Abstracts Clinical Lymphoma, Myeloma & Leukemia September 2023 S326 Five of 7 patients underwent alloHSCT from matched unrelated donors and 5/7 patients received a non-myeloablative conditioning regimen. Of note, 3/7 patients had already received venetoclaxbased therapy before alloHSCT. Interventions: Venetoclax was administered at 400 mg daily to all except two patients, who received 200 mg and 300 mg daily, respectively. All patients received venetoclax as a single agent, except for one patient who received venetoclax plus obinutuzumab. Results: In post-transplant patients, venetoclax was safe, with adverse events (AEs) no different from those registered in clinical trials, neutropenia and infections being the most relevant (5/7 patients). Venetoclax did not impact graft versus host disease (GvHD) course: 4/7 patients with pre-existing chronic GvHD had no exacerbation after venetoclax start, and only one patient developed GvHD during venetoclax therapy. During treatment, 2/5 patients had improved GvHD symptoms and in 3/5, the dose of steroid therapy was reduced. No patient needed to start additional immunosuppressive therapy. Five of 7 patients had a clinical response, with two achieving undetectable minimal residual disease in bone marrow. By the time of data collection, 2 patients had a persistent response after 2 years of venetoclax treatment. Conclusions: To our knowledge, this is the largest reported series of CLL patients treated with venetoclax after alloHSCT. In this cohort of heavily pretreated and high-risk patients, previous alloHSCT did not compromise sensitivity to venetoclax, which was capable of inducing objective responses without exacerbating GvHD. Keywords: CLL, venetoclax, alloHSCT CLL-354 First Line Treatment of Chronic Lymphocytic Leukemia (CLL) Patients With Obinutuzumab Based Therapy: Single‑Center Experience Sanja Trajkova PhD, Aleksandra Pivkova-Veljanovska PhD, Svetlana Krstevska -Balkanov PhD, Marija Popova- Labacevska MD, Nevenka Ridova MD, Simona Stojanovska-Jakimovska MD, Milche Cvetanovski MD, Lazar Chadievski MD, Bozidar Kocoski MD, Irina Panovska-Stavridis PhD University clinic for hematology, Skopje, Macedonia, the former Yugoslav Republic of Context: Monoclonal antibodies (mAbs) targeting CD20 on B lymphocytes are of importance in the treatment of B-cell malignancies. Objective: In recent years, a great effort has been made to develop novel mAbs that can provide greater efficacy than well-known rituximab. A second class of mAbs obinutuzumab was presented as a more powerful tool in the treatment of this group of patients. Design and Setting: In this retrospective study, 72 patients with symptomatic CLL were included. CLL patients were diagnosed and treated at the University Clinic of Hematology from January 2019 to January 2023. Patients: All the patients were evaluated for traditional clinical and laboratory prognostic factors and newer prognostic factors including IGHV mutation status and CLL prognostic and predictive genetic abnormalities. Results: Most of the patients treated with obinutuzumab have Binet B stage (56%). The mutational status of the variable region of the immunoglobulin heavy chain (IGHV) in 64% of the CLL patients treated with obinutuzumab was unmutated. The most common chromosomal abnormalities detected were del(13) and del(11q), found in 14% of the CLL patients. The most frequent adverse events (AEs) were tumor lysis syndrome and leukopenia. Conclusion: Analysis of initial results of application of obinutuzumab-based therapy allows us to conclude that this therapeutic modality is not linked to severe AEs that would limit the administration of therapy. Keywords: CLL, anti-CD20 monoclonal antibody, obinutuzumab, treatment CLL-375 Outcomes of U.S. Military Veterans With Chronic Lymphocytic Leukemia (CLL) Treated With Different First‑Line Treatments From 1998 to 2020 Helen Ma MD1,2, Susan O’Brien MD2, Pankaj Gupta MD1 1VA Long Beach, Long Beach, USA. 2University of California, Irvine, Orange, USA Context: Targeted therapies such as Bruton tyrosine kinase inhibitors and BCL-2 inhibitors were approved for first-line treatment of CLL. The impact of these therapies on outcomes of CLL in U.S. military veterans, in whom lymphoid malignancies may be associated with unique epidemiological factors, remains unknown. Objective: Determine whether choice of first-line treatment of CLL is associated with differences in survival in U.S. veterans. Design: Retrospective study (January 1998–December 2020) comparing first-line treatments in veterans diagnosed with CLL. Overall survival was calculated from date of first treatment until last cut off. Cox regression was performed on patients who received: 1) targeted therapies (ibrutinib, acalabrutinib, and venetoclax +/- monoclonal antibody [mAb]); 2) chemoimmunotherapy; 3) chemotherapy; and 4) monoclonal antibodies. Setting: U.S. National VA Healthcare System. Patients: Veterans with CLL, listed in the VA Central Cancer Registry. Main Outcome Measure: Overall survival (OS) from start of first-line treatment. Results: Of 16,331 veterans diagnosed with CLL (98% male), 6,332 received treatment. Use of targeted agents for first-line therapy increased from 0% in 1998– 2005 to almost 80% in 2020. Specific targeted agents (n=1379) mostly comprised ibrutinib (93%). Of the others (n=4953), 2568 (41%), 1647 (26%), and 738 (12%) patients were treated with chemoimmunotherapy, chemotherapy, and monoclonal antibody, respectively. Median OS was 6.1 years (95% CI: 5.7–6.4), 5.4 years (95% CI: 5.1–not reached), 4.6 years (95% CI: 3.8–5.2), and 3.6 years (95% CI: 3.4–3.8) for chemoimmunotherapy, targeted therapy, mAb, and chemotherapy, respectively. Those treated with chemoimmunotherapy were significantly younger than those treated with other therapies. In a multivariate Cox regression analysis, older age at diagnosis (HR 1.042, 95% CI: 1.024–1.061), choice of firstline therapy: targeted therapies (HR 0.637, 95% CI: 0.543–0.747, P<0.0001), chemoimmunotherapy (HR 0.803, 95% CI: 0.7340.870, P<0.0001), and mAb (HR 0.835, 95% CI: 0.738–0.946, P=0.0044) compared to chemotherapy, and any exposure to targeted treatments (HR 0.424, 95% CI: 0.384–0.468, P<0.0001) were
RkJQdWJsaXNoZXIy MTk3NTQxMg==