 (23); 5347–56, 2005). Thrombocytopenia was frequently observed and was dose limiting. The current study tested whether low-doses (25mg) of temsirolimus could produce a similar overall response rate (ORR) with less toxicity. Methods: Eligible patients had biopsy proven cyclin D1 positive MCL and had relapsed or were refractory to therapy. Patients received temsirolimus 25mg IV weekly as a single agent. Patients were restaged after 1 cycle (4 doses), after 3 cycles, and every 3 cycles thereafter. Patients with a tumor response after 6 cycles were eligible to continue drug for a total of 12 or 2 cycles after complete remission (CR) and then were observed without maintenance. The goal was to achieve an ORR of at least 20%. Results: Twenty-nine patients were enrolled between March and August 2005. Twenty-two patients have completed therapy. One patient with a major protocol violation on cycle-1 and one ineligible patient were excluded, leaving 27 evaluable patients. The ORR was 41% (11/27), with 1 CR and 10 PRs. Early evaluation of TTP showed a median of 5.5 months (95% CI: 3.3–7.7) and the duration of response for the 11 responders was 6.2 months (95% CI: 3.6 to not yet reached). These results compare favorably with the 6.5 months and 6.9 months, respectively, found in previous trials that used 250 mg. The median dose delivered per month was 80 mg (range, 10–100 mg). Sixteen (59%) of patients required a dose reduction. The median time on treatment was 4.4 months (95% CI, 3.3–7.7). The incidence of grade 3 and 4 thrombocytopenia was 12% and 0%, respectively. One patient experienced grade 5 infection without neutropenia, which was considered unrelated to CCI-779. Conclusions: Single agent CCI-779 at a dose of 25mg has anti-tumor activity in relapsed MCL similar to the 250 mg dose. This study indicates that combinations of temsirolimus with other agents should be feasible.

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Autologous stem cell transplant for primary CNS lymphoma results in prolonged progression free and overall survival

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Background: Survival for patient with primary CNS lymphoma (PCNSL), in general, is poor with patients requiring frequent chemotherapy treatments or receiving whole-brain radiation therapy, which can potentially result in significant neurologic decline and dementia. Because of the improved survival of high risk patients with aggressive lymphoma undergoing autologous stem cell transplant (ASCT), we began ASCT for patients with PCNSL in first or later remission with chemotherapy sensitive disease. We now report on outcomes of patients who have had at least 1 year follow up post ASCT. Methods: Between June, 2000 and September, 2004, 11 patients underwent ASCT for PCNSL. The medical records of consenting patients were abstracted for the following information. Median age at transplant was 47 years old (range 30–67). Median number of prior treatments 1 (range 1–3). Median time from diagnosis to transplant was 7.5 months (range 2.9 to 75.8). Median International Extranodal Working Study Group Prognostic Score: 2 (range 0–3). Disease status at transplant: First CR 5 patients, later CR or PR 6 patients. Results: Eleven patients underwent ASCT for PCNSL and have a minimum of 1 year follow-up. All patients received BEAM conditioning. Median follow up was 28.3 months. Four patients have relapsed at a median of 200 days (range 40–523). Of the patients who relapsed, one has died of disease progression and the remaining three are alive after additional therapy. Median overall survival and progression free survival from transplant have not been reached. Two year overall and event free survival are 89% and 61%, respectively. Conclusions: Although limited by patient selection and retrospective biases, this review suggests that ASCT for PCNSL demonstrates improved overall survival when compared to historical controls with similar PCNSL Prognostic Scores (2 year survival for patients from diagnosis with PS 2–3 was 48% in a prior published study). ASCT in first remission in patients with PCNSL appears promising and may limit the need for additional therapy which can be myelosuppressive or result in neurologic decline.

No significant financial relationships to disclose.

Absolute lymphocyte count prior to rituximab therapy predicts time to progression in patients with follicular grade 1 lymphoma

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Background: The immunologic mechanisms of action of rituximab have been described as complement mediated lysis, vaccine like effect, antibody-dependent cellular cytotoxicity (ADCC) and the cellular microenvironment. We hypothesized that in the treatment of follicular grade 1 lymphoma (FL), the presence of a stronger host immune status prior to rituximab therapy would result in a prolonged time to progression (TTP). As a surrogate marker for immune status, we evaluated the absolute lymphocyte count (ALC) prior to rituximab treatment. Methods: Between 1996 and 2002, 1,104 consecutive FL patients were evaluated at Mayo Clinic Rochester. Of these patients, we retrospectively analyzed a group of all FL patients who received rituximab (375 mg/m2 once a week for four weeks) alone at any time during their lymphoma treatment at the Mayo Clinic (n=79). The primary end-point was to assess the impact of ALC just prior to rituximab therapy on TTP for FL. Results: The median age of the cohort was 56.6 years (range: 25–98 years). The median follow-up was 12.5 months (range: 1–76 months). An ALC count of ≥ 890 cells/μL prior to rituximab therapy predicted a longer TTP compared with an ALC < 890 cells/μl (25 months versus 8 months, respectively, p < 0.0124). A higher complete response rate was observed in the ALC ≥ 890 cells/μL group compared with the ALC < 890 cells/μL group [15/40 (38%) vs 5/39 (13%), p < 0.035]. The groups were balanced regarding the Follicular Lymphoma International Prognostic Index (FLIPI) (p = 0.794). Multivariate analysis demonstrated ALC ≥ 890 cells/μL prior to rituximab therapy as an independent prognostic factor for TTP when compared to hemoglobin, LDH, and Ann Arbor stage. The ALC was independent of the FLIPI in multivariate analysis. Conclusions: This data supports the hypothesis that a higher lymphocyte count, as a marker of the immune status of the patient, predicts for a longer TTP following rituximab therapy.

No significant financial relationships to disclose.

Allogeneic stem cell transplantation and donor lymphocyte infusions for chronic myelomonocytic leukemia

Prognosis in chronic myelomonocytic leukemia (CMML) is unfavorable and the optimal therapy remains uncertain. Currently, allogeneic stem cell transplantation is the only known curative therapeutic option. However, the data available are limited and restricted to small retrospective series. There is even less information on the use of donor lymphocyte infusions (DLI) for this disease. We reviewed our experience of allogeneic stem cell transplantation and DLI for adults with CMML. Seventeen consecutive adults underwent allogeneic stem cell transplantation from related (n=14) or unrelated (n=3) donors. Median age was 50 years (range 26-60). Seven patients (41%) demonstrated relapse or persistent disease at a median of 6 months (range 3-55.5). Five patients underwent DLI for morphologic relapse and one for mixed donor chimerism. Two patients achieved durable complete remissions of 15 months each. The overall transplant-related mortality was 41% (n=7). With a median follow-up of 34.5 months, three patients (18%) currently remain alive and in continuous CR. The current study demonstrates a graft-versus-leukemia effect in CMML, both for allogeneic stem cell transplantation and for DLI. Nevertheless, consistent with reported experience of others, overall outcomes remain less than optimal and unpredictable.

Risk-adjusted manipulation of melphalan dose before stem cell transplantation in patients with amyloidosis is associated with a lower response rate

High-dose chemotherapy and autologous stem cell transplantation are used increasingly to treat patients with light-chain-related amyloidosis (AL). Treatment-related mortality is approximately 15%. To enable more patients to undergo stem cell transplantation, a risk-adapted strategy has been developed to treat with lower chemotherapy doses those patients who are at excessive risk. It is unclear whether reducing the chemotherapy dose in patients at excessive risk of treatment toxicity reduces the overall response. We retrospectively reviewed 171 AL patients who underwent conditioning chemotherapy with stem cell transplantation. The patients comprised two groups: those receiving standard high-dose melphalan and those receiving intermediate-dose melphalan. Responses were categorized as hematologic response, which used criteria for myeloma response. The two groups showed statistically significant differences; the overall response rates were 75% in the high-dose group and 53% in the intermediate-dose group although treatment-related mortality was the same in both groups. Reducing the melphalan dose appeared to render more AL patients eligible for stem cell transplantation but sacrificed an element of response. Methods are needed to reduce treatment-related toxicity so that more patients can receive full-dose conditioning chemotherapy.

A phase I study of 153Sm-EDTMP with fixed high-dose melphalan as a peripheral blood stem cell conditioning regimen in patients with multiple myeloma

Despite response rates of 30% after high-dose chemotherapy with autologous hematopoietic stem cell transplant, patients with multiple myeloma are not cured. 153Samarium ethylenediaminetetramethylenephosphonate (153Sm-EDTMP; Quadramet) is a short-range, beta-emitting therapeutic radiopharmaceutical with avid skeletal uptake. In total, 12 patients were treated with escalating doses of 153Sm-EDTMP (N=3/group; 6, 12, 19.8, and 30 mCi/kg) and a fixed dose of melphalan (200 mg/m(2)). No dose limiting toxicity was seen. To better standardize the marrow compartment radiation dose, the study was modified such that an additional six patients were treated at a targeted absorbed radiation dose to the red marrow of 40 Gy based on a trace labeled infusion 1 week prior to the therapy. Despite rapid elimination of unbound radiopharmaceutical via kidneys and bladder, no episodes of nephrotoxicity, hemorrhagic cystitis, or delayed radiation nephritis were observed with a median follow-up of 31 months (range 8.5-44). Median times to ANC>0.5 and platelet >20 x 10(6)/l were 12 and 11 days, respectively, with no graft failures. Overall response rate was 94% including seven very good partial responses and five complete responses. Addition of 153Sm EDTMP to melphalan conditioning appears to be safe, well-tolerated and worthy of further study.

Infused peripheral blood autograft absolute lymphocyte count correlates with day 15 absolute lymphocyte count and clinical outcome after autologous peripheral hematopoietic stem cell transplantation in non-Hodgkin's lymphoma

Absolute lymphocyte count at day 15 (ALC-15) after autologous peripheral blood hematopoietic stem cell transplantation (APHSCT) is an independent prognostic factor for survival in non-Hodgkin's lymphoma (NHL). Factors affecting ALC-15 remain unknown. We hypothesized that dose of infused autograft lymphocytes (A-ALC) directly impacts upon ALC-15. A total of 190 consecutive NHL patients received A-ALC between 1993 and 2001. The primary end point was correlation between A-ALC and ALC-15. A strong correlation was identified (r=0.71). A higher A-ALC was infused into patients achieving an ALC-15 > or =500/microl vs ALC-15 <500/microl (median of 0.68 x 10(9)/kg (0.04-2.21 x 10(9)/kg), vs 0.34 x 10(9)/kg (0.04-1.42 x 10(9)/kg), P<0.0001). The median follow-up for all patients was 36 months (maximum of 109 months). The A-ALC threshold was determined at 0.5 x 10(9)/kg. The median overall survival (OS) and progression-free survival (PFS) times were longer in patients who received an A-ALC >/=0.5 x 10(9)/kg vs A-ALC <0.5 x 10(9)/kg (76 vs 17 months, P<0.0001; 49 vs 10 months, P<0.0001, respectively). Multivariate analysis demonstrated A-ALC to be an independent prognostic indicator for OS and PFS. These data support our hypothesis that ALC-15 and survival are dependent upon the dose of infused A-ALC in NHL.