VERITAC-2: a Phase III study of vepdegestrant, a PROTAC ER degrader, versus fulvestrant in ER+/HER2- advanced breast cancer.

Vepdegestrant (ARV-471) is an oral PROTAC ER degrader that binds an E3 ubiquitin ligase and ER to directly trigger ubiquitination of ER and its subsequent proteasomal degradation. In a first-in-human Phase I/II study, vepdegestrant monotherapy was well tolerated with clinical activity in pretreated patients with ER+/HER2- advanced breast cancer. The global, randomized Phase III VERITAC-2 study compares efficacy and safety of vepdegestrant versus fulvestrant in adults with ER+/HER2- advanced breast cancer after treatment with a CDK4/6 inhibitor plus endocrine therapy. Progression-free survival by blinded independent central review (primary end point) will be assessed in the intention-to-treat population and ESR1 mutation-positive subpopulation. Secondary end points include overall survival, tumor response, safety, pharmacokinetics, patient-reported outcomes, and circulating tumor DNA biomarkers.Clinical trial registration: NCT05654623 (ClinicalTrials.gov).

VERITAC-2 is a clinical trial comparing vepdegestrant, a new drug that degrades estrogen receptors, to an existing treatment called fulvestrant in patients with ER+/HER2- advanced breast cancer: Estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer grows in response to estrogen, a hormone in the body, and has low levels or no HER2 protein. People living with ER+/HER2- advanced breast cancer that has grown, spread to another part of the body, or cannot be removed by surgery are often treated with cyclin-dependent kinase (CDK) 4/6 inhibitors and endocrine therapies, but their cancer may get worse on these treatments and new treatments are needed. Fulvestrant, an endocrine therapy that attaches to estrogen receptors, lowers estrogen's effect on tumors and can slow or stop cancer growth. Vepdegestrant, a new medicine being tested for ER+ breast cancer, is a PROteolysis TArgeting Chimera (PROTAC) protein degrader that attaches to estrogen receptors and causes them to be tagged for removal by the cell's natural protein disposal system. By removing estrogen receptors, vepdegestrant may cause tumors to stop growing or shrink.This paper describes the Phase III VERITAC-2 clinical study comparing vepdegestrant versus fulvestrant in people living with ER+/HER2- advanced breast cancer previously treated with a CDK4/6 inhibitor and endocrine therapy.Patients will be randomly assigned to receive vepdegestrant (a pill taken once daily by mouth) or fulvestrant (a shot given into the muscle). The purpose of the study is to find out how long people live without their cancer getting worse with vepdegestrant or fulvestrant. VERITAC-2 will also look at how long people live during the study, side effects people may experience, and the overall well-being of people throughout the study.

A dose escalation/expansion study evaluating dose, safety, and efficacy of the novel tyrosine kinase inhibitor surufatinib, which inhibits VEGFR 1, 2, & 3, FGFR 1, and CSF1R, in US patients with neuroendocrine tumors.

Surufatinib, is a potent inhibitor of vascular endothelial growth factor receptors 1-3; fibroblast growth factor receptor-1; colony-stimulating factor 1 receptor. This Phase 1/1b escalation/expansion study in US patients with solid tumors evaluated 5 once daily (QD) surufatinib doses (3 + 3 design) to identify maximum tolerated dose (MTD), recommended Phase 2 dose (RP2D), and evaluate safety and efficacy at the RP2D in 4 disease-specific expansion cohorts including pancreatic neuroendocrine tumors [pNET] and extrapancreatic NETs [epNET]. MTD and RP2D were 300 mg QD (escalation [n = 35]); 5 patients (15.6%) (Dose Limiting Toxicity [DLT] Evaluable Set [n = 32]) had DLTs. Pharmacokinetics were dose proportional. Estimated progression-free survival (PFS) rates at 11 months were 57.4% (95% confidence interval [CI]: 28.7, 78.2) and 51.1% (95% CI: 12.8, 80.3) for pNET and epNET expansion cohorts, respectively. Median PFS was 15.2 (95% CI: 5.2, not evaluable) and 11.5 (95% CI: 6.5,11.5) months. Response rates were 18.8% and 6.3%. The most frequent treatment-emergent adverse events (both cohorts) were fatigue (46.9%), hypertension (43.8%), proteinuria (37.5%), diarrhea (34.4%). Pharmacokinetics, safety, and antitumor efficacy of 300 mg QD oral surufatinib in US patients with pNETs and epNETs are consistent with previously reported studies in China and may support applicability of earlier surufatinib studies in US patients. Clinical trial registration: Clinicaltrials.gov NCT02549937.

Phase 1b study of anti-NaPi2b antibody-drug conjugate lifastuzumab vedotin (DNIB0600A) in patients with platinum-sensitive recurrent ovarian cancer.

OBJECTIVE: This study investigated the safety and tolerability of lifastuzumab vedotin (DNIB0600A) (LIFA), an antibody-drug conjugate, in patients with recurrent platinum-sensitive ovarian cancer (PSOC). METHODS: In this open-label, multicenter phase 1b study, LIFA was administered intravenously once every 3 weeks (Q3W) with starting dose 1.2 mg/kg in a 3 + 3 dose-escalation scheme. All patients received carboplatin at dose AUC 6 mg/mL·min (AUC6) Q3W for up to 6 cycles. Dose expansion cohorts were enrolled ± bevacizumab 15 mg/kg Q3W. RESULTS: Patients received LIFA at 1.2, 1.8, and 2.4 mg (n = 4, 5, and 20, respectively) with carboplatin. The maximum tolerated dose was not reached. The recommended phase 2 dose (RP2D) was LIFA 2.4 mg/kg + carboplatin AUC6 (cycles 1-6), with or without bevacizumab 15 mg/kg. Twelve patients received RP2D with bevacizumab. All patients experienced ≥1 adverse event (AE). The most common treatment-related AEs were neutropenia, peripheral neuropathy, thrombocytopenia, nausea, fatigue, anemia, diarrhea, vomiting, hypomagnesaemia, aspartate aminotransferase increased, alanine aminotransferase increased, and alopecia. Thirty-four (83%) patients experienced grade ≥ 3 AEs, the most frequent of which were neutropenia and thrombocytopenia. Nine (22%) patients experienced serious AEs. Pulmonary toxicities (34%), considered a potential risk of LIFA, included one patient who discontinued study treatment due to grade 2 pneumonitis. The median duration of progression-free survival was 10.71 months (95% CI: 8.54, 13.86) with confirmed complete/partial responses in 24 (59%) patients. Pharmacokinetics of mono-therapy LIFA was similar in combination therapy. CONCLUSION: LIFA in combination with carboplatin ± bevacizumab demonstrated acceptable safety and encouraging activity in PSOC patients.

Avelumab, an anti-PD-L1 antibody, in patients with locally advanced or metastatic breast cancer: a phase 1b JAVELIN Solid Tumor study.

PURPOSE: Agents targeting programmed death receptor 1 (PD-1) or its ligand (PD-L1) have shown antitumor activity in the treatment of metastatic breast cancer (MBC). The aim of this study was to assess the activity of avelumab, a PD-L1 inhibitor, in patients with MBC. METHODS: In a phase 1 trial (JAVELIN Solid Tumor; NCT01772004), patients with MBC refractory to or progressing after standard-of-care therapy received avelumab intravenously 10 mg/kg every 2 weeks. Tumors were assessed every 6 weeks by RECIST v1.1. Adverse events (AEs) were graded by NCI-CTCAE v4.0. Membrane PD-L1 expression was assessed by immunohistochemistry (Dako PD-L1 IHC 73-10 pharmDx). RESULTS: A total of 168 patients with MBC, including 58 patients with triple-negative breast cancer (TNBC), were treated with avelumab for 2-50 weeks and followed for 6-15 months. Patients were heavily pretreated with a median of three prior therapies for metastatic or locally advanced disease. Grade ≥ 3 treatment-related AEs occurred in 13.7% of patients, including two treatment-related deaths. The confirmed objective response rate (ORR) was 3.0% overall (one complete response and four partial responses) and 5.2% in patients with TNBC. A trend toward a higher ORR was seen in patients with PD-L1+ versus PD-L1- tumor-associated immune cells in the overall population (16.7% vs. 1.6%) and in the TNBC subgroup (22.2% vs. 2.6%). CONCLUSION: Avelumab showed an acceptable safety profile and clinical activity in a subset of patients with MBC. PD-L1 expression in tumor-associated immune cells may be associated with a higher probability of clinical response to avelumab in MBC.

CHAMBER: A Regional Performance Improvement CME Initiative for Breast Cancer Health Care Providers.

CHAMBER was a regional educational initiative for providers of care to patients with HER2+ breast cancer. The study goals were to (1) enhance testing for HER2/neu overexpression in patients with invasive breast cancer; (2) increase the appropriate use of targeted therapy for patients with HER2+ breast cancer; and (3) enhance patients' coping ability. This Performance Improvement Continuing Medical Education (PI-CME) initiative included clinical practice assessment, educational activities, and reassessment. Chart review revealed a high rate of HER2 testing (98%) before and after education. Targeted therapy for patients with HER2+ breast cancer declined after the program (from 96% to 61%), perhaps attributable to an increase in awareness of medical reasons to avoid use of targeted therapy. Assessment for patients' emotional coping ability increased after education (from 55% to 76%; P=.01). Rates of testing for HER2 amplification and assessment of emotional well-being after education were consistent with ASCO Quality Oncology Practice Initiative benchmark values. Documentation of actions to address emotional problems remained an area for improvement.

Datopotamab Deruxtecan in Advanced or Metastatic HR+/HER2- and Triple-Negative Breast Cancer: Results From the Phase I TROPION-PanTumor01 Study.

PURPOSE: Datopotamab deruxtecan (Dato-DXd) is an antibody-drug conjugate consisting of a humanized antitrophoblast cell-surface antigen 2 (TROP2) monoclonal antibody linked to a potent, exatecan-derived topoisomerase I inhibitor payload via a plasma-stable, selectively cleavable linker. PATIENTS AND METHODS: TROPION-PanTumor01 (ClinicalTrials.gov identifier: NCT03401385) is a phase I, dose-escalation, and dose-expansion study evaluating Dato-DXd in patients with previously treated solid tumors. The primary study objective was to assess the safety and tolerability of Dato-DXd. Secondary objectives included evaluation of antitumor activity and pharmacokinetics. Results from patients with advanced/metastatic hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer (BC) or triple-negative BC (TNBC) are reported. RESULTS: At data cutoff (July 22, 2022), 85 patients (HR+/HER2- BC = 41, and TNBC = 44) had received Dato-DXd. The objective response rate by blinded independent central review was 26.8% (95% CI, 14.2 to 42.9) and 31.8% (95% CI, 18.6 to 47.6) for patients with HR+/HER2- BC and TNBC, respectively. The median duration of response was not evaluable in the HR+/HER2- BC cohort and 16.8 months in the TNBC cohort. The median progression-free survival in patients with HR+/HER2- BC and TNBC was 8.3 and 4.4 months, respectively. All-cause treatment-emergent adverse events (TEAEs; any grade, grade ≥3) were observed in 100% and 41.5% of patients with HR+/HER2- BC and 100% and 52.3% of patients with TNBC. Stomatitis was the most common TEAE (any grade, grade ≥3) in both HR+/HER2- BC (82.9%, 9.8%) and TNBC (72.7%, 11.4%) cohorts. CONCLUSION: In patients with heavily pretreated advanced HR+/HER2- BC and TNBC, Dato-DXd demonstrated promising clinical activity and a manageable safety profile. Dato-DXd is currently being evaluated in phase III studies.

Adjuvant Abemaciclib Plus Endocrine Therapy for Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative, High-Risk Early Breast Cancer: Results From a Preplanned monarchE Overall Survival Interim Analysis, Including 5-Year Efficacy Outcomes.

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.Two years of adjuvant abemaciclib combined with endocrine therapy (ET) resulted in a significant improvement in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) that persisted beyond the 2-year treatment period in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer (EBC). Here, we report 5-year efficacy results from a prespecified overall survival (OS) interim analysis. In the intent-to-treat population, with a median follow-up of 54 months, the benefit of abemaciclib was sustained with hazard ratios of 0.680 (95% CI, 0.599 to 0.772) for IDFS and 0.675 (95% CI, 0.588 to 0.774) for DRFS. This persistence of abemaciclib benefit translated to continuous separation of the curves with a deepening in 5-year absolute improvement in IDFS and DRFS rates of 7.6% and 6.7%, respectively, compared with rates of 6% and 5.3% at 4 years and 4.8% and 4.1% at 3 years. With fewer deaths in the abemaciclib plus ET arm compared with the ET-alone arm (208 v 234), statistical significance was not reached for OS. No new safety signals were observed. In conclusion, abemaciclib plus ET continued to reduce the risk of developing invasive and distant disease recurrence beyond the completion of treatment. The increasing absolute improvement at 5 years is consistent with a carryover effect and further supports the use of abemaciclib in patients with high-risk EBC.

Discovery and Clinical Proof-of-Concept of RLY-2608, a First-in-Class Mutant-Selective Allosteric PI3Kα Inhibitor That Decouples Antitumor Activity from Hyperinsulinemia.

PIK3CA (PI3Kα) is a lipid kinase commonly mutated in cancer, including ∼40% of hormone receptor-positive breast cancer. The most frequently observed mutants occur in the kinase and helical domains. Orthosteric PI3Kα inhibitors suffer from poor selectivity leading to undesirable side effects, most prominently hyperglycemia due to inhibition of wild-type (WT) PI3Kα. Here, we used molecular dynamics simulations and cryo-electron microscopy to identify an allosteric network that provides an explanation for how mutations favor PI3Kα activation. A DNA-encoded library screen leveraging electron microscopy-optimized constructs, differential enrichment, and an orthosteric-blocking compound led to the identification of RLY-2608, a first-in-class allosteric mutant-selective inhibitor of PI3Kα. RLY-2608 inhibited tumor growth in PIK3CA-mutant xenograft models with minimal impact on insulin, a marker of dysregulated glucose homeostasis. RLY-2608 elicited objective tumor responses in two patients diagnosed with advanced hormone receptor-positive breast cancer with kinase or helical domain PIK3CA mutations, with no observed WT PI3Kα-related toxicities. SIGNIFICANCE: Treatments for PIK3CA-mutant cancers are limited by toxicities associated with the inhibition of WT PI3Kα. Molecular dynamics, cryo-electron microscopy, and DNA-encoded libraries were used to develop RLY-2608, a first-in-class inhibitor that demonstrates mutant selectivity in patients. This marks the advance of clinical mutant-selective inhibition that overcomes limitations of orthosteric PI3Kα inhibitors. See related commentary by Gong and Vanhaesebroeck, p. 204 . See related article by Varkaris et al., p. 227 . This article is featured in Selected Articles from This Issue, p. 201.

Prevalence and impact of correlative science in breast cancer phase II trials.

Correlative science (CS) can potentially augment clinical trial results by identifying biomarkers of response and resistance to a novel intervention. We evaluated recently published breast cancer phase II trials (BP2T) to determine prevalence, characteristics, and outcomes of CS. Through Pubmed, we identified BP2T of systemic therapy published between June 2005 and June 2010. A study-specific abstraction tool recorded trial characteristics, CS endpoints, source of tissue, adequacy of samples, biopsy safety, and CS outcomes. BP2T authors were contacted to verify abstraction results. Results were abstracted from 298 eligible trials enrolling 18,782 patients, of which 81 (27.2 %) involved CS. Of these, 57 (70.4 %) included tissue with 16 (28 %) using optional research biopsies and 17 (30 %) requiring mandatory research biopsies. No trial addressed biopsy safety issues. Trials were more likely to include CS if they were: industry versus non-industry sponsored (33.7 % vs. 17.1 %, p = 0.0017), neoadjuvant versus metastatic setting (47 % vs. 21.2 %, p = 0.0001), or U.S. versus non-U.S. trials (37 % vs. 21 %, p = 0.005). A minority of phase II breast cancer trials include CS representing a missed opportunity to learn more from clinical research. When CS is included, consistent reporting of endpoints, feasibility, outcomes, and safety is needed.

Landscape of baseline and acquired genomic alterations in circulating tumor DNA with abemaciclib alone or with endocrine therapy in advanced breast cancer.

PURPOSE: To identify potential predictors of response and resistance mechanisms in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) treated with the CDK4/6 inhibitor abemaciclib +/- endocrine therapy (ET), baseline and acquired genomic alterations in circulating tumor DNA (ctDNA) were analyzed and associated with clinical outcomes. PATIENTS AND METHODS: MONARCH 3: postmenopausal women with HR+, HER2- ABC and no prior systemic therapy in the advanced setting were randomized to abemaciclib or placebo plus nonsteroidal aromatase inhibitor (NSAI). nextMONARCH: women with HR+, HER2- metastatic breast cancer that progressed on/after prior ET and chemotherapy were randomized to abemaciclib alone (two doses) or plus tamoxifen. Baseline and end-of-treatment plasma samples from patients in MONARCH 3 and nextMONARCH (monotherapy arms) were analyzed to identify somatic genomic alterations. Association between genomic alterations and median progression-free survival (mPFS) was assessed. RESULTS: Most patients had ≥1 genomic alteration detected in baseline ctDNA. In MONARCH 3, abemaciclib+NSAI was associated with improved mPFS versus placebo+NSAI, regardless of baseline alterations. ESR1 alterations were less frequently acquired in the abemaciclib+NSAI arm than placebo+NSAI. Acquired alterations potentially associated with resistance to abemaciclib +/- NSAI included RB1 and MYC. CONCLUSIONS: In MONARCH 3, certain baseline ctDNA genomic alterations were prognostic for ET but not predictive of abemaciclib response. Further studies are warranted to assess whether ctDNA alterations acquired during abemaciclib treatment differ from other CDK4/6 inhibitors. Findings are hypothesis-generating, further exploration is warranted into mechanisms of resistance to abemaciclib and ET.

First-in-human Study of AZD5153, A Small-molecule Inhibitor of Bromodomain Protein 4, in Patients with Relapsed/Refractory Malignant Solid Tumors and Lymphoma.

AZD5153, a reversible, bivalent inhibitor of the bromodomain and extraterminal family protein BRD4, has preclinical activity in multiple tumors. This first-in-human, phase I study investigated AZD5153 alone or with olaparib in patients with relapsed/refractory solid tumors or lymphoma. Adults with relapsed tumors intolerant of, or refractory to, prior therapies received escalating doses of oral AZD5153 once daily or twice daily continuously (21-day cycles), or AZD5153 once daily/twice daily continuously or intermittently plus olaparib 300 mg twice daily, until disease progression or unacceptable toxicity. Between June 30, 2017 and April 19, 2021, 34 patients received monotherapy and 15 received combination therapy. Dose-limiting toxicities were thrombocytopenia/platelet count decreased (n = 4/n = 2) and diarrhea (n = 1). The recommended phase II doses (RP2D) were AZD5153 30 mg once daily or 15 mg twice daily (monotherapy) and 10 mg once daily (intermittent schedule) with olaparib. With AZD5153 monotherapy, common treatment-emergent adverse events (TEAE) included fatigue (38.2%), thrombocytopenia, and diarrhea (each 32.4%); common grade ≥ 3 TEAEs were thrombocytopenia (14.7%) and anemia (8.8%). With the combination, common TEAEs included nausea (66.7%) and fatigue (53.3%); the most common grade ≥ 3 TEAE was thrombocytopenia (26.7%). AZD5153 had dose-dependent pharmacokinetics, with minimal accumulation, and demonstrated dose-dependent modulation of peripheral biomarkers, including upregulation of HEXIM1. One patient with metastatic pancreatic cancer receiving combination treatment had a partial response lasting 4.2 months. These results show AZD5153 was tolerable as monotherapy and in combination at the RP2Ds; common toxicities were fatigue, hematologic AEs, and gastrointestinal AEs. Strong evidence of peripheral target engagement was observed.

The (R)evolution of Social Media in Oncology: Engage, Enlighten, and Encourage.

SUMMARY: Social media (SoMe) platforms have the ability to strengthen the oncology community, leading to intellectual connections that with time develop into friendships. SoMe has immense potential in all areas of medicine, and SoMe in oncology is proof of this, raising awareness about clinical trials, promoting cancer prevention techniques, amplifying oncology information, enabling diverse viewpoints into conversations, as well as educating colleagues regardless of geography.

Adavosertib with Chemotherapy in Patients with Primary Platinum-Resistant Ovarian, Fallopian Tube, or Peritoneal Cancer: An Open-Label, Four-Arm, Phase II Study.

PURPOSE: This study assessed the efficacy, safety, and pharmacokinetics of adavosertib in combination with four chemotherapy agents commonly used in patients with primary platinum-resistant ovarian cancer. PATIENTS AND METHODS: Women with histologically or cytologically confirmed epithelial ovarian, fallopian tube, or peritoneal cancer with measurable disease were enrolled between January 2015 and January 2018 in this open-label, four-arm, multicenter, phase II study. Patients received adavosertib (oral capsules, 2 days on/5 days off or 3 days on/4 days off) in six cohorts from 175 mg once daily to 225 mg twice daily combined with gemcitabine, paclitaxel, carboplatin, or pegylated liposomal doxorubicin. The primary outcome measurement was overall response rate. RESULTS: Three percent of patients (3/94) had confirmed complete response and 29% (27/94) had confirmed partial response. The response rate was highest with carboplatin plus weekly adavosertib, at 66.7%, with 100% disease control rate, and median progression-free survival of 12.0 months. The longest median duration of response was in the paclitaxel cohort (12.0 months). The most common grade ≥3 adverse events across all cohorts were neutropenia [45/94 (47.9%) patients], anemia [31/94 (33.0%)], thrombocytopenia [30/94 (31.9%)], and diarrhea and vomiting [10/94 (10.6%) each]. CONCLUSIONS: Adavosertib showed preliminary efficacy when combined with chemotherapy. The most promising treatment combination was adavosertib 225 mg twice daily on days 1-3, 8-10, and 15-17 plus carboplatin every 21 days. However, hematologic toxicity was more frequent than would be expected for carboplatin monotherapy, and the combination requires further study to optimize the dose, schedule, and supportive medications.

Safety of bevacizumab in patients with metastatic breast cancer.

Five randomized phase III trials - AVF2119g, E2100, AVADO, RIBBON-1, and RIBBON-2 - have reported data on the efficacy and safety of bevacizumab, combined with a variety of chemotherapy agents and in various settings, in patients with metastatic breast cancer (MBC). The E2100 trial demonstrated a significant improvement in progression-free survival according to the independent review facility, from 5.8 to 11.3 months when bevacizumab was combined with paclitaxel (p < 0.0001) as first-line therapy in patients with HER2-nonamplified MBC; subsequent trials of bevacizumab as first-line (AVADO, RIBBON-1) and second-line (RIBBON-2) therapy for patients with HER2-nonamplified MBC have also met their primary end point of prolonging progression-free survival (PFS). Accumulating safety data for bevacizumab in MBC show that it is generally well tolerated and associated with predictable adverse events, including hypertension and proteinuria. The majority of adverse events are mild and manageable, but bevacizumab is also associated with some severe toxicities. The management of bevacizumab-related adverse events in MBC has improved with increased experience. This review summarizes bevacizumab efficacy in MBC and focuses on bevacizumab-related toxicities as reported in 5 phase III clinical trials. Current adverse event management strategies, based on guidelines and experience from these trials, are outlined.

Interstitial Lung Disease Induced by Anti-ERBB2 Antibody-Drug Conjugates: A Review.

IMPORTANCE: In the past decade, ERBB2 (formerly HER2)-directed antibody-drug conjugates (ADCs) have substantially changed treatment of both advanced and early-stage ERBB2-positive breast cancer. Novel conjugates are now showing activity in trials of other ERBB2-associated tumors, leading to the recent US Food and Drug Administration approval of trastuzumab deruxtecan for ERBB2-positive gastric cancer, as well as beneficial results in colorectal, lung, and bladder cancer. It is thus possible that anti-ERBB2 ADCs may become a treatment option for multiple types of tumors because many have at least some expression of ERBB2. Despite an improved overall therapeutic index, clinical observations have recently raised a concern regarding potential lung toxicity of anti-ERBB2 ADCs. Deaths related to interstitial lung disease (ILD) have been reported with variable incidence in trials testing anti-ERBB2 conjugates, warranting appropriate training of clinicians for the identification and management of this toxic effect. OBSERVATIONS: Although no specific guidelines are available for the diagnosis and management of ADC-related ILD, some recommendations can be derived based on general principles adopted for drug-induced and immunotherapy-related ILD. Overall, in symptomatic ILD, the ADC should be discontinued. Reintroduction of the conjugate can be considered only in asymptomatic cases after complete resolution. Corticosteroids represent the cornerstone of ILD treatment, and dosing should be adapted according to the severity of the event. Additional treatments can be considered based on the clinical scenario. CONCLUSIONS AND RELEVANCE: This review summarizes the current knowledge on the pathogenesis and epidemiologic characteristics of anti-ERBB2 ADC-related lung toxicity, proposing strategies for its diagnosis and treatment. Earlier diagnosis and more adequate treatment of ADC-induced ILD may improve the therapeutic index of this important class of anticancer agents, allowing for a safe expansion of anti-ERBB2 ADCs across tumor types.

Impact of Anti-HER2 Treatments Combined With Atezolizumab on the Tumor Immune Microenvironment in Early or Metastatic Breast Cancer: Results From a Phase Ib Study.

BACKGROUND: Despite advances, there continues to be unmet need in breast cancer. Combining anti-programmed death-ligand 1 (PD-L1) cancer immunotherapy atezolizumab with other targeted therapies may enhance T-cell-dependent cytolytic antitumor activity. METHODS: This open-label, phase Ib study evaluated the safety of atezolizumab-based combinations with antibody-dependent cellular cytotoxicity or antibody-drug conjugate (ADC) agents. Patients with unresectable human epidermal growth factor receptor 2-positive (HER2+) locally advanced or metastatic breast cancer (mBC) received atezolizumab with trastuzumab/pertuzumab, atezolizumab with the ADC ado-trastuzumab emtansine (T-DM1), or atezolizumab with trastuzumab/pertuzumab and docetaxel. In an early-breast cancer (eBC) "window of opportunity" study, patients with operable HER2+ locally advanced or inflammatory eBC received neoadjuvant atezolizumab with trastuzumab/pertuzumab or atezolizumab/T-DM1, followed by docetaxel, carboplatin, and trastuzumab/pertuzumab. Exploratory outcomes included tumor response and biomarkers. RESULTS: By March 15, 2019, 73 patients were enrolled. Safety findings were consistent with the treatment components' individual profiles. Objective responses were observed in 2 of 6 and 5 of 14 patients in 2 mBC cohorts receiving atezolizumab/T-DM1 and in 6 of 6 patients with mBC receiving atezolizumab, trastuzumab/pertuzumab, and docetaxel. PD-L1 in immune cells was the only biomarker that increased with atezolizumab/T-DM1. In the window of opportunity cohorts, PD-L1 levels and CD8+ T-cell infiltration increased from baseline in HER2+ eBC tumors receiving atezolizumab with trastuzumab/pertuzumab or T-DM1, irrespective of response. Despite increases in T-cell and B-cell gene signatures with trastuzumab/pertuzumab, but not T-DM1, neither combination promoted T-cell receptor clonal expansion. CONCLUSION: Atezolizumab with antibody-dependent cellular cytotoxicity or ADC agents appears safe and may activate the adaptive immune system of patients with HER2+ eBC tumors more than those with mBC tumors.

First-in-Human, Phase 1 Dose-Escalation Study of Biparatopic Anti-HER2 Antibody-Drug Conjugate MEDI4276 in Patients with HER2-positive Advanced Breast or Gastric Cancer.

MEDI4276 is a biparatopic tetravalent antibody targeting two nonoverlapping epitopes in subdomains 2 and 4 of the HER2 ecto-domain, with site-specific conjugation to a tubulysin-based microtubule inhibitor payload. MEDI4276 demonstrates enhanced cellular internalization and cytolysis of HER2-positive tumor cells in vitro This was a first-in-human, dose-escalation clinical trial in patients with HER2-positive advanced or metastatic breast cancer or gastric cancer. MEDI4276 doses escalated from 0.05 to 0.9 mg/kg (60- to 90-minute intravenous infusion every 3 weeks). Primary endpoints were safety and tolerability; secondary endpoints included antitumor activity (objective response, progression-free survival, and overall survival), pharmacokinetics, and immunogenicity. Forty-seven patients (median age 59 years; median of seven prior treatment regimens) were treated. The maximum tolerated dose was exceeded at 0.9 mg/kg with two patients experiencing dose-limiting toxicities (DLTs) of grade 3 liver function test (LFT) increases, one of whom also had grade 3 diarrhea, which resolved. Two additional patients reported DLTs of grade 3 LFT increases at lower doses (0.4 and 0.6 mg/kg). The most common (all grade) drug-related adverse events (AEs) were nausea (59.6%), fatigue (44.7%), aspartate aminotransferase (AST) increased (42.6%), and vomiting (38.3%). The most common grade 3/4 drug-related AE was AST increased (21.3%). Five patients had drug-related AEs leading to treatment discontinuation. In the as-treated population, there was one complete response (0.5 mg/kg; breast cancer), and two partial responses (0.6 and 0.75 mg/kg; breast cancer)-all had prior trastuzumab, pertuzumab, and ado-trastuzumab emtansine (T-DM1). MEDI4276 has demonstrable clinical activity but displays intolerable toxicity at doses >0.3 mg/kg.

Next-Generation Sequencing of Patients With Breast Cancer in Community Oncology Clinics.

PURPOSE: Molecular biomarkers informing disease diagnosis, prognosis, and treatment decisions in patients with breast cancer are being uncovered by next-generation sequencing (NGS) technologies. In this study, we survey how NGS is used for patients with breast cancer in real-world settings with a focus on physician behaviors and sequencing results. METHODS: We conducted a retrospective analysis of patients with breast cancer who received NGS testing from commercial vendors as part of standard of care from 2014 to 2019. A total of 2,635 NGS reports from 2,316 unique breast cancer patients were assessed. Hormone receptor and human epidermal growth factor receptor 2 statuses were abstracted from patient medical records. Comparative gene amplification and mutation frequencies were analyzed using Pearson's correlation and Lin's concordance statistics. RESULTS: The number of physicians ordering NGS tests for patients with breast cancer increased more than six-fold from 2014 to 2019. Tissue- and plasma-based tests were ordered roughly equally by 2019, with plasma-based testing ordered most frequently in hormone receptor-positive subtypes. Patients with triple-negative breast cancer were most likely to receive NGS testing. Gene amplifications including ERBB2 were detected less frequently in our real-world data set as compared to previous genomic landscape studies, whereas the opposite was true for gene mutations including ESR1. Pathogenic mutations in the PI3K pathway (38.6%) and DNA damage repair pathway (11.0%) were frequently reported. Alterations were also reported across other cellular pathways. CONCLUSION: Overall, we found that an increasing number of physicians in community settings are adopting NGS in the care of patients with breast cancer. Discrepancies between our real-world NGS data and previous genomic landscape studies are likely owed to the prevalence of plasma-based testing in community oncology clinics, as the reference data were from tissue-based NGS alone.