3 research outputs found
Recommended from our members
Limited Duration Loncastuximab Tesirine with Rituximab Induces High Complete Metabolic Response Rate in High-Risk Relapsed/Refractory Follicular Lymphoma - a Phase 2 Study
Introduction: There is no standard-of-care for treatment of relapsed/refractory (rel/ref) follicular lymphoma (FL) with worse prognosis in those demonstrating progression of disease within 24 months (POD24) from frontline immunochemotherapy. Loncastuximab tesirine (loncastuximab) is an antibody-drug conjugate comprising a monoclonal antibody directed against CD19 and a DNA cross-linking pyrrolobenzodiazepine. Preclinical data demonstrated synergistic activity between rituximab-induced cytotoxicity and loncastuximab. Here we report pre-specified initial results of a single-institution investigator-initiated study evaluating this combination for the first time in FL (NCT04998669). Methods: Adult patients with rel/ref FL previously treated with ≥1 line of systemic therapy presenting GELF criteria or POD24 at enrollment were eligible.Primary study endpoint was complete response (CR) by week 12 PET/CT based on Lugano 2014 criteria. Bone marrow biopsy was required at screening and repeated at week 12 if initial involvement. The initial 21 weeks of therapy consisted of 4 weekly doses of rituximab i.v. 375mg/m 2 followed by 1 dose every 8 weeks for a total of 5 doses in association with loncastuximab i.v. 0.15mg/kg every 3 weeks for 2 doses followed by 0.075mg/kg every 3 weeks for a total of 7 doses. Patients achieving CR by week 21 PET/CT discontinued loncastuximab and received two more doses of rituximab every 8 weeks. Premedication with dexamethasone 4 mg twice daily for 3 days was required with loncastuximab. No antibiotic or growth factor prophylaxis was mandated by study protocol. Enrollment occurred according to a Simon's minimax two-stage design with a total sample size of 39 patients based upon a projected CR rate ≥50% vs ≤30% (H0), type I error alpha 5%, power 80%. In stage 1, 19 patients enrolled and 7 or more CRs were required to proceed with stage II. In stage II, an additional 20 patients will be enrolled. Based on n=39, a total of ≥17 CRs are required for rejecting the H0. Results: Twenty-six patients have been enrolled from January 2022 to July 2023, 25 evaluable for toxicity (1 patient has not yet initiated treatment) and 21 for response. Median age was 68 years (range 47 to 89). Most were women (n=14; 54%), with advanced-stage (n=20; 77%), high-risk FLIPI score (n=13; 50%), and 12 (46%) demonstrating POD24 after immunochemotherapy. Median lines of prior therapy were 1 (range 1 to 6). R-CHOP was most common first-line therapy (n=14; 54%) followed by bendamustine with rituximab and single-agent rituximab (n=6; 23%; each). Most common grade 1 adverse events (AEs) included alkaline-phosphatase (48%), ALT (44%), AST (36%) elevation; maculo-papular rash (44%), fatigue (28%), thrombocytopenia (28%), photosensitivity (28%), leg edema (24%), and anasarca (20%). Grade 2 AEs were alkaline phosphatase elevation (12%), anasarca (8%) and leg edema (4%) Grade 3 AEs included neutropenia (n=2; 8%), and one case each (4%) of cellulitis and pleural effusion. Neutropenia was the only grade 4 AE in a patient post-CAR T-cell. All toxicities resolved with supportive management and dose delays (n= 4); no treatment-related deaths occurred during study period. CR was observed in 7 of the initial 10 patients meeting pre-specified criteria to proceed to stage II. Among 21 patients evaluable for response, the overall response rate at week 12 was 95.2% [CR rate of 66.7% (n=14), partial response (PR) rate of 28.6% (n=6)]. All CR were maintained and 4 of the 6 PR (2 patient have not yet re-evaluated) improved to CR at week 21 for a best CR rate of 86% (n= 18). Baseline bone marrow involvement by FL resolved in all patients (n=5) at week 12 reassessment. Two patients were removed from the study. One patient due to disease progression on week 12 PET/CT with biopsy-proven diffuse large B-cell lymphoma in a kidney mass and another with cholangiocarcinoma, who achieved CR with respect to known lymphoma involvement. Both lesions were present before study enrollment but radiologically considered FL. All seven patients who completed the study remained in CR after end of treatment for a median follow up of 4.8 months (range 3.2 to 6.7) ( Figure 1). Updated analysis will be presented at the meeting. Conclusion: A limited duration program combining loncastuximab with rituximab in patients with rel/ref FL is well tolerated and highly effective with a metabolic CR rate of 86% including high-risk patients with POD24 and/or high disease burden
Recommended from our members
Distinct Patterns of CD4+ and CD8+ T-Cell Clonal Expansion Enable Broad Clinical Responses to Pembrolizumab + GVD in Patients with Relapsed Hodgkin Lymphoma
Introduction: Classical Hodgkin lymphoma (cHL) is characterized by immune dysregulation, with recurrent amplifications of the 9p24 locus encoding several genes including CD274 (PD-L1), PDCD1LG2 (PD-L2), and JAK2, frequent genetic and epigenetic downregulation of major histocompatibility complex (MHC)-I and (MHC)-II, and a tumor microenvironment (TME) defined by T-cell infiltration and high rates of PD-L1 expression. PD-1 blockade is highly active both as single agent and in combination with chemotherapeutic agents in relapsed/refractory (RR) cHL. However, the mechanism by which PD-1 blockade promotes clinical responses in combination with chemotherapy, and whether the mechanism of action varies based on tumor or TME-specific expression of either MHC or PD-L1 remains unclear. Methods: We previously conducted a phase II study in patients with relapsed or refractory cHL evaluating pembrolizumab in combination with gemcitabine, vinorelbine and liposomal doxorubicin (P-GVD) before proceeding to high-dose therapy and autologous hematopoietic cell transplantation (AHCT) (Moskowitz AJ et al, JCO 2021). Treatment consisted of 2 to 4 cycles of P-GVD followed by AHCT. We performed combined single-cell surface protein identification, RNA sequencing, and (T cell receptor) TCR sequencing using the 10x Genomics Single Cell Immune Profiling Platform on paired C1D1 and C3D1 peripheral blood mononuclear cells (PBMCs) from 23 patients who received P-GVD and 5 control patients with relapsed cHL treated with standard chemotherapy regimens. Expression of MHC-I, MHC-II, and PD-L1 on both Hodgkin Reed Sternberg (HRS) cells and within the TME was assessed by immunohistochemistry. Results:Of 38 evaluable pts, the complete response (CR) rate after 2 or 4 cycles of P-GVD was 95%. After a median follow-up of 40 months (range: 2-56), only 1 pt experienced relapse 23 months after AHCT and another pt died 41 months after AHCT while in remission due to unrelated causes. The estimated 40-month progression-free survival (PFS) is 96% (95% CI: 91-100). CITE-Sequencing of PBMCs across 56 samples from 28 patients revealed predominantly CD4+ T, CD8+ T, NK, and myeloid cells within the peripheral blood, with smaller proportions of hematopoietic progenitors and plasmacytoid dendritic cells. Combined RNA and TCR analysis of the T-cell compartment revealed significant pre-treatment clonal expansion of both CD4+ and CD8+ T-cells exhibiting a cytotoxic phenotype, including expression of GZMH, KLRG1, and CCL5 by CD8+ T-cells and expression of PRF1, NKG7, GNLY, FGFBP2, and GZMH by CD4+ T-cells ( Fig. 1A). Correlation of pre-treatment clonal expansion with tumor-specific MHC status demonstrated that clonal expansion of CD8+ T-cells was more robust in patients whose tumors expressed either MHC-I or MHC-II; conversely, clonal expansion of CD4+ T-cells was most robust in tumors expressing MHC-II but lacking MHC-I, suggesting cytotoxic CD4+ T-cell responses may promote anti-tumor immunity in MHC-I-deficient tumors ( Fig. 1B). Both CD4+ and CD8+ T-cell clonal expansion was highest in patients whose tumors expressed high levels of PD-L1 on stromal cells. Treatment with P-GVD did not result in further clonal expansion of either CD4+ or CD8+ T-cells but did increase expression of cytotoxic genes in pre-treatment expanded CD4+ T-cells, including NKG7 and PLEK, while downregulating negative genes of T-cell function in pre-treatment expanded CD8+ T-cells, including TNFAIP3 and DUSP1, suggesting that P-GVD promotes anti-tumor immunity in cHL by enhancing the cytotoxicity of tumor-reactive expanded CD4+ and CD8+ T-cells. Conclusions: Treatment of relapsed cHL with P- GVD resulted in durable remissions in patients undergoing AHCT. Distinct patterns of peripheral blood T-cell expansion were observed based on MHC-I and MHC-II expression on tumor cells, with CD4+ T-cell clonal expansion uniquely expanding in patients with MHC-I-deficient tumors. Further analysis of the impact of P-GVD on T-cell differentiation and function is ongoing. AcknowledgementT: Supported in part by a research grant from Investigator-Initiated Studies Program of Merck Sharp & Dohme LLC. The opinions expressed in this paper are those of the authors and do not necessarily represent those of Merck Sharp & Dohme LLC
Recommended from our members
Multicenter Study of Mantle Cell Lymphoma Outcomes Following First-Line Bendamustine-Rituximab and Second-Line Bruton's Tyrosine Kinase Inhibitor Therapy
Background: Bendamustine and rituximab (BR) is a standard-of-care first-line (1L) therapy for older or unfit patients with mantle cell lymphoma (MCL). The SHINE trial compared BR with rituximab maintenance plus ibrutinib vs placebo in patients ≥65 years old and showed that the ibrutinib arm had significantly improved progression-free survival (PFS; median 80.6 vs 52.9 months) but similar overall survival (OS; 57% vs 55% at 7 years) compared to the placebo arm. Whether sequential treatment with BR in 1L and a Bruton's tyrosine kinase inhibitor (BTKi) in second-line (2L) can result in a similar cumulative PFS compared to 1L BR plus BTKi combination therapy is unknown. To provide insight to this question, we modeled observational data to evaluate MCL outcomes after 1L BR and 2L BTKi therapy in the BTKi era. Methods: Patients with MCL who received 1L BR with or without rituximab maintenance in 2014-2020 at one of the 27 participating centers were included. Exclusion criteria included participation in the SHINE or ECHO trials, any additional 1L therapy other than BR (with or without rituximab maintenance), and stem cell transplant consolidation after 1L BR. Baseline characteristics, treatment, and follow-up data were abstracted by chart review. Event-free survival (EFS) was defined as time from index line treatment start to the first event (progression, relapse, retreatment, or death). OS was defined as time from index line treatment start to death. Using an intention-to-treat (ITT) framework, EFS2 was defined as time from 1L BR start to progression, relapse, or retreatment following 2L BTKi treatment or death. Patients who received a non-BTKi treatment at 2L were censored for EFS2 at 2L treatment start; living patients without an event following 1L BR or 2L BTKi were censored for EFS2 at last follow-up. Results: A total of 618 patients with MCL who received 1L BR in 2014-2020 were included. The median age was 71 (IQR 65-76) years, and 447 (72%) were male. 59 (11%) patients had an ECOG PS ≥2, 566 (93%) had stage III-IV disease, and simplified MIPI was low in 105 (21%), intermediate in 200 (39%), and high in 202 (40%) patients. The median follow-up following 1L BR start was 57.4 (95% CI 53.8-63.2) months. Response data were available in 580 patients, and the best ORR was 92% (79% complete response [CR] and 13% partial response [PR]). 258 (42%) patients received rituximab maintenance. As of last follow-up, 255 patients were alive and in remission after 1L BR, 92 patients died without 2L therapy, and 271 patients received a 2L therapy. The median EFS was 34.1 (95% CI 31.0-40.0) months. The median OS was 97.8 (95% CI 81.2-NA) months, the 5-year OS rate was 58.6% (95% CI 54.4-63.2), and the 7-year OS rate was 56.7% (95% CI 52.4-61.5) (Fig 1). Among the 271 patients who started a 2L treatment, 203 (75%) received a BTKi at 2L - 101 (50%) ibrutinib, 76 (37%) acalabrutinib, and 26 (13%) zanubrutinib. The median follow-up following 2L BTKi start was 38.5 (95% CI 31.3-45.1) months. Response data were available in 171 patients, and the best ORR was 64% (36% CR, 28% PR). The median EFS was 10.7 (95% CI 7.7-14.0) months, and the median OS was 24.8 (95% CI 17.3-33.1) months with 2L BTKi therapy (Fig 2). By ITT analysis, the median EFS2 following 1L BR and 2L BTKi was 72.1 (95% CI 56.7-97.8) months (Fig 1). A subset analysis of patients aged ≥65 years (n=471; 198 [42%] received rituximab maintenance) showed similar results. The median EFS with 1L BR was 32.7 (95% CI 29.1-36.3) months. The median OS was 81.5 (95% CI 65.0-NA) months, and the 7-year OS rate was 53.3% (95% CI 48.3-58.7). 208 patients received a 2L therapy, 163 (79%) with a BTKi. The median EFS was 11.5 (95% CI 7.6-15.8) months, and the median OS was 21.0 (95% CI 14.0-29.6) months with 2L BTKi therapy. By ITT analysis, the median EFS2 following 1L BR and 2L BTKi was 58.0 (95% CI 50.2-77.0) months. Conclusion: In this multicenter retrospective study, initiation of 1L BR (with or without rituximab maintenance) resulted in a 7-year OS of 57%. Median EFS2 for sequential 1L BR and 2L BTKi was 72.1 months. In context, the SHINE study reported a median PFS of 80.6 months in the BR (with rituximab maintenance) plus ibrutinib arm and a 7-year OS of 57% in the ibrutinib arm and 55% in the placebo arm, where 39% of patients received a BTKi in 2L. Within the constraints of observational data, our results provide support for sequential use of BR in 1L and BTKi in 2L for patients with MCL