Citations

Abstract Background: Adjuvant ET has been the standard of care for patients with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) EBC. A significant proportion of patients with increased risk still experience disease relapse despite available ET and more optimum ET is needed to prevent patients developing incurable metastatic cancer. Distant recurrence risk ranges from 20% to 40% after 5 years of adjuvant ET, depending on clinicopathological (clin-path) features at diagnosis. Consequently, there is a need to further optimize adjuvant treatment, particularly in those patients who are at increased risk of recurrence. Imlunestrant is an orally bioavailable selective estrogen receptor degrader (SERD) with pure antagonistic properties and the potential to overcome ET resistance. In early phase trials, imlunestrant monotherapy showed favorable safety with pharmacokinetic (PK) exposures exceeding fulvestrant and preliminary efficacy in ER+, HER2- advanced breast cancer patients (EMBER, Jhaveri 2022) along with robust biological/pharmacodynamic activity and tolerability in EBC (EMBER-2, Neven). Trial Design: EMBER-4 is a randomized, open-label, global phase 3 study comparing imlunestrant versus physicians’ choice of ET, in patients who are at an increased risk of recurrence based on clin-path features and who have received 2 to 5 years of standard adjuvant ET. Approximately 6,000 patients will be randomized 1:1 to receive imlunestrant (400 mg daily) for 5 years or physicians’ choice of adjuvant ET (tamoxifen or an aromatase inhibitor, AI, dosed per label). Study treatment duration is 5 years. Males and pre-/peri-menopausal women will receive concomitant treatment with a GnRH agonist if receiving imlunestrant or an AI. Stratification factors include time from initial adjuvant ET, use of prior adjuvant cyclin dependent kinase 4/6 inhibitors, nodal status, menopausal status, and geographic region. Eligibility criteria: Eligible patients are adult males and females (pre-, peri- or postmenopausal) with ER+, HER2- EBC who have completed definitive locoregional therapy and have received 2 to 5 years of prior adjuvant ET without disease recurrence, but who are at increased risk of recurrence based on clin-path features at diagnosis. Prior (neo) adjuvant chemotherapy and/or targeted therapy with a CDK4/6- or PARP- inhibitor is permitted. Study endpoints: The primary endpoint is invasive disease-free survival (IDFS), excluding second non-breast primary invasive cancers. Key secondary endpoints include distant relapse-free survival, overall survival, IDFS including second non-breast primary invasive cancers, safety, PK and patient reported outcomes. Recruitment for EMBER-4 begins globally in Q4 2022. Citation Format: Komal Jhaveri, Joyce O’Shaughnessy, Fabrice Andre, Matthew P. Goetz, Nadia Harbeck, Miguel Martín, Francois-Clement Bidard, Zachary M. Thomas, Suzanne Young, Roohi Ismail-Khan, Lillian M. Smyth, Michael Gnant. EMBER-4: A phase 3 adjuvant trial of imlunestrant vs standard endocrine therapy (ET) in patients with ER+, HER2- early breast cancer (EBC) with an increased risk of recurrence who have previously received 2 to 5 years of adjuvant ET [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT1-01-02.

Abstract Background Adjuvant abemaciclib (a CDK4 and 6 inhibitor) combined with ET resulted in significant and clinically meaningful improvement in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) in patients (pts) with HR+, HER2-, node-positive, high risk EBC in the monarchE trial, and is an approved adjuvant therapy for these patients. Here we present efficacy results from a pre-specified overall survival interim analysis (OS IA2) which was planned to occur 2 years (yrs) after the primary outcome analysis. Methods Pts were randomized (1:1) to receive ET for up to 10 yrs +/- abemaciclib for 2 yrs (study treatment period). High-risk EBC was defined as either ≥4 positive axillary lymph nodes (ALN), or 1-3 ALN with either Grade 3 disease and/or tumor ≥5 cm (Cohort 1). While the proliferation biomarker Ki-67 was centrally assessed in all pts with available tissue sample, an additional smaller group of pts with 1-3+ ALN and central Ki-67 ≥20% as the only high-risk feature were included (Cohort 2). The intent-to-treat (ITT) population consisted of both Cohort 1 (5120 pts) and Cohort 2 (517 pts). Hazard ratios (HR) were estimated using Cox proportional hazard model. Results At a median follow-up of 42 months, all pts were off abemaciclib. IDFS and DRFS data illustrate a sustained benefit beyond the treatment period. In the ITT population, the HR for IDFS was 0.664 (95% CI: 0.578, 0.762) and DRFS was 0.659 (95% CI: 0.567, 0.767). At 4 yrs, this reflected an improvement in IDFS rates from 79.4% to 85.8% (absolute difference 6.4%), and in DRFS rates from 82.5% to 88.4% (absolute difference 5.9%). The continued separation of the curves was associated with an increase in absolute benefit in IDFS 4-year rates compared to 2-and 3-year IDFS rates (absolute difference 2.8% and 4.8% respectively). While OS remained immature, there was a lower number of deaths observed in the abemaciclib plus ET arm compared to the ET alone arm (157 [5.6%] vs 173 [6.1%], HR 0.929 [95% CI: 0.748, 1.153], p = 0.503), suggesting that the robust benefit in IDFS and DRFS began to translate into a numerically favorable OS HR. As previously described, within Cohort 1, a Ki-67 index of ≥20% was associated with a worse prognosis, but similar abemaciclib treatment effects were observed regardless of Ki-67 index. No new safety signals were observed. Conclusion The clinically meaningful benefit of adjuvant abemaciclib added to ET in HR+, HER2-, node-positive, high-risk EBC persists beyond completion of abemaciclib therapy, yielding an increase in absolute IDFS and DRFS benefit at 4 yrs. While OS remains immature at this time, the lower number of deaths in the abemaciclib arm compared to the ET arm suggest that a survival signal favoring abemaciclib is emerging. Citation Format: Stephen Johnston, Masakazu Toi, Joyce O’Shaughnessy, Priya Rastogi, Mario Campone, Patrick Neven, Chiun Sheng Huang, Jens Huober, Georgina Garnica Jaliffe, Irfan Cicin, Sara Tolaney, Matthew P. Goetz, Hope Rugo, Elżbieta Senkus, Laura Testa, Lucia Del Mastro, Chikako Shimizu, Ran Wei, Ashwin Shahir, Maria Munoz, Belen San Antonio, Valerie Andre, Nadia Harbeck, Miguel Martín. Abemaciclib plus endocrine therapy for HR+, HER2-, node-positive, high-risk early breast cancer: results from a pre-planned monarchE overall survival interim analysis, including 4-year efficacy outcomes [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS1-09.

Abstract Background: Late recurrence of breast cancer after 5 years accounts for about 50% of recurrences in hormone receptor (HR)-positive early breast cancer (EBC). TAILORx established non-inferiority of adjuvant endocrine therapy (ET) given for at least 5 years to chemotherapy plus ET (CET) in EBC and a 21-gene recurrence score (RS) of 11-25, although there was some chemotherapy benefit in women Methods: Eligibility criteria included women 18-75 years with HR-positive, HER2-negative, T1b-T2N0 EBC who agreed to have CT assigned or randomized based on the RS assay. The primary endpoint was invasive disease-free survival (iDFS) in the RS 11-25 group. The “primary analysis” refers to the original prespecified analysis for the primary IDFS endpoint (836 IDFS events at full information in the RS 11-25 group) after a median of 7.5 years. The “updated analysis” was performed after a median followup of 11.0 and 10.4 years in the randomized and overall populations, respectively. Results:10,253 eligible women enrolled between 4/7/06-10/6/10.The updated analysis includes substantially more events that the primary analysis, including IDFS events (1819 vs. 1210), distant recurrences (561 vs. 384), locoregional +/- distant recurrences (764 vs. 543), and deaths (910 vs. 499). The table provides 5 and 12-year event rates (and standard errors) for all arms, and comparisons of the randomized arms. The primary trial conclusions remain unchanged: ET was non-inferior to CET in the randomized group with a RS 11-25. Although recurrence occurred in < 10% by 12 years for a RS 0-25, late recurrence events beyond 5 years exceeded earlier recurrence. Non-recurrence events occurred in about 13% at 12 years (~1%/year), contributing substantially to the IDFS rates. For women Conclusions: The current updated analysis confirms findings from the original primary analysis that ET is non-inferior to CET in HR-positive, HER2-negative, node-negative EBC and a RS 11-25. As in the original primary analysis, the subgroup of women Citation Format: Joseph Sparano, Robert J. Gray, Della Makower, Kathy S. Albain, Daniel F. Hayes, Charles Geyer, Elizabeth Dees, Matthew P. Goetz, John A. Olson Jr, Tracy G. Lively, Sunil Badve, Thomas Saphner, Lynne I. Wagner, Timothy Whelan, Virginia Kaklamani, George Sledge. Trial Assigning Individualized Options for Treatment (TAILORx): An Update Including 12-Year Event Rates [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS1-05.

Abstract BACKGROUND: Abnormalities of the PI3kinase/AKT/mTOR signaling network are common in breast cancer (BC) and are associated with endocrine resistance. Everolimus, an mTOR-inhibitor increased PFS when combined with endocrine therapy (ET) in the metastatic setting and is thought to revert endocrine resistance. S1207 is a phase III randomized, placebo-controlled trial evaluating the role of everolimus in combination with ET in the adjuvant setting among patients with high-risk hormone receptor-positive, HER2-negative BC (NCT01674140). METHODS: Eligible patients were >18 years of age with histologically confirmed invasive hormone receptor-positive and HER2-negative high-risk BC. Four risk groups were defined as: 1) > 2cm node-negative disease (or pN1mi), and either an Oncotype DX® Recurrence Score (RS) > 25 or MammaPrint® high-risk category (MP high); 2) 1-3 positive nodes and either RS >25, MP high or a pathological grade 3 tumor; 3) >4 positive lymph nodes. Patients treated with neoadjuvant chemotherapy were eligible if: 4) after surgery had >1 lymph node involvement. Patients were randomized 1:1 to physician’s choice adjuvant ET in combination with one year of everolimus (10 mg PO daily) or ET plus placebo stratified by risk group. The primary endpoint was invasive disease-free survival (IDFS) evaluated by a stratified log-rank test. Secondary endpoints included overall survival (OS) and safety. The hazard ratio (HR) for treatment efficacy was estimated using Cox regression with stratification by risk groups. Subset analyses included preplanned evaluation within risk group and exploratory analyses of menopausal status and age. RESULTS: 1,939 patients were randomized between September 2013 and May 2019, of them 1,792 were eligible and included in the analysis (896 per arm). Primary reason for ineligibility was timing after chemotherapy/radiation or not high risk. Median age was 54 years (22-85) and 32% were premenopausal. With a median follow-up of 50.5 months, there were 389 IDFS events as of May 2022 (data cutoff). 5-year IDFS was 74.8% among patients treated with everolimus and 73.9% among patients treated with placebo, HR=0.93 (95% CI 0.76-1.14). However, the proportional hazards assumption was violated (p=0.02) suggesting differential treatment effect over time. The HR during the one year of treatment was 0.72 (95% CI 0.47-1.10) while after one year it was 1.00 (95% CI 0.80-1.26). The 5-year OS was 87.6% in the everolimus arm and 85.5% in the placebo arm, HR=0.98 (95% CI 0.75-1.28). Analysis by risk group did not show higher everolimus benefit as risk increased. No difference in IDFS or OS was seen among postmenopausal patients (IDFS HR=1.08 [95% CI 0.85-1.36], OS HR=1.19 [95% CI 0.87-1.61]). Among premenopausal patients, everolimus was associated with improved IDFS (HR=0.63 [95% CI 0.43-0.93]) and OS (HR=0.48 [95% CI 0.26-0.88]). Treatment completion of randomized therapy was lower in the everolimus arm compared to placebo (47.9% v 72.7%). Grade 3 and 4 toxicities were noted in 6.5% and 0.5% of patients in the placebo arm and in 31.2% and 3.7% in the everolimus arm respectively. CONCLUSIONS: Addition of one year of adjuvant everolimus to standard adjuvant ET did not improve IDFS or OS and was associated with low completion rate and increased AEs. Among premenopausal patients there was a benefit in IDFS and OS that is hypothesis generating. Future translational studies will evaluate potential predictors of everolimus benefit and drug toxicity. Citation Format: Marianna Chavez, Jieling Miao, Lajos Pusztai, Matthew P. Goetz, Priya Rastogi, Patricia A. Ganz, Eleftherios (Terry) Mamounas, Soonmyung Paik, Hanna Bandos, Wajeeha Razaq, Anne O’Dea, Virginia Kaklamani, Andrea L.M. Silber, Lisa E. Flaum, Eleni Andreopolu, Joseph Baar, Albert G. Wendt, Jennifer F. Carney, Priyanka Sharma, Julie R. Gralow, Danika L. Lew, William E. Barlow, Gabriel N. Hortobagyi. Results from a phase III randomized, placebo-controlled clinical trial evaluating adjuvant endocrine therapy +/- 1 year of everolimus in patients with high-risk hormone receptor-positive, HER2-negative breast cancer: SWOG S1207 [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS1-07.

ImportanceAnthracyclines increase the risk for congestive heart failure (CHF); however, long-term cumulative incidence and risk factors for CHF after anthracycline therapy are not well defined in population-based studies.ObjectiveTo compare the long-term cumulative incidence of CHF in patients with breast cancer or lymphoma treated with anthracycline therapy compared with healthy controls from the same community.Design, Setting, and ParticipantsThis retrospective population-based case-control study included data from the Rochester Epidemiology Project. Participants included residents of Olmsted County, Minnesota, diagnosed with breast cancer or lymphoma from January 1985 through December 2010 matched for age, sex, and comorbidities with healthy controls, with a final ratio of 1 case to 1.5 controls. Statistical analysis was performed between July 2017 and February 2022.ExposuresCancer treatment and CHF risk factors.Main Outcomes and MeasuresThe main outcome was new-onset CHF, as defined by the modified Framingham criteria. Cox proportional hazards regression was used to estimate hazard ratios (HRs) to compare the risk of CHF in participants with cancer vs controls, adjusted for age, sex, diabetes, hypertension, hyperlipidemia, coronary artery disease, obesity, and smoking history.ResultsA total of 2196 individuals were included, with 812 patients with cancer and 1384 participants without cancer. The mean (SD) age was 52.62 (14.56) years and 1704 participants (78%) were female. Median (IQR) follow-up was 8.6 (5.2-13.4) years in the case group vs 12.5 (8.7-17.5) years in the control group. Overall, patients with cancer had higher risk of CHF compared with the control cohort even after adjusting for age, sex, diabetes, hypertension, coronary artery disease, hyperlipidemia, obesity, and smoking status (HR, 2.86 [95% CI, 1.90-4.32]; P < .001). After adjusting for the same variables, CHF risk was greater for patients with cancer receiving anthracycline (HR, 3.25 [95% CI, 2.11-5.00]; P < .001) and was attenuated and lost statistical significance for patients with cancer not receiving anthracyclines (HR, 1.78 [95% CI, 0.83-3.81]; P = .14). Higher cumulative incidence for patients treated with anthracyclines vs comparator cohort was observed at 1 year (1.81% vs 0.09%), 5 years (2.91% vs 0.79%), 10 years (5.36% vs 1.74%), 15 years (7.42% vs 3.18%), and 20 years (10.75% vs 4.98%) (P < .001). There were no significant differences in risk of CHF for patients receiving anthracycline at a dose of less than 180 mg/m2 compared with those at a dose of 180 to 250 mg/m2 (HR, 0.54 [95% CI, 0.19-1.51]) or at a dose of more than 250 mg/m2 (HR, 1.23 [95% CI, 0.52-2.91]). At diagnosis, age was an independent risk factor associated with CHF (HR per 10 years, 2.77 [95% CI, 1.99-3.86]; P < .001).Conclusions and RelevanceIn this retrospective population-based case-control study, anthracyclines were associated with an increased risk of CHF early during follow-up, and the increased risk persisted over time. The cumulative incidence of CHF in patients with breast cancer or lymphoma treated with anthracyclines at 15 years was more than 2-fold that of the control group.

Background: Abemaciclib is the first and only cyclin-dependent kinases 4 and 6 inhibitor approved for adjuvant treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2−), node-positive, and high-risk early breast cancer (EBC), with indications varying by geography. Premenopausal patients with HR+, HER2− tumors may have different tumor biology and treatment response compared to postmenopausal patients. Objectives: We describe the efficacy and safety of abemaciclib plus endocrine therapy (ET) for the large subgroup of premenopausal patients with HR+, HER2− EBC in monarchE. Design: Randomized patients (1:1) received adjuvant ET with or without abemaciclib for 2 years plus at least 3 additional years of ET as clinically indicated. Methods: Patients were stratified by menopausal status (premenopausal versus postmenopausal) at diagnosis. Standard ET (tamoxifen or aromatase inhibitor) with or without gonadotropin-releasing hormone agonist was determined by physician’s choice. Invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) by menopausal status were assessed at data cutoff on 1 April 2021 (median follow-up of 27 months). Results: Among randomized patients, 2451 (43.5%) were premenopausal and 3181 (56.4%) were postmenopausal. The choice of ET for premenopausal patients varied considerably between countries. Treatment benefit was consistent across menopausal status, with a numerically greater effect size in premenopausal patients. For premenopausal patients, abemaciclib with ET resulted in a 42.2% and 40.3% reduction in the risk of developing IDFS and DRFS events, respectively. Absolute improvement at 3 years was 5.7% for IDFS and 4.4% for DRFS rates. Safety profile for premenopausal patients was consistent with the overall safety population. Conclusion: Abemaciclib with ET demonstrated clinically meaningful treatment benefit for IDFS and DRFS versus ET alone regardless of menopausal status and first ET, with a numerically greater benefit in the premenopausal compared to the postmenopausal population. Safety data in premenopausal patients are consistent with the overall safety profile of abemaciclib.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. The combined analysis of SOFT-TEXT compared outcomes in 4,690 premenopausal women with estrogen/progesterone receptor–positive (ER/PgR+) early breast cancer randomly assigned to 5 years of exemestane + ovarian function suppression (OFS) versus tamoxifen + OFS. After a median follow-up of 9 years, exemestane + OFS significantly improved disease-free survival (DFS) and distant recurrence-free interval (DRFI), but not overall survival, compared with tamoxifen + OFS. We now report DFS, DRFI, and overall survival after a median follow-up of 13 years. In the intention-to-treat (ITT) population, the 12-year DFS (4.6% absolute improvement, hazard ratio [HR], 0.79; 95% CI, 0.70 to 0.90; P < .001) and DRFI (1.8% absolute improvement, HR, 0.83; 95% CI, 0.70 to 0.98; P = .03), but not overall survival (90.1% v 89.1%, HR, 0.93; 95% CI, 0.78 to 1.11), continued to be significantly improved for patients assigned exemestane + OFS over tamoxifen + OFS. Among patients with human epidermal growth factor receptor 2-negative tumors (86.0% of the ITT population), the absolute improvement in 12-year overall survival with exemestane + OFS was 2.0% (HR, 0.85; 95% CI, 0.70 to 1.04) and 3.3% in those who received chemotherapy (45.9% of the ITT population). Overall survival benefit was clinically significant in high-risk patients, eg, women age < 35 years (4.0%) and those with > 2 cm (4.5%) or grade 3 tumors (5.5%). These sustained reductions of the risk of recurrence with adjuvant exemestane + OFS, compared with tamoxifen + OFS, provide guidance for selecting patients for whom exemestane should be preferred over tamoxifen in the setting of OFS. [Media: see text]

Abstract Androgen receptor (AR) is expressed in 80% to 90% of estrogen receptor α–positive (ER+) breast cancers. Accumulated evidence has shown that AR is a tumor suppressor and that its expression is associated with improved prognosis in ER+ breast cancer. However, both a selective AR agonist (RAD140) and an AR inhibitor (enzalutamide, ENZ) have shown a therapeutic effect on ER+ breast cancer, so the potential for clinical application of AR-targeting therapy for ER+ breast cancer is still in dispute. In this study, we evaluated the efficacy of ENZ and RAD140 in vivo and in vitro in AR+/ER+ breast cancer models, characterizing the relationship of AR and ER levels to response to AR-targeting drugs and investigating the alterations of global gene expression and chromatin binding of AR and ERα after ENZ treatment. In the AR-low setting, ENZ directly functioned as an ERα antagonist. Cell growth inhibition by ENZ in breast cancer with low AR expression was independent of AR and instead dependent on ER. In AR-high breast cancer models, AR repressed ERα signaling and ENZ promoted ERα signaling by antagonizing AR. In contrast, RAD140 activated AR signaling and suppressed AR-high tumor growth by deregulating ERα expression and blocking ERα function. Overall, analysis of the dynamic efficacies and outcomes of AR agonist, and antagonist in the presence of different AR and ERα levels reveals regulators of response and supports the clinical investigation of ENZ in selected ER+ tumors with a low AR/ER ratio and AR agonists in tumors with a high AR/ER ratio. Significance: The ratio of androgen receptor to estrogen receptor in breast cancer dictates the response to AR-targeted therapies, providing guidelines for developing AR-directed treatment strategies for patients with breast cancer.

ImportanceCytokine storm due to COVID-19 can cause high morbidity and mortality and may be more common in patients with cancer treated with immunotherapy (IO) due to immune system activation.ObjectiveTo determine the association of baseline immunosuppression and/or IO-based therapies with COVID-19 severity and cytokine storm in patients with cancer.Design, Setting, and ParticipantsThis registry-based retrospective cohort study included 12 046 patients reported to the COVID-19 and Cancer Consortium (CCC19) registry from March 2020 to May 2022. The CCC19 registry is a centralized international multi-institutional registry of patients with COVID-19 with a current or past diagnosis of cancer. Records analyzed included patients with active or previous cancer who had a laboratory-confirmed infection with SARS-CoV-2 by polymerase chain reaction and/or serologic findings.ExposuresImmunosuppression due to therapy; systemic anticancer therapy (IO or non-IO).Main Outcomes and MeasuresThe primary outcome was a 5-level ordinal scale of COVID-19 severity: no complications; hospitalized without requiring oxygen; hospitalized and required oxygen; intensive care unit admission and/or mechanical ventilation; death. The secondary outcome was the occurrence of cytokine storm.ResultsThe median age of the entire cohort was 65 years (interquartile range [IQR], 54-74) years and 6359 patients were female (52.8%) and 6598 (54.8%) were non-Hispanic White. A total of 599 (5.0%) patients received IO, whereas 4327 (35.9%) received non-IO systemic anticancer therapies, and 7120 (59.1%) did not receive any antineoplastic regimen within 3 months prior to COVID-19 diagnosis. Although no difference in COVID-19 severity and cytokine storm was found in the IO group compared with the untreated group in the total cohort (adjusted odds ratio [aOR], 0.80; 95% CI, 0.56-1.13, and aOR, 0.89; 95% CI, 0.41-1.93, respectively), patients with baseline immunosuppression treated with IO (vs untreated) had worse COVID-19 severity and cytokine storm (aOR, 3.33; 95% CI, 1.38-8.01, and aOR, 4.41; 95% CI, 1.71-11.38, respectively). Patients with immunosuppression receiving non-IO therapies (vs untreated) also had worse COVID-19 severity (aOR, 1.79; 95% CI, 1.36-2.35) and cytokine storm (aOR, 2.32; 95% CI, 1.42-3.79).Conclusions and RelevanceThis cohort study found that in patients with cancer and COVID-19, administration of systemic anticancer therapies, especially IO, in the context of baseline immunosuppression was associated with severe clinical outcomes and the development of cytokine storm.Trial RegistrationClinicalTrials.gov Identifier: NCT04354701

Neoadjuvant chemotherapy (NAC) remains the cornerstone of the treatment for triple negative breast cancer (TNBC), with the goal of complete eradication of disease. However, for patients with residual disease after NAC, recurrence and mortality rates are high and the identification of novel therapeutic targets is urgently needed. We quantified tyrosine phosphorylation (pTyr)-mediated signaling networks in chemotherapy sensitive (CS) and resistant (CR) TNBC patient-derived xenografts (PDX), to gain novel therapeutic insights. The antitumor activity of SFK inhibition was examined in vivo. Treated tumors were further subjected to phosphoproteomic and RNAseq analysis, to identify the mechanism of actions of the drug. We identified Src Family Kinases (SFKs) as potential therapeutic targets in CR TNBC PDXs. Treatment with dasatinib, an FDA approved SFK inhibitor, led to inhibition of tumor growth in vivo. Further analysis of post-treatment PDXs revealed multiple mechanisms of actions of the drug, confirming the multi-target inhibition of dasatinib. Analysis of pTyr in tumor specimens suggested a low prevalence of SFK-driven tumors, which may provide insight into prior clinical trial results demonstrating a lack of dasatinib antitumor activity in unselected breast cancer patients. Taken together, these results underscore the importance of pTyr characterization of tumors, in identifying new targets, as well as stratifying patients based on their activated signaling networks for therapeutic options. Our data provide a strong rationale for studying SFK inhibitors in biomarker-selected SFK-driven TNBC.