Abstract
Background:
Most patients with metastatic breast cancer (MBC) are eligible for treatment with trastuzumab deruxtecan (T-DXd). No data are available to guide treatment after exposure to T-DXd.
Methods:
We utilized a nationwide electronic health record-derived, deidentified database to review data of patients with MBC who initiated T-DXd between 12/2019 and 9/2023 and who received an additional line of treatment after T-DXd. Tumors were categorized as HER2-positive if ever positive before T-DXd, HER2-negative if never HER2-positive before T-DXd. We compared real-world progression-free survival (rwPFS) and overall survival for post-T-DXd treatments using the Kaplan-Meier method and the log-rank test.
Results:
We identified 793 patients receiving a post-T-DXd treatment. Post-T-DXd treatment outcomes differed significantly by MBC subtype: median rwPFS was 4.6 months for HER2-positive, 3.4 months for hormone receptor- (HR)-positive/HER2-negative and 2.8 months for triple-negative MBC (p<0.001). Outcomes with post-T-DXd treatments also varied significantly according to treatment regimen (p<0.001). Among patients with HER2-positive MBC, median rwPFS ranged from 6.7 months with endocrine treatment regimens to 2.3 months with sacituzumab govitecan (SG). Among patients with HR-positive/HER2-negative MBC, rwPFS ranged from 5.9 months with eribulin to 2.5 months with SG. Among patients with triple-negative MBC, poor outcomes (rwPFS ≤3 months) were observed with most treatment regimens, including SG (3 months), eribulin (2 months) and multiagent chemotherapy (2.5 months).
Conclusions:
Outcomes of post-T-DXd treatments differ significantly by MBC subtype and type of regimen administered. The use of SG immediately after T-DXd was associated with relatively short rwPFS across subtypes, highlighting some degree of cross-resistance with T-DXd.
Introduction
Trastuzumab deruxtecan (T-DXd) is an anti-HER2 antibody-drug conjugate (ADC) composed of a humanized monoclonal antibody (trastuzumab) linked to a topoisomerase 1 inhibitor (DXd, exatecan derivative) via a cleavable tetrapeptide-based linker, with a drug-to-antibody ratio of 8. Since its first approval in 2019 for patients with pretreated HER2-positive MBC, T-DXd has been tested and found to outperform traditional chemotherapy also for patients with lower HER2 expressions. As a result, T-DXd currently represents an established treatment option for patients with HER2-positive and HER2-negative (low or ultralow) metastatic breast cancer (MBC)[1–4], with over 90% of patients with MBC currently eligible for T-DXd treatment[5].
Despite often deriving meaningful clinical benefit from T-DXd, most patients with MBC ultimately discontinue the ADC due to progression or toxicity, with additional anti-cancer treatment needed to control their disease[1–4]. In this setting, no prospective evidence is available to guide treatment decisions: the activity of most treatment regimens after T-DXd remains unclear, with clinical choices based on trial data from the pre-T-DXd era[6].Such practice raises the risk of administering ineffective treatment and exposing patients to earlier progression and unnecessary toxicities, particularly given the current approval of three distinct topoisomerase 1 ADCs (T-DXd, datopotamab deruxtecan [Dato-DXd], sacituzumab govitecan [SG]) for treating MBC. These ADCs were developed in parallel, with no prospective trial that has ever compared their activity and with limited evidence on the benefit of their use in sequence.
We sought to inform evidence-based choices in the post-T-DXd setting by comparing the performance of different regimens commonly administered after T-DXd in a large U.S.-based database, with subgroup analyses by MBC subtype and focus on the sequencing of ADCs.
Methods
We conducted a retrospective observational study using the nationwide, longitudinal Flatiron Health electronic health record (EHR)-derived, deidentified database, comprising patient-level structured and unstructured data originated from ~280 U.S. cancer clinics (~800 sites of care) and curated via technology-enabled abstraction[7–12]. The data are deidentified and subject to obligations to prevent reidentification and protect patient confidentiality. The study was reviewed by the Yale Human Investigations Committee and determined not to constitute human subjects research.
We included patients with metastatic breast cancer (MBC) who initiated trastuzumab deruxtecan (T-DXd) between December 2019 and September 2023 and subsequently received at least one additional line of non–T-DXd anticancer therapy (Figure 1). Hormone receptor (HR) status was determined from the most recent biopsy prior to T-DXd. HER2 status was classified based on all available data before T-DXd: patients were considered HER2-positive if ever positive; those without any prior HER2-positive result were categorized as HER2-low (IHC 1+ or 2+ non-amplified) or HER2-0 (IHC 0) using the most recent biopsy.
Figure 1 – Derivation of the study cohort.
Flowchart illustrates patient selection for inclusion in the analytic cohort from an initial population of metastatic breast cancer patients who initiated T-DXd within the study period of December 2019 to December 2023. Patients without HER2 status prior to T-DXD initiation or without a non-T-DXd treatment following T-DXd were excluded. The final cohort (N = 793) was stratified by HER2 Status: HER2+ (N=419), HR+/HER2− (N = 292), and HR−/HER2− (N=82).
Abbreviations: HER2, human epidermal growth factor receptor 2; HR, hormone receptor.
Clinicopathologic and demographic data from patients was abstracted from the Flatiron database. Race and ethnicity data in Flatiron are typically collected via patient intake forms or interviews and documented by clinical teams in EHR systems. The data may be self-reported or recorded by staff, depending on the practice. The “Other” race category includes patients of lower representation in the U.S. population, such as American Indian or Alaska Native and Native Hawaiian or other Pacific Islander, and patients who fall under multiple race categories. Birth sex is recorded as either “male” or “female.”
Statistical Analysis
The primary and secondary endpoints were real-world PFS (rwPFS) with the immediate post-T-DXd regimen and overall survival (OS), respectively. rwPFS was defined as the duration from post T-DXd treatment initiation to either documented tumor progression or death from any cause, whichever occurs first, with censoring based on the last confirmed activity date. OS was defined as the duration from post T-DXd treatment initiation to death, with censoring based on the last confirmed activity date.
Flatiron abstracts information on real-world progression (rwP) as documented by a treating clinician. rwP is defined as the earliest progression after a 14-day exclusion period from post T-DXd treatment initiation. Flatiron’s mortality data leverage multiple death data sources, including EHR, Social Security Death Index (SSDI) and obituary data, and has been benchmarked against the national death Index (NDI), the established gold standard.[13] These mortality data are used to determine death events for our rwPFS and OS analyses. Censoring for both rwPFS and OS is based on the last confirmed activity date, namely the last date in the EHR showing the patient is alive, based on either a visit within Flatiron’s network or clinician-confirmed treatment.
rwPFS and OS were estimated using the Kaplan-Meier method, with start of the post-T-DXd regimen serving as time zero. We used the log-rank test to evaluate differences in rwPFS and OS among MBC subtypes and across different post T-DXd treatment regimens. We also performed a binary comparison of SG versus all other treatment regimens, with adjustment for prior lines of treatment, by applying Cox Proportional Hazards models and log-rank tests.
Tests of statistical significance were two-sided, with a cutoff of 0.05 for statistical significance. For all outcome variables, 95% confidence intervals are provided to show precision of the estimates. All statistical analyses were performed using SAS version 9.4, R version 4.3.1, and STATA/MP 18.0.
Results
We identified 793 patients who received another line of systemic therapy after discontinuing T-DXd (Table 1, Table S1). In terms of disease subtype, 419 (53.8%) had HER2-positive, 292 (36.8%) had HR-positive/HER2-negative and 82 (10.3%) had triple-negative disease (Table 1). Median age was 58 years, 62.2% were White and 32.4% had de novo MBC. Median prior lines in the metastatic setting (including any prior line of endocrine treatment, chemotherapy and also including T-DXd) were 4 in each subgroup (range: 1, 14) and 4 for most regimens (Table 2); 76.8% (n=609) experienced progression on prior T-DXd, whereas 23.2% (n=184) discontinued prior T-DXd for other reasons. The most commonly administered post-T-DXd regimens were the combination of capecitabine, tucatinib and trastuzumab for HER2-positive MBC and SG for both HR-positive/HER2-negative and for triple-negative MBC (Table 2). Of 21 patients with HER2-positive disease who received SG after T-DXd, 61.9% (n=13/21) had converted to HER2-negative disease at the time of receipt of SG.
Table 1.
Patient characteristics
| Overall (N=793) | HER2+ (N=419) | HR+/HER2− (N=292) | HR−/HER2− (N=82) | P-Valuea | |
|---|---|---|---|---|---|
|
| |||||
| Age (years)b | 0.04 | ||||
| Mean (SD) | 56.7 (12.4) | 55.8 (12.4) | 58.2 (11.8) | 56.5 (13.9) | |
| Median [Min, Max] | 58.0 [25.0, 84.0] | 56.0 [25.0, 82.0] | 59.0 [26.0, 84.0] | 58.5 [28.0, 82.0] | |
|
| |||||
| N (%) | |||||
|
| |||||
| Age at Diagnosis (years)b | 0.44 | ||||
| <65 | 570 (71.9) | 309 (73.7) | 205 (70.2) | 56 (68.3) | |
| ≥65 | 223 (28.1) | 110 (26.3) | 87 (29.8) | 26 (31.7) | |
|
| |||||
| Race/Ethnicity | 0.82 | ||||
| Asian | ≤26 (≤3.3) | 14 (3.3) | 7 (2.4) | ≤5 (≤6.1) | |
| Black/African American | 96 (12.1) | 56 (13.4) | 29 (9.9) | 11 (13.4) | |
| Hispanic/Latino | 79 (10.0) | 42 (10.0) | 28 (9.6) | 9 (11.0) | |
| White | 493 (62.2) | 251 (59.9) | 192 (65.8) | 50 (61.0) | |
| Other/Missingc | ≥99 (≥12.5) | 56 (13.4) | 36 (12.3) | ≥7 (≥8.5) | |
|
| |||||
| ECOG Performance Status | 0.29 | ||||
| 0-1 | 320 (40.4) | 152 (36.3) | 125 (42.8) | 43 (52.4) | |
| 2-4 | ≤30 (≤3.8) | 17 (4.1) | 8 (2.7) | ≤5 (≤6.1) | |
| Missing | ≥443 (≥55.9) | 250 (59.7) | 159 (54.5) | ≥34 (≥41.5) | |
|
| |||||
| Practice Typed | 0.16 | ||||
| Academic | 211 (26.6) | 102 (24.3) | 81 (27.7) | 28 (34.1) | |
| Community | 582 (73.4) | 317 (75.7) | 211 (72.3) | 54 (65.9) | |
|
| |||||
| Location | 0.93 | ||||
| Midwest | 74 (9.3) | 38 (9.1) | 29 (9.9) | 7 (8.5) | |
| Northeast | 104 (13.1) | 55 (13.1) | 38 (13.0) | 11 (13.4) | |
| South | 246 (31.0) | 139 (33.2) | 86 (29.5) | 21 (25.6) | |
| West | 116 (14.6) | 66 (15.8) | 37 (12.7) | 13 (15.9) | |
| Missing | 253 (31.9) | 121 (28.9) | 102 (34.9) | 30 (36.6) | |
|
| |||||
| Insurance Type | 0.52 | ||||
| Commercial | 279 (35.2) | 141 (33.7) | 107 (36.6) | 31 (37.8) | |
| Medicare | 252 (31.8) | 125 (29.8) | 99 (33.9) | 28 (34.1) | |
| Other, including Medicaid | 61 (7.7) | 34 (8.1) | 21 (7.2) | 6 (7.3) | |
| Uninsured/Unknown | 201 (25.3) | 119 (28.4) | 65 (22.3) | 17 (20.7) | |
|
| |||||
| Year of Diagnosis | <0.001 | ||||
| 2011-2016 | ≥137 (≥17.3) | 88 (21.0) | 44 (15.1) | ≥5 (≥6.1) | |
| 2017-2018 | ≤164 (≤20.7) | 104 (24.8) | 55 (18.8) | ≤5 (≤6.1) | |
| 2019-2020 | 257 (32.4) | 130 (31.0) | 99 (33.9) | 28 (34.1) | |
| 2021-2022 | 213 (26.9) | 88 (21.0) | 86 (29.5) | 39 (47.6) | |
| Missing | ≥22 (≥2.8) | 9 (2.1) | 8 (2.7) | ≥5 (≥6.1) | |
|
| |||||
| Disease-Free Intervals | <0.001 | ||||
| 0 months (De novo) | 257 (32.4) | 164 (39.1) | 71 (24.3) | 22 (26.8) | |
| < 24 months | 97 (12.2) | 44 (10.5) | 35 (12.0) | 18 (22.0) | |
| ≥ 24 months | 439 (55.4) | 211 (50.4) | 186 (63.7) | 42 (51.2) | |
|
| |||||
| Prior Lines of Therapye | 0.05 | ||||
| Median [Min, Max] | 4.0 [1.0, 14.0] | 4.0 [1.0, 14.0] | 4.0 [1.0, 12.0] | 4.0 [1.0, 12.0] | |
One-Way ANOVA tests were conducted for continuous variables and Chi-square tests for categorical variables across the HER2 subgroups.
Patients with a Birth Year of [Data Cutoff Year(2024) - 85] or earlier may have an adjusted Birth Year in Flatiron Health datasets due to patient deidentification requirements.
The “Other/Missing” race category includes patients of lower representation in the U.S. population, such as American Indian or Alaska Native and Native Hawaiian or other Pacific Islander; patients who fall under multiple race categories; and patients whose race was not reported.
Practice Type is categorized as patients who either only received care at academic cancer centers (Academic) or received care at either academic cancer centers or community oncology practices (Community)
Prior lines of therapy represent the total treatment regimens preceding post T-DXd treatment line
Abbreviations: HER2, human epidermal growth factor receptor 2; HR, hormone receptor
Table 2.
Prior Lines of Therapy for Common Post T-DXd Treatments by HER2 Subtype
| N (%)a | Prior Lines of Therapyb Median [Min, Max] | |
|---|---|---|
| HER2+ (N = 419) | ||
|
| ||
| Cape / Trastuzumab / Tucatinib | 118 (28.2) | 4.0 [1.0, 11.0] |
| Endocrine treatment | 66 (15.8) | 4.0 [1.0, 11.0] |
| Chemo + anti-HER2 mAb(s) | 60 (14.3) | 4.0 [1.0, 12.0] |
| anti-HER2 mAb(s) +/− TKI | 45 (10.7) | 4.0 [1.00, 14.0] |
| T-DM1 | 33 (7.9) | 3.0 [1.0, 7.0] |
| Sacituzumab govitecan | 21 (5.0) | 4.0 [1.0, 10.0] |
|
| ||
| HR+/HER2− (N = 292) | ||
|
| ||
| Sacituzumab govitecan | 87 (29.8) | 4.0 [1.0, 12.0] |
| Endocrine treatment | 64 (21.9) | 4.0 [1.0, 10.0] |
| Taxane | 25 (8.6) | 5.0 [2.0, 7.0] |
| Capecitabine | 24 (8.2) | 4.0 [2.0, 7.0] |
| Eribulin | 19 (6.5) | 5.0 [3.0, 10.0] |
| Anthracycline | 16 (5.5) | 4.0 [1.0, 10.0] |
|
| ||
| HR−/HER2− (N = 82) | ||
|
| ||
| Sacituzumab govitecan | 18 (22.0) | 3.5 [1.0, 7.0] |
| Eribulin | 14 (17.1) | 4.0 [2.0, 12.0] |
| Multiagent chemotherapy | 11 (13.4) | 4.0 [1.0, 10.0] |
| Anthracycline | ≤5 (≤6.1) | 5.0 [4.0, 9.0] |
Frequencies and percentages of the most common post T-DXd treatment ordered by prevalence
Prior lines of therapy represent the total treatment regimens preceding post T-DXd treatment line
Abbreviations: T-DXd, trastuzumab deruxtecan; HER2, human epidermal growth factor receptor 2; mAb(s), monoclonal antibodies; TKI, tyrosine kinase inhibitor; T-DM1, trastuzumab emtansine
Outcomes with post-T-DXd treatments differed significantly by MBC subtype. Median rwPFS was 4.6 months for HER2-positive, 3.4 months for HR-positive/HER2-negative and 2.8 months for triple-negative MBC (p<0.001, Figure 2A). Median OS was 13.0 months for HER2-positive, 8.5 months for HR-positive/HER2-negative and 5.4 months for triple-negative MBC (p<0.001, Figure 2B). Similar results were observed among patients with prior progression on T-DXd (p<0.001, Figure S1), whereas numerically longer rwPFS was observed among patients starting a post-T-DXd regimen in the absence of disease progression (p=0.09, Figure S2).
Figure 2 -. Outcomes with post-trastuzumab deruxtecan (T-DXd) treatments according to breast cancer subtype.
• 2A: Median rwPFS and 95% CI, months
• 2B: Median OS and 95% CI, months
Abbreviations: rwPFS, real-world progression-free survival; OS, overall survival; CI, confidence interval; HER2, human epidermal growth factor receptor 2; HR, hormone receptor
Outcomes with post-T-DXd treatments varied significantly by treatment regimen (p<0.001, Figure 3). Among patients with HER2-positive MBC, rwPFS ranged between 6.7 months with endocrine treatment (ET)-based regimens, 4.7 months with tucatinib, trastuzumab and capecitabine, 4.7 months with chemotherapy plus anti-HER2 antibodies, 4.6 months with trastuzumab emtansine (T-DM1) to 2.3 months with SG. Similarly, among patients with HR-positive/HER2-negative MBC, rwPFS ranged from 5.9 months with eribulin, 5.8 months with capecitabine, 4.6 months with taxanes, 4.1 months with ET-based regimens to 2.5 months with SG. Among patients with triple-negative MBC, poor outcomes (rwPFS ≤3 months) were observed with most treatment regimens, including SG (3 months), eribulin (2 months) and multiagent chemotherapy (2.5 months).
Figure 3. Outcomes with post-trastuzumab deruxtecan (T-DXd) treatments according to the specific treatment regimen and by disease subtype.
Abbreviations: HER2, human epidermal growth factor receptor 2; HR, hormone receptor; mAb(s), monoclonal antibodies; TKI, tyrosine kinase inhibitor; TDM-1, trastuzumab emtansine.
Due to Flatiron’s policy, any instances of patient discontinuation of T-DXd prior to progression that involved fewer than five patients were not displayed
Across all patients, after adjustment for prior lines of treatment, receipt of SG was associated with shorter rwPFS compared to other regimens (3.4 vs. 5.0 months, hazard ratio [HzR] 1.6, p<0.001, Figure 4). When restricting to patients with estrogen receptor- (ER)-positive/HER2-negative disease (n=142), SG was associated with significantly shorter rwPFS compared with common chemotherapies administered for this disease (rwPFS 3.0 vs. 5.9 months, HzR 1.58, p=0.047, Figure 5). SG also yielded a similar rwPFS (median 2.6 months) and poor OS (median 5.6 months) when administered after T-DXd plus an additional intervening treatment (Figure 6). Patients retaining favorable rwPFS with SG were more likely to have been exposed for a shorter time to prior T-DXd (Table S2).
Figure 4. Post-trastuzumab deruxtecan outcomes with sacituzumab govitecan vs. any other treatment regimen among patients with metastatic breast cancer, adjusted for prior lines of therapy.
Abbreviations: rwPFS, real-world progression-free survival; CI, confidence interval
Figure 5. Post-trastuzumab deruxtecan outcomes with sacituzumab govitecan vs. commonly administered chemotherapies among patients with ER-positive/HER2-negative metastatic breast cancer, adjusted for prior lines of therapy.
Abbreviations: ER, estrogen receptor; HER2, human epidermal growth factor receptor 2; rwPFS, real-world progression-free survival; CI, confidence interval
Figure 6. Outcomes with sacituzumab govitecan given after trastuzumab deruxtecan and after an additional line of intervening systemic treatment.
Abbreviations: rwPFS, real-world progression-free survival; OS, overall survival; CI, confidence interval
Discussion
This is the largest study to date looking at post-T-DXd treatment outcomes with different treatment regimens. We found that median rwPFS for post-T-DXd treatments ranged between 2.8 and 4.6 months depending on MBC subtype, highlighting the relevant unmet need in this setting. Importantly, distinct post-T-DXd regimens exhibited different performance: the use of SG after T-DXd led to poor outcomes (rwPFS ≤3 months) across subtypes, including when used after an intervening treatment, whereas more favorable outcomes (rwPFS 4-6 months) were observed with several other treatments.
The present study’s results may inform clinical practice for patients after T-DXd. In the HER2-positive MBC post-T-DXd setting, patients still appear to derive benefit from the tucatinib triplet, ET, T-DM1 or chemotherapy. Such treatments performed particularly well among patients who started a post-T-DXd regimen in the absence of disease progression (rwPFS ~10 months for ET and anti-HER2 mAb(s) +/− TKI, ~15 months for T-DM1), possibly because these treatments were administered as form of maintenance. This finding is particularly intriguing in light of the positive results of DESTINY-Breast09,[14] which may move T-DXd to the first line setting for HER2-positive disease. In this setting, the strategy of induction cytotoxic treatment followed by maintenance therapy has long been utilized according to the CLEOPATRA trial, and studies looking at specific post-T-DXd maintenance strategies (such as the ongoing DEMETHER phase 2 trial, NCT06172127) are warranted.
In HR-positive/HER2-negative MBC, based on our data, T-DXd-pretreated patients may derive a more prolonged control of disease with conventional chemotherapies over another topoisomerase1-antibody-drug conjugate (ADC). This finding is particularly relevant given that SG was the most commonly administered post-T-DXd treatment for HR-positive/HER2-negative MBC in our study (~30%) and given the recent approval of a third topoisomerase1-ADC for MBC (datopotamab deruxtecan) [15], in the setting of having over 100 additional topoisomerase1-ADC in current active development.[16]
Our data are consistent with smaller retrospective studies, which found a median PFS of approximately 2-3 months with a second topoisomerase1-ADC administered in sequence.[17–23] Prospective trials are ongoing to address the question of ADC sequencing (e.g. NCT06100874, NCT06533826, NCT06263543, NCT06774027, NCT06686394), although none compares a topoisomerase1-ADC to chemotherapy or definitively addresses the question of the optimal post-T-DXd treatment.
Of note, our results suggest that resistance to ADCs is meaningfully associated with the payload: indeed, patients with progression on T-DXd derived a reasonable rwPFS on T-DM1, which also targets HER2 but delivers a distinct payload. Conversely, despite targeting a distinct antigen (Trop2), SG led to short rwPFS after T-DXd, possibly due to the overlap in mechanism of action of the payload. This finding has broad implications in the field, calling for development of ADCs with differentiated mechanism of action of their payloads to limit cross resistance.
Limitations of our study include the retrospective design, limited numbers in some subgroups (e.g. the TNBC subgroup), heterogeneity in treatments administered and lack of randomization, which may have led to selection biases with impact on treatment outcomes. Indeed, patients may have received specific treatment regimens based on the aggressiveness of the disease or other disease- and patient-specific features. Nonetheless, the limitations listed above are mitigated in part by the large overall population included and standardized methods utilized to annotate EHR-derived data in the Flatiron Health database.[7]
Conclusions
In conclusion, our large retrospective study found that outcomes of post-T-DXd treatments differed significantly by MBC subtype and type of regimen administered. The use of SG immediately after T-DXd was associated with relatively short rwPFS across subtypes, highlighting some degree of cross resistance among topoisomerase1-ADCs and suggesting that switching mechanism of action of the regimen may be more beneficial among patients with T-DXd-refractory disease.
Supplementary Material
Acknowledgements:
We thank Valerie Hope Goldstein, a full-time employee of Dana-Farber Cancer Institute, for editorial and submission assistance.
Funding/Role of the Funder:
We acknowledge support of the Terri Brodeur Breast Cancer Foundation (to Paolo Tarantino), a METAvivor Early Career Investigator Award (to Paolo Tarantino), and a Saverin Award (to Paolo Tarantino).
Disclosure of Potential Conflicts of Interest:
Dr. Tarantino declares research funding (to institution) from AstraZeneca; advisory/consultant role for AstraZeneca, Daiichi Sankyo, Eli Lilly, Gilead, Menarini/Stemline, Novartis, Roche/Genentech. Dr. Lin reports institutional research support from Genentech (and Zion Pharmaceutical as part of GNE), Pfizer, Merck, Seattle Genetics (now Pfizer), Olema Pharmaceuticals, AstraZeneca; consulting honoraria from Puma, Seattle Genetics, Daiichi-Sankyo, AstraZeneca, Olema Pharmaceuticals, Janssen, Blueprint Medicines, Stemline/Menarini, Artera Inc., Eisai; royalties from UpToDate (book); and travel support from Olema Pharmaceuticals and AstraZeneca. SMT reports consulting or advisory roles for Novartis, Pfizer/SeaGen, Merck, Eli Lilly, AstraZeneca, Genentech/Roche, Eisai, Bristol Myers Squibb/Systimmune, Daiichi-Sankyo, Gilead, Blueprint Medicines, Reveal Genomics, Sumitovant Biopharma, Artios Pharma, Menarini/Stemline, Aadi Bio, Bayer, Jazz Pharmaceuticals, Natera, Tango Therapeutics, eFFECTOR, Hengrui USA, Cullinan Oncology, Circle Pharma, Arvinas, BioNTech, Launch Therapeutics, Zuellig Pharma, Johnson&Johnson/Ambrx, Bicycle Therapeutics, BeiGene Therapeutics, Mersana, Summitt Therapeutics, Avenzo Therapeutics, Aktis Oncology, Celcuity, Boehringer Ingelheim, and Samsung Bioepis; research funding from Genentech/Roche, Merck, Exelixis, Pfizer, Lilly, Novartis, Bristol Myers Squibb, AstraZeneca, NanoString Technologies, Gilead, SeaGen, OncoPep, Daiichi-Sankyo, Menarini/Stemline, and Jazz Pharmaceuticals; and travel support from Lilly, Gilead, Jazz, Pfizer, Arvinas, and Roche. The remaining authors declare no conflicts of interest.
Footnotes
Trial Registration: N/A
Prior Presentation: This study was presented at the 2024 San Antonio Breast Cancer Symposium (SABCS) held in December 2024 in San Antonio, TX.
Data Availability Statement:
The data that support the findings of this study were originated by and are the property of Flatiron Health, Inc., which has restrictions prohibiting the authors from making the data set publicly available. Requests for data sharing by license or by permission for the specific purpose of replicating results in this manuscript can be submitted to PublicationsDataAccess@flatiron.com.
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Data Availability Statement
The data that support the findings of this study were originated by and are the property of Flatiron Health, Inc., which has restrictions prohibiting the authors from making the data set publicly available. Requests for data sharing by license or by permission for the specific purpose of replicating results in this manuscript can be submitted to PublicationsDataAccess@flatiron.com.