1L Cohort Research Articles

A phase II, multi-center, open-label study to evaluate the safety and efficacy of YH003 in combination with toripalimab (anti-PD-1 mAb) in patients with unresectable/metastatic pancreatic ductal adenocarcinoma (PDAC).

4146 Background: Pancreatic cancer therapy remains a formidable challenge. Although chemotherapy offers tumor control and clinical stabilization, both standard regimens are limited in response durability and incur toxicity. YH003, a humanized agonistic anti-CD40 monoclonal antibody specifically recognizes and agonizes CD40 to enhance immune responses, has demonstrated good safety and promising antitumor activity in Phase I clinical studies in patients with solid tumors. Here, we report the results of the phase II study of YH003 plus Toripalimab with/without chemotherapy, as 1L or 2L treatment in patients with metastatic PDAC. Methods: Patients with unresectable/metastatic (u/m) PDAC were enrolled into two Cohorts. In the second and plus line (2L+) Cohort, patients who had confirmed progressive disease during treatment with first line standard of therapy were enrolled and received 0.3 mg/kg YH003 plus 240 mg Toripalimab, iv, every 21 days. In the 1L Cohort, patients without any prior systemic treatment were enrolled and received 0.3 mg/kg YH003 plus 240 mg Toripalimab plus nab-paclitaxel + gemcitabine, iv, every 21 days. The treatment continued for 12 months if subject was deriving an ongoing clinic benefit. The primary endpoint was overall Response Rate (ORR) by investigator’s assessment per RECIST 1.1. The medium Progression-Free Survival (mPFS) and Overall Survival (mOS) were secondary endpoints. Results: A total of 92 patients were enrolled including 45 subjects for the 2L+ Cohort and 47 subjects for the 1L Cohort. In the 2L+ Cohort, 40 (including 14 Caucasians) of 45 patients had at least 1 evaluable post-treatment tumor assessment, the unconfirmed ORR was observed in 4 patients (10.0%) with 4 partial responses (PR). 10 patients (25.0%) had stable disease (SD), and the Disease Control Rate (DCR) was 35.0%. The mOS was 7.23 months. For the Caucasian subgroup (n = 14), the ORR was 7.1%, DCR was 50%, mPFS was 2.25 months and mOS 9.54 months. For the 1L Cohort, 43 (including 10 Caucasians) of 47 patients had at least 1 evaluable post-treatment tumor assessment, the unconfirmed ORR was observed in 12 patients (27.9%) with 1 CR and 11 PR. 23 patients (53.5%) had SD, and the DCR was 81.4%. The mOS time was 12.12 months. For the Caucasian subgroup (n = 10), the ORR was 50%, DCR was 100%, mPFS was 11.27 months and mOS 19.78 months. The grade 3 or above adverse events that occurred in the 92 patients were 57.8% (26/45) in 2L+ Cohort and 74.5% (35/47) in 1L Cohort. There is no significant safety signal from the study. Conclusions: The results of the phase II study have shown that YH003 plus Toripalimab with/without chemotherapy, as 1L or 2L treatment in patients with u/m PDAC have promising antitumor activity and response durability, especially in the Caucasian subgroups. Both treatment regimens are well tolerated. Clinical trial information: NCT05031494 .

A real-world study on biomarker retesting among patients with non-small cell lung cancer and disparity in outcomes.

8590 Background: Prior studies revealed sociodemographic disparities in biomarker testing among patients (pts) with advanced/metastatic non-small cell lung cancer (a/mNSCLC). However, the association of testing disparities with clinical outcomes among real-world pts requires further characterization. Methods: This retrospective study used ConcertAI Patient360™ US dataset to assess biomarker testing disparities and their association with median overall survival (mOS) among adults with a/mNSCLC (2017–2022) who received ≥1 line of therapy with ≥90-day follow-up. Analyses were conducted in pts who initiated first-line (1L) treatment and stratified by setting (community vs academic) and race. Biomarker testing is a curated data element in this database, leveraging structured and unstructured electronic medical record data and includes the following biomarkers ALK, BRAF, EGFR, KRAS, MET amp, MET exon 14, NTRK, PD-L1, RET, and ROS1. Biomarker testing to inform 1L decision was defined as testing before 1L start. Testing to inform second-line (2L) decision was defined as testing after 1L start and before 2L start. Variables were compared using chi-square or ANOVA tests. Unadjusted and adjusted OS using multivariate Cox proportional hazards are reported. Results: Of 3678 pts included in the 1L cohort, 3127 (85%) received 1L testing. In community settings, 22% of Black pts vs 15% of White pts did not receive 1L testing (P=0.002), whereas 1L testing rates between races were similar in academic settings (Table). In 2L community setting among pts who received 1L but not 2L testing, mOS was 5.9 vs 9.9 months in Black (n=54) vs White (n=529) pts, respectively (P=0.35). In 2L community setting among pts who were and were not tested prior to 1L and not tested at 2L, mOS was 5.9 vs 10.1 months in Black (n=62) vs White (n=613) pts, respectively (P=0.27). Accounting for recorded sociodemographic and clinical characteristics at baseline, differences in OS by testing setting and status start to normalize to the reference group. Disparities within groups appear to potentially exist despite no statistical significance (except for ECOG score of 2+). Conclusions: Despite small 2L sample sizes and lack of significance, disparities in testing rates and outcomes were observed, which may be overcome by normalizing testing across race and treatment setting to potentially improve pt outcomes. Further analysis can be performed across census regions. Further research is needed to confirm the impact of lack of biomarker testing on pt outcomes on a broader scale, particularly around characteristics that may impact outcomes but were undetected in this dataset. [Table: see text]

Prospective real-world evidence for the use of immune-checkpoint inhibitors and BRAF-targeted therapy in advanced melanoma from a large Canadian cohort.

e21533 Background: Clinical trial evidence showed that anti-PD1 ± anti-CTLA4 as well as BRAF ± MEK-inhibitors for BRAF-mutated tumours dramatically improved outcomes for patients with advanced melanoma. Large prospective data sets provide real-world insight into the management of patients with advanced melanoma in routine practice. Methods: Patients ≥ 18 years with unresectable or metastatic melanoma receiving therapy with first- (1L) or second-line (2L) anti-PD1 alone (PD1), with anti-CTLA4 (C-IO) or combination BRAF- and MEK-inhibitors (C-TT) were enrolled in a multi-centre prospective observational study across Canada. Data was collected from May 1, 2016 to November 30, 2021 and entered into the Canadian Melanoma Research Network Registry to include demographics and clinical details. Each patient was followed until death, up to 3 years, or date of data extraction, whichever occurred first. Results: Data for 401 (1L) and 128 (2L) patients was analyzed. There was a significant difference in the age at diagnosis for PD1 (69.2y), C-IO (57.8y), and C-TT (58.8y) in the 1L cohort (p < 0.0001) and 2L cohort (59.5y, 50.8y, and 50.9y respectively; p = 0.036). Patients treated with either C-IO or C-TT had a significantly higher baseline LDH (p = 0.0003) and proportion with brain metastases (p = 0.021) compared to PD1. The probability of survival for PD1, C-IO, and C-TT at 1 year was 0.85, 0.78, and 0.66; and at 3 years was 0.63, 0.54, and 0.36 respectively. The probability of survival for 2L PD1, C-IO, and C-TT at 1 year was 0.81, 0.53, and 0.56; and at 3 years was 0.55, 0.42, and 0.20 respectively. When comparing treatment regimens, the overall survival (OS) in 1L and 2L showed a superior survival for PD1 when compared with C-TT using a pairwise log-rank comparison (p < 0.0001 and p = 0.0009). There was no difference between C-IO and C-TT, or C-IO and PD1 in 1L or 2L. Using a Cox proportional hazard model for OS, the presence of brain metastases was significant only in 1L (HR 1.663, p = 0.01). There was no difference in OS based on age in either 1L or 2L for all treatments. When comparing regimens, the progression-free survival (PFS) in 1L showed no difference using a pairwise log-rank comparison; however, there was a significant improvement in PFS in 2L for PD1 compared with C-TT (p = 0.0014). There was no difference in PFS between C-IO and C-TT, or C-IO and PD1 in 2L. Conclusions: This real-world data suggests that patient selection is key when deciding on the most appropriate treatment in 1L or 2L as PD1 therapy appeared to have superior OS and PFS across comparisons. Patients with high-risk features such as high LDH and the presence of brain metastases received C-IO or C-TT more often than PD1. Age was not associated with OS in 1L or 2L for each treatment.

An open-label, multicenter study investigating RP3 oncolytic immunotherapy in combination with first- or second-line systemic atezolizumab plus bevacizumab in patients with locally advanced unresectable or metastatic hepatocellular carcinoma.

TPS576 Background: Despite advances in treatment for unresectable hepatocellular carcinoma (HCC), long-term survival rates remain poor. The combination of atezolizumab (Atezo) plus bevacizumab (Bev) is approved frontline therapy for advanced HCC, but a minority of patients (pts) respond and secondary resistance usually occurs within months. HCC has an immune-suppressed tumor microenvironment (TME), mediated by activated immune checkpoint signaling and angiogenesis pathways, which may contribute to therapeutic resistance. RP3 is a genetically modified herpes simplex virus type 1 (HSV-1) that expresses the fusogenic gibbon ape leukemia virus glycoprotein with the R sequence deleted (GALV-GP-R–), an anti–CTLA-4 antibody-like molecule, CD40 ligand, and 4-1BB ligand. The direct oncolytic effect coupled with immune stimulation by RP3 in the TME is intended to provide systemic antitumor activity and synergize with anti–PD-1/PD-L1 agents, such as Atezo. Preclinical data have demonstrated improved distribution of oncolytic HSV within tumors in combination with Bev, supporting the clinical combination of RP3 with Bev. This study will evaluate the safety and efficacy of RP3 combined with Atezo plus Bev as first- (1L) and second-line (2L) systemic therapies for unresectable and advanced HCC (NCT05733598). Methods: The 1L and 2L cohorts will each enroll up to 30 pts. Pts in the 1L cohort may not have received prior systemic treatment; pts in the 2L cohort must have progressed on or following 1 prior line of systemic therapy, which must have included a PD-1/PD-L1–directed agent. Key inclusion criteria include advanced unresectable HCC with ≥1 measurable tumor of ≥1 cm in longest diameter, Child-Pugh class A, and an Eastern Cooperative Oncology Group performance status of 0 to 1. Key exclusion criteria include untreated esophageal and/or gastric varices with bleeding or at high risk for bleeding and macroscopic invasion of the tumor into any major blood vessel(s) and/or main bile ducts. Pts with a history of medically refractory hepatic encephalopathy and/or hepato-renal syndrome are also excluded. Pts in the 1L cohort will receive Atezo 1200 mg and Bev 15 mg/kg every 3 weeks (Q3W) together with RP3 intratumorally Q3W for a total of up to 8 doses. Pts in the 2L cohort will receive RP3 every 2 weeks for 4 doses with Bev Q3W starting on cycle (C)1 day (D)1, then RP3 and Bev Q3W for up to 4 more doses with Atezo Q3W being added on C4D1. The primary endpoint is the overall response rate (ORR) by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Secondary endpoints are safety, ORR using HCC modified RECIST, duration of response, complete response rate, and progression-free survival. Clinical trial information: NCT05733598 .

A phase 1b study of sotorasib combined with panitumumab as second-line treatment of KRAS G12C-mutated colorectal cancer.

128 Background: In the CodeBreaK 101 phase 1b study, sotorasib, a KRASG12C inhibitor, plus panitumumab, an anti-epidermal growth factor receptor (EGFR) monoclonal antibody, showed acceptable safety and promising efficacy for patients with chemorefractory KRAS G12C–mutated metastatic colorectal cancer: an objective response rate (ORR) of 30% and median progression-free survival (PFS) of 5.7 months were observed. Here, we evaluated sotorasib plus panitumumab in the second-line (2L) setting. Methods: CodeBreaK 101 (NCT04185883) subprotocol H includes dose exploration and expansion in multiple cohorts. Patients eligible for the 2L sotorasib plus panitumumab dose-expansion cohort were KRASG12C inhibitor–naïve and had received no more than one prior regimen for metastatic disease. Patients received oral sotorasib at 960 mg daily and IV panitumumab 6 mg/kg every 2 weeks. The primary endpoint was safety. Secondary endpoints included efficacy endpoints. Results: As of May 23, 2023, this cohort was fully enrolled; all 20 patients (50% female, median age 60.0 years) were included in this analysis. All patients received fluoropyrimidine-based treatment and 17 (85%) patients received oxaliplatin-based treatment as first-line therapy. Any-grade treatment-related adverse events (TRAEs) occurred in 19 (95%) patients. The most common any-grade TRAEs were dermatitis acneiform (60%), dry skin (55%), pruritus (45%), and hypomagnesemia (30%). Grade ≥3 TRAEs occurred in 4 (20%) patients and included fatigue, hypomagnesemia, decreased appetite, and rash (5% each). No TRAEs were grade ≥4 or resulted in treatment discontinuation or deaths. Confirmed ORR was 30% (95% CI: 11.9, 54.3). The disease control rate was 90% (95% CI: 68.3, 98.8). At a median follow-up of 11.3 months (95% CI: 5.6, not estimable), median PFS was 8.3 months (95% CI: 4.3, 14.1). Conclusions: This is the first report of safety and efficacy from a 2L cohort evaluating a KRASG12C inhibitor plus an anti-EGFR antibody in KRAS G12C-mutated metastatic colorectal cancer. The toxicities of sotorasib plus panitumumab were consistent with the expected safety profile of the individual agents and with that reported previously for this combination; the ORR was similar to that previously observed for this combination in a more chemorefractory population. The ORR and PFS of sotorasib plus panitumumab compare favorably to current standard approaches in the 2L treatment of metastatic colorectal cancer. Clinical trial information: NCT04185883 .

Incremental Healthcare Resource Utilization and Costs Associated with Non-Optimal Treatment in Patients with Chronic Myeloid Leukemia in Chronic Phase (CML-CP) Treated with Tyrosine Kinase Inhibitors (TKI) in Early Lines of Therapy in the United States (US)

Introduction: TKIs are the standard of care for CML-CP. Although effective TKI options are available in early lines of therapy of CML, patients may experience intolerance or resistance to TKI leading to non-optimal treatment (NOPT). This retrospective cohort study assessed the incremental healthcare resource utilization (HRU) and medical costs associated with NOPT in patients with CML treated in first-line (1L) or second-line (2L) TKI therapy in the US. Methods: Adult patients with CML who received 1L TKI therapy with imatinib, dasatinib, nilotinib, or bosutinib (1L cohort), and those who received 2L TKI therapy with imatinib, dasatinib, nilotinib, bosutinib, or ponatinib (2L cohort), in 2012 or later, were selected from the OptumInsight Clinformatics database (01/2007-06/2022). Patients were required to have ≥2 years of continuous health plan coverage post-1L/2L initiation (1L/2L index date). Patients were classified in NOPT subgroup if they met one of the following criteria: 1) treatment discontinuation/switch within the first 6 months post-index, or 2) temporary treatment interruption and/or dose reduction within the first 6 months post-index followed by treatment discontinuation within the first 12 months post-index, or 3) low treatment adherence (proportion of days covered [PDC] ≤50%). Patients were classified in the reference (REF) subgroup if they met one of the following criteria: 1) high treatment adherence (PDC >90%) and no treatment discontinuation, 2) high treatment adherence (PDC >90%) and treatment discontinuation occurring more than 12 months post-index. All-cause HRU (inpatient [IP] admissions, outpatient [OP] visits, and emergency department [ED] visits) and associated medical costs (2022 USD) were measured during the 2 years post-index and reported per-patient-per-year (PPPY). Incremental HRU and costs of NOPT (vs. REF) were estimated using multivariable Poisson regressions and two-part models (adjusted for age, gender, race, region, health plan type, time from CML diagnosis to index date, and Darkow Disease Complexity Index), respectively. Adjusted incidence rate ratios (IRR) and mean cost differences (Δ) were reported along with p-value, estimated using bootstrap technique. All analyses were conducted separately in the 1L and 2L cohorts. Results: Of 2,043 patients that initiated 1L TKI therapy in 2012 or later, 197 patients were included in NOPT subgroup (median age: 69 years; 52.3% female; 68.5% White) and 284 in REF subgroup (median age: 62 years; 40.1% female; 74.6% White). Patients in NOPT subgroup had 80% more IP admissions (adjusted IRR=1.8; p <0.001) with twice more IP days (adjusted IRR=2.0; p=0.024), 30% more OP visits (adjusted IRR=1.3; p=<0.001) in the first 2 years post-index, as compared to REF subgroup. Consistently, patients in NOPT subgroup had higher medical costs (adjusted Δ=$13,551 PPPY; p=0.012) mainly driven by higher IP costs (adjusted Δ =$5,989 PPPY; p=0.028) along with numerically higher OP costs (adjusted Δ=$5,483 PPPY; p=0.060) in the first 2 years post-index, as compared to REF subgroup ( Figure 1). Of 586 patients that initiated 2L TKI therapy in 2012 or later, 69 patients were included in NOPT subgroup (median age: 67 years; 60.9% female; 76.8% White) and 72 in REF subgroup (median age: 68 years; 51.4% female; 69.4% White). Patients in NOPT subgroup had 3 times more IP admissions (adjusted IRR=3.1; p <0.001) with almost 7 times more IP days (adjusted IRR=6.7; p<0.001), 80% more ED visits (adjusted IRR=1.8; p=0.036), and numerically more OP visits (adjusted IRR=1.2; p=0.056) in the first 2 years post-index, as compared to REF subgroup. Consistently, patients in NOPT subgroup had higher medical costs (adjusted Δ=$30,962 PPPY; p=0.008) mainly driven by higher OP costs (adjusted Δ=$8,380 PPPY; p=0.016) and higher ED costs (adjusted Δ=$4,332 PPPY; p=0.012) along with numerically higher IP costs (adjusted Δ=$14,063 PPPY; p=0.100) in the first 2 years post-index, as compared to REF subgroup ( Figure 1). Conclusions: In this study of patients with CML-CP non-optimal treatment resulting in early treatment discontinuation/switch or dose interruptions/reduction in the first 6 months from treatment initiation or low adherence with the currently approved TKIs in 1L and 2L therapy for CML was associated with significant incremental economic burden. This highlights the need for more tolerable therapeutic options early in the treatment course.

Real-World Effectiveness and Safety Outcomes of Acalabrutinib Treatment By Line of Therapy in Patients with Chronic Lymphocytic Leukemia and/or Small Lymphocytic Lymphoma

Background: Acalabrutinib is a second-generation Bruton tyrosine kinase inhibitor (BTKi) approved by the Food and Drug Administration for the treatment of chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). Data from phase 3, randomized, controlled trials of acalabrutinib, as monotherapy or in combination with obinutuzumab, in patients with treatment-naive (TN) and relapsed/refractory (R/R) CLL with long-term follow-up, including ELEVATE-TN, ELEVATE-RR, and ASCEND, have demonstrated sustained improvement vs comparators in progression-free survival and overall survival (OS) with cardiovascular (CV) and bleeding events consistent with previous reports (Sharman et al. J Clin Oncol. 2021; Byrd et al. J Clin Oncol. 2021; Ghia et al. Blood. 2022). As real-world evidence of the acalabrutinib effectiveness and safety profile is limited in CLL/SLL patients, this study aimed to describe time to next treatment (TTNT), OS, and CV and bleeding events in patients receiving first-line (1L) and later-line (2L+) acalabrutinib for the treatment of CLL/SLL in the real-world setting. Methods: A retrospective, observational analysis was conducted utilizing the Optum Clinformatics © Data Mart claims and electronic medical record database to identify patients aged ≥18 years with TN or R/R CLL/SLL who initiated acalabrutinib in any line of therapy (LoT) on or after November 21, 2019 (FDA approval date for acalabrutinib). Patients with CLL/SLL were required to have ≥6 months of continuous enrollment in the Optum database system prior to acalabrutinib treatment initiation. Patients were followed until the earliest of last day of data availability, death, or end of study period (September 30, 2022). Treatment effectiveness was described as TTNT (time from acalabrutinib initiation to next LoT or death of any cause) and OS (time from acalabrutinib initiation to date of death from any cause or end of study period). The Kaplan-Meier (KM) method was used to estimate TTNT and OS. Patients who continued treatment at the last follow-up were censored. CV and bleeding events were assessed in all patients who initiated acalabrutinib. All outcomes were evaluated in patients who received 1L or 2L+ acalabrutinib therapy. Results: A total of 530 patients were identified and included in the analysis. Of these patients, 63% (n=334) received 1L acalabrutinib and 37% (n=196) received 2L+ acalabrutinib. At acalabrutinib initiation, the mean age was 72.8 years in the 1L cohort and 74.2 years in the 2L+ cohort; 61.7% (121/196) of patients treated with 2L+ acalabrutinib had prior BTKi therapy prior to acalabrutinib initiation (ibrutinib, n=120; zanubrutinib, n=1). Distributions of gender and race were similar between the cohorts. At baseline, 18.1%, 75.3%, and 16.0% of patients had atrial fibrillation/flutter, hypertension, and bleeding episodes, respectively. With a median follow-up of 8.9 months in the 1L cohort and 12.4 months in the 2L+ cohort, the median TTNT and OS were not reached in either cohort. At 18 months, the proportion of patients remaining on treatment was 82% in the 1L cohort and 78% in the 2L+ cohort ( Figure 1). Of the patients that progressed, the median TTNT was 4.0 months in the 1L cohort (n=33) and 4.2 months in the 2L cohort (n=31). The 18-month OS rate was 90% and 85% for the 1L and 2L+ cohorts, respectively ( Figure 2). After initiation of acalabrutinib treatment, the incidence rates of atrial fibrillation/flutter, hypertension, and bleeding events were 2.7%, 8.9%, and 2.7% of patients in the 1L cohort and 7.4%, 2.4%, and 3.3% of patients in the 2L+ cohort, respectively, who had no history of these events prior to treatment with acalabrutinib. Conclusions: This is the first study demonstrating real-world effectiveness (OS and TTNT) and safety data of acalabrutinib treatment in first-line and later-line therapy. While clinical trial and clinical practice settings may differ, overall, the survival findings in this study were similar to those of acalabrutinib trials. The observed incidence rates of CV and bleeding events were not inconsistent with those observed in published acalabrutinib trials.

Treatment Patterns and Modifications of Tyrosine Kinase Inhibitors (TKI) Therapy in Early Lines in Patients with Chronic Myeloid Leukemia in Chronic Phase (CML-CP): Real-World Analysis from a Large Commercial Claims Database in the United States (US)

Introduction: Although current TKI options are often successful in managing CML-CP in early lines of therapy, patients may experience issues related to tolerability or resistance to TKIs. Physicians often have to proceed with treatment modifications including discontinuation, switching, temporary interruptions, or dose modifications when the patient's current treatment is not working as expected. This retrospective cohort study assessed these TKI therapy management patterns in patients with CML in first-line (1L) or second-line (2L) treatment in the US. Methods: A large administrative claims database of commercially insured patients, the OptumInsight Clinformatics database (January 2007-June 2022), was used to select adult patients with CML who received 1L TKI therapy (imatinib, dasatinib, nilotinib, or bosutinib; 1L cohort) and those who received 2L TKI therapy (imatinib, dasatinib, nilotinib, bosutinib, or ponatinib; 2L cohort), with treatment initiation (index date) on or after 2012. Patients were required to have ≥6 months of continuous health plan enrollment pre-index, with no hematopoietic stem cell transplantation (HSCT) or CML-related chemotherapy treatments for accelerated phase (AP) or blast crisis (BC) pre-index. Treatment modifications assessed post-index included 1) treatment discontinuation, defined as the earliest of HSCT/treatment switch (defined below)/initiation of a CML-related chemotherapy for AP or BC, 2) treatment switch defined as initiation of another TKI/omacetaxine mepesuccinate, 3) temporary treatment interruption defined as gap of ≥ 14 days followed by resuming the index TKI, and 4) dose reduction (as compared to the initial dose) were assessed. Time to first event post-index were conducted using Kaplan Meier analyses for each of these treatment modifications, in 1L and 2L cohorts, separately. Results: A total of 2,043 patients were included in the 1L cohort with 47.8% of them receiving imatinib, 31.0% dasatinib, 19.2% nilotinib, and 2.0% bosutinib (median age: 64 years; 44.9% female; 69.7% White; 49.5% with Medicare advantage plan operated by commercial insurance [Part C]). Patients in the 1L cohort were observed for a mean (SD) period of 29.1 (27.3) months from index date to earliest of loss of follow-up/end of data. Overall, more than a quarter of patients (27.3%) experienced treatment discontinuation, with rates of discontinuation of 16.1% at 6 months, 25.0% at 12 months, and 33.5% at 24 months post-index ( Figure 1). Treatment switch was observed in 26.0% of the patients, with rates of 15.5% at 6 months and 24.4% at 12 months post-index. The proportion of patients with temporary treatment interruption was 18.6%, with rates of 20.6% at 6 months and 22.2% at 12 months post-index. Dose reduction (as compared to initial dose) occurred in 21.9% of patients, with rates of 18.8% at 6 months and 23.3% at 12 months post-index. A total of 586 patients were included in the 2L cohort with 23.0% of them receiving imatinib, 36.9% dasatinib, 26.6% nilotinib, 10.9% bosutinib and 2.6% ponatinib (median age: 65 years; 47.3% female; 72.5% White; 48.3% with Medicare advantage plan operated by commercial insurance [Part C]). Patients in the 2L cohort were observed for a mean (SD) period of 28.4 (25.4) months from index date to earliest of loss of follow-up/end of data. Almost a third of patients (32.8%) experienced treatment discontinuation, with rates of discontinuation of 22.1% at 6 months, 29.9% at 12 months, and 43.1% at 24 months post-index ( Figure 1). Treatment switch was observed in 30.5% of patients, with rates of 20.5% at 6 months and 28.3% at 12 months post-index. The proportion of patients with temporary treatment interruption was 21.3%, with rates of 24.8% at 6 months and 25.4% at 12 months post-index. Dose reduction as compared to initial dose occurred in 20.6% of patients, with rates of 17.5% at 6 months and 27.2% at 12 months post-index. Conclusions: Findings from this real-world study demonstrate that almost a quarter of patients with CML treated with current TKI treatment options in 1L or 2L experienced treatment discontinuation/switch in the first year from TKI initiation suggesting lack of optimal response/tolerability to currently available TKIs, with more pronounced rates in 2L. This suggests that unmet clinical needs still persist in this population, warranting optimal 1L and 2L treatment options with better tolerability profile for CML management.

ASC2ESCALATE: A US Phase 2, Open-Label, Single-Arm, Dose-Escalation Study of Asciminib (ASC) Monotherapy in Patients (Pts) with Chronic Myeloid Leukemia in Chronic Phase (CML-CP) As Second-Line (2L) and First-Line (1L) Treatment

CONCLUSIONS Adenosine triphosphate (ATP)-competitive tyrosine kinase inhibitors (TKIs) have increased survival in CML, although resistance and intolerance remain challenges, which often necessitate switch to another TKI. Many pts discontinue 1L treatment due to resistance/intolerance and switch to 2L therapy, to which resistance is typically higher. A need exists for effective, safe treatment options for pts in 1L and 2L. ASC is thefirst approved BCR::ABL1 inhibitor that Specifically Targets the ABL Myristoyl Pocket (STAMP), with activity against most BCR::ABL1 kinase domain mutations conferring resistance to ATP-competitive TKIs, potentially providing a new early-line treatment option. ASC was first approved in the United States for pts with CML-CP after ≥2 TKIs at 80 mg once daily (QD) or 40 mg twice daily (BID) and for pts with CML-CP with the T315I mutation at 200 mg BID. A large, phase 1, dose-escalation trial (NCT02081378) demonstrated efficacy and tolerability of ASC across a broad range of dosages. Also, with >2 years of follow-up, ASC demonstrated superior efficacy and better safety and tolerability compared with bosutinib in pts with CML-CP without the T315I mutation after ≥2 prior TKIs in the phase 3 ASCEMBL study (NCT03106779). We describe the phase 2 ASC2ESCALATE trial investigating efficacy and safety of ASC with dose escalation in pts with CML-CP receiving ASC as their 2L or 1L therapy. This is a phase 2, open-label, multicenter, single-arm, dose-escalation study with sites in the United States (NCT05384587) (Figure). Pts receiving ASC as their 2L TKI must be adults with non-T315I CML-CP who discontinued their first ATP-competitive TKI for warning response ( BCR::ABL1IS >1%-10% after 6 months or >0.1%-1% after 12 months of 1L treatment), resistance ( BCR::ABL1IS >10% after 6-12 months or >1% or loss of major molecular response [MMR] after >12 months of 1L treatment), or intolerance (with BCR::ABL1IS >0.1% at screening). In addition to pts receiving ASC as their 2L TKI, a separate cohort of newly diagnosed pts will be included, and these pts may receive up to 4 weeks of prior treatment with imatinib or an approved second-generation TKI (Table). All pts will start treatment with ASC 80 mg QD. Pts achieving BCR::ABL1IS ≤1% at 6 months will continue at the same dose; pts not achieving BCR::ABL1IS ≤1% at 6 months will have their dose escalated to 200 mg QD. In pts not achieving MMR at 12 months, dose escalation from 80 to 200 mg QD or from 200 mg QD to 200 mg BID will occur or the pt will be taken off the study. If pts have grade ≥3 or persistent grade 2 toxicity refractory to optimal management, no dose escalation will occur, and pts will remain on ASC at their most current dose. This dose-escalation strategy applies to both the 2L and 1L cohorts. The primary endpoint is MMR rate at 12 months in pts using ASC as their 2L TKI. As all primary and secondary endpoints for the 2L cohort will be measured for the 1L cohort as secondary endpoints, the MMR rate at 12 months in pts receiving ASC as their 1L TKI is a secondary endpoint. Additional secondary endpoints are the same for both 2L and 1L cohorts and include MMR rates at 3, 6, 18, and 24 months; MMR rates by all scheduled time points; MR 2 ( BCR::ABL1IS ≤1%), MR 4 ( BCR::ABL1IS ≤0.01%), and MR 4.5 ( BCR::ABL1IS ≤0.0032%) at and by scheduled time points; time to and duration of MMR; time to treatment failure; progression-free survival; overall survival; and safety/tolerability. Exploratory endpoints include assessment of BCR::ABL1 mutations. ASC2ESCALATE is the first clinical trial designed to assess pts with CML-CP using ASC as their 2L TKI and will provide critical information on efficacy and safety of dose escalation in pts for whom certain response milestones are not met in 2L and 1L. Dose escalation of ASC in 2L and 1L is another treatment strategy and results from ASC2ESCALATE will add to the growing body of evidence for using ASC to treat pts with CML-CP. Recruitment for pts using ASC as their 2L TKI began November 2022, and as of July 10, 2023, 5 pts have been enrolled in this cohort; Up to 92 and 90 pts are estimated to enroll in the 2L and 1L cohorts, respectively, across 90 sites.

Real-World Patterns of Care and Financial Burden of Patients with Follicular Lymphoma in the United States

Introduction: Follicular lymphoma (FL) is the most common indolent non-Hodgkin lymphoma and accounts for nearly a quarter of cases. As a heterogenous disease with an estimated 20% having progression of disease within 24 months of first FL therapy, FL often quickly becomes relapsed or refractory (R/R) to current therapy. The objective of this study was to evaluate the real-world treatment patterns, time to next treatment, and associated costs and healthcare resource utilization (HCRU) in patients with FL in the United States. Methods: A retrospective observational study was conducted using an integrated real-world database including linked data from the Symphony Integrated Dataverse (IDV ®), electronic medical records, specialty pharmacy, and in-office dispensing datasets. Patients were included in the study if they were ≥ 18 years old and initiated a first-line (1L), second-line (2L), third-line (3L), or fourth-line (4L) of therapy for FL between 1/1/2019 and 12/31/2022. Patients were categorized by line of therapy into non-mutually exclusive cohorts based on the date of initiation of their treatment regimen. Each line of therapy cohort was followed for a minimum of 90 days through lost to follow-up or end of the study period (3/31/2023). Patients were also required to have continuous pre-index enrollment of 365 days to record baseline comorbidities. Demographics, clinical characteristics, and treatment regimens were examined for each line of therapy cohort. Within each line of therapy, patients were categorized into 6 mutually exclusive subgroups based on their treatment regimens: bendamustine + rituximab (BR), rituximab monotherapy (R-mono), cyclophosphamide, doxorubicin, prednisone, rituximab + vincristine (R-CHOP), bendamustine + obinutuzumab (BO), lenalidomide + rituximab (R2), and other treatments for all other regimens. Advancement to the next line of therapy, treatment regimen distribution, and switching for each cohort and subgroup were evaluated during the follow-up period. Treatment duration, time to next treatment (TTNT), HCRU and pharmacy costs were measured for each cohort and treatment regimen during the follow-up period. HCRU included outpatient visits and hospital claims, reported as per patient per month (PPPM) over the time on each treatment regimen. Results: The study population included 9,579 patients initiating 1L, and then 3,061, 952 and 263 patients who received 2L, 3L, and 4L, respectively. The median follow-up was 719 days (1L), 652 days (2L), 578 days (3L), and 468 (4L). Mean age at index was similar across treatment lines, ranging from 66.7 years (1L) to 67.9 years (4L). Males represented a little under half (47.3%) in 1L cohort but increased slightly with subsequent lines (49.3%, 2L; 54.9%, 3L; 70% 4L). The most common baseline comorbidities across treatment lines were hypertension (1L=35.2%; 2L=32.3%; 3L=29.8%; and 4L=28.1%) and gastrointestinal disease (1L=23.9%; 2L=22.2%; 3L=22.2%; and 4L=22.1%). Across all treatment lines, R-mono was the most common regimen (1L=34.1%; 2L=29.0%; 3L=23.8%; and 4L=18.6%) followed by BR (1L=32.8%; 2L=17.3%; 3L=12.0%; and 4L=11.4%), and R-CHOP (1L=14.5%; 2L=12.8%; 3L=10.1%; and 4L=9.5%). Median TTNT across all regimens was 417 days (159, 691) in 1L, 444.5 days (225, 661) in 2L, 414 days (174, 784) in 3L, and 382.5 days (200.5, 599.5) in 4L (Figure 1). Mean (standard deviation; SD) of all-cause outpatient visits PPPM were 5.99 (4.86) in 1L, 6.06 (5.42) in 2L, 6.27 (6.04) in 3L, and 6.25 (5.95) in 4L. Mean (SD) of FL-specific outpatient visits PPPM were 4.59 (4.00) in 1L, 4.49 (4.31) in 2L, 4.57 (4.93) in 3L, and 4.42 (4.65) in 4L. The mean all-cause hospitalizations PPPM were 0.35 (1.72) in 1L, 0.79 (3.36) in 2L, 1.94 (6.29) in 3L, and 1.85 (5.00) in 4L. The mean FL-related hospitalizations PPPM were 0.13 (0.76) in 1L, 0.18 (1.02) in 2L, 0.36 (1.56) in 3L, and 0.45 (2.12) in 4L (Figure 2). Average pharmacy costs PPPM increased from $1,033 ($3,963.8) in 1L to $2,166.6 ($6,001.1) in 2L, and $2,943.7 ($6,413.1) to $3,374.1 ($7,361.3) in 3L and 4L, respectively. Conclusions: Real-world treatment patterns for patients with FL were shown to be mostly consistent with clinical guidelines. This study highlighted that TTNT decreased while hospitalizations and pharmacy costs increased as line of therapy progressed, suggesting high financial burden and unmet need for better treatment options for R/R FL patients.

An open-label, multicenter study investigating RP3 oncolytic immunotherapy in combination with first- or second-line systemic atezolizumab and bevacizumab therapy in patients with locally advanced unresectable or metastatic hepatocellular carcinoma.

TPS4178 Background: Despite advances in treatment for unresectable hepatocellular carcinoma (HCC), long-term survival rates remain poor. The combination of bevacizumab (Bev) and atezolizumab (Atezo) is the preferred frontline therapy for advanced HCC, but a minority of patients (pts) respond, and secondary resistance usually occurs within months. HCC has an immune-suppressed tumor microenvironment, mediated by activated immune checkpoint signaling and angiogenesis pathways, which may contribute to therapeutic resistance. RP3 is a genetically modified herpes simplex virus type 1 (HSV-1) that expresses the fusogenic gibbon ape leukemia virus glycoprotein with the R sequence deleted (GALV-GP-R–), an anti–CTLA-4 antibody-like molecule, CD40 ligand, and 4-1BB ligand. The direct oncolytic effect coupled with immune stimulation by RP3 in the tumor microenvironment is intended to provide systemic antitumor activity and enhance therapeutic response to anti–PD-1/PD-L1 agents, such as Atezo. Preclinical data have demonstrated improved distribution of oncolytic HSV within tumors in combination with Bev, supporting the clinical combination of RP3 with Bev. This study will evaluate the safety and efficacy of RP3 combined with Atezo and Bev as first- (1L) and second-line (2L) systemic therapies for unresectable and advanced HCC. Methods: The 1L and 2L cohorts will each enroll up to 30 pts. Pts in the 1L cohort may not have received prior systemic treatment; pts in the 2L cohort must have progressed on or following one prior line of systemic therapy, which must have included a PD-1/PD-L1−directed agent. Key inclusion criteria include advanced, unresectable HCC with ≥1 measurable tumor of ≥1 cm in longest diameter, Child-Pugh Class A, and Eastern Cooperative Oncology Group performance status of 0−1. Key exclusion criteria include untreated esophageal and/or gastric varices with bleeding or at high risk for bleeding and macroscopic invasion of tumor into any major blood vessel(s) and/or main bile ducts. Pts with a history of medically refractory hepatic encephalopathy and/or hepato-renal syndrome are also excluded. Pts in the 1L cohort will receive 1200 mg Atezo and 15 mg/kg Bev every 3 weeks (Q3W) together with RP3 intratumorally Q3W for a total of up to 8 doses. Pts in the 2L cohort will receive RP3 every 2 weeks for 4 doses with Bev Q3W starting on cycle (C) 1 day (D) 1, then RP3 and Bev Q3W for up to 4 more doses with Atezo Q3W being added on C4D1. The primary endpoint is overall response rate (ORR) by Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Secondary endpoints are safety, ORR using HCC modified RECIST, duration of response, complete response rate, and progression-free survival. Clinical trial information: NCT05733598 .

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.

An open-label, multicenter study investigating RP3 oncolytic immunotherapy in combination with first- or second-line systemic atezolizumab and bevacizumab therapy in patients with locally advanced unresectable or metastatic hepatocellular carcinoma.

TPS623 Background: Despite advances in treatment for unresectable hepatocellular carcinoma (HCC), long-term survival rates remain poor. The combination of bevacizumab (Bev) and atezolizumab (Atezo) is the preferred frontline therapy for advanced HCC, but a minority of patients (pts) respond, and secondary resistance usually occurs within months. HCC has an immune-suppressed tumor microenvironment, mediated by activated immune checkpoint signaling and angiogenesis pathways, which may contribute to therapeutic resistance. RP3 is a genetically modified herpes simplex virus 1 (HSV-1) that expresses the fusogenic GALV-GP R- protein, an anti–CTLA-4 antibody-like molecule, CD40 ligand, and 4-1BB ligand. The direct oncolytic effect coupled with immune stimulation by RP3 in the tumor microenvironment is intended to provide systemic anti-tumor activity and reverse therapeutic resistance to anti-PD-1/PD-L1 agents. Pre-clinical data has demonstrated improved distribution of oncolytic HSV within tumors in combination with Bev supporting the clinical combination of RP3 with Bev. RP3 combined with anti-PD1 therapy has demonstrated clinical activity and safety in pts with various malignant solid tumors. This study will evaluate the safety and efficacy of RP3 combined with Atezo and Bev as 1st (1L) and 2nd (2L) line systemic therapies for inoperable and advanced HCC. Methods: The 1L and 2L cohorts will each enroll up to 30 pts with advanced, unresectable HCC. Pts in the 1L cohort may not have received prior systemic treatment; pts in the 2L cohort must have progressed on or following one prior line of systemic therapy, which must have included a PD-(L)1 directed agent. Key inclusion criteria include advanced unresectable HCC with at least 1 measurable tumor of ≥1 cm in longest diameter, Childs-Pugh Class A, and ECOG Score of 0 or 1. Important exclusion criteria include untreated esophageal and/or gastric varices with bleeding or at high risk for bleeding, and macroscopic invasion of tumor into major blood vessels and/or main bile ducts. Pts with a history of medically refractory hepatic encephalopathy and/or hepato-renal syndrome are also excluded. Pts in 1L cohort will receive 1200 mg Atezo and 15mg/kg Bev Q3W together with RP3 intratumorally (IT) Q3W for a total of up to 8 doses. In 2L pts will receive RP3 Q2W for 4 doses with Bev Q3W starting on C1D1, then RP3 and Bev Q3W for up to 4 more doses with Atezo Q3W being added on C4D1. The primary endpoint includes overall response rate (ORR) by RECIST v1.1. Secondary endpoints are safety, ORR using HCC mRECIST, duration of response, complete response rate, and progression-free survival.

Real-World Outcomes with First-Line Ibrutinib (Ibr) Versus Chemoimmunotherapy (CIT) in Patients with Chronic Lymphocytic Leukemia (CLL)/Small Lymphocytic Lymphoma (SLL): Final Analysis Results from the InformCLL Registry

Background: The therapeutic landscape for CLL/SLL has rapidly evolved with the introduction of novel agents such as Ibr. The informCLL registry (PCYC-1134; NCT02582879) is the largest US-based prospective, observational registry of patients (pts) initiating FDA-approved treatment for CLL/SLL in the era after approval of Ibr. Here, we report real-world (RW) outcomes in pts with CLL/SLL receiving first-line (1L) therapy, including comparison of 1L Ibr versus CIT, from the final analysis of informCLL. Methods: Pts with CLL/SLL who initiated FDA-approved treatment (within ±45 days of enrollment) were enrolled between 10/2015 and 6/2019. Pts were primarily enrolled from community-based practices (comprising 93% of sites). Data were collected for baseline characteristics, treatment patterns, and safety. Time to next treatment (TTNT) was estimated by Kaplan-Meier method and for comparison of outcomes with 1L Ibr versus CIT, by Cox proportional hazards regression analysis in weighted cohorts. Inverse probability of treatment weighting (IPTW) was performed to balance the baseline characteristics between cohorts. Adverse events (AEs) were evaluated using overall incidence and exposure-adjusted incidence rates (EAIRs). Results: Of the 1459 eligible pts enrolled, 854 were treated in the 1L setting (59%). In the overall 1L cohort, median age was 70 years (≥75 years in 33%); 90% had ECOG performance status of 0 or 1; 47% had Rai stage III/IV (among n=547 with Rai staging); median Charlson Comorbidity Index (CCI) score was 1 (range 0-12) with CCI ≥3 in 16%; median time from initial diagnosis to 1L treatment was 19 mo. FISH testing data were available in 57% of pts in the 1L cohort; among these pts, 12% had del(17p). The most common 1L therapies were Ibr (45%; single-agent Ibr in 43% of all 1L therapies) and CIT (43%: most commonly BR, 24%); immunotherapy was given in 11% while chemotherapy (0.9%) and other novel agents (0.7%) were rare. With a median follow-up of 31.8 mo in the 1L cohort, median TTNT was not reached (NR); estimated proportions of pts without next-line therapy (NLT) were 79% at 24 mo, 71% at 36 mo, and 64% at 48 mo. The 1L cohort included 383 pts treated with Ibr and 363 pts treated with CIT; median follow-up was 31.4 mo for the Ibr cohort and 34.3 mo for CIT. Compared with the CIT cohort, pts in the Ibr cohort were older, had longer time from diagnosis to treatment, were more likely to have a history of other malignancy, and were more likely to have del(17p) or TP53 mutation (Table). Baseline characteristics in the weighted cohorts were balanced. In the IPTW-adjusted cohorts, median TTNT was NR for Ibr and 56.5 mo for CIT; TTNT was improved with Ibr relative to CIT (hazard ratio 0.744; 95% CI, 0.563-0.981) (Figure). Estimated proportions free of NLT in the weighted Ibr cohort were 75% at 36 mo and 69% at 48 mo; rates in the weighted CIT cohort were 66% and 57%, respectively. Median duration of index treatment was 24.0 mo for 1L Ibr and 4.7 mo for CIT. In the Ibr cohort (n=383), serious AEs occurred in 144 pts (38%), most commonly (≥3% of pts) pneumonia (n=23; 6%) and atrial fibrillation (Afib; n=21; 5%); AEs led to discontinuation of Ibr in 135 pts (35%), most commonly Afib (n=19; 5%) and fatigue (n=12; 3%). In the CIT cohort (n=363), serious AEs occurred in 85 pts (23%), most commonly febrile neutropenia (n=13; 4%) and pneumonia (n=11; 3%). AEs led to discontinuation of CIT in 61 pts (17%), and no single AE term led to discontinuation in ≥3% of pts (most common was anemia, 2%). EAIRs per 100 pt-mo for serious AEs were 1.93 with Ibr and 4.55 with CIT. EAIRs per 100 pt-mo for AEs leading to discontinuation were 1.53 with Ibr and 3.09 with CIT. Conclusion: In this large RW registry of pts with CLL/SLL, results from IPTW-adjusted analysis showed that 1L Ibr was associated with longer TTNT than CIT, with sustained benefit up to 4 years of follow-up. Pts receiving 1L Ibr therapy tended to be older, more often had a history of other malignancy, and more often had high-risk genomic features (del(17p) or TP53 mutation among those tested) than pts treated with CIT. The spectrum and frequency of AEs observed with these 1L regimens appear consistent with data from clinical studies and other RW studies. When adjusted for exposure, rates of AEs leading to discontinuation and serious AEs were lower with Ibr than CIT. Future analyses examining the impact of factors such as age/comorbidity and race are warranted to further our understanding of RW outcomes in pts with CLL/SLL. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Real-world overall survival of patients receiving cetuximab in later lines of treatment for metastatic colorectal cancer.

Aim: To examine characteristics of and treatment duration and real-world overall survival (rwOS) in patients receiving cetuximab as second-line (2L) or third-line (3L) treatment for metastatic colorectal cancer. Materials & methods: This was a retrospective study of 1096 and 684 patients in 2L and 3L cohorts, respectively. Results: The most common cetuximab-based regimens were cetuximab+ folinic acid, fluorouracil and irinotecan (2L: 44%; 3L: 32%) and cetuximab+irinotecan (2L: 28%; 3L: 35%). Kaplan-Meier survival estimates and stepwise Cox regression model analysis demonstrated mediantreatment duration and rwOS of 3.7 and 14.4 months, respectively, in patients receiving treatment in the 2L cohort. In the 3L cohort, treatment duration was 3.3 months and rwOS was 12.0 months. Conclusion: This large real-world study provides evidence of rwOS in patients with metastatic colorectal cancer receiving cetuximab-based regimens as 2L or 3L treatment.

349P Analysis of plasma angiogenesis factors on the efficacy of 2nd-line (2L) chemotherapy (chemo) combined with angiogenesis inhibitors (AIs) in metastatic colorectal cancer (mCRC): Results from GI-SCREEN CRC Ukit study

Angiogenesis factors have been reported as prognostic and predictive biomarkers of AIs for mCRC, but its significance as a predictor of efficacy in 2L chemo combined with AIs has not been established. In 295 enrolled patients (pts) with mCRC receiving chemo plus AI in 2L treatment from Sep 2017 to Dec 2020, serial plasma samples were prospectively collected at the time points of pre- and post-treatment. 17 plasma angiogenesis factors were analyzed by the multiplex assay with Luminex technology. Interactions of their pre-treatment measurements with treatment groups on PFS were assessed via Cox proportional hazards model. The strength of interactions was examined using estimated generalized propensity score as weight, and the continuous plasma angiogenesis variables were dichotomized according to the median. The significance level for the interaction was defined as two-sided p ≤0.1. 283 pts were included in adjusted 2L cohort (chemo plus bevacizumab [BEV [reference]: n=100], FOLFIRI plus ramucirumab [RAM: n=98], FOLFIRI plus aflibercept [AFL: n=85]). Baseline characteristics in this cohort were as follows; median age 67 years; male 57.2%; left-sided tumor 70.3%; RAS mutant 50.2%; prior BEV 72.8%. Propensity-score weighted Cox model for PFS compared RAM with BEV showed significant interactions in HGF (median 174 pg/mL, High: HR 1.278, Low: HR 0.737, interaction p = 0.0485), sVEGFR-1 (median 985 pg/mL, High: HR 0.692, Low: HR 1.419, interaction p = 0.0106), and sVEGFR-3 (median 17200 pg/mL, High: HR 0.658, Low: HR 1.396, interaction p = 0.0065). On the other hand, there were no significant interactions for PFS compared AFL with BEV.Table: 349PBelow medianAbove medianInteraction p-value∗BEVRAMBEVRAMBelow vs above medianHGF6.9 m6.7 m4.0 m2.1 m0.0485sVEGFR-16.2 m3.9 m5.9 m5.8 m0.0106sVEGFR-36.4 m3.7 m5.7 m6.7 m0.0065Median PFS, ∗defined as p ≤0.1 Open table in a new tab Pre-treatment plasma HGF, sVEGFR-1 and sVEGFR-3 could be biomarkers that contribute to the optimal regimen selection of FOLFIRI plus RAM or chemo+BEV in 2L treatment of mCRC.

Clinical management of metastatic hormone receptor-positive, HER2-negative breast cancer (MBC) after CDK 4/6 inhibitors: a retrospective single-institution study.

Cyclin-dependent kinase 4/6 inhibitors (CDK4/6is), in combination with endocrine therapy (ET), are standard either in the first (1L) or second-line (2L) setting for the treatment of hormone receptor (HR) positive, HER2-negative metastatic breast cancer (MBC). However, the optimal sequencing of treatments after progression on CDK4/6i remains unknown. We performed a single-institution analysis to identify treatments and outcomes after progression on a CDK4/6i. We identified patients with HR-positive, HER2-negative MBC prescribed a CDK4/6i in the 1L or 2L settings from December 2014 to February 2018 at Mayo Clinic in Rochester, Minnesota. Outcomes were collected through September 30, 2020. Palbociclib, in combination with letrozole or fulvestrant, was the most prescribed CDK4/6i. The 1L and 2L CDK4/6i cohorts exhibited comparable overall survival (OS), but progression-free survival (PFS) was longer in the 1L than the 2L cohort [28.2months (95% CI 19.6-34.9) vs 19.8months (95% CI 15.7-29.6)]. The most common post-CDK4/6i treatments were PI3K/mTOR inhibitors (PI3K/mTORi), single-agent ET, or chemotherapy. PFS in the 1L CDK4/6i cohort following PI3K/mTORi was 8.5months (95% CI 5.5months-NE), single-agent ET was 6.0months (95% CI 3.3-14.0months), and chemotherapy PFS was 5.4months (95% CI 3.3months-NE). Following progression on a CDK 4/6i, mPFS was short, with similar PFS times comparing chemotherapy and ET, with slightly longer PFS for targeted strategies (PI3K/mTOR). These results highlight a major need to better understand the mechanisms of CDK4/6i resistance and identify new therapeutic strategies for these patients.

Analysis of plasma angiogenesis factors on the efficacy of first-line (1L) chemotherapy (chemo) combined with biologics in RAS wild-type metastatic colorectal cancer (mCRC): Results from GI-SCREEN CRC Ukit study.

3530 Background: Angiogenesis factors have been reported as prognostic and predictive biomarkers of angiogenesis inhibitors for mCRC (Weickhardt AJ. Br J Cancer 2015. Tabernero J. Ann Oncol 2018). We investigated whether plasma angiogenesis factors could predict the efficacy of biologics combined with chemo in 1L treatment in patients (pts) with RAS wild-type mCRC. Methods: Serial plasma samples were prospectively collected at the time points of pre- and post-treatments in mCRC pts receiving biologics in either 1L or 2nd-line (2L) chemo. From Sep 2017 to Dec 2020, 497 pts were enrolled [1L chemo plus bevacizumab (1L BEV, n=102), 1L chemo plus anti-EGFR antibody (1L aEGFR, n=100), 2L chemo plus bevacizumab (n=100), 2L FOLFIRI plus RAM (n=99), 2L FOLFIRI plus aflibercept (n=85) and other treatment (n=11)]. Total of 17 plasma angiogenesis factors (HGF, PlGF, VEGF-A, VEGF-D, Angiopoietin-2, IFN-γ, IL-6, IL-8, sNeuropilin-1, TSP-2, OPN, sVEGFR1, sVEGFR2, sVEGFR3, sICAM-1, sVCAM-1, and TIMP-1) were analyzed by the multiplex assay with Luminex® technology. Interactions of their pre-treatment measurements with treatment groups on PFS and OS were assessed via Cox proportional hazards model. The strength of interactions was estimated using a propensity score weighting analysis, and the continuous plasma angiogenesis variables were categorized according to the median. The significance level in the interaction was defined as p≤0.1. Results: 133 pts were included in adjusted RAS wild-type 1L cohort (1L BEV: n=33, 1L aEGFR [reference]: n=100). Baseline characteristics of adjusted RAS wild-type 1L cohort were as follows; median age 64 years; male 62.4%; left-sided tumor 88.7%; triplet chemo 15.0%. Propensity-score weighted Cox model for OS showed significant interactions in IL-8 (median 8.03 pg/mL, high: HR 1.738, p=0.0838, Low: HR 0.479, p=0.2624, interaction p=0.0283), sVEGFR-1 (median 1,350 pg/mL, high: HR 0.333, p=0.1770, Low: HR 1.311, p=0.3004, interaction p=0.0777), and sVCAM-1 (median 1,020,000 pg/mL, high: HR 0.100, p=0.0558, Low: HR 1.616, p=0.1765, interaction p=0.0011). In terms of PFS, there were significant interactions in IL-8 (high: HR 1.322, p=0.0418, Low: HR 0.517, p=0.0528, interaction p=0.0752) and sVCAM-1 (high: HR 0.285, p=0.0414, Low: HR 1.200, p=0.7725, interaction p=0.0156). Conclusions: Pre-treatment plasma IL-8 and sVCAM-1 could be predictive biomarkers for efficacy of biologics combined with chemo in 1L treatment of RAS wild-type mCRC. Clinical trial information: UMIN000028616. [Table: see text]

Cost drivers associated with diffuse large B-cell lymphoma (DLBCL) in Japan: A structural equation model (SEM) analysis.

Diffuse large B-cell lymphoma (DLBCL) is an aggressive non-Hodgkin’s lymphoma of increasing prevalence in Japan. However, patients with relapsed or refractory disease to first line treatment (rrDLBCL) have been found to shoulder greater economic burden and have poor survival with subsequent lines of therapy. The relative impact of individual patient attributes on total medical cost among patients with rrDLBCL receiving second or third line (2L/3L) therapy was assessed. Structural equation modelling was used to identify potential cost drivers of total medical costs incurred by treatment and procedures in a Japanese retrospective claims database. From the database, rrDLBCL patients on 2L or 3L of treatment were grouped into respective cohorts. The mean [median] (SD) total medical cost of care for the 2L cohort was 73,296.40 [58,223.11] (58,409.79) US dollars (USD) and 75,238.35 [60,477.31] (59,583.66) USD for the 3L cohort. The largest total effect on medical cost in both cohorts was length of hospital stay (LOS) (β: 0.750 [95%CI: 0.728, 0.772] vs β: 0.762 [95%CI: 0.729, 0.794]). Length of hospital stay and potential heart disease complications due to line of treatment were the primary drivers of total cost for patients who had received at least 2L or 3L therapy for rrDLBCL.

A Real-World Analysis of the Use of Systemic Therapy in Malignant Pleural Mesothelioma and the Differential Impacts on Overall Survival by Practice Pattern

IntroductionMalignant pleural mesothelioma (MPM) is an aggressive malignancy that affects older adults with frequent comorbidities, making real-world treatment decisions challenging. This study compares the overall survival (OS) of patients with MPM by physician’s choice of first-line (1L) platinum chemotherapy (PC), second-line (2L) immunotherapy versus chemotherapy, and by receipt of maintenance therapy (MT). MethodsThe study included patients diagnosed with advanced MPM in the Flatiron Health electronic health record–derived database who initiated PC with pemetrexed in the 1L setting between 2011 and 2019. Patients in the 2L therapy analysis received single-agent chemotherapy versus immunotherapy after the progression of disease from our 1L cohort. Patients in the MT cohort were identified on the basis of continued receipt of pemetrexed with or without bevacizumab after dropping PC at prespecified intervals. The OS of patients by choice of 1L PC, 2L immunotherapy versus chemotherapy, and receipt of MT was summarized by means of Kaplan-Meier survival estimates and compared in the context of propensity score matching weighted analyses. ResultsIn propensity score matching weighting analysis from 2065 patients with MPM, there was no evidence of an OS difference by choice of 1L PC (hazard ratio [HR] = 1.08, 95% confidence interval [CI]: 0.89–1.31, p = 0.43), suggestive evidence of an OS difference by choice of 2L immunotherapy versus chemotherapy (HR = 0.68, 95% CI: 0.42–1.08; p = 0.10), and no evidence of an OS difference by receipt of MT (HR = 0.92, 95% CI: 0.72–1.16, p = 0.46). ConclusionsUsing real-world, propensity score–matched weighted analysis of MPM, we found there was no difference in OS by choice of 1L PC, 2L immunotherapy or chemotherapy, or by receipt of MT.