# HER2 CR: HCP commentary report > 37 verified statements (23 from clinicians verified by NPI or staff page) from 10 commentary sources · 5 findings · updated Nov 1, 2026 ## Report - Trial: Personalized Detection of ctDNA for Patients With HER2-Positive Metastatic Breast Cancer Who Achieved Durable Response by Anti-HER2 Treatment - NCT ID: NCT06663787 - Registry: https://clinicaltrials.gov/study/NCT06663787 - Sponsor: Nagoya City University - Phase: Observational - Status: Active, not recruiting - Version: v1.0.0, edition 1 - Accepted: 2026-11-01 - Last checked: 2026-11-01 - Release hash: 7fc98ec6e6682b5c8613d78e0681571e9fcb8e12a181583b6abb29ef3ef301c4 ## Counts - HCP commentary sources screened: 13 - Sources cited by verified statements: 11 - Verified statements: 37 - From speakers with a confirmed clinical role (verified by the NPI registry or their own institution's staff page): 23 - Findings: 5 - Named people in screened sources (unnamed speakers and accounts not counted): 11 - Voices cited: 9 - Cited voices identity-verified: 8 - Organisational or shared accounts (not counted as people): 1 Counts describe the retained sources. They do not estimate how many HCPs hold a view. ## Abstract HER2 CR assesses circulating tumor DNA (ctDNA) status in durable responders with HER2-positive metastatic breast cancer; the discussion distinguishes investigating anti-HER2 cessation from establishing safety. The report cites six physicians, five of them medical oncologists, and examines assay sensitivity and ctDNA monitoring alongside imaging. What assay definitions, serial-response criteria and prospective safety evidence would justify treatment breaks without replacing imaging or confusing chemotherapy withdrawal with anti-HER2 cessation? The sources place HER2-CR’s initial results at ESMO 2026. ## Open Medical Affairs question What assay definition, serial-response criteria and prospective safety evidence would justify a treatment break without displacing imaging or confusing chemotherapy withdrawal with anti-HER2 cessation? Raised by the leading finding. The report shows what clinicians said and the sources behind it; it does not settle the question. ## Findings (titles) - F1. Enthusiasm supports testing treatment cessation, not declaring it safe - F2. Assay sensitivity changes the meaning of a negative result - F3. Where does ctDNA response monitoring fit alongside imaging? - F4. Chemotherapy withdrawal is not the same decision as stopping anti-HER2 maintenance - F5. Stop HER2 addresses a separate, explicit treatment-break question ## What sits behind each finding Counts describe what the report retained, not how many clinicians hold a view. A statement can support more than one finding. | Finding | Statements | Passages | Sources | Named voices | Counterview | Limitations | | --- | ---: | ---: | ---: | ---: | --- | ---: | | F1 | 14 | 9 | 9 | 6 | none recorded | 3 | | F2 | 6 | 4 | 3 | 2 | none recorded | 3 | | F3 | 8 | 4 | 1 | 2 | none recorded | 3 | | F4 | 7 | 6 | 2 | 2 | none recorded | 4 | | F5 | 5 | 4 | 3 | 2 | none recorded | 3 | ### What the statements are | Finding | Views | Questions and uncertainty | Clinical experience | Comparisons | Restated results and context | Passages supporting | Passages giving context | Sources by kind | Feeds the Medical Affairs question | | --- | ---: | ---: | ---: | ---: | ---: | ---: | ---: | --- | --- | | F1 | 7 | 1 | 0 | 0 | 6 | 16 | 0 | 7 posts and articles, 1 podcast or video, 1 registry | yes | | F2 | 3 | 0 | 0 | 1 | 2 | 8 | 0 | 1 post or article, 1 podcast or video, 1 registry | yes | | F3 | 6 | 1 | 0 | 0 | 1 | 12 | 0 | 1 podcast or video | yes | | F4 | 1 | 1 | 3 | 0 | 2 | 7 | 1 | 2 podcasts and video | yes | | F5 | 3 | 0 | 0 | 0 | 2 | 7 | 0 | 1 post or article, 1 podcast or video, 1 registry | yes | ### Trial dimensions - Primary endpoint: The status of ctDNA: F1 (4 shared claims) - Population and setting: F1 (4 shared claims) - The comparison: F1 (6 shared claims), F5 (1 shared claims) - Safety and tolerability: F1 (2 shared claims), F4 (2 shared claims) ## Sample findings Paraphrased; the full report links each statement to its source. ### F1. Enthusiasm supports testing treatment cessation, not declaring it safe An X post by a medical oncologist addressed the questions of ctDNA-guided de-escalation research and treatment-discontinuation safety in relation to HER2 CR. The full HER2-CR results article and a separate protocol were not available in the sources reviewed for this edition. Source: X thread, 2026-10-26. ## What's inside | Section | Items | Access | | --- | ---: | --- | | Findings with interpretation, counterviews and limits | 5 | Titles free | | Detailed analysis | 6 sections | Paid | | Verified statements with short source quotes and links | 37 | Paid | | Trial aspects mapped | 8 | Free | | Sources with links | 11 | Counts free | | Speaker attribution for cited voices | 9 | Paid | ## Trial aspects 8 discussed · 0 no commentary found · 0 assessment incomplete. | Aspect | Coverage | Statements | Sources | | --- | --- | ---: | ---: | | Primary endpoint: The status of ctDNA | discussed | 4 | 3 | | Population and setting | discussed | 4 | 4 | | The comparison | discussed | 6 | 5 | | Safety and tolerability | discussed | 4 | 3 | | Ultrasensitive testing and the meaning of ctDNA negativity | discussed | 5 | 2 | | Routine monitoring, imaging and patient support | discussed | 8 | 1 | | Continued maintenance versus chemotherapy withdrawal | discussed | 7 | 2 | | Stop HER2 and the separate treatment-break research question | discussed | 4 | 2 | An aspect marked incomplete is a question the public commentary did not let us answer. We show it rather than hide it. ## Sources | Channel | Screened | Cited | | --- | ---: | ---: | | X threads | 10 | 7 | | YouTube | 3 | 3 | | Registry (primary source, cited for context) | not screened | 1 | - Screened window: 2025-10-16 to 2026-10-28 - Cited window: 2025-10-16 to 2026-10-26 - Retrieved: 2026-11-01 Screened sources were retrieved for this trial. Cited sources back at least one verified statement and include primary sources used for context. ## The trial From ClinicalTrials.gov. - Title: Personalized Detection of ctDNA for Patients With HER2-Positive Metastatic Breast Cancer Who Achieved Durable Response by Anti-HER2 Treatment - Registry: NCT06663787 (https://clinicaltrials.gov/study/NCT06663787) - Study IDs: HER2 CR · 80-24-0057 (Nagoya City Unversity) - Sponsor: Nagoya City University - Design: Observational · observational, cohort, prospective - Status: Active, not recruiting - Enrollment: 50 (estimated) - Start: 2024-04-01 (actual) - Primary completion: 2026-12-31 (estimated) - Primary endpoint: The status of ctDNA (1 year) - Intervention: Trastuzumab (Herceptin) (drug) - Intervention: SIgnatera (diagnostic test) ## Scope and limits This report does not judge efficacy, estimate HCP prevalence or consensus or give treatment advice. - Discussion that does not name the trial may be missing from this edition. - Some clinician views in the sources used in this report are not yet captured as evidence in this edition. - Some passages in the sources used in this report were not fully assessed for clinician views, so a view there may be missing from this edition. - 25 statements in the sources reviewed for this edition are about other patients or topics, or only mention the trial, and are not counted. - Further source limits: discussion that describes the trial without naming it may be incomplete; some discussion that describes the trial without naming it may be missing; sources about other trials are not included. - Commentary on ctDNA status and subsequent outcomes, limitations of conventional disease assessment, and the evidence needed to establish clinical utility is not fully covered. This report should not be used to infer that those views were absent from the sources. - The full HER2-CR results article and a separate protocol were not available. Reported numerical findings are attributed summaries rather than an independently assessed full results report; registry material describes planned assessments. - Drug-label material was unavailable. The adverse-effect comments should be read as a speaker's regimen description, not a comprehensive safety assessment or a comparison of stopping versus continuing treatment. - Some speakers' identities or clinical roles are not established in the sources used in this report; each statement is attributed only as far as its source shows. - No individual is identified for the BC Tube statements. Presentation relays, reposts and repeated quoted posts should not be counted as additional independent clinical opinions. - The broader recordings discuss related monitoring and treatment-duration questions, including separate datasets and Stop HER2. Their findings, eligibility descriptions and expected reporting timelines must not be transferred to HER2-CR, and different source dates do not establish a change of mind. - The treatment-continuation examples are not a complete account of maintenance alternatives or decisions after focal progression. How reports are built and checked: https://www.erudio.com/methods ## Editions and corrections - v1.0.0, accepted 2026-11-01: current edition Last checked for new commentary 2026-11-01. No corrections. Versions follow semver: a new or changed finding is a minor version, more evidence without a material change is a patch. ## Offer - Size: Focused (37 verified statements) - Current edition: $750. A purchase starts a check for new commentary and any newer edition follows at no charge - 3 months of weekly updates: $1,300 - 6 months of weekly updates: $1,900 - 12 months of weekly updates: $2,600 - Optional identity linkages (12-month updates only, product updates-12-identities; speakers are named and described in every report): NPI and other verified IDs at $15 per identity-verified person in the edition at purchase (8 now), at most $750; people verified later in the term at no charge - Pricing: https://www.erudio.com/pricing - Buy now (card, through Stripe): https://www.erudio.com/reports/her2-cr-nct06663787 - Agents: POST https://www.erudio.com/api/orders with {"report": "her2-cr-nct06663787", "product": "edition" | "updates-3" | "updates-6" | "updates-12" | "updates-12-identities", "buyer_email": "...", "licence_key": ""}; it returns a payment link for your user (and a pay_url your own MPP or x402 payment client can pay over HTTP 402, when offered), and once paid the status_url returns your license key. Send the same key with every later order so all reports sit on one key. The buyer gets their account key by email, which reads every report bought with their address; recover_key (POST https://www.erudio.com/api/keys/recover) sends it again - Talk to Audun Utengen and Tom Lee (invoice, PO, questions): https://www.erudio.com/contact?report=her2-cr-06663787 ## Cite Erudio Health. HER2 CR (NCT06663787): HCP commentary report. Edition 1, v1.0.0. Accepted Nov 1, 2026. https://www.erudio.com/reports/her2-cr-nct06663787 ## Machine access - JSON: https://www.erudio.com/reports/her2-cr-nct06663787.json - Markdown: https://www.erudio.com/reports/her2-cr-nct06663787.md - MCP, no sign-in: https://mcp.erudio.com/free, tool `get_report_card` with `{"slug": "her2-cr-06663787"}`