Baidoun, Firas

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.

Abstract In the pre–novel agent era, the median postprogression overall survival (PPS) of patients with classic Hodgkin lymphoma (cHL) who progress after autologous stem cell transplant (ASCT) was 2 to 3 years. Recently, checkpoint inhibitors (CPI) and brentuximab vedotin (BV) have improved the depth and durability of response in this population. Here, we report the estimate of PPS in patients with relapsed cHL after ASCT in the era of CPI and BV. In this multicenter retrospective study of 15 participating institutions, adult patients with relapsed cHL after ASCT were included. Study objective was postprogression overall survival (PPS), defined as the time from posttransplant progression to death or last follow-up. Of 1158 patients who underwent ASCT, 367 had progressive disease. Median age was 34 years (range, 27-46) and 192 were male. Median PPS was 114.57 months (95% confidence interval [CI], 91-not achieved) or 9.5 years. In multivariate analysis, increasing age, progression within 6 months, and pre-ASCT positive positron emission tomography scan were associated with inferior PPS. When adjusted for these features, patients who received CPI, but not BV, as first treatment for post-ASCT progression had significantly higher PPS than the no CPI/no BV group (hazard ratio, 3.5; 95% CI, 1.6-7.8; P = .001). Receipt of allogeneic SCT (Allo-SCT) did not improve PPS. In the era of novel agents, progressive cHL after ASCT had long survival that compares favorably with previous reports. Patients who receive CPI as first treatment for progression had higher PPS. Receipt to Allo-SCT was not associated with PPS in this population.

e19548 Background: Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare lymphoma accounting for less than 1% of mature T-cell lymphomas. Its natural history is not understood due to lack of large studies with long-term followup and an optimal therapeutic approach is not well-defined. Methods: The National Cancer Database was queried for patients aged 18 years and older diagnosed with SPTCL between 2004 and 2018. We excluded patients who lost to follow-up. Kaplan-Meier and multivariate Cox regression were used in the analyses. Results: 353 patients with SPTCL were included. 63% were females, 62% Caucasian, and 26% African American, 50% had early stage (I and II) and 32% had advanced stage (III and IV). 58.4% received chemotherapy, 38.2% did not receive chemotherapy and 3.4% had unknown chemotherapy status. The median age at diagnosis was 49 years (range 18-90). The median overall survival (mOS) for the whole cohort was not reached In early-stage (N = 178), 49.5% had chemotherapy with 39% receiving single-agent chemotherapy and 60% receiving multi-agent chemotherapy. 18.5% received radiation. In advanced-stage (N = 112), 75.9% received chemotherapy with 19% receiving single-agent chemotherapy and 81% receiving multi-agent chemotherapy. 9.8% received radiation There was no significant difference in the mOS between advanced-stage and early-stage (161.5 months vs not reached, P = 0.051) In early stage, there was no significant difference in the OS between chemotherapy and no chemotherapy (mOS was not reached in both groups, P = 0.324). The same trend was seen in the advanced stage (mOS was not reached in both groups, P = 0.851) Compared to Caucasian, African American patients were younger (median age 47 vs 54 years), but there was no significant difference in disease stage, receiving chemotherapy or radiation or other disease related characteristics (IPI score, B-symptoms, and HIV infection). African American patients had better OS (mOS was not reached, P = 0.003). This significant difference was seen in early stage (mOS was not reached, P = 0.003), but not in advanced stage (mOS 162 vs 122 months, P = 0.113) On multivariate analysis, age and Charlson-Deyo score ≥3 were associated with worse OS (HR 1.028 95% CI 1.005-1.052; P = 0.018 and HR 14.711 95% CI 2.316-93.449; P = 0.004, respectively), whereas disease stage and chemotherapy status did not affect the OS (HR 0.938 95% CI 0.545-1.617; P = 0.819, HR 1.271 95% CI 0.175-9.255; P = 0.813, and HR 0.922 95% CI 0.489-1.738; P = 0.802, respectively). Conclusions: Our study indicates that SPTCL is predominantly an indolent lymphoma associated with long-term survival irrespective of stage and chemotherapy. A conservative therapeutic approach appears to be more appropriate than intensive therapeutic approach in most patients. A risk stratification algorithm is needed to determine the therapeutic intensity.

7575 Background: Extranodal natural killer/T-cell lymphoma (ENKTL), nasal type, is a rare and aggressive Epstein-Barr virus driven lymphoma, which is most prevalent in East Asia and Latin America. There have been very few large studies outside of Asia. Therapeutic and survival outcomes have not been well characterized in the US. Methods: The National Cancer Database was queried for patients who were diagnosed at aged ≥18 years between 2004 and 2019. Patients who were lost to follow-up were excluded. Kaplan-Meier and multivariate Cox regression analyses were performed. Results: The cohort consists of 2,036 evaluable patients with 68% males, 74% Caucasian, 22% Hispanic Caucasian and 9% African American. The median age at diagnosis was 54 (18-90) years. The median follow up was 71 months (95% CI 66.8-75.7). Early-stage disease (I and II) was reported in 64% while advanced stage disease (III and IV) constituted 36%. Treatment groups include chemotherapy alone (29%), radiation alone (10%), combined modality therapy (CMT-chemoradiation) (42%). The median overall survival (OS) for the whole cohort was 27 months (95% CI 20.6-33.7). Median OS was better in patients with early stage compared to advanced stage disease (90 vs. 6 months, P < 0.001). Among therapeutic groups in early-stage disease, CMT (N = 616) had significantly better median OS than radiation alone (N = 152) or chemotherapy alone (N = 168) (194 vs. 34 vs. 14 months, P < 0.001). No significant difference was seen between radiation alone and chemotherapy alone (P = 0.617). Among patients treated with CMT, chemotherapy-first CMT (N = 134) had better OS than radiation-first CMT (N = 347) (median OS not reached vs. 194 months, P = 0.017). In the advanced stage disease, chemotherapy-treated patients (N = 418) had better median OS compared to patients who did not receive chemotherapy (N = 103) (7.6 vs 1.3 months, P < 0.001). Among patients who received chemotherapy, patients consolidated with SCT (N = 59) had better median OS compared to the patients who received chemotherapy only (N = 353) (63 vs 6 months, P < 0.001) In multivariate analysis, factors associated with worse OS were age (HR 1.021 95% CI 1.015-1.026; P < 0.001) and B-symptoms (HR 1.463 95% CI 1.276-1.678; P < 0.001). Whereas factors associated with better OS were early stage (HR 0.450 95% CI 0.387-0.524, P < 0.001), radiation therapy (HR 0.526 95% CI 0.458-0.603, P < 0.001) and chemotherapy (HR 0.546 95% CI 0.473-0.630, P < 0.001). Conclusions: The study represents one of the largest studies on ENKTL in the US. Early-stage disease is highly curable with CMT with chemotherapy-first sequencing being superior to radiation-first sequencing. Advanced stage disease is associated with extremely poor prognosis overall but is associated with a significant improvement in OS with consolidative SCT with possible role of consolidative RT in advanced stage.

563 Background: Cholangiocarcinoma is a rare malignancy with poor prognosis and outcome despite therapy. It accounts for 2.2% of all new cancer cases and 5% of all cancer deaths. Surgical resection is still the main therapeutic approach, whereas the role of peri-operative chemotherapy is debatable. Methods: The National Cancer Database (NCDB) was queried for patients diagnosed with non-metastatic biliary adenocarcinoma at age 18 or older between 2004 and 2019. After excluding patients with unknown timing of surgery and chemotherapy, patients who died within 90 days of the most definitive primary site surgery and patients lost to follow-up, we split the cohort into three groups according to the clinical stage (stage I-III). Then, we evaluated the overall survival (OS) between the different treatment modalities (surgery only, adjuvant chemotherapy and neoadjuvant chemotherapy) in each group. We studied the OS using Kaplan-Meier estimates and multivariate cox regression analyses to evaluate factors associated with OS. Results: A total of 35,260 patients with non-metastatic cholangiocarcinoma were included in the analysis, of which 50.4% were females, 83% Caucasians, 9.5% African Americans. The median age at diagnosis was 70 (range 18-90). 14,757 (41.9%) were stage I, 12,472 (35.4%) stage II and 8,031 (22.8%) stage III. 7,286 (20.7%) had surgical resection only, 8,144 (23.1%) had chemotherapy only, 6,964 (19.7%) had surgical resection with perioperative chemotherapy and 12,866 (36.5%) did not receive any treatment. We compared survival between different treatment modalities based on clinical stage. In stage I, we found patient who were treated with surgery only had better median OS (mOS) compared to adjuvant chemotherapy (65.7 vs 50.4 months, P<0.001) and no statistically significant difference between neoadjuvant chemotherapy and surgery only (mOS 79.8 vs 65.7 months, P=0.63). Whereas in stage II, patients who were treated with adjuvant and neoadjuvant chemotherapy had better mOS compared to those treated with surgery only (33.9 and 40.3 vs 29.9 months with P<0.001 and P=0.005, respectively). Same trend was seen in stage III, patients who were treated with adjuvant and neoadjuvant chemotherapy had better mOS compared to surgery only (22.6 and 41.5 vs 19.5 months, respectively with P<0.001 for all). In multivariate analysis, adjuvant and neoadjuvant chemotherapy did not affect the OS in all stages, except in stage III where neoadjuvant chemotherapy was associated with better OS (HR 0.646 95% CI 0.530-0.786; P<0.001). Conclusions: Adjuvant and neoadjuvant chemotherapy do not seem to have survival benefit in early stage (stage I and II) cholangiocarcinoma. Whereas neoadjuvant chemotherapy tends to improve OS in stage III.