Tx Patterns Research Articles

Real-world (rw) treatment (tx) patterns and overall survival (OS) in patients (pts) with locally advanced/metastatic urothelial carcinoma (la/mUC) treated with avelumab first-line maintenance (1LM): Updated results from the SPEAR Bladder II study.

393 Background: Avelumab 1LM tx is approved in the US for pts with la/mUC who do not have disease progression after platinum-based chemotherapy (PBC). The tx landscape is evolving due to the recent approvals of newer therapies for pts with la/mUC. This study examines rw tx patterns, tx sequencing post avelumab 1LM, and OS in pts with la/mUC who initiated 1L tx in the US community oncology setting. Methods: This retrospective cohort study used the US Oncology Network (iKnowMed) EHR database. The study included adult pts (≥18 years) with la/mUC initiating 1L tx (index date) between Dec 1, 2019, and Nov 30, 2023. Pts were censored for OS at their last contact date or the end of study period, Feb 28, 2024. Descriptive statistics were used to describe tx patterns. Kaplan-Meier analysis was used to evaluate OS from the start of 1LM or second-line (2L) enfortumab vedotin (EV) treatment post avelumab 1LM. Results: A total of 1,658 pts with la/mUC initiated 1L tx with a median (range) follow-up of 9.0 months (0.1-50.4). The median (range) age at diagnosis was 73 years (31-90+), 74.7% were male and 47.1% had ECOG performance status ≤1. The 1L therapies included: IO monotherapy (41.2%), PBC only (32.4%), PBC followed by avelumab 1LM (11.2%), and other tx (15.1%). Since the US FDA approval (June 30, 2020), the utilization of avelumab 1LM among 1L PBC users ranged from 25.0% to 32.9% in 2023. Median (range) follow-up from the start of avelumab 1LM was 9.1 months (0.5-42.2). During the study observation period, 44 pts (23.7%) remained on avelumab 1LM. Median (95% CI) OS from start of avelumab 1LM was 18.5 months (13.8-23.8). Among the overall study cohort, 598 (36.1%) and 196 pts (11.8%) received 2L and third-line tx, respectively. The most common 2L therapies were IO monotherapy (44.1%) and EV monotherapy (23.9%). After discontinuation of avelumab 1LM, 81 pts (43.5%) received 2L tx, 48 (59.3%) of those received EV; median OS from start of 2L EV was 12.7 months (7.2-16.5). Conclusions: These rw study findings demonstrate avelumab 1LM effectiveness for pts whose disease has not progressed on 1L PBC and provides evidence of the use of 2L EV after avelumab 1LM. There was an increased uptake of avelumab 1LM since its FDA approval. Survival outcomes are consistent with the JAVELIN Bladder 100 clinical trial and other rw studies that had shorter follow-up. We observed high IO monotherapy use despite the platinum-ineligible population typically making up 11% of pts with la/mUC. 1 Some of these pts treated with IO monotherapy may benefit from alternative 1L regimens. Future rw studies are needed to further characterize contemporary tx patterns, optimal tx sequencing, and survival in pts with la/mUC amidst the evolving tx landscape. 1 Gupta S, et al. JNCI 2024;116(4):547–554.

Real-world (rw) treatment (tx) patterns and clinical outcomes among patients (pts) with metastatic urothelial carcinoma (mUC) receiving first-line (1L) systemic tx and avelumab 1L maintenance (1LM): Results from the IMPACT UC-III study.

390 Background: Avelumab 1LM is a standard of care for pts with mUC that has not progressed after 1L platinum-based chemotherapy (PBC). Immuno-oncology (IO) monotherapy is considered in pts with mUC who are ineligible to receive PBC. Recently approved 1L tx options include enfortumab vedotin + pembrolizumab and nivolumab + gemcitabine/cisplatin. This US retrospective study examined pt characteristics, tx patterns, and clinical outcomes among pts with mUC receiving 1L tx, including avelumab 1LM. Methods: Pts with mUC (bladder cancer; stage IIIB or IV, or ≥2 claims with ICD-10 diagnoses for metastatic cancer) aged ≥18 years, who initiated 1L tx (index date) from Jan 1, 2020 to Jul 31, 2023, were identified from the Healthcare Integrated Research Database (HIRD®; claims and clinical data from the health plan’s Cancer Care Quality Program). Clinical outcomes, including time to next tx (TTNT; time from 1L tx initiation to second-line tx) and overall survival (OS), were evaluated post index date. Pt characteristics and tx patterns were summarized using descriptive statistics. Avelumab 1LM use was identified on/after June 30, 2020 and ≤90 d after 1L PBC discontinuation. OS from the start of 1L tx or 1LM was analyzed using Kaplan-Meier methodology. Results: Of 2,820 pts with mUC, 1L tx was PBC in 37.0% (n=1,044), IO monotherapy in 39.0% (n=1,099), and other tx in 24.0% (n=677; antibody-drug conjugates and non-PBC). Among pts who received 1L PBC, 15.0% (n=157) initiated avelumab 1LM within 90 days of completing 1L PBC. Avelumab uptake in 2020-2023 by year was 10.8% (Jun-Dec 2020), 29.9%, 34.4%, and 24.8% (Jan-Aug 2023), respectively; 38.9% of pts were still receiving avelumab at the end of the study period. In the 1L PBC and IO cohorts, mean age (SD) was 65.5 (11.1) and 74.6 (10.7) years, respectively. 60% of pts were male. In the 1L PBC and 1L IO monotherapy cohorts, respectively, median follow-up (IQR) was 11.2 (5.6-20.3) and 8.6 (4.0-17.7) months (mo); median TTNT (IQR) was 4.8 (2.8-8.3) and 5.5 (2.8-11.0) mo; and median OS (95% CI) was 29.7 (25.1-37.2) and 20.0 (17.1-25.6) mo. In pts who received avelumab 1LM, median follow-up (IQR) from start of 1L PBC was 14.6 (9.2-21.3) mo; median TTNT (IQR) was 7.6 (6.2-12.3) mo; median time on avelumab tx was 5.0 (1.8-10.2) mo; and 1- and 2-year OS rates, respectively, from start of avelumab 1LM were 78% and 65%, and from start of 1L PBC were 84% and 68% (median OS was not estimable because >50% of pts remained alive at the end of the study period). Conclusions: Despite advances in 1L tx for mUC, IO monotherapy remains a prevailing option for older, commercially insured patients in the US. In this descriptive rw study, pts treated with 1L PBC had longer OS than pts treated with 1L IO monotherapy. Future studies with longer follow-up are needed to further evaluate pt outcomes.

Analysis of real-world (RW) pomalidomide (pom) dosing patterns in patients (pts) with multiple myeloma (MM) from the Flatiron database.

e19508 Background: Pom is an immunomodulatory drug commonly used in combination with other antimyeloma therapies for the treatment (tx) of pts with MM. However, there is a paucity of data on RW dosing patterns with pom and associated tx outcomes. We report RW pom dosing patterns and effectiveness using RW data to inform potential pom dosing strategies as part of combination tx regimens. Methods: RW pom data in pts with MM were derived from the US Flatiron Health deidentified electronic health record (EHR) database (Jan 2011–Nov 2021). Pom starting dose (1, 2, 3, or 4 mg) and line of therapy (LOT) were identified from EHRs. Tx patterns were captured per LOT; pts could receive >1 pom-containing tx regimen/LOT. Pts receiving pom were followed until Dec 2023 for outcome analysis. Overall survival (OS) and time to next tx (TTNT) were estimated using the Kaplan-Meier method and analyzed by log-rank testing. Results: Of 15,378 pts with MM, 2,034 had an order for pom, of whom 1,344 received pom and 880 had LOT data. The most common initial pom dose was 4 mg (50%), followed by 2 mg (30%), 3 mg (16%), and 1 mg (4%). The most common pom-containing tx regimens were: daratumumab + pom + dexamethasone (d; 29%), pom + d (18%), and carfilzomib + pom + d (14%); 6% of pts received pom monotherapy. Retreatment with pom was infrequent, with 84% of pts receiving only 1 pom-containing LOT. Most pts (n=652, 74%) remained on the initial pom dose received; of these, 367 pts remained on an initial dose of 4 mg. Among pts who changed dose (n=227, 26%), 36% changed from 2 mg and 36% changed from 4 mg. Of pts who received an initial dose of 4 mg and changed dose (n=81), 43%, 51%, and 6% reduced to 3, 2, and 1 mg, respectively. Of pts who received an initial dose of 2 mg and changed dose (n=82), 17% reduced to 1 mg. Among pts who received an initial dose of <4 mg and changed dose, dose escalation was common (67% of pts with a 3 mg initial dose increased to 4 mg; 33% and 50% of pts with a 2 mg initial dose increased to 3 and 4 mg, respectively). Outcome analysis of pts with LOT and available follow-up data suggest that initial pom dose had no impact on OS and TTNT (Table). Log-rank analysis of OS and TTNT between the initial doses of 2 and 4 mg showed no significant difference among all pts ( P=0.32) or in pts who changed dose ( P=0.29). Conclusions: RW analyses show that most pts remain on the initial pom dose received, but some pts changed doses. Pom, most commonly used in combination regimens, can be used across an initial dose range with no impact on efficacy in pts with MM. Optimal pom dosing may vary across pts and combination regimens; pom dosing should be tailored to pt needs per disease and tx factors. [Table: see text]

Characteristics and treatment (Tx) patterns (TxP) of high-risk biochemically recurrent (HR-BCR) non-metastatic castration-sensitive prostate cancer in the real-world by race, age, and prostate-specific antigen (PSA) doubling time (PSADT).

Characteristics and treatment (Tx) patterns (TxP) of high-risk biochemically recurrent (HR-BCR) non-metastatic castration-sensitive prostate cancer in the real-world by race, age, and prostate-specific antigen (PSA) doubling time (PSADT).

Treatment (Tx) patterns, efficacy and safety of eribulin for advanced and heavily pretreated breast cancer (ABC): Updated results from a single-center, real-world study.

e13118 Background: We evaluated the Tx patterns, efficacy and safety of eribulin for heavily pretreated ABC in real-world practice. Previous results were reported at the 2023 ASCO (e13118), updated results for longer follow-up and additional enrollment are presented here. Methods: Patients (pts) with ABC who had progression on anthracycline taxane Tx and received eribulin (1.4 mg/m2 IV on Days 1 and 8 of a 21-day cycle) between April 2020 and October 2023 were enrolled. Response was evaluated using RECIST v1.1. Pts were considered as taxanes sensitive if taxanes treatment duration of last line use exceeds 6 months, otherwise were considered as taxanes resistant. Results: 89 pts were enrolled. Median (range) age was 54 (30–79) years; 80.9% had an Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0–1, and 40.4% pts had a median of 3 prior lines of chemotherapy. 67.4% of pts had Ki67 >30% and 46.0% had HR+/HER2− disease. 88.7% of pts had visceral metastasis. Eribulin was monotherapy in 30.3% of pts, and combined with bevacizumab, capecitabine, bevacizumab + capecitabine, and anti-HER2 agents in 28.1%, 9.0%, 3.4%, and 25.8%, respectively. The objective response rate was 22.5%; disease control rate was 84.3%. Median progression-free survival (PFS) overall was 6.0 (95% CI, [3.5–8.5]) months (mo). Univariate analysis indicated pts with HER2+ disease had longer PFS than pts with HR+/HER2− or triple-negative BC (median, 13.5, 4.5, and 3.7 mo, respectively; P = 0.011; Table). Pts with Ki67 expression ≤30% had longer PFS than pts with Ki67 >30% (median, 8.0 vs. 4.0 mo; P = 0.02). Pts with grade I-II had longer PFS than pts with grade III (median, 10.5 vs. 4.0 mo; P = 0.003). Pts sensitive to Taxane had longer PFS than pts resistant to Taxane (median, 8.0 vs. 4.0 mo; P = 0.007). Among the 18 pts with a partial response, median PFS was 11.4 mo. The most common adverse events were leukopenia (44.9%), neutropenia (37.1%) and anemia (36.0%). Neurotoxicity was rare (6.7%). Conclusions: In this single-center study of pts with heavily pre-treated ABC in China, eribulin Tx resulted in favorable PFS irrespective of molecular subtype, with a manageable safety profile. In pts with a large tumor burden and a good PS, eribulin-based combinations may further improve outcomes. [Table: see text]

Real-world treatment (Tx) sequences and time to discontinuation (rwTTD) in the first-line (1L) metastatic castration-resistant prostate cancer (mCRPC) setting.

55 Background: There is limited real-world data on tx sequencing in metastatic prostate cancer. Additionally, while guidelines support adding novel hormonal agents (NHA) to androgen deprivation tx (ADT) for metastatic hormone-sensitive prostate cancer, use is limited because of clinical and/or pt-driven factors. We evaluated tx patterns, rwTTD, and time-to-chemotherapy (rwTTC) for 1L mCRPC pts, including Black/African Americans (BAA) treated predominantly in a community oncology setting. Additionally, we analyzed systemic treatments prior to 1L mCRPC as well as progression to 2L mCRPC. Methods: This retrospective study included pts with mCRPC from the nationwide Flatiron Health EHR-derived, deidentified database who initiated 1L tx between 1/2013 and 1/2023. Study end was 4/2023. Tx patterns were described by time period (TP) of 1L initiation: TP1 - 01/2013–12/2017 and TP2 - 01/2018–01/2023; Kaplan-Meier analyses were conducted for rwTTD/TTC and a Cox proportional hazards regression model was used to determine the association between pt characteristics and rwTTD/TTC for 1L mCRPC. Subgroup analyses were performed for BAAs. Results: Of the 8915 1L-tx pts (median age 74 yrs), 871 (10%) were BAA (median age 70 yrs) and 5870 (66%) were NHA-naïve at 1L mCRPC. Overall, the percent of pts who were NHA-naïve decreased from 2018 (72%) to 2023 (39%) and a similar trend was observed for BAA (74% [2018] to 25% [2023]). 1L NHA use in mCRPC increased from TP1 to TP2 (overall: 70% to 80%; BAA: 73% to 83%), primarily driven by enzalutamide (Enz) (overall: 30% to 39%; BAA: 33% to 38%) and decrease in chemotherapy (overall: 16% to 12%; BAA: 17% to 13%). The top 3 1L mCRPC regimens for the overall population and BAA were abiraterone (Abi) (35%; 38%), Enz (32%; 33%), and docetaxel (10%; 11%). Among pts who progressed to 2L mCRPC, the most common sequences for patients tx with Abi or Enz for 1L mCRPC were ADT monotherapy in the prior line of tx and a switch to Abi (19%) or Enz (24%) upon progression from 1L to 2L. 1L rwTTD for the overall cohort is in the Table. Age ≥80 years, ECOG PS ≥1, socioeconomic status = 5 (highest), and median time ≤39.8 months from initial dx to mCRPC were associated with a higher hazard of discontinuation (all p ≤0.05). Conclusions: Overall, most pts received their first NHA in 1L mCRPC; NHA use increased and chemotherapy use decreased from TP1 to TP2. There was heterogeneity in tx sequences in patients treated with an NHA in 1L mCRPC; some pts were rechallenged with a different NHA in 2L despite lack of robust prospective data to support use. Overall, 1L rwTTD was short with a small numerical increase in TP2. Factors contributing to discontinuation, such as treatment resistance, need to be better understood to further improve real-world outcomes. [Table: see text]

P1037 Treatment sequences and time on specific treatments in patients with inflammatory bowel disease under advanced treatment – a German claims data analysis

Abstract Background The number of advanced therapies (ADT) approved for the treatment (Tx) of inflammatory bowel disease (IBD) in is increasing, however, yet no guidance on optimal sequencing of treatments is available in Germany (and elsewhere). This study aims to investigate applied Tx sequences of ADT in claims data based on real-world setting across Germany in patients (pts) with IBD. Methods A retrospective healthcare claims data analysis was conducted using claims data from approx. 4.5 Mio pts within German statutory health insurance, including pts diagnosed with Crohn’s disease (CD) and ulcerative colitis (UC) from 2014 to 2021. Pts were followed up for at least 6 months after the first prescription of ADT (index date) if not deceased. A pre-index period of at least 12 months was applied to only include pts naïve to ADT. The study assessed Tx sequences and time to next treatment (TTNT) among other parameters. Data was not adjusted to disease severity and only descriptively reflects real world Tx patterns within the database. Results The database included 15.041/18.361 pts with CD/UC. Pts with CD/UC starting ADT between 2014 to 2021 received either Adalimumab (ADA: 923/337), Infliximab (IFX: 616/419), Ustekinumab (UST: 113/25) or Vedolizumab (VDZ: 139/248). In an analysis of ADT sequences and TTNT defined as start of first line (1L) Tx to start of second line (2L) Tx we found that during the observation period the majority of pts (71.4%) have not switched to 2L Tx yet. In 1L, ADA was observed as the preferred Tx in CD pts (51.5%) followed by IFX (34.4%), VDZ (7.8%) and UST (6.3%), in UC pts IFX (40.7%) was mostly prescribed as 1L followed by ADA (32.8%), VDZ (24.1%) and UST (2.4%). The proportion (%) of pts not switched to 2L Tx within one year for CD/UC were: ADA (83.6/70.3), IFX (79.0/73.1), UST (93.5/96.0) and VDZ (85.4/86.6). Within three years proportions of pts not switched to 2L Tx changed for CD/UC: ADA (68.1/54.5), IFX (57.8/56.8), UST (82.5/72.0) and VDZ (72.7/73.0) (table1). For pts who had a switch to a different ADT, the switch occurred within one year in over 50% of all pts. Most Tx switches (45.8%) were observed in pts who received IFX as 1L Tx, both in the UC and CD population. The majority of CD pts that received 2L Tx were switched to UST (35.7%), while in UC, a high proportion of pts were switched to VDZ (44.3%). Further Tx pathways and proportions of switches are summarized in Figure 1. Conclusion The study found that most IBD pts started ADT with ADA or IFX, but unadjusted time on 1L data may suggest a trend towards superior TTNT of VDZ and UST in UC and CD. Data should be interpreted carefully, as pts for >1L are limited and UST and VDZ were approved during the study period.

The Cytogenetic and Molecular Testing Landscape in Patients with Newly Diagnosed Acute Myeloid Leukemia in Routine Clinical Practices in the United States

Background: The prognostic and treatment (Tx) landscape for newly diagnosed acute myeloid leukemia (ND AML) has evolved in recent years; several novel therapies have been recommended in Tx guidelines. Tx for patients (pts) with actionable IDH1, IDH2, or FLT3 mutations includes Venetoclax (Ven)-based regimens (i.e. Ven+hypomethylating agents [HMAs] and Ven+low-dose cytarabine), HMA monotherapy (i.e. Azacitidine [Aza] or decitabine), and targeted Tx (i.e. ivosidenib±Aza, enasidenib±Aza, sorafenib±HMAs, and gilteritinib+Aza). This study aims to better understand the cytogenetic and molecular testing landscape among pts with ND AML receiving first-line (1L) Tx in routine clinical settings in the United States (US). Methods: This retrospective cohort study used data from the Flatiron Health database: a US nationwide, electronic health record-derived de-identified database. Pts with ND AML, aged ≥18 years, diagnosed with AML between January 1, 2020, and December 31, 2022, with ≥2 visits recorded within 3 months of AML diagnosis (Dx), and 1L Tx initiated any time after AML Dx were included.Pts with secondary AML, acute promyelocytic leukemia or t(9;22) were excluded. Descriptive analyses evaluated the cytogenetic testing pattern, molecular testing pattern (including next generation sequencing [NGS] and polymerase chain reaction [PCR]), and 1L Tx pattern for pts harboring IDH1/2 or FLT3 mutations (categorized as Ven-based, HMA monotherapy, and targeted Tx). Results: A total of 1577 pts met the study criteria. Overall, 95% (n=1501) of pts received a cytogenetic test and 91% (n=1434) received molecular testing that corresponded to a positive or negative result from the first specimen collected. Of the pts with molecular testing, 70% (n=1005) were treated in the community setting, 27% (n=390) in the academic setting, and 3% (n=39) in both academic and community settings. NGS was the most used molecular testing technique in all settings (76%, 50%, and 61% in the community setting, academic setting, and both settings, respectively) vs PCR (11%, 34%, and 26%, respectively). Testing rates were relatively consistent from 2020 to 2022 ( Figure). Bone marrow aspirate alone was the most common specimen type used for molecular testing (82%, 65% and 72%, in the community setting, academic setting, and both settings, respectively), followed by blood only (14%, 25%, and 21%, respectively). A total of 78% of pts treated in the community setting had their first specimen collected at AML Dx for molecular testing (vs 63% in the academic setting and 59% in both settings). Overall, 85% of pts treated in the community setting had their first specimen collected for molecular testing before 1L Tx initiation (vs 75% in the academic setting and 90% in both settings), and 35% had repeated molecular testing (proxy by second specimen collected) after 2 weeks of 1L Tx initiation (vs 40% in the academic setting and 29% in both settings). Of the pts who received molecular testing, 25% (n=365) harbored IDH1/2 or FLT3 mutations. A total of 39% (n=142) of pts with IDH1/2 or FLT3 mutations received Ven-based Tx, 9% (n=34) received HMA monotherapy, 3% (n=12) received targeted Tx, and 49% (n=177) received chemotherapy excluding HMAs. Conclusions: This study found that cytogenetic and molecular testing have been integrated into routine clinical care settings for pts with ND AML receiving 1L Tx. The consistent testing rates in recent years, common use of NGS molecular testing technique, and the majority of pts having first specimen collected for molecular testing prior to 1L Tx initiation reflect physicians' intention to leverage molecular data to better inform Tx decisions. The subset of pts with second specimen collected for molecular testing after 2 weeks of 1L Tx initiation suggests some physicians' efforts to evaluate new and/or persistent targeted stable mutations. Although the rate of molecular testing was high, nearly half of pts harboring IDH1/2 or FLT3 mutations received Tx guideline recommended regimens, and Ven-based Tx was more commonly administered than HMA monotherapy or targeted Tx; suggesting physicians are more commonly choosing a mutation agnostic Tx approach in ND AML. Future studies are warranted to better understand potential barriers to the timely report of molecular testing results in routine clinical practice for pts with AML.

Economic burden in patients (pt) with CLL/SLL (CLL) who received ≥ 2 prior lines of therapy (LOT), including a Bruton tyrosine kinase inhibitor (BTKi): A SEER-Medicare analysis.

24 Background: In third-line or later (3L+) CLL, there is no standard of care after failure of oral-targeted treatments (tx) (eg, BTKi, B-cell lymphoma 2 inhibitor [BCL2i]). There is limited real-world evidence on tx received and economic burden among pts with advanced CLL. Therefore, this study assessed tx patterns, health care resource utilization (HCRU), and costs in 3L+ Medicare-enrolled pts with CLL who received prior BTKi. Methods: A retrospective study was conducted using SEER data from 2010 to 2017 linked to Medicare claims data through 12/31/2019. Eligible pts had a CLL diagnosis, were ≥ 66 y of age at diagnosis, received ≥ 2 prior LOTs, including a BTKi, and initiated a subsequent LOT. Index date was defined as start of 3L+ tx after discontinuation of prior LOT containing a BTKi. Pts were continuously enrolled in Medicare parts A, B, and D ≥ 6 mo before and ≥ 1 mo after index date. Baseline pt characteristics, HCRU, and associated health care costs in the postindex period were summarized descriptively. HCRU and costs (adjusted to 2019 US dollars) were reported as mean CLL-related and all-cause per pt per month (PPPM). Results: Among 98 eligible pts with post-BTKi 3L+ CLL, mean age was 78 y; 54.1% were male. Pts had a median of 2 prior LOTs with median postindex follow-up of 12 mo. Mean Charlson Comorbidity Index score was 2.8. The top 3 index LOT txs received were chemotherapy with anti-CD20 monoclonal antibodies (mAb [19.4%]), anti-CD20 mAb monotherapy (19.4%), and BCL2i monotherapy (14.3%). In the postindex period, 90.8% of pts had ≥ 1 office visit; 63.3% had ≥ 1 inpatient admission with a mean length of stay of 7.6 d. All-cause mean PPPM HCRU was 2.3 office visits, 1.8 hospital outpatient visits, 0.02 skilled nursing facility (SNF) visits, 1.6 ancillary care visits, 0.2 emergency room (ER) visits, and 0.2 inpatient admissions. Total all-cause mean (standard deviation [SD]) PPPM cost was $12,679 ($15,123). The main drivers of total all-cause PPPM cost were inpatient admissions ($4891) followed by drugs ($4379), hospital outpatient ($2338), office visits ($412), ancillary care ($412), SNF ($140), and ER ($26). CLL-related HCRU and costs are shown in the Table. CLL-related PPPM costs accounted for 83% of total all-cause costs with a mean (SD) of $10,501 ($14,052). Conclusions: Our study demonstrated that Medicare-enrolled pts with 3L+ CLL who received prior BTKi experienced high economic burden (mean monthly cost of $12,679). Inpatient admissions and drugs were the largest cost drivers. Considering the survival in this population (median OS of 33.1 mo; Awan et al. Blood 2022), the lifetime economic burden to Medicare could be significant. [Table: see text]

Real-world overall survival (OS) of patients (pts) with metastatic urothelial carcinoma (mUC) receiving first-line (1L) systemic therapy (tx): Results from IMPACT UC II.

529 Background: Urothelial cancer (UC) is the most common urinary system cancer. The IMPACT UC II study aimed to assess tx patterns and clinical outcomes in pts with mUC treated with platinum-based chemotherapy or immuno-oncology monotherapy (IO-mono) in 1L. Methods: This was a retrospective claims analysis of pts diagnosed with mUC from July 2015 to June 2020 and continuously enrolled for 6 mo before and ≥6 mo after index date (ie, date of first claim) using Optum Research Database, which represents ≈8% of commercially insured and 18% of Medicare Advantage (MAPD) populations. Pts were followed up until disenrollment, study end in August 2021, or death. Analyses examined OS and time to 2L tx (TT2L) in three tx cohorts: cisplatin (cis)-based, carboplatin (carbo)-based, or IO-mono. Results: Of 3,006 pts diagnosed with mUC, 1,037 received 1L tx: 365 (35.2%) with cis-based tx; 337 (32.5%) with carbo-based tx, and 335 (32.3%) with IO-mono. Among treated pts, mean age was 72.5 years (SD, 9.9 years), 72.3% were male, and 77.4% were MAPD insured. At baseline, pts receiving cis-based tx had a lower percentage of ≥3 comorbidities (defined by National Cancer Institute criteria): cis-based, 22.2%; carbo-based, 39.5%; and IO-mono, 45.1%. Among 290 pts (27.9%) receiving 2L tx, carbo-based tx had the shortest median TT2L (5.7 mo). Pts receiving cis-based tx had the longest median OS (27.4 mo). Relative to cis-based tx, multivariable–adjusted mortality risk was 2 times higher with IO-mono (hazard ratio [HR], 2.0; 95% CI, 1.6-2.5) and 1.5 times higher with carbo-based tx (HR, 1.5; 95% CI, 1.3-1.9) (Table). Conclusions: This study shows that, before avelumab 1L maintenance approval, the majority of pts did not receive any systemic anticancer tx. following mUC diagnosis. In 1L, after multivariable adjustment (including for baseline comorbidities), real-world OS was lower in pts receiving carbo-based tx and IO-mono compared with cis-based tx. Future research should examine outcomes with newer standard of care.[Table: see text]

Treatment (tx) patterns and real-world outcomes among patients (pt) with mantle cell lymphoma (MCL) in the Flatiron database.

152 Background: Despite the increasing number of tx options for MCL, data on novel agents and associated OS are scarce. We assessed the tx patterns and estimated OS by line of therapy (LOT) among pts with MCL in the United States (US). Methods: This retrospective observational study using the Flatiron Health database included pts aged ≥ 18 y at initial MCL diagnosis who received first-line (1L) systemic tx for MCL during the index period (01/01/2011–03/31/2022) on the date of 1L tx initiation. Pts who had < 1 mo of data after the index date, received clinical study drug during the study period, or had other primary cancer diagnoses or active primary malignancies were excluded. Time to next tx (TTNT) was calculated from LOT start date to next LOT start date. OS was estimated using Kaplan-Meier methodology. Results: Of 4846 pts diagnosed with MCL, 2072 met all eligibility criteria and were included in the final cohort. The median age was 69 y; pts were mostly male (71%), from the Southern US (43%), had commercial health plan insurance (47%), and had stage IV disease at diagnosis (64%). The median length of follow-up from index was 27.4 mo. The most common 1L tx was bendamustine + rituximab (29%) and ibrutinib was the most common second-line (2L) and third-line or later (3L+) tx (25.5% and 10.5%, respectively); only 17% received a stem cell transplant. Median TTNT and OS were similar across subgroups (Table). Median time to start of LOT, TTNT, and OS for subgroups of pts who (1) received ≥ 2 LOTs, including an alkylating agent, Bruton tyrosine kinase inhibitor, and CD20-targeting agent (TRANSCEND NHL 001, MCL cohort eligibility criteria; n = 508); (2) received second-line or later (2L+) tx (n = 859); and (3) received 3L+ tx (n = 363) are shown in the Table. Conclusions: Bendamustine + rituximab and ibrutinib were the most common tx in 1L and 2L/3L+, respectively, among pts receiving approved tx. For all pts/subgroups,median TTNT was longest for the 1L LOT; median OS was longest from 1L start date. Diminishing TTNT and OS in subsequent LOTs after 1L tx provide benchmarks for future tx.[Table: see text]

FRI514 Treatment Of Hypothyroidism By Age And Sex In The United States: A National Health And Nutrition Examination Survey (NHANES) And Optum Claims Data Analysis

Abstract Disclosure: A. Tessnow: None. K.L. Wyne: None. C.P. Schneiderman: Employee; Self; Abbvie. Stock Owner; Self; Abbvie. B. Pinsky: Employee; Self; Abbvie. Stock Owner; Self; Abbvie. D. Guo: Employee; Self; Abbvie. Stock Owner; Self; Abbvie. B. Barger: Employee; Self; Abbvie. Stock Owner; Self; Abbvie. O. Antunez Flores: Employee; Self; Abbvie. Stock Owner; Self; Abbvie. Background: Recently updated hypothyroidism (HT) prevalence in the United States (US) using NHANES and Optum Claims data (OCD) showed an increasing prevalence of overall HT from 9.6% in 2012 to 11.7% in 2019. Objectives: Characterize treatment pattern of overt HT (OHT) in the US with NHANES 2009-12 cycles and OCD during 2019. Methods: Combined NHANES Survey data from the 2009-12 cycles and OCD for 2019 were utilized. Patients age ≥12 years old were included in the NHANES thyroid profile sub-sample; for Optum patients ≥18 were included and women who were pregnant were excluded. Disease status was determined from blood samples (NHANES), labs (OCD) or evidence of HT Tx. OHT was defined as presence of elevated thyroid-stimulating hormone (TSH >4.0 mIU/L) and a subnormal or low level of free thyroxine (FT4 < 0.8 ng/dL); patients with a documented prescription (Rx) for HT Tx with levothyroxine or liothyronine were also categorized with OHT regardless of lab values. The results were stratified by age (12/18-44, 45-59, 60+) and sex, concurrently. NHANES data was further stratified by insurance status (private or Medicare vs neither) and excluded sub-clinical HT to parallel OCD estimates. Results: Among both the OCD and matched NHANES cohorts, overall Tx of OHT was 83.6% & 79.5% respectively. The OCD cohort showed both males and females having similar Tx patterns across age and sex strata, ranging from 78.6% of males aged 60+ with evidence of Rx, to 91.3% of females aged 45-59. Among NHANES strata, overall Tx rates increased as age increases (ages 12-44 = 62% to 60+ = 87.5%) and higher in females than in males, especially among those aged 60+ years (ages 12-44 F:M; 66.2% - 53.2%, ages 45-59; 81.3% - 71.1%, and 60+; 93.7% - 67.0%). Sex differences were less pronounced, and the Tx rates tend to be lower among those aged 60+ years in OCD analysis (ages 18-44 F:M; 90.1% - 85.7%, ages 45-59; 91.3% - 87.8%, and 60+; 82.0% - 78.6%). Among the NHANES strata not privately or Medicare insured, OHT Tx rates overall were 55.9%, with younger females and males < 60 years old showing the lowest treatment rates (M 12-44 - 0% F 12-44 - 30%). Study Limitations: Claims data may incompletely capture the conditions and outcomes documented in the medical records and prevalence may be overestimated due to miss or rule out coding. The active surveillance of thyroid function conducted in NHANES might also have contributed to the differences. Likewise, NHANES may overestimate OHT as no re-testing occurs for thyroid function. Conclusions: This study provides important updates to the treatment of HT by age-groups and sex using both total and insured population estimates. Differences between NHANES and OCD Tx patterns may be due to the population-based approach of NHANES compared to care-seeking behavior as observed in claims data. Further analyses to delineate treatment patterns by age & sex will be completed to better understand the treated and untreated population. Presentation: Friday, June 16, 2023

1148P Avelumab as second-line or later (2L+) treatment (tx) in patients (pts) with metastatic Merkel cell carcinoma (mMCC): Real-world tx patterns in France

1148P Avelumab as second-line or later (2L+) treatment (tx) in patients (pts) with metastatic Merkel cell carcinoma (mMCC): Real-world tx patterns in France

Real-World Treatment Patterns of Older Adults with Locally Advanced SCCHN Using SEER-Medicare

Roughly 50-67% of patients with squamous cell carcinomas of the head and neck (SCCHN) present with locally advanced (LA) disease and 65% of them relapse after initial therapy. The standard of care for LA SCCHN is definitive therapy (DT), a combination of surgery and or radiation therapy (RT), with or without platinum-based chemotherapy/cetuximab (chemo), that has been shown to optimize long term disease control. Few published analyses have characterized recent real-world treatment (Tx) patterns of older adults with LA SCCHN in the US. We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, a linkage of cancer registry and claims data, to identify patients diagnosed with LA SCCHN (first and only cancer) from 2010 to 2017 who initiated a relevant Tx (Tx initiation date defined as index date) and were continuously enrolled in Medicare Parts A, B, and D from 12 months pre-index until death or 12 months post-index. We used clinical guidelines regarding timing and frequency of treatments to build an algorithm that used Medicare claims to categorize initial Tx as non-DT, non-surgical DT (concomitant chemo+RT (cCRT) or chemotherapy before RT/cCRT), or surgical DT (surgery then RT/cCRT ± prior chemo). We identified 1052 older adults with LA SCCHN (median age 73 years, 37% female, and 81% non-Hispanic white) whose initial treatment was started a median of 26 days after initial diagnosis. Of the 610 patients who received a DT as their initial Tx, 23.3% of patients had a subsequent Tx: 3.8% received immunotherapy-containing regimens (IO), and the most common subsequent Tx were surgery only (7.7%), chemotherapy only (3.6%), and RT only (3.4%). The median time to next Tx (TTNT) differed by DT category and primary tumor site. (Table 1) CONCLUSION: In this descriptive analysis, we provided an update on the Tx patterns of older adults with LA SCCHN in the US, for whom there have been no novel FDA approvals in over a decade. We found that a large proportion (42%) of patients did not receive DT regimens in the real-world setting despite known benefits in LA SCCHN. Roughly a quarter of patients required subsequent Tx. Availability of IO was low due to approvals after 2017. These findings suggest a need for novel therapies that can improve outcomes in LA SCCHN.

Real-world outcomes by race in patients (pts) with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL): Final analysis results from the informCLL registry.

7536 Background: informCLL is a large, US-based, prospective, observational registry of pts with CLL/SLL initiating treatment (tx) in the era after approval of ibrutinib (Ibr). Here, we report real-world tx patterns and outcomes by race and line of therapy (LOT) from the final analysis of informCLL. Methods: Pts with CLL/SLL who initiated FDA-approved tx were enrolled between 10/2015 and 6/2019. Baseline characteristics, tx patterns, time to next tx (TTNT), OS, and safety are summarized by race (focus on Black and White pts) and LOT (first-line [1L] or relapsed/refractory [R/R], with focus on 1L). Results: Of 1459 eligible pts enrolled, 105 were Black (1L, n=58; R/R, n=47), 1323 were White (1L, n=779; R/R, n=544), and 31 were of other races (Asian [n=6], Native American [n=4], other/not reported [n=21]). Relative to White pts, 1L-treated Black pts were younger (median age 65 vs 70 y) and had worse performance status (ECOG status ≥1: 59% vs 50%), more advanced disease (Rai stage III-IV: 55% vs 46%), shorter time from diagnosis to 1L tx (median 7 vs 19 mo), and lower rates of del(17p) among tested pts (6% vs 13%). Across race, Ibr was the most common 1L tx (Black, n=29 [50%]; White, n=346 [44%]) followed by CIT (Black, n=25 [43%]; White, n=331 [42%]). With median follow-up of approximately 32 mo in 1L-treated pts, the estimated rate of freedom from next-line therapy at 36 mo was similar between Black and White pts across all-treated pts and among Ibr-treated subgroups (Table). Estimated 36-mo OS rates in all-treated pts were also similar by race, with a high OS rate observed among Ibr-treated Black pts (97% at 36 mo). In multivariate analyses (MVA) in 1L-treated pts, male gender, poorer ECOG status, and increased comorbidity burden were independent predictors of decreased OS while race was not associated with OS. In 1L Ibr-treated pts, the only factor associated with decreased OS in MVA was longer time from diagnosis to 1L tx. Rates of serious AEs and AEs leading to tx discontinuation appeared similar across race (Table). Conclusions: Although historical retrospective studies from the pre-novel agent era have shown poorer clinical outcomes among Black pts with CLL relative to non-Black pts, results from informCLL show similar or potentially improved outcomes, including OS, among 1L Ibr-treated Black pts relative to White pts. These results suggest that access to novel agents such as Ibr may in part overcome historical disparities in clinical outcomes by race in pts with CLL. Clinical trial information: NCT02582879 . [Table: see text]

Clinical value of timely targeted therapy (TT) for patients with advanced non-small cell lung cancer (aNSCLC) with actionable driver oncogenes (ADO).

6507 Background: Recent real-world studies observed that some aNSCLC pts with ADO initiated non-targeted therapy (non-TT) before biomarker test results became available. This study assesses the clinical impact of the timing of first line (1L) TT in aNSCLC pts with ADO. Methods: In a retrospective analysis of the nationwide Flatiron Health electronic health record-derived de-identified database, pts aged ≥18 years, diagnosed (Dx) with aNSCLC between 1/1/2015-10/18/2022, had ADO (ALK, BRAF, EGFR, RET, MET, ROS-1, or NTRK) based on biomarker testing ≤ 90 days of advanced Dx, and received 1L treatment (tx) were included. Cohorts were defined by tx patterns after test result: Cohort 1 received 1L TT ≤ 42 days; Cohort 2 initiated 1L non-TT before or after testing but switched to TT ≤ 42 days; Cohort 3 initiated non-TT before or after testing and did not switch to TT ≤ 42 days. Pts were followed from test results + 42 days until 11/30/2022 or death, whichever earliest. Multivariate Cox regression evaluated real-world progression-free survival (rwPFS) and overall survival (OS) between cohorts. Results: A total of 5156 aNSCLC pts with ADO were included: 79% were treated in the community setting and 56% received NGS testing. Most common ADO were EGFR and ALK for both Cohort 1 (78% and 13%) and Cohort 2 (67% and 24%); EGFR (39%) and BRAF (35%) for Cohort 3. Cohort 3 included more rare mutations (MET, NTRK, RET). Statistically significant differences were observed in gender, race/ethnicity, practice type, and area-level socioeconomic status across all cohorts. There was no significant difference in outcomes observed between Cohort 2 and 1, but significantly inferior outcomes in Cohort 3 vs 1. Conclusions: Our findings demonstrated better outcomes with upfront 1L TT vs non-TT in aNSCLC pts with ADO. The comparable outcomes between pts who received 1L TT after test result and pts who switched to TT ≤ 42 days of test result available underscore the importance of timely tx decisions based on ADO detection in lieu of tx-switch at progression. Opportunities remain to improve utilization of NGS to identify all ADO upfront to inform the appropriate 1L TT when indicated. [Table: see text]

The evolution of treatment patterns in patients (pts) with locally advanced or metastatic urothelial cancer (la/mUC) and clinical outcomes: Results of a longitudinal observational cohort study in England.

e16559 Background: Treatment (tx) guidelines for pts with la/mUC in England have evolved over the last decade following the approval of successive immune checkpoint inhibitors (ICIs). However, the impact of this evolution on routine clinical practice (RCP) remains unclear. We aimed to describe shifts in tx patterns and associated clinical outcomes in RCP in England. Methods: This retrospective cohort study included pts aged ≥18 years, with primary stage III/IV UC diagnosis (dx) between Jan 1, 2013 and Dec 31, 2020, in the National Cancer Registration Dataset with follow-up to May 31, 2022. Pts’ dx were stratified at Dec 31, 2017, to split the cohort into pre- and post-ICI eras. Lines of systemic therapy were derived via an algorithm using data from the Systemic Anti-Cancer Therapy dataset. Summary statistics and overall survival (OS) were calculated and compared using χ2 and log-rank tests, respectively. The Kaplan-Meier method was used to estimate median OS from dx and from systemic tx initiation. Results: In the pre- and post-ICI groups, the majority of pts were male (65.7% and 65.5%) and mean modified Charlson-Deyo Comorbidity Index was 3.4 and 3.5, respectively. Mean age was 73.2 years in both groups, while a higher percentage of pts in pre-ICI era had stage IV disease at dx (68.3% and 50.0%; p<0.001). The rate of first line (1L) tx increased from 30.4% to 35.3% (p<0.001) and second line (2L) from 31.2% to 37.3% (p<0.001). The proportion of pts who received ICI in any line increased from 13.7% to 31.6% (p<0.001). Median OS from 1L tx improved from 13.8 to 15.5 mo. Conclusions: While pt demographics did not change considerably between the two groups, 1L and 2L tx rates moderately increased over time, although remained below 40%. In both groups, >85% of treated pts received 1L platinum chemotherapy, consistent with guidelines. In the post-ICI era, approximately one-third of treated pts received ICI therapy in any line. Improved OS from 1L tx could be partially attributable to the increased availability and uptake of ICIs. [Table: see text]

Treatment (Tx) patterns, efficacy and safety of eribulin for advanced and heavily pretreated breast cancer (ABC): A single-center, real-world study.

e13118 Background: We evaluated the Tx patterns, efficacy and safety of eribulin for heavily pretreated ABC in real-world practice. Methods: Patients (pts) with ABC who had progression on anthracycline/taxane Tx and received eribulin (1.4 mg/m2 IV on Days 1 and 8 of a 21-day cycle) between April 2020 and August 2022 were enrolled. Response was evaluated using RECIST v1.1. Results: 73 pts were enrolled. Median (range) age was 54 (30–79) years; 78.1% had an Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0–1, and pts had a median of 3 prior lines of chemotherapy. 69.9% of pts had Ki67 >30% and 52.1% had HR+/HER2− disease. 90.4% of pts had visceral metastasis. Eribulin was monotherapy in 28.8% of pts, and combined with bevacizumab, capecitabine, bevacizumab + capecitabine, and anti-HER2 agents in 28.8%, 10.9%, 4.1%, and 27.4%, respectively. The objective response rate was 24.7%; disease control rate was 75.3%. Median progression-free survival (PFS) overall was 6.0 (95% CI, [3.8–8.2]) months (mo). Univariate analysis indicated pts with HER2+ disease had longer PFS than pts with HR+/HER2− or triple-negative BC (median, 8.0, 6.0, and 3.0 mo, respectively; P = 0.049). Pts with Ki67 expression ≤30% had longer PFS than pts with Ki67 >30% (median, 8.0 vs. 4.0 mo; P = 0.024). Pts with late relapse (disease-free survival [DFS] >24 mo) had longer PFS than pts with early recurrence (DFS 6–24 mo) or de novo disease (DFS <6 mo; median PFS, 9.0, 4.5, and 3.6 mo, respectively; P = 0.026). Among 38 pts with HR+/HER2− ABC, pts who received eribulin plus capecitabine had longer PFS than pts who received eribulin monotherapy (median 11.4 vs. 4.0 mo, P = 0.021). Among the 18 pts with a partial response, median PFS was 9.5 mo. Multivariate analysis indicated line of Tx predicted PFS; pts who received eribulin as line 1–3 had longer PFS than pts who received eribulin as line >3 (HR=0.42 [95% CI, 0.19–0.93]; P = 0.034). The most common adverse events were leukopenia (43.2%), anemia (37.9%), and neutropenia (37.8%). Neurotoxicity was rare (2.7%). Conclusions: In this single-center study of pts with heavily pre-treated ABC in China, eribulin Tx resulted in favorable PFS irrespective of molecular subtype, with a manageable safety profile. In pts with a large tumor burden and a good PS, eribulin-based combinations may further improve outcomes. [Table: see text]

A real-world evaluation of treatment (Tx) patterns and outcomes of acute myeloid leukemia (AML) induction therapies in the community setting.

e19006 Background: AML is an aggressive hematologic malignancy of older adults (median age at diagnosis: 68 y); median overall survival (mOS) is low, even with Tx. The VIALE-A study changed the standard of care by combining venetoclax (VEN) with a hypomethylating agent (HMA), extending mOS from 9 to 14 mo. With the evolving Tx landscape and growing availability of less-intensive induction chemotherapy (IC), it is important to understand the impact of these Tx in the real world. This study evaluated Tx patterns and clinical outcomes for patients (pts) with AML who received intensive IC, VEN-based Tx (eg, VEN + azacitidine), or non-VEN-based low-intensity (NVB-LI) Tx (eg, a single HMA) in the first-line (1L) setting. Methods: A retrospective, observational, US-based, cohort study was conducted utilizing electronic health record data from adults with AML who initiated 1L IC between 01/01/2016 and 12/31/2019, or 1L VEN-based Tx or 1L NVB-LI Tx between 01/01/2019 and 12/31/2020. Eligible pts had ≥6 mo of follow-up after 1L initiation (or <6 mo due to death). Pts who received AML Tx as part of clinical trials were excluded. Remission was defined as a physician-reported best response of complete remission (CR), CR with incomplete hematologic improvement, or CR with no measurable residual disease. Time-to-event outcomes were assessed using the Kaplan–Meier method; all other data were summarized using descriptive statistics. Results: A total of 451 pts were included; 54% were male, 70% were White. Median follow-up was 17 mos. Mean age at 1L initiation was 52, 73, and 76 y in the IC, VEN, and NVB-LI cohorts, respectively. Among the 207 pts in the IC cohort, 99% discontinued Tx during follow-up, 85% of whom discontinued due to completion of Tx. Among the 152 pts in the VEN cohort and 92 in the NVB-LI cohort, 72% and 75% discontinued Tx, respectively, primarily due to disease progression (59% and 68% of discontinuing pts, respectively). Median duration of 1L Tx was 2, 11, and 7 mo in the IC, VEN and NVB-LI cohorts, respectively. In the IC, VEN, and NVB-LI cohorts, 80%, 45%, and 20% of pts achieved remission during 1L Tx; median time to remission was 1, 3, and 3 mo, respectively. Median relapse-free survival was not reached during follow-up in any of the cohorts. In the IC cohort mOS was not reached; mOS was 17 mo in the VEN cohort, and 9 mo in the NVB-LI cohort. Conclusions: Pts receiving 1L IC had the highest rate of remission, the shortest time to remission, and the most favorable mOS among all Tx cohorts, supporting continued intensive chemotherapeutic approaches with curative intent in eligible pts. mOS favored combination VEN-based Tx over NVB-LI, suggesting that VEN-based therapies may provide more benefit for pts ineligible for IC. Further research is warranted to determine the most appropriate Tx approach for pts with AML based on Tx effectiveness, pt medical history, and IC eligibility.

REAL‐WORLD DURATION OF VENETOCLAX TREATMENT FOR CHRONIC LYMPHOCYTIC LEUKEMIA AND SMALL LYMPHOCYTIC LYMPHOMA

Introduction: Venetoclax (V) is an approved fixed-duration treatment (tx) for chronic lymphocytic leukemia and small lymphocytic lymphoma (CLL/SLL), as a 12-cycle regimen (∼12 mos) with obinutuzumab (O) in the first-line (1L) setting or as a 24-cycle regimen (∼24 mos) with rituximab (R) in the relapsed/refractory (R/R) setting. We analyzed real-world tx patterns of V+O in 1L and V+R in R/R settings in patients (pts) with CLL/SLL in the United States. Methods: A retrospective cohort analysis was conducted using the IQVIA PharMetrics® Plus database to identify pts ≥18 y treated with V+O (1L cohort; May 2019 to September 2021) or V+R (R/R cohort; June 2018 to September 2021). Start of tx regimen was defined as the index date. All pts were required to have ≥1 diagnosis code for CLL/SLL and continuous enrollment 12 mos prior to and ≥3 mos after index date. Duration of tx (DoT) was defined as time from index date to earliest of either tx discontinuation (i.e., ≥60-d gap in V prescription refills) or censoring (i.e., end of follow-up). Fixed-duration tx cycle was defined as 12- or 24-cycle dosing (days 336−364 for 1L setting and days 707−735 for R/R setting, based on the dosing schedule plus 28 days). Kaplan-Meier analysis was used to estimate the probability of remaining on tx for the 1L and R/R cohorts. Results: A total of 116 pts in 1L setting (mean age, 62.3 y) and 145 pts in R/R setting (mean age, 64.2 y) were identified; 48.3% of R/R pts had prior targeted therapy. Median (95% CI) DoT in V+O pts (n = 115) was 12.4 (11.5, 13.4) mos over a median follow-up of 11.4 mos; probability of remaining on tx at 12, 18, and 24 mos was 56.4%, 20.2%, and 5.1%. Median (95% CI) DoT in V+R pts (n = 133) was 24.5 (13.4, 25.2) mos over a median follow-up of 15.5 mos; probability of remaining on tx at 24, 30, and 36 mos was 53.8%, 19.0%, and 19.0%. Among V+O pts, 47.8% (55/115) had ≥12 mos follow-up, of whom 9.1% had fixed cycles and 38.2% discontinued early (median DoT: 4.6 mos). Among V+R pts, 29.3% (39/133) had ≥24 mos follow-up, of whom 5.1% had fixed cycles and 46.2% discontinued early (median DoT: 7.1 mos). The remaining pts in each cohort had DoT >12 or 24 cycles (Table). Conclusions: While median DoT was approximately 12 mos for V+O-treated pts (1L setting) and 24 mos for V+R-treated pts (R/R setting), a high number of pts did not maintain the fixed-dosing schedule. This study provides evidence that a V-based approach may not be suitable for all pts with CLL/SLL. Encore Abstract—previously submitted to regional or national meetings (up to <1’000 attendees), EHA 2023 The research was funded by: AstraZeneca Keyword: Chronic Lymphocytic Leukemia (CLL) Conflicts of interests pertinent to the abstract A. Teschemaker Employment or leadership position: AstraZeneca Stock ownership: AstraZeneca S. Hakre Employment or leadership position: AstraZeneca Stock ownership: AstraZeneca J. Tse Research funding: AstraZeneca Pharmaceuticals. IQVIA received research funding from AstraZeneca to conduct this study. N. F. Shaikh Research funding: AstraZeneca Pharmaceuticals. IQVIA received research funding from AstraZeneca to conduct this study. Y. Gu Research funding: AstraZeneca Pharmaceuticals. IQVIA received research funding from AstraZeneca to conduct this study. A. Near Research funding: AstraZeneca Pharmaceuticals. IQVIA received research funding from AstraZeneca to conduct this study.