Positron emission tomography derived metrics in relapsed or refractory large B-cell lymphoma with residual disease before autologous stem cell transplant

Autologous Stem Cell Transplant in Fit Patients With Late Relapsed Diffuse Large B-Cell Lymphoma That Responded to Salvage Chemotherapy

The standard of care (SOC) for fit patients with relapsed diffuse large B-cell lymphoma (DLBCL) ≥12 months after completing frontline therapy is salvage chemotherapy (ST) followed by autologous stem cell transplant (ASCT). However, this strategy may not be optimal for patients with certain clinical characteristics. We retrospectively studied 151 patients with DLBCL that relapsed ≥12 months after R-CHOP or R-CHOP-like frontline therapy who underwent ST and ASCT at Mayo Clinic between July 2000 and December 2017 or the University of Iowa between April 2003 and April 2020. Clinical characteristics, treatment information, and outcome data were abstracted. Progression-free survival (PFS) and overall survival (OS) from the time of ASCT were analyzed using the Kaplan-Meier method. The median time from frontline therapy completion to 1st relapse was 26.9 months. The median line of ST was 1 (range 1-3), and 17 (11%) patients required >1 line of ST. Best response before ASCT was partial response (PR) in 60 (40%) and complete response (CR) in 91 (60%) patients. The median age at ASCT was 64 yr (range 19-78), and 36 (24%) patients were of ≥70 yr. The median follow-up after ASCT was 87.3 months. The median PFS and OS were 54.5 and 88.9 months, respectively. There was no significant difference in PFS and OS based on the age at ASCT (including patients aged ≥70-78 yr), sex, transplant era, time to relapse, LDH, extranodal site involvement, and central nervous system/nerve involvement at relapse. However, patients with advanced-stage relapse had inferior PFS than those with early-stage relapse (median 45.3 versus 124.7 months, P = .045). Patients who required > 1 line of ST, compared to those requiring 1 line, had significantly inferior PFS (median 6.1 versus 61.4 months, P < .0001) and OS (17.8 versus 111.7 months, P = .0004). There was no statistically significant difference in survival in patients who achieved PR versus CR, though numerically inferior in the former, with median PFS of 38.9 versus 59.3 months (P = .23) and median OS of 78.3 versus 111.7 months (P = .62). Patients achieving CR after 1 line of ST had excellent post-ASCT outcomes, with median PFS of 63.7 months. In conclusion, survival after ASCT was unfavorable in patients with late relapsed DLBCL (≥12 months) who required more than 1 line of ST to achieve PR or CR, and such patients should be treated with alternative therapies. Conversely, survival was favorable in patients who required only 1 line of ST, supporting the current clinical practice of ASCT consolidation in these patients. Moreover, outcomes were favorable in patients aged ≥70 to 78 yr at ASCT, similar to younger patients, highlighting the safety and feasibility of this approach in such patients.

Autologous stem cell transplant in fit patients with refractory or early relapsed diffuse large B-cell lymphoma that responded to salvage chemotherapy

Chimeric antigen receptor T-cell therapy is the new standard of care in fit patients with refractory or early relapsed diffuse large B-cell lymphoma (DLBCL). However, there may still be a role for salvage chemotherapy (ST) and autologous stem cell transplant (ASCT) in certain circumstances (e.g., lack of resources for chimeric antigen receptor T-cell therapy, chemosensitive relapses). We retrospectively studied 230 patients with refractory or early relapsed DLBCL who underwent ST and ASCT. The median line of ST was one (range, 1-3). Best response before ASCT was complete response in 106 (46%) and partial response in 124 (54%) patients. The median follow-up after ASCT was 89.4 months. The median progression-free (PFS) and overall survival (OS) were 16.1 and 43.3 months, respectively. Patients relapsing between 6 to 12 months after frontline therapy had a numerically better median PFS (29.6 months) and OS (88.5 months). Patients who required one line of ST, compared to those requiring more than one line, had a better median PFS (37.9 vs. 3.9 months; P=0.0005) and OS (68.3 vs. 12.0 months; P=0.0005). Patients who achieved complete response had a better median PFS (71.1 vs. 6.3 months; P<0.0001) and OS (110.3 vs. 18.9 months; P<0.0001) than those in partial response. Patients who achieved complete response after one line of ST had the most favorable median PFS (88.5 months) and OS (117.2 months). Post-ASCT survival outcomes of patients with refractory or early relapsed DLBCL appeared reasonable and were particularly favorable in those who required only one line of ST to achieve complete response before ASCT, highlighting the role of this procedure in select patients with chemosensitive disease.

Are dynamic or fixed FDG-PET measures of disease of greater prognostic value in patients with relapsed/refractory diffuse large B-cell lymphoma undergoing autologous haematopoietic stem cell transplantation?

Positron emission tomography (PET) response assessment using the Deauville score has prognostic utility in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) undergoing autologous stem-cell transplantation (ASCT). Improved predictive methods are required to identify patients with poor outcomes who may be better considered for other salvage options. We investigated the prognostic value of mean tumour volume (MTV) and maximum standardised uptake value (SUVmax) at pre-salvage and pre-ASCT time-points, and the quantitative changes between scans (∆MTV and ∆SUVmax). One hundred and twenty-five patients with R/R DLBCL underwent salvage immunochemotherapy and ASCT: 80 patients had pre-salvage PET and 90 had pre-ASCT PET available. With a median follow-up of 5.6 years, 5-year progression-free survival (PFS) and overall survival (OS) were 52% and 65%, respectively. For patients with PET-positive residual disease after salvage therapy, pre-ASCT MTV was a significant negative prognosticator for PFS (HR 1.19 per 100 ml, p < 0.001) and OS (HR 1.78 per 100 ml, p < 0.001). Similarly, pre-ASCT SUVmax was negatively associated with PFS (HR 1.08, p < 0.001) and OS (HR 1.08, p < 0.001). Notably, pre-salvage MTV and SUVmax and ∆MTV and ∆SUVmax were not associated with PFS or OS. In conclusion, pre-ASCT MTV and SUVmax appear to be of greater predictive value than the degree of response. Potential application may exist for PET-directed management of R/R DLBCL patients.

The role of additional chemotherapy prior to autologous HCT in patients with relapse/refractory DLBCL in partial remission-A retrospective multicenter study

OBJECTIVES

To evaluate the role of additional chemotherapy before autologous hematopoietic cell transplantation (HCT) in patients with relapse/refractory diffuse large B-cell lymphoma (DLBCL) who achieve partial remission following first salvage therapy.

METHODS

We conducted a multicenter retrospective study of all adult patients with DLBCL who underwent HCT between 2008 and 2020 and achieved partial response (PR) after the first salvage and were either referred directly to HCT (n = 47) or received additional salvage therapy before HCT (n = 22).

RESULTS

Post-HCT CR rate and progression-free survival were comparable between the two groups (66% vs. 68%, p = .86 and median not reached vs. 10.2 months [95% confidence interval, CI 7.1-12.3], p = .27, respectively). Median overall survival (OS) and estimated 3-year OS favored patients who were directly referred to HCT (105.8 [95% CI 63-148] months vs. 14.5 [95% CI 0-44] months, p = .035, and 65% [95% CI 51%-75%] vs. 40% [95% CI 21%-53%], p = .035, respectively). In Cox regression model, while International Prognostic Index and primary refractory versus relapse disease did not impact OS, allocation to a second salvage regimen and older age were both associated with inferior survival (hazard ratio [HR] = 2.57 95% CI 1.1-5.8, p = .023 and HR = 1.04 95% CI 0.99-1.2, p = .064, respectively).

CONCLUSIONS

Referring patients with chemotherapy-sensitive disease in PR directly to HCT is associated with better OS compared to those receiving additional lines of treatment.

Do we have to exclude all relapsed diffuse large B-cell lymphoma patients not in complete remission from autologous stem cell transplant?

Treatment of relapsed/refractory diffuse large B-cell lymphoma remains a challenge with the advent of chimaeric antigen receptor CAR-T cell treatment. Whether or not eligibility criteria should replace the standard autologous transplantation is debated. By using PET-derived parameters, the report of Cherng and colleagues suggests that patients with positive residual mass can have a five-year survival of 54% with standard treatment.