Citations

ABSTRACT Background Prior studies in the pre‐MRI era suggest that patients with NCCN Intermediate and High Risk Grade Group 1 prostate cancer (GG1 PCa) on biopsy have increased risk for adverse oncologic outcomes. However, prostate MRI has altered patient selection for biopsy and improved prostate sampling. Herein, we examined factors associated with adverse pathologic features (APF) at radical prostatectomy (RP) and biochemical recurrence (BCR) among patients with GG1 in the MRI era. Methods A prospectively maintained institutional prostate cancer registry identified patients with GG1 PCa on biopsy who underwent RP from 2000 to 2023, stratified by MRI use. Multivariable logistic regression and Cox regression identified factors associated with APF at RP (GG3‐5, ≥ pT3a, or pN1) and BCR free survival (two consecutive PSA ≥ 0.2 ng/mL), respectively. Results Among patients without MRI ( n = 6732), NCCN risk group was associated with APF, BCR, and distant metastasis. Among 302 patients with GG1 and pre‐operative MRI, NCCN risk group was associated with neither APF nor BCR. Age (OR 1.07, 95% CI 1.01–1.14, p = 0.01), PIRADS ( p = 0.01), and % core positivity (OR 1.02, 95% CI 1.00–1.03, p = 0.04) were associated with APF. Age (HR 1.07, 95% CI 1.01–1.13, p = 0.03), APF (HR 4.36, 95% CI 2.14–8.86, p < 0.001), and positive margins (HR 4.88, 95% CI 2.39–9.98, p < 0.001) were associated with BCR. Conclusions Prior to prostate MRI, NCCN risk groups offered meaningful prognostication among patients with GG1 PCa. However, the utility of NCCN risk groups for GG1 in the MRI era appears limited. Contemporary risk stratification for GG1 should focus on biopsy and MRI characteristics rather than NCCN criteria.

Study Design. Post hoc analysis of prospectively-collected data. Objective. To identify factors predicting the most (and least) satisfaction following surgery for cervical spondylotic myelopathy (CSM). Summary of Background Data. Patient satisfaction affects long-term outcomes after surgery but the preoperative factors that influence postoperative satisfaction have not been well studied in patients with CSM. Methods. We conducted a post hoc analysis of prospectively-collected data from the Quality Outcomes Database (QOD) CSM registry cohort. Baseline and surgical characteristics were compared for patients with CSM reporting the most [North American Spine Society Satisfaction Score (NASS) 1] and least (NASS 4) satisfaction 24 months postoperatively. A multivariable logistic regression model was constructed using backward stepwise elimination to determine significant predictors of most versus least satisfaction. Twenty-four-month patient-reported outcomes (PROs) were compared. Results. Overall, 1141 patients were prospectively enrolled with 948 (83.1%) reaching 24-month follow-up. Of these, 699 met prespecified inclusion criteria: 610 (87.3%) were most satisfied and 89 (12.7%) were least satisfied. Though there were mean improvements in all 24-month PROs for the most satisfied cohort ( P <0.001), there were no significant improvements in 24-month PROs for the least satisfied cohort ( P >0.05). Using multivariable logistic regression modeling, a preoperative symptom of upper extremity weakness (OR=2.5, P =0.003), subjective myelopathy (OR=2.0, P =0.04), absence of numbness complaints (OR=2.2, P =0.003), symptom duration under 12 months (OR=1.6, P =0.047), Caucasian race (OR=2.3, P =0.001), participation in activities outside of the home (OR=2.0, P =0.04), anterior approach (OR=2.3, P <0.001), and higher baseline quality of life (OR=4.0, P =0.01) were predictive of the most satisfaction. Conclusion. Compared with the least satisfied, those most satisfied following surgery for CSM more often had a preoperative symptom of arm weakness, subjective myelopathy, the absence of numbness complaints, symptom duration under 12 months, higher baseline quality of life, and participation in activities outside of the home. Compared with a posterior approach, an anterior approach was associated with the most satisfaction. Taken together, early surgical treatment--before myelopathic symptoms significantly impact one's quality of life--may be considered to optimize patient satisfaction following CSM surgery.

ABSTRACT Background While guidelines state that patients with NCCN favorable intermediate risk (FIR) prostate cancer (PCa) may consider active surveillance (AS), there is a relative lack of longer term follow up data informing AS inclusion criteria of patients with Grade Group (GG) 2 prostate cancer in the MRI era. Here we evaluate patient outcomes from a MRI‐screened AS‐eligible cohort of FIR GG2 PCa receiving radical prostatectomy (RP). Methods Patients with prostate MRI, NCCN FIR GG2 PCa (PSA < 10 ng/mL, ≤ cT2a, < 50% core positivity), and no prior treatments who underwent RP from 2015 to 2023 were included from a prospectively maintained prostatectomy registry. Primary outcomes were adverse pathologic features (APF) at RP (GG3‐5, ≥ pT3a, or pN1) and biochemical recurrence (BCR). Logistic regression and Cox regression identified factors associated with APF at RP and time to BCR, respectively. Results Of 522 patients, 110 (21%) had APF at RP and 45 (9%) developed BCR with median follow up 2.4 years (IQR 1.3–2.8). On multivariable logistic regression, % Gleason pattern 4 (%GP4, %GP4 > 25% OR 2.14, 95% CI 1.28–3.58, p = 0.004) was independently associated with APF. On multivariable Cox regression for time to BCR, PSAD (HR 1.06, 95% CI 1.04–1.09, p < 0.001) and positive surgical margins (HR 1.06, 95% CI 1.09–3.78, p = 0.03) were independently associated with BCR. PIRADS, % core positivity, and specimen involvement were associated with neither APF nor BCR. Conclusions % Gleason pattern 4 > 25% and PSAD are the primary factors associated with adverse outcomes and should be considered for patients with FIR GG2 PCa considering active surveillance. PIRADS and measures of biopsy cancer volume were not associated with APF or BCR. These results may inform patient selection for active surveillance among patients with FIR GG2 PCa.

496 Background: Approximately 10% of patients with renal cell carcinoma (RCC) have an associated venous tumor thrombus (VTT), the presence of which impacts surgical management and increases perioperative risk. Historical systemic therapy regimens had limited success in downsizing VTT; however, the impact of immune checkpoint inhibitors (ICIs) on VTT shrinkage is unknown. Our primary objective is to assess VTT shrinkage comparing responses to ICI versus non-ICI regimens. Methods: This multicenter retrospective cohort study included patients with RCC and VTT from 2006-2024 who received upfront systemic therapy. Patients were evaluated at tertiary referral centers across Mayo Clinic Rochester, Florida, and Arizona. Systemic therapies were categorized as ICI versus non-ICI regimens. VTT length was quantified by distance relative to the superior border of the renal vein ostium. The primary outcome was change in VTT length on serial imaging as measured by absolute length reduction (cm), RECIST version 1.1 criteria, and Mayo VTT level reclassification. Linear mixed-effect models (LMMs) identified associations with VTT shrinkage and clinicopathologic features. Results: A total of 108 patients with median age 65 years (IQR 57-71) were included, of whom 49 (45%) received ICI regimens. ICI regimens were associated with greater VTT shrinkage (1cm vs 0.1 cm, p=0.025), increased RECIST responses (51% vs 32%, p=0.046), and a higher rate downstaging per Mayo VTT level (33% vs 12%, p=0.008) compared to non-ICI regimens. On multivariable LMM analysis, ICI regimens remained more likely to result in VTT shrinkage compared to non-ICI regimens (-0.12 cm/month, 95% CI –0.24-0.00, p=0.046). Absence of abdominal lymphadenopathy was also associated with VTT shrinkage (-0.18cm/month, 95% CI -0.06- -0.30, p=0.004). Initial Mayo VTT level, IMDC risk, and number of metastatic sites were not associated with VTT shrinkage. Conclusions: Treatment with ICI-regimens resulted in VTT shrinkage and Mayo VTT level reduction. This is a particularly important area of exploration as radical nephrectomy and tumor thrombectomy carry up to a 40% risk of peri-operative major complications. These data support using ICI regimens for patients with RCC with VTT who are not candidates for upfront surgery and prioritizing ICI regimens in neoadjuvant clinical trials.

BACKGROUND AND OBJECTIVES: Minimum clinically important differences (MCIDs) for patient-reported outcome metrics (PROMs) in patients with cervical spondylotic myelopathy (CSM) lack consensus on the most appropriate calculation method. This retrospective study aimed to identify the optimal MCIDs for commonly used PROMs in CSM. METHODS: The CSM database from the Quality Outcomes Database SpineCORe Study Group was analyzed. Baseline, 3-month, and 24-month PROM values for Neck Disability Index (NDI), 5-dimension Euro-quality of life (EQ-5D) in quality-adjusted life years, modified Japanese Orthopaedic Association (mJOA) score, and neck/arm pain numeric rating scale (NRS) were collected. MCIDs were calculated for each PROM using previously validated techniques. MCID values were compared using the area under the curve (AUC) with the North American Spine Society satisfaction scale as an anchor. RESULTS: A total of 1141 patients with CSM undergoing surgery were included in this analysis. Improvement of ≥30% from baseline was the optimal MCID for NDI and neck/arm NRS. At 24 months, the optimal percentage cutoff MCID for these instruments resulted in AUCs of 0.76, 0.72, and 0.67, similar to the 30% improvement method, with AUCs of 0.73, 0.71, and 0.67, respectively. Numeric cutoffs (0.065 at 3 months; 0.149 at 24 months) were the superior MCIDs for EQ-5D. For mJOA score, a severity-adjusted MCID outperformed other methods, yielding an AUC of 0.67 at 24 months. MCIDs were achieved in 63% of patients for NDI, 59% for neck pain NRS, 61% for arm pain NRS, 52% for EQ-5D, and 59% for mJOA score at 24 months. CONCLUSION: Using the Quality Outcomes Database SpineCORe data set, we defined optimal MCIDs for key PROMs in CSM. A ≥30% improvement from baseline was optimal in NDI and arm/neck NRS. An absolute numeric cutoff was superior for EQ-5D (0.149 at the 24-month follow-up). A severity-adjusted MCID performed best for mJOA score. These redefined benchmarks better capture the treatment impact and guide care decisions for patients with CSM.

Abstract The benefit of rituximab maintenance after first-line (1L) bendamustine-rituximab (BR) in patients with mantle cell lymphoma (MCL) remains uncertain, with inconsistent results from the phase 2 MAINTAIN trial and several retrospective studies. We conducted a large retrospective study at 27 US and Canadian academic centers to examine the benefit of rituximab maintenance after BR. A total of 911 patients received 1L BR between 2010 and 2020, and 703 had an objective response and no evidence of disease progression at the 3-month post-BR landmark. Among those, 394 (56%) received rituximab maintenance and 309 (44%) did not, with largely similar baseline patient and disease characteristics. In the landmark analysis, rituximab maintenance was associated with improved event-free survival (EFS; median, 49.9 vs 29.7 months; P&lt; .001) as well as overall survival (OS; median, 109.5 vs 74.2 months; P&lt; .001). The EFS and OS benefits were observed across most of the subgroups. EFS and OS differences were statistically significant in those who achieved a complete response to 1L BR (n = 590; median EFS, 62.7 vs 31.1 months [P&lt; .001]; median OS, 136.1 vs 75.3 months [P&lt; .001]), but the analysis among those who achieved a partial response to 1L BR was limited by the small sample size. These results provide additional evidence for the survival benefit of rituximab maintenance after BR in MCL and support its use in clinical trial design and routine practice.

Abstract Introduction: cBTKi have made a substantial impact in pts w/ MCL, but pts who develop PD while on treatment w/ cBTKi have historically had poor responses to subsequent lines of therapy (LOT). Brexucel, lisocel, and the non-covalent BTKi pirto have been approved in this population. While two RW studies have substantiated the benefit of brexucel, similar data for pirto are lacking. Accordingly, we aimed to evaluate the outcomes of pts treated w/ pirto in the RW setting. Methods: We performed a multi-center retrospective cohort study of adult pts w/ a diagnosis of MCL who experienced PD after any approved cBTKi and subsequently received pirto. Pts who received pirto w/ bridging intent and those who switched to pirto due to intolerance of cBTKi were excluded. The 95% exact binomial confidence intervals (CI) were calculated for overall response rate (ORR) and complete response rate (CRR). Progression-free survival (PFS) and overall survival (OS) were defined as the time from pirto start to PD or death, whichever occurred first, and the time from pirto start to death, respectively, and calculated w/ the Kaplan-Meier method. The log-rank test was used to compare survival curves. A multivariate (MV) Cox proportional hazard model was built to calculate adjusted hazard ratio (aHR). Analyses were performed w/ SAS, version 9.4. Results: Data on 111 pts w/ MCL treated across 21 institutions were collected. Median (mdn) age was 72 (range 33 – 93) years. Twenty-seven pts (24%) were female, 3 (3%) were Asian, 5 (5%) Black, 9 (8%) Hispanic, 86 (77%) White. Among the 53 (48%) pts w/ available MIPI-c at diagnosis, 28 (53%) pts were high-risk. Ki67 at diagnosis was available in 84 (76%) pts: of those, 58 (69%) had a Ki67 ≥30%, and 41 (49%) ≥50%. TP53 mutational status was available in 70 (63%) pts: 33 (47%) had documented TP53 mutation and 10/52 (19%) pts had a disease w/ complex karyotype. Pts had a mdn of 3 (range 1 – 9) prior LOT (n=106). Ninety-one pts (86%) received chemo-immunotherapy (CIT), 16 (15%) autologous stem cell transplant, 19 (18%) venetoclax (ven), 29 (27%) chimeric antigen receptor T-cell, 4 (4%) allogeneic stem cell transplant. For cBTKi, 39 (35%) pts received ibrutinib, 56 (50%) pts acalabrutinib, 33 (30%) pts zanubrutinib, and 17 (15%) pts received more than one cBTKi. The mdn time from the last dose of cBTKi to pirto start was 55 (range 0 – 2587) days, w/ 51 (46%) pts who switched from a cBTKi directly to pirto. Thirty (27%) pts had no response (stable disease or PD as best response) to cBTKi, and 40 (36%) pts had no response to the last LOT. Two (2%) pts received pirto in combination w/ CIT, 8 (7%) w/ an anti-CD20 monoclonal antibody (mAb), 11 (10%) w/ ven ± a mAb, while 86 (77%) pts as single agent. In 104 (94%) pts, pirto was given at full dose, 10 (9%) pts had a subsequent dose reduction. A total of 35 serious (grade ≥3) adverse events (AE) were documented in 27 (24%) pts: 4 (4%) pts had a serious bleeding AE, 5 (5%) pts a serious cardiac AE, 10 (9%) a serious GI AE, and 16 (14%) a serious infectious AE. Ninety-eight (88%) pts were evaluable for response. The ORR was 40% (95% CI 30% – 50%) w/ a CRR of 29% (95% CI 20%– 39%). At the last follow-up, 29 (26%) pts remained on pirto w/ a mdn treatment duration of 15.1 months (range 0.4 – 26). Fifty-eight (52%) pts died, 35 (78%) because of PD. At a mdn follow-up of 15.8 (range 0.4 – 26) months among survivors, the mdn PFS was 4.7 months (95% CI 3.3 – 8.2) and the mdn OS was 13 months (95% CI 9.2 – not available). Using the log-rank test, age (quartile groups), number of LOT (1-2 vs. 3-4 vs. 5+), time from cBTKi to pirto (quartile groups), Ki67≥30%, and high MIPI-C did not result in a statistically significant difference in PFS (p&gt;0.05). Presence of TP53 mutation was associated w/ a non-statistically significant adverse trend in PFS (p=0.0585). No response to cBTKi and Ki67≥50% were associated w/ a statistically significant inferior PFS in log-rank test (p=&lt;0.05), which persisted in a MV Cox regression model (aHR 2.4, 95% CI 1.4-4.2, and aHR 2.6, 95% CI 1.6-4.4, respectively). Conclusions: This is the first RW report on pirto in MCL pts. In this high-risk population, ORR to pirto was comparable to the BRUIN trial, while PFS was significantly worse, especially in pts w/ no response to cBTKi and w/ a high Ki67. However, prolonged remissions were seen in a subset of pts, suggesting that a better characterization of this population w/ durable benefit from pirto is needed.

Abstract Introduction: The introduction of the Bruton tyrosine kinase inhibitor acalabrutinib combined with bendamustine and rituximab (ABR) as first-line (1L) therapy for mantle cell lymphoma (MCL) in older patients (pts) is reshaping the approach to treatment sequencing in this disease. The primary analysis of the phase 3 ECHO trial (NCT02972840) with data cutoff Feb 15, 2024 (median time on study 44.9 mo) demonstrated improved progression-free survival (PFS) with ABR vs placebo plus BR (PBR; hazard ratio [HR] 0.73; 95% confidence interval [CI] 0.57–0.94; P=0.0160) in pts ≥65 y with treatment-naive (TN) MCL. Here we present updated results after 50 mo of follow-up, including time to next treatment 2 (TTNT2; ie, initiation of third-line [3L] therapy). Methods: Pts aged ≥65 y with TN MCL and ECOG performance status ≤2 were randomly assigned 1:1 to receive ABR or PBR. Randomization was stratified according to geographic region and simplified MIPI score. BR was given for 6 cycles followed by rituximab maintenance for 2 y in pts achieving a partial or complete response (CR). Acalabrutinib (100 mg twice daily) or placebo was administered at study start until progressive disease (PD) or unacceptable toxicity. Crossover to acalabrutinib was permitted at PD. The primary endpoint was PFS per independent review committee. TTNT2, which was used as a surrogate for PFS2 (time from initial treatment to second disease progression), was defined as time from randomization to second subsequent (3L) antilymphoma therapy after discontinuation of randomized treatment or death. Results: In total, 299 pts were randomized to each arm; median age was 71 y. At data cutoff (February 15, 2025), median (range) time on study was 51.86 (0.03–93.04) mo and median (range) follow-up through reverse Kaplan-Meier method for PFS was 60.8 (0–88.5) mo. Median TTNT2 was not reached (NR) in the ABR arm and 73.8 mo in the PBR arm, establishing a 24% reduction in the risk of initiating 3L therapy or death with ABR vs PBR (stratified HR 0.76; 95% CI 0.59–0.98). In total, 33 (11.0%) and 100 (33.4%) pts received second-line [2L] treatment (median time to 2L therapy, 26.3 vs 19.6 mo) and 10 (3.3%) and 37 (12.4%) received 3L treatment in the ABR and PBR arms, respectively. When COVID-19 deaths were censored (in alignment with prespecified analyses from the primary study), the HR further improved (stratified HR 0.67; 95% CI 0.50–0.89; median TTNT2 NR in any arm). In total, 71.6% and 78.3% of pts discontinued acalabrutinib and placebo, respectively; the most common reasons (&gt;5%) for discontinuation were adverse events (AEs; 44.5%, ABR; 32.4%, PBR) and objective PD (12.7%, ABR; 30.8%, PBR). Median PFS was 72.5 and 47.8 mo in the ABR and PBR arms, respectively (stratified HR 0.68; 95% CI 0.53–0.87; P=0.002). In total, 108 (36.1%) and 116 (38.8%) pts in each arm died; median overall survival (OS) was NR in both arms (stratified HR 0.87; 95% CI 0.67–1.13), with a 36-mo OS rate of 73.8% with ABR vs 68.3% with PBR. With 1 additional year of follow-up since the primary analysis, rates of grade ≥3 AEs and serious AEs in the ABR arm were comparable to previously reported rates, indicating that prolonged acalabrutinib exposure does not appear to result in cumulative toxicities. Three new cases of grade 3/4 neutropenia were reported, with no marked changes in the rates of grade ≥3 or serious infections. The rate of grade ≥3 cardiac events remained consistent with the primary analysis. In the ABR arm, 1 new case of grade 3/4 atrial fibrillation and 1 new case of grade 3/4 hypertension were reported. Rates of thrombocytopenia, major hemorrhage, and ventricular tachyarrhythmia remain unchanged. Conclusion: In this updated analysis of the ECHO trial, despite crossover to acalabrutinib being permitted in the PBR arm, fewer pts in the ABR arm were in need of subsequent treatment (2L and 3L), with longer TTNT2 in the ABR arm. These results suggest that 1L treatment with ABR provides a 24% reduction in risk of initiating 3L therapies or death. Further follow-up has demonstrated that ABR offers improved efficacy (ie, PFS) vs PBR, with no long-term safety concerns with acalabrutinib maintenance. The updated safety findings further support the favorable benefit–risk profile of acalabrutinib in TN MCL. Altogether, these data support the potential of acalabrutinib in combination with BR as 1L treatment, rather than in later lines, to modify long-term treatment outcomes in pts with TN MCL.

Abstract Background: Despite the efficacy of covalent Bruton tyrosine kinase inhibitors (cBTKi) in R/R MCL, patients (pts) ultimately discontinue treatment due to intolerance or development of resistance and disease relapse. Pirtobrutinib is a highly selective, non-covalent BTKi that inhibits BTK with low nM potency throughout the daily dosing interval. Pirtobrutinib was safe and effective in the phase 1/2 BRUIN study in pts with R/R B-cell malignancies, including those previously treated with a BTKi. Pirtobrutinib is approved in the EU for adults with R/R MCL after prior treatment with a BTKi (EMA Conditional Approval, Oct 2023), and in the USA for adults with R/R MCL after ≥ 2 lines of systemic therapy, including a BTKi (FDA Accelerated Approval, Jan 2023).Here, we report the final results from the phase 1/2 BRUIN study (NCT03740529), with a follow-up period of up to 5 yrs, focusing on the efficacy and safety of pirtobrutinib in all R/R MCL pts. Methods: Pts with R/R MCL who received ≥1 prior lines of therapy (including BTKi) were eligible for treatment with pirtobrutinib monotherapy. Key endpoints included overall response rate (ORR), duration of response (DOR) and progression-free survival (PFS), all assessed by independent review committee (IRC) per Lugano 2014 criteria (presented here) and investigator, overall survival (OS), and safety. Pts were included across the range of doses evaluated in dose escalation and expansion (25-300 mg/day). A data cutoff on 27 January 2025 was utilized, with a median study follow-up of 17.5 months (range, 0.5-69.6). Results: Among the 166 pts with R/R MCL, 153 (92%) received the pirtobrutinib approved dose of 200 mg/day, 152 (92%) had received prior cBTKi, of which 128 (84.2%) discontinued any prior cBTKi due to progressive disease (PD), and 15 (9.9%) due to toxicity. The cBTKi-pre-treated pts had a median age of 70 yrs (range, 46-88), 52% had intermediate-risk and 28.3% had high-risk sMIPI scores. The median number of prior lines of therapy was 3 (range 1-9), with most pts having received a prior anti-CD20 antibody (96.7%) and chemotherapy (90.1%). Additional prior therapies included hematopoietic stem cell transplantation (21.7%; 19.7% auto and 4.6% allo), BCL-2 inhibitor (15.8%), CAR-T cell therapy (8.6%). As of the data cutoff, 11 (7.2%) pts who received a prior cBTKi and 6 (42.9%) cBTKi naïve pts remained on treatment. The cBTKi pre-treated pts had an ORR of 49.3% (95% CI, 41.1-57.6), including 15.8% complete responses (CR) (n=24) and 33.6% partial responses (PR) (n=51). The 75 responding pretreated pts had a median DOR of 21.6 months (95% CI, 9.2-27.2) at a median follow-up of 24 months. The ORR among 128 pts who had discontinued any prior cBTKi due to PD and 15 pts who discontinued due to toxicity was 43.0% and 93.3%, respectively. The median PFS and OS for cBTKi pre-treated pts were 5.6 months (95% CI, 5.3-9.2) and 23.9 months (95% CI, 17.3-51.5), respectively. Fourteen pts (9.2%) were censored for PFS due to subsequent anticancer therapy without documented PD, including 8 pts who received CAR-T. The cBTKi naïve pts (n=14) had an ORR of 85.7% (95% CI, 57.2-98.2), including 50.0% CR (n=7) and 35.7% PR (n=5). The 12 responding naïve pts had a median DOR of 42.7 months (95% CI, 25.8-NE) at a median follow-up of 43 months. The median PFS and OS in the cBTKi naïve pts were 44.6 months (95% CI, 16.7-NE) and not reached (95% CI, 33.5-NE), respectively. Among all R/R MCL pts (n=166), the most frequent treatment-emergent adverse events (TEAE), regardless of attribution, were fatigue (31.9%), diarrhea (22.9%), anemia (18.1%), and dyspnea (18.1%). The most common Grade ≥3 TEAE was neutropenia/neutrophil count decreased (13.3%), and the rate of Grade ≥3 infections was 21.1%. Grade ≥3 hemorrhage/hematoma (2.4%) and all-grade atrial fibrillation/flutter (3.6%) were infrequent. In total, 13 (7.8%) pts had a fatal TEAE, with 4 (2.4%) classified as infections. Overall, 8 pts (4.8%) had treatment-related AE leading to dose reductions, and 6 (3.6%) had treatment-related AE leading to pirtobrutinib discontinuation. Conclusion: Pirtobrutinib continues to demonstrate efficacy in pts with heavily pre-treated R/R MCL including both those who previously received a cBTKi and those who were BTKi-naïve. The safety profile of pirtobrutinib remained favorable with a low-rate of dose reductions/discontinuations due to drug-related toxicity. No new safety signals were identified after up to 5 yrs of follow-up.