Back to Authors

Nowakowski, Grzegorz S.

https://orcid.org/0000-0002-6955-9393

Mayo Clinic

Mayo Clinic

Citations 513

Characteristics and outcome of patients with MYD88 wild-type Waldenström Macroglobulinemia.
Zanwar, Saurabh , Abeykoon, Jithma P. , Ansell, Stephen M. , Thompson, Carrie A. , King, Rebecca L. , He, Rong , Benanni, Nora N, Nowakowski, Grzegorz S. , Warsame, Rahma , Kyle, Robert A. , Kumar, Shaji , Kapoor, Prashant , Paludo, Jonas , Gertz, Morie A. , Gonsalves, Wilson I. , Muchtar, Eli

Journal of Clinical Oncology | May 25, 2020 | Volume: 38 | Issue: 15_suppl | Pages: 8550-8550

10.1200/jco.2020.38.15_suppl.8550 Get It

8550 Background: Waldenström Macroglobulinemia (WM) is a rare lymphoplasmacytic malignancy characterized by the presence of a recurrent point mutation in the MYD88 gene (MYD88L265P) in 80-95% of cases. Patients with MYD88WT genotype comprise a small subset that responds poorly to ibrutinib and other Bruton tyrosine kinase inhibitors. We examined the characteristics and outcome of WM patients with MYD88WT genotype predominantly treated with non-BTK inhibitor based therapies. Methods: Patients with a diagnosis of WM seen at Mayo Clinic, Rochester, between 1996 and 2018 were included. Their characteristics and outcomes were assessed from the time of active disease. Marrow MYD88 genotyping was assessed with an allele specific PCR assay (analytic sensitivity 1%). Categorical and continuous variables were compared using Chi square and Wilcoxon tests, respectively. Time-to-event analyses were performed using Kaplan Meier test. Results: Of 986 patients with active WM, MYD88 genotype data were available in 331 (34 %) patients; 72 (22%) and 260 (78%) patients harbored MYD88WT and MYD88L265P genotypes, respectively. The median follow-up was 5.8 years (95% CI: 5.0-6.5 years) from active WM; 6 years MYD88WT vs 5.4 years for MYD88L265P cohort. Median age was 63 years and 66 years in the MYD88WT and MYD88L265P cohorts, respectively (p = 0.07) with 46% and 53% patients being ≥65 years of age, respectively (p = 0.36). Pre-treatment marrow lymphoplasmacytic (LPL) infiltrate (median 40% for MYD88WT vs 60% for MYD88L265P; p = 0.001) and beta-2 microglobulin (median 3 µg/mL for MYD88WT vs 3.9 µg/mL for MYD88L265P; p = 0.02) were lower in the MYD88WT compared to the MYD88L265P cohort; other laboratory parameters at active disease were comparable. Per IPSSWM prognostic criteria, MYD88WT had fewer patients in the high risk group (18% for MYD88WT vs 42% MYD88L265P; p = 0.03). Patients with MYD88WT had higher likelihood of histological transformation [18% for MYD88WT vs 4% for MYD88L265P; odds ratio 5.8 (95% CI: 2.5-13.5; p < 0.0001)]. Among patients with treatment data available, only 35 (11%) patients received ibrutinib. The 5-year overall survival (OS) from active disease was comparable (85% in MYD88WT vs 82% in MYD88L265P cohort; p = 0.7). Conclusions: MYD88WT genotype in WM is associated with lower marrow LPL infiltration, lower likelihood of high-risk IPSSWM categorization and a higher likelihood of histological transformation in comparison to MYD88L265P mutant subpopulation. MYD88 genotype does not affect the OS from active disease in predominantly non-BTK inhibitor treated patients.
Prognostic relevance of CD4+ T-cells in the microenvironment of newly diagnosed follicular lymphoma (FL) patients is independent of the tumor gene expression profile.
Feldman, Andew L., Huet, Sarah , Tesson, Bruno , Novak, Anne J. , Nowakowski, Grzegorz S. , Ansell, Stephen M. , Mondello, Patrizia , Famà, Angelo , Larson, Melissa C. , Yang, Zhi-Zhang , Villasboas, José C. , Slager, Susan L. , Link, Brian K. , Syrbu, Sergei , Habermann, Thomas M. , Witzig, Thomas E. , Salles, Gilles , Cerhan, James R.

Journal of Clinical Oncology | May 25, 2020 | Volume: 38 | Issue: 15_suppl | Pages: 8052-8052

10.1200/jco.2020.38.15_suppl.8052 Get It

8052 Background: A significant proportion of patients with FL experience an early relapse and a subsequent poor outcome. While several prognostic indices have been developed, none were designed to predict early failure. Recently, we established that lack of intrafollicular CD4+ T-cell expression predicted risk of early failure, and integrating this microenvironment biomarker with the Follicular Lymphoma International Prognostic Index, termed BioFLIPI, further improved identification of FL patients at risk of early failure ( Blood 2019;134(suppl1):121). However, the microenvironment may be influenced by the genetic composition of tumor. We investigated whether the CD4 biomarker and BioFLIPI were impacted by genetic features of the tumor as assessed by a 23-gene expression prognostic score ( Lancet Oncol 2018;19:549-61). Methods: Of the 186 cases with FL grade 1-3A treated with immunochemotherapy (IC) in our prior study, 152 had digital expression quantification of 23 selected genes (23-GEP score), which used RNA from formalin-fixed, paraffin-embedded samples. Event-free survival (EFS) was defined as time from diagnosis to progression, relapse, retreatment, or death. Early failure was defined as failing to achieve EFS at 24 months. Risk of early failure was estimated using odds ratios (ORs) and 95% confidence intervals from logistic regression models. We also used Cox regression to assess associations with continuous EFS and overall survival (OS). Results: 28% of patients failed to achieve EFS24. Lack of CD4+ intrafollicular expression (38% of patients, OR = 2.33, p = 0.024) and high risk 23-GEP score (26% of patients, OR = 3.52, p = 0.001) each predicted early failure, and in a multivariable model that included FLIPI, both CD4+ (OR = 2.26, p = 0.046) and 23-GEP score (OR = 2.26, p = 0.0.057) remained predictors. Similarly, BioFLIPI modeled as a continuous score (1-4, OR per one point increase = 2.31, p < 0.001) predicted early failure, and the association remained (OR = 2.14, p < 0.001) when the high risk 23-GEP score (OR = 2.79, p = 0.013) was included in the model. When stratified on 23-GEP score, BioFLIPI was a stronger predictor of early failure in low risk (74%, OR = 2.51, p = 0.002) relative to high risk (26%, OR = 1.55, p = 0.27) patients. Similar patterns were observed for EFS and OS. Conclusions: CD4+ T-cell infiltrate and tumor gene expression appear to be independently predictive of early failure in newly diagnosed FL patients treated with IC. Future studies should integrate and validate these measures.
MAGNIFY phase IIIb interim analysis of induction R2 followed by maintenance in relapsed/refractory indolent NHL.
Andorsky, David , Coleman, Morton , Yacoub, Abdulraheem , Melear, Jason M., Fanning, Suzanne, Lansigan, Frederick , Reynolds, Chris, Nowakowski, Grzegorz S. , Gharibo, Mecide, Ahn, Jung Ryun, Ju, Li, Rummel, Mathias , Sharman, Jeff P. , Investigators, on behalf of the MAGNIFY Trial, Lansigan, Frederick , Kolibaba, Kathryn S. , Investigators, on behalf of the MAGNIFY Trial

Journal of Clinical Oncology | May 25, 2020 | Volume: 38 | Issue: 15_suppl | Pages: 8046-8046

10.1200/jco.2020.38.15_suppl.8046 Get It

8046 Background: Patients (pts) with relapsed iNHL have limited standard treatment options. The immunomodulatory agent lenalidomide shows enhanced activity with rituximab (ie, R2), which recently reported 39.4-mo median PFS in R/R iNHL pts (AUGMENT; J Clin Oncol. 2019;37:1188). Methods: MAGNIFY is a multicenter, phase IIIb trial in pts with R/R FL gr1-3a, MZL, or MCL (NCT01996865) exploring optimal lenalidomide duration. Lenalidomide 20 mg/d, d1-21/28 + rituximab 375 mg/m2/wk c1 and then q8wk c3+ (R2) are given for 12c followed by 1:1 randomization in pts with SD, PR, or CR to R2 vs rituximab maintenance for 18 mo. Data presented here focus on induction R2 in efficacy-evaluable FL and MZL pts (MCL not included) receiving ≥ 1 treatment with baseline/post-baseline assessments to analyze the primary end point of ORR by 1999 IWG criteria. Results: As of June 16, 2019, 393 pts (81% FL gr1-3a; 19% MZL) were enrolled with a median follow up of 23.7 mo (range, 0.6-57.8) for censored pts (n = 335). Median age was 66 y (range, 35-91), 83% had stage III/IV disease, with a median of 2 prior therapies (95% prior rituximab-containing). ORR was 69% with 40% CR/CRu (Table). Median DOR was 39.0 mo, and median PFS was 40.1 mo. 199 pts (51%) have completed 12c of R2, and 188 (48%) have been randomized and entered maintenance. 139 pts (35%) prematurely discontinued both lenalidomide and rituximab, primarily due to AEs (n = 52, 13%) or PD (n = 45, 11%). Most common all-grade AEs were 48% fatigue, 43% neutropenia, 36% diarrhea, 31% nausea, and 30% constipation. Grade 3/4 AE neutropenia was 36% (9 pts [2%] had febrile neutropenia); all other grade 3/4 AEs occurred in < 7% of pts. Conclusions: R2 is active with a tolerable safety profile in pts with R/R FL and MZL, including rituximab-refractory, double-refractory, and early relapse pts. Clinical trial information: NCT01996865 . [Table: see text]
RE-MIND study: A propensity score-based 1:1 matched comparison of tafasitamab + lenalidomide (L-MIND) versus lenalidomide monotherapy (real-world data) in transplant-ineligible patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL).
Nowakowski, Grzegorz S. , Frezzato, Maurizio, Barbui, Anna Maria , Castellino, Claudia, Meli, Erika, Fowler, Nathan , Feinberg, Bruce A. , Tillmanns, Sascha, Parche, Stephan, Fingerle-Rowson, Guenter, Winderlich, Mark, Ambarkhane, Sumeet, Rodgers, Thomas D. , Marino, Dario , Salles, Gilles , Zinzani, Pier Luigi

Journal of Clinical Oncology | May 25, 2020 | Volume: 38 | Issue: 15_suppl | Pages: 8020-8020

10.1200/jco.2020.38.15_suppl.8020 Get It

8020 Background: Patients with R/R DLBCL ineligible for autologous stem cell transplant (ASCT) have a poor prognosis. In these patients, tafasitamab (anti-CD19 antibody) plus lenalidomide (LEN) has shown encouraging results in the open-label, single-arm, phase II L-MIND study (n = 81; NCT02399085). To evaluate the contribution of tafasitamab to the activity of this doublet, we conducted a global, real-world study of patients treated with LEN monotherapy (RE-MIND; NCT04150328). Here we present the primary analysis of a 1:1 patient-level matched comparison between the L-MIND and RE-MIND cohorts. Methods: Patients treated with LEN monotherapy for R/R DLBCL were enrolled in the observational, retrospective RE-MIND cohort. As in L-MIND, patients had 1–3 prior systemic therapies, including ≥1 CD20-targeting regimen; were aged ≥18 years; and were not eligible for ASCT. A 1:1 estimated propensity score (ePS) matching methodology ensured balancing of nine pre-specified baseline covariates. The primary analysis set, Matched Analysis Set 25 (MAS25), included patients who received a LEN starting dose of 25 mg/day. The primary endpoint was investigator-assessed best objective response rate (ORR). Key secondary endpoints included overall survival (OS) and complete response (CR) rate. Results: 490 patients were enrolled in RE-MIND across 58 centers in the US and Europe, of which 140 fulfilled the ePS matching criteria. The MAS25 included 76 patients each from the two cohorts. Baseline characteristics between cohorts were comparable. The primary endpoint was met with a significantly better ORR of 67.1% (95% CI: 55.4–77.5) for the L-MIND cohort versus 34.2% (95% CI: 23.7–46.0) for the RE-MIND cohort (odds ratio 3.89; 95% CI: 1.90–8.14; p < 0.0001). The CR rate was 39.5% (95% CI: 28.4–51.4) in the L-MIND cohort and 13.2% (95% CI: 6.5–22.9) in the RE-MIND cohort. A significant difference in OS favored the L-MIND cohort (HR = 0.499; 95% CI: 0.317–0.785). ORR and CR outcomes in the RE-MIND cohort were similar to the published literature for LEN monotherapy in R/R DLBCL. Conclusions: Significantly better ORR, CR and OS indicate potential synergistic effects of the tafasitamab + LEN combination in ASCT-ineligible R/R DLBCL. ePS-based 1:1 matching allows robust estimation of the treatment effect of tafasitamab when added to LEN. RE-MIND demonstrates the utility of real-world data in interpreting non-randomized trials. Clinical trial information: NCT04150328 .
Quality of life (QOL), financial burden, and perception of care in patients enrolled on clinical trials (CTs).
Allmer, Cristine, Yost, Kathleen J. , Warsame, Rahma , Thanarajasingam, Gita , Nowakowski, Grzegorz S. , Ansell, Stephen M. , Thompson, Carrie A. , Kumar, Shaji , Sidana, Surbhi , Larson, Melissa C. , Dueck, Amylou C. , Cerhan, James R. , Paludo, Jonas , Rajkumar, S. Vincent , Habermann, Thomas M. , Lin, Yi , Gertz, Morie A. , Witzig, Thomas E. , Dispenzieri, Angela , Gonsalves, Wilson I.

Journal of Clinical Oncology | May 25, 2020 | Volume: 38 | Issue: 15_suppl | Pages: e19112-e19112

10.1200/jco.2020.38.15_suppl.e19112 Get It

e19112 Background: We sought to study the longitudinal QOL, financial burden and perception of care (PoC) in patients with multiple myeloma (MM) or lymphoma (LYM) enrolled on CTs vs. those receiving standard care (Non-CT). Methods: QOL was evaluated using the FACT-G questionnaire (baseline, 1, 2, 3, 6 & 12 months). Financial burden was evaluated using 10 questions adapted from the MEPS survey and PoC was evaluated using 6 questions adapted from the CAHPS survey (baseline, 3, 6 & 12 months). Results: 35 (28%) of 123 enrolled patients were treated on CTs. Demographics, QOL and financial burden are shown in the Table. Baseline QOL scores were similar in CT vs non-CT groups. Age, gender and self-reported performance status were significantly associated with baseline QOL, while lines of therapy & cancer type were not. There were no significant differences in change in QOL vs. baseline in patients treated on CTs vs. non-CTs at 1, 2, 3, 6 and 12 months from baseline, including the total FACT-G score and the subdomains of functional, physical, emotional and social well-being. Within each group, there was a decline in QOL over the first 3 months, specifically physical WB, which gradually returned to baseline. Baseline answers to financial burden questions were similar, except patients on CTs reported less need for taking extended time-off from work (22% vs. 46%, p = 0.02). The only statistically significant difference in individual Qs over 1 year was ‘worry about having to pay large medical bills’ at the 6-month timepoint (CT: 0%, non-CT: 52%, p = 0.01). Using a composite score from 4 MEPS questions, financial burden over time was lower in the CT group, though the differences were not statistically significant. There were no significant differences in PoC at baseline, 3, 6 and 12 months in the two groups based on answers to each of the six questions adapted from the CAHPS survey. Conclusions: Over 1 year, patients on CTs experienced a similar QOL and perceived their care to be similar as non-CT patients. Financial burden was lower in the CT group, though differences were not statistically significant. [Table: see text]
Impact of organ function based standard exclusion criteria in diffuse large b-cell lymphoma (DLBCL) patients: Who gets left behind?
Khurana, Arushi , Mwangi, Raphael , Nowakowski, Grzegorz S. , Ansell, Stephen M. , LaPlant, Betsy, Habermann, Thomas M. , Link, Brian K. , Cerhan, James R. , Maurer, Matthew J. , Witzig, Thomas E.

Journal of Clinical Oncology | May 25, 2020 | Volume: 38 | Issue: 15_suppl | Pages: e14100-e14100

10.1200/jco.2020.38.15_suppl.e14100 Get It

e14100 Background: Only 3-5% of adult cancer patients in the US enroll in clinical trials. Patients with organ dysfunction are often excluded from clinical trials, regardless of specific drug metabolism or relative function of the organ. The ASCO and the US FDA recommend modernizing criteria related to baseline organ function and comorbidities. In hematological malignancies, often the disease itself is the reason for organ function derangement. In order to better inform clinical trial eligibility and improve participation in the future, we evaluated the impact of baseline organ function on the potential eligibility for clinical trial enrollment for real world patients with newly diagnosed DLBCL. Methods: Consecutive, newly diagnosed lymphoma patients were offered enrollment from 2002-2015 into the Molecular Epidemiology Resource (MER) of the University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence. This analysis is based on 1270 DLBCL patients receiving immunochemotherapy. Baseline organ function parameters were identified from the exclusion criteria for hemoglobin, absolute neutrophil count (ANC), platelet count, creatinine, and bilirubin reported in recent frontline trials in DLBCL (Table). Abstracted clinical labs from the MER were used to determine the percent of patients that would be excluded based on the criteria. Results: We determined that 11-23% of MER DLBCL patients receiving standard of care frontline therapy would have been excluded in the various trials utilizing baseline organ function alone (Table). Hemoglobin and renal function had the greatest impact on exclusion. Conclusions: Current national and international (phase II and III) trials are excluding up to 23% of patients from clinical trial participation based on organ function alone in DLBCL. These data will be useful in future clinical trial development to meet ASCO recommendations to increase trial accrual, while balancing the drug toxicities and patient safety. An online tool was developed based on these results to aid future trial development. [Table: see text]
Transforming the site feasibility assessment process for oncology clinical trials.
Kurbegov, Dax, Nowakowski, Grzegorz S. , Kim, Edward S. , Hurley, Patricia A., Waterhouse, David

Journal of Clinical Oncology | May 25, 2020 | Volume: 38 | Issue: 15_suppl | Pages: e14092-e14092

10.1200/jco.2020.38.15_suppl.e14092 Get It

e14092 Background: Current methods to assess trial sites for clinical trial participation are onerous, with unnecessary redundancies and no-value steps that impact research site resources and clinical trial participation. This project sought stakeholder feedback on recommendations to transform industry sponsor and contract research organization (CRO) processes for evaluating sites for trials. Methods: An ASCO task force developed recommendations to improve the feasibility assessment process and standardize and centralize questions and forms. A survey was conducted with sites, industry trial sponsors, and CROs to obtain feedback and assess buy-in for the recommendations. Results: Respondents were from 28 oncology research sites (19 academic, 9 community-based), 8 sponsors, and 4 CROs. All stakeholders agreed that the current process is burdensome (93% sites, 90% sponsors, 100% CROs), standardization will improve the process (86% sites, 87% sponsors, 75% CROs). All agreed a centralized portal will reduce burdens (93% sites, 100% sponsors, 75% CROs) and expedite trial start-up (89% sites, 100% sponsors, 75% CROs). Site certification was a viable option for sites (86%) and CROs (75%), but less so for sponsors (57%). Most respondents preferred a two-tier model: 1) a short site questionnaire followed by a pre-study visit for new interactions, and 2) only a pre-study site visit or a teleconference if there is an existing relationship. The greatest benefits were time savings, expedited start-up, reduction in personnel resources, and cost savings. The greatest barriers to adoption were buy-in and alignment from sponsors/CROs and insufficient information about site or protocol. Top predictors of a site’s success on a trial were physician engagement, available patients, and site experience. Conclusions: Site feasibility assessments are important for all stakeholders to establish trial suitability. However, current methods impose tremendous burdens on site resources (reported by authors elsewhere). While this sample is limited, the proposed process and standardization changes show promise to reduce burdens and costs for all stakeholders and expedite patient enrollment onto clinical trials.
Early Impact of COVID-19 on the Conduct of Oncology Clinical Trials and Long-Term Opportunities for Transformation: Findings From an American Society of Clinical Oncology Survey
Hurley, Patricia A. , Kim, Edward S. , Nowakowski, Grzegorz S. , Schilsky, Richard L. , Hurley, Patricia , Waterhouse, David , Harvey, R. Donald , Levit, Laura A. , Klepin, Heidi D. , Mileham, Kathryn Finch , Schenkel, Caroline , Davis, Courtney , Bruinooge, Suanna S.

JCO Oncology Practice | May 12, 2020 | Volume: 16 | Issue: 7 | Pages: 417-421

10.1200/op.20.00275 Get It

The coronavirus disease 2019 (COVID-19) pandemic has disrupted all aspects of clinical care, including cancer clinical trials. In March 2020, ASCO launched a survey of clinical programs represented on its Cancer Research Committee and Research Community Forum Steering Group and taskforces to learn about the types of changes and challenges that clinical trial programs were experiencing early in the pandemic. There were 32 survey respondents; 14 represented academic programs, and 18 represented community-based programs. Respondents indicated that COVID-19 is leading programs to halt or prioritize screening and/or enrollment for certain clinical trials and cease research-only visits. Most reported conducting remote patient care where possible and remote visits and monitoring with sponsors and/or contract research organizations (CROs); respondents viewed this shift positively. Numerous challenges with conducting clinical trials were reported, including enrollment and protocol adherence difficulties with decreased patient visits, staffing constraints, and limited availability of ancillary services. Interactions with sponsors and CROs about modifying trial procedures were also challenging. The changes in clinical trial procedures identified by the survey could serve as strategies for other programs attempting to maintain their clinical trial portfolios during the COVID-19 pandemic. Additionally, many of the adaptations to trials made during the pandemic provide a long-term opportunity to improve and transform the clinical trial system. Specific improvements could be expanded use of more pragmatic or streamlined trial designs, fewer clinical trial–related patient visits, and minimized sponsor and CRO visits to trial programs.
Cyclophosphamide Mobilization Does Not Improve Outcome in Patients Transplanted for Multiple Myeloma.
Nowakowski, Grzegorz S. , Lacy, Martha Q. , Hayman, Suzanne R. , Litzow, Mark R. , Gastineau, Dennis A., Dingli, David , Dispenzieri, Angela , Gastineau, Dennis A. , Gertz, Morie A.

Blood | April 19, 2020 | Volume: 106 | Issue: 11 | Pages: 1165-1165

10.1182/blood.v106.11.1165.1165 Get It

Abstract Patients with multiple myeloma (MM) who undergo high dose therapy (HDT) followed by autologous stem cell transplantation (ASCT) and achieve a complete response (CR) have a superior overall survival (OS) and time to progression (TTP). Thus achieving a CR is an important goal of therapy with ASCT. Cyclophosphamide has significant activity against MM and is often used in high doses prior to ASCT for mobilization of hematopoietic stem cells. We hypothesized that high dose cyclophosphamide (HDC) may further improve CR rates in patients undergoing ASCT. Methods: The Mayo Clinic myeloma transplant database was searched for patients without circulating myeloma cells who had stem cell mobilization with hematopoietic growth factor (HGF) alone or HDC followed by HGF. Relevant demographic, clinical and laboratory characteristics were abstracted. The main outcome studied was the impact of HDC on CR rates and time to progression (TTP) to myeloma. Results: We identified 201 patients without circulating myeloma cells. Of these, 127 were mobilized with HDC and HGF and 74 with HGF alone. The two cohorts were similar with respect to age, gender, isotype, B2M, plasma cell labeling index, cytogenetics, conditioning regimen, disease status at time of transplant with no statistically significant differences between the two cohorts. CR rates were 37.4 and 41.3% (p=0.6115) for patients mobilized with HDC/HGF and HGF respectively. TTP was 19.9 and 17.6 months (p=0.6039) respectively. The median number of collection sessions for patients mobilized with HDC/HGF was 2 (1–10) and those mobilized with HGF was 4 (1–10) (p&lt;0.0001). In a multivariate analysis for TTP, cytogenetics and achieving a CR were the only independent variables (p=0.0012 and p&lt;0.0001). Conclusion: HDC for autologous hematopoietic stem cell collection reduces the number of collections necessary to support HDT/ASCT. However, HDC does not increase CR rates or improve on TTP for patients undergoing ASCT.
Proteomic Analysis of Chronic Lymphocytic Leukemia Cells Identifies Vimentin as a Novel Prognostic Factor for Aggressive Disease.
Nowakowski, Grzegorz S. , Bone, Nancy D., Morice, William G. , Barnidge, David R. , Jelinek, Diane F., Tschumper, Renee C. , Rassenti, Laura Z., Lee, Yean Kee , Morice, William George , Shanafelt, Tait D. , Zent, Clive S. , Kipps, Thomas J. , Kay, Neil E.

Blood | April 19, 2020 | Volume: 106 | Issue: 11 | Pages: 707-707

10.1182/blood.v106.11.707.707 Get It

Abstract The IgVH mutation status is an independent predictor of time to treatment and survival in CLL. However, the biological basis of this difference is unknown. Clinical use of the IgVH mutation status as a prognostic marker is limited due to the technical difficulties of assessing this feature. As such, we probed for differences in protein expression by CLL cells with unmutated (UM) vs mutated (M) IgVH using phage peptide display libraries (PDPL). Methods: PDPL consists of phages engineered to express random peptides (7-mer) on the coat protein. From approximately 2x1011 phages displaying all possible permutations of 7-mer peptide, we selected phages binding to UM cells by incubation with 106 UM cells and elution of bound phages. Then, from numerous phages initially binding to UM cells, we subtracted phages binding to M cells by multiple incubations with M cells (106). Thus, the phages that bound only to UM cells were selected. The procedure was repeated multiple times to increase selection specificity. The peptide sequences displayed by selected phages were evaluated. We identified phage targets on UM cells by immunoprecipitation (IP) of CLL protein with specific phage and by sequencing of precipitated protein. The expression of target protein in CLL cells was confirmed by immunobloting and flow cytometry. Results: Sequencing of phages from the 3rd round of selection (UM v. M) revealed several peptides, with the most predominant being FPSAHFL. IP identified the cellular target for FPSAHFL as vimentin, an intermediate filament protein involved in cell motility and activation. The level of vimentin expressed by CLL cells varied between patient samples (n=15). UM CLL cases were found to express higher levels of vimentin (the mean MFI was 1002; SD 381), than cases of M CLL (mean MFI 547; SD 109), p=0.0128. To evaluate the prognostic significance of vimentin, we assessed vimentin expression by flow cytometry in a separate subgroup of 40 CLL patients. Archived cell samples collected between 6/2000 – 6/2001 were used. The median follow up was 81 months (40–233). Vimentin expression (MFI) as a continuous variable was a risk factor for a shortened time to treatment (TTT) with a proportional hazard ratio of 4.152 (95% CI 1.33–15.220, p=0.0317). Using MFI closest to the median (and rounded to 2 decimal places) as a cutoff, we stratified patients in high (n=21) and low (n=19) vimentin expression groups. The median times to treatment (TTT) in patients with high vs low level expression of vimentin were 2.8 and 12.9 years respectively, p=0.0025 (Fig.). Conclusion: Using novel proteomic technology, we found that CLL cells with unmutated IgVH expressed higher levels of vimentin than CLL cells with mutated IgVH. A high-level of vimentin expression defined by flow cytometry appears to be associated with high-risk disease. Validation of these findings could allow for the vimentin level to be used as a surrogate marker for expression of unmutated IgVH in CLL. Figure Figure