Clinical and Genomic Characteristics of Patients with Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Metastatic Breast Cancer Following Progression on Cyclin-Dependent Kinase 4 and 6 Inhibitors.

PURPOSE: We explored the clinical and genomic characteristics of hormone receptor-positive (HR+), HER2-negative (HER2-) metastatic breast cancer (MBC) after progression on cyclin-dependent kinase 4 and 6 inhibitors (CDK4 and 6i) ± endocrine therapy (ET) to understand potential resistance mechanisms that may aid in identifying treatment options. EXPERIMENTAL DESIGN: Patients in the United States with HR+, HER2- MBC had tumor biopsies collected from a metastatic site during routine care following progression on a CDK4 and 6i ± ET (CohortPost) or prior to initiating CDK4 and 6i treatment (CohortPre) and analyzed using a targeted mutation panel and RNA-sequencing. Clinical and genomic characteristics were described. RESULTS: The mean age at MBC diagnosis was 59 years in CohortPre (n = 133) and 56 years in CohortPost (n = 223); 14% and 45% of patients had prior chemotherapy/ET, and 35% and 26% had de novo stage IV MBC, respectively. The most common biopsy site was liver (CohortPre, 23%; CohortPost, 56%). CohortPost had significantly higher tumor mutational burden (TMB; median 3.16 vs. 1.67 Mut/Mb, P < 0.0001), ESR1 alteration frequency (mutations: 37% vs. 10%, FDR < 0.0001; fusions: 9% vs. 2%, P = 0.0176), and higher copy-number amplification of genes on chr12q15, including MDM2, FRS2, and YEATS4 versus patients in the CohortPre group. In addition, CDK4 copy-number gain on chr12q13 was significantly higher in CohortPost versus CohortPre (27% vs. 11%, P = 0.0005). CONCLUSIONS: Distinct mechanisms potentially associated with resistance to CDK4 and 6i ± ET, including alterations in ESR1 and amplification of chr12q15 and CDK4 copy-number gain, were identified.

Real world incidence and management of adverse events in patients with HR+, HER2- metastatic breast cancer receiving CDK4 and 6 inhibitors in a United States community setting.

OBJECTIVE: To examine the real-world incidence and management of select adverse events (AEs) among female patients with hormone receptor positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC), receiving a cyclin-dependent kinase 4 and 6 (CDK4 and 6) inhibitor (palbociclib, abemaciclib, or ribociclib). METHODS: This retrospective study analyzed data from the US Oncology Network iKnowMed electronic health record database for 396 patients with an initial MBC diagnosis on/after 1 January 2014 and receipt of first CDK4 and 6 regimen between 1 January 2017 and 31 December 2018. In this descriptive study, the proportion of patients who experienced select AEs and associated dose modifications or discontinuations were reported. The occurrence of select healthcare resource utilization categories was also reported. RESULTS: Median follow-up time was 451, 262, and 355 days for patients in the palbociclib, abemaciclib, and ribociclib cohorts, respectively. The most common AEs were neutropenia (palbociclib, 44.8%; abemaciclib, 10.6%; ribociclib, 36.3%), diarrhea (palbociclib, 8.0%; abemaciclib, 43.0%; ribociclib, 8.8%), and fatigue (palbociclib, 12.9%; abemaciclib, 17.6%; ribociclib, 16.5%). AEs resulted in a treatment hold among 91 (23.0%), a dose reduction among 86 (21.7%), and permanent discontinuation among 48 (12.1%) patients overall. CONCLUSIONS: This real-world study provides insight into the occurrence of AEs which varied by CDK4 and 6 inhibitor. Compared to clinical trials, frequencies of AEs were numerically lower but dose reductions due to AEs were numerically higher. It is possible these differences reflect proactive management of AEs on the part of clinicians to help patients remain on therapy.

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4 and 6 inhibitors) have changed the landscape for the treatment of metastatic breast cancer (MBC) among patients who are hormone receptor positive (HR+) and human epidermal growth factor receptor 2 negative (HER2−). An understanding of the real-world management of adverse events (AEs) will help optimize treatment strategies. Here, data from the US Oncology Network electronic health record database for 396 HR+, HER2−, MBC patients receiving a CDK4 and 6 inhibitor were examined to describe the proportion of patients who experienced select AEs and the associated outcomes of these AEs. Compared to clinical trials, frequencies of AEs were numerically lower but dose reductions due to AEs were numerically higher. It is possible that these differences reflect a proactive management of AEs on the part of clinicians to help patients remain on therapy.

Treatment patterns, adverse events, and direct and indirect economic burden in a privately insured population of patients with HR+/HER2- metastatic breast cancer in the United States.

BACKGROUND: Real-world evidence specific to HR+/HER2- metastatic breast cancer (MBC) prior to introduction of CDK4/6 inhibitors is limited. In an effort to provide context for the introduction of new treatments, we assessed treatment patterns, adverse events, productivity loss, and direct/indirect economic burden in a privately insured population of patients with HR+/HER2- MBC. RESEARCH DESIGN AND METHODS: Using a retrospective cohort design, patients aged 18-64 years, selected from MarketScan databases (2007-2014), were analyzed using descriptive and multivariable methods. RESULTS: Among 5,563 eligible patients, endocrine therapy was the most common first-line (1L) therapy; its utilization trended downward from 63% (1L) to 23% (4L), with a simultaneous increase in chemotherapy use, 25% (1L) to 50% (4L). Two hundred and seventy-eight unique treatment regimens were used in the 1L setting. The average per patient monthly all-cause costs were $14,424. The 12-month indirect costs for short-term disability were substantially higher in MBC patients ($10,397) than in matched noncancer patients ($394). CONCLUSION: The increasing use of chemotherapy as patients progressed to second and later lines and the substantial direct/indirect economic burden underscore an unmet need. The high number of 1L regimens highlights significant heterogeneity and a lack of consensus related to the management of HR+/HER2- MBC in routine practice.

Real-world treatment patterns and outcomes of abemaciclib for the treatment of HR+, HER2- metastatic breast cancer.

OBJECTIVE: This retrospective observational study described baseline characteristics, real-world treatment patterns, and outcomes among patients with metastatic breast cancer treated with abemaciclib in the United States. METHODS: De-identified electronic health record-derived data were used to describe patients who began abemaciclib treatment on or after 30 June 2016 and ≥4 months before data cutoff (31 December 2018). Real-world response (rwR) and real-world progression assessments were abstracted from clinical documentation. Descriptive statistics were used to calculate the real-world best response. The Kaplan-Meier method estimated real-world time to first response (rwTTFR) and real-world progression-free survival (rwPFS). RESULTS: The median age of 118 female patients at abemaciclib initiation was 66.5 years (interquartile range, 57.0, 73.0). The breakdown of patients who received abemaciclib in first, second, third, or later lines was 28.8%, 21.2%, 20.3%, and 29.7%, respectively. Patients received abemaciclib as monotherapy (12.7%) or in combination with endocrine therapy: fulvestrant (59.3%); aromatase inhibitor (22.9%); aromatase inhibitor and fulvestrant (5.1%). There were 68 patients (57.6%) with ≥1 rwR assessment: 41.2% with a real-world complete response or real-world partial response. Median rwTTFR was 3.6 months (95% confidence interval, 3.5, 5.2). Twelve-month rwPFS probability was 61.7%. CONCLUSIONS: This study represents utilization and outcomes associated with abemaciclib approximately 1 year following FDA approval. Treatment patterns demonstrated heterogeneity and, as in clinical trials, patients appeared to benefit from abemaciclib treatment in the real world. More research investigating outcomes associated with abemaciclib treatment is needed, with larger samples and longer follow-up to enable closer evaluation by subgroup, regimen, and line of therapy.

Frequency of skeletal-related events and associated healthcare resource use and costs in US patients with multiple myeloma.

OBJECTIVE: A potential complication for all new multiple myeloma (MM) patients is the clinical presentation of osteolytic lesions which increase the risk for skeletal-related events (SREs). However, the contribution of SREs to the overall economic impact of MM is unclear. The impact of SREs on healthcare resource utilization (HCRU) and costs for US patients with MM was analyzed in Truven Health Marketscan Commercial Claims and Medicare Supplemental Databases. METHODS: Adults diagnosed with MM between January 1, 2005 and December 31, 2010 with ≥2 claims ≥30 days apart (first claim = index date) were included. SREs included: hypercalcemia, pathologic fracture, surgery for the prevention and treatment of pathologic fractures or spinal cord compression, and radiation for bone pain. Rates of HCRU (outpatient [OP], inpatient [IP], emergency room [ER], orthopedic consultation [OC], and ancillary) and healthcare costs were compared between MM patients with and without SREs. Inverse propensity weighting was applied to adjust for potential bias. RESULTS: Of 1028 MM patients (mean age = 67, standard deviation = 13.2), 596 patients with ≥1 SRE and 432 without SREs were assessed. HCRU rates in IP, ER, and ancillary (p < 0.01) and mean total costs of OP, IP, and ER were significantly higher (p < 0.05) for patients with vs without SREs during follow-up. HCRU rates also increased with SRE frequency (p < 0.05 in OP, IP, ER, OC, and ancillary), as did mean total healthcare costs, except for OC (p < 0.001). LIMITATIONS: A broad assessment of pharmacotherapy for the treatment of MM was not an objective of the current study. Bisphosphonate use was evaluated; however, results were descriptively focused on frequency of utilization only and were not included in the broader cost and HCRU analysis. CONCLUSIONS: Among US patients with MM, higher SRE frequency was associated with a significant trend of higher HCRU and total healthcare costs in several settings.

Healthcare costs, treatment patterns, and resource utilization among pancreatic cancer patients in a managed care population.

BACKGROUND: Pancreatic adenocarcinoma has few effective treatment options and poor survival. The objective of this study was to characterize treatment patterns and estimate the costs and resource use associated with its treatment in a commercially-insured US population. METHODS: In this retrospective claims-based analysis, individuals ≥18 years old with evidence of pancreatic adenocarcinoma between January 1, 2001 and December 31, 2010 were selected from a managed care database. Treatment phase (either initial non-metastatic or metastatic) was determined using a claims-based algorithm. Patients in the pancreatic cancer population were matched 1:3 to a control population. Resource use (events/person-years), treatment patterns, and healthcare costs (per-patient per-month, PPPM) were determined during a variable length follow-up period (from first pancreatic cancer diagnosis to earliest of death, disenrollment, or study end). RESULTS: In this study, 5262 pancreatic cancer patients were matched to 15,786 controls. Rates of office visits, inpatient visits, ER visits, and inpatient stays, and mean total all-cause healthcare costs PPPM ($15,480 vs $1001) were significantly higher among cancer patients than controls (all p < 0.001). Mean inpatient costs were the single largest cost driver ($9917 PPPM). Also, mean total all-cause healthcare costs were significantly higher during the metastatic treatment phase vs the initial treatment phase of non-metastatic disease ($21,637 vs $10,358, p < 0.001). CONCLUSIONS: These results indicate that pancreatic cancer imposes a substantial burden on the US healthcare system, and that treatment of more advanced disease is significantly more costly than initial treatment of non-metastatic disease. LIMITATIONS: Additional research is needed to validate the accuracy of the claims-based algorithms used to identify the treatment phase.