Jason A. Mouabbi MD (@JAMouabbi) ranks #13 among US breast cancer KOLs on X in 2026, by engagement from fellow physicians. 22 physicians shared, quoted or replied to their posts this year. Most-discussed trials in 2026: TROPION-Breast02, SERENA-6, VIKTORIA-1. CMS Open Payments lists $84,179 in 2025 general payments.
At a Glance
- 4 posts naming a trial in 2026
- 4 trials discussed by name
- Breast Cancer: US #13, Global #26 · 22 physicians engaged
- CMS Open Payments lists $84,179 in 2025 general payments.
This Month
What Jason A. Mouabbi MD has posted in the last 30 days. Updated November 10, 2026.
🧠 CNS activity of a TROP2 ADC in a randomized phase 3. #ESMO26 LBA96: brain mets analysis of TROPION-Breast02, Dato-DXd vs chemo in 1L TNBC patients who are not IO candidates. 🧵 #bcsm 61 of 644 patients had asymptomatic, stable brain mets (30 untreated, 31 previously treated). 24 had measurable intracranial disease. 🙌🏻 Intracranial response: ORR 62.5% vs 37.5%, including a complete response 12-week intracranial disease control 75% vs 50% 🙌🏻 CNS PFS 9.5 vs 2.6 mo, HR 0.27 (95% CI 0.13–0.56). Systemic PFS in the brain mets group: 7.7 vs 3.5 mo, HR 0.37. The signal held in *untreated* brain mets: PFS HR 0.29, OS HR 0.35. That's the group where systemic options matter most. Bottom line: Dato-DXd is a reasonable systemic choice for 1L TNBC with brain mets.
Next meeting to watch: SABCS 2026 · San Antonio · Dec 8–11, 2026
Who Amplifies Jason A. Mouabbi MD
Physicians who reposted Jason A. Mouabbi MD’s trial posts most often in 2026.
2026 Rankings
| List | US rank | Global rank | Physicians engaged | Physician engagements | |
|---|---|---|---|---|---|
| Breast Cancer | #13 | #26 | 22 | 22 | Full ranking |
Trials Jason A. Mouabbi MD Discussed in 2026
| Trial | Posts | Rank among physicians posting | Latest |
|---|---|---|---|
| TROPION-Breast02 | 1 | #11 of 26 | Oct 24, 2026 |
| SERENA-6 | 1 | #10 of 39 | Sep 4, 2026 |
| VIKTORIA-1 | 1 | #11 of 23 | Jun 2, 2026 |
| NATALEE | 1 | #15 of 46 | May 30, 2026 |
Jason A. Mouabbi MD on TROPION-Breast02
🧠 CNS activity of a TROP2 ADC in a randomized phase 3. #ESMO26 LBA96: brain mets analysis of TROPION-Breast02, Dato-DXd vs chemo in 1L TNBC patients who are not IO candidates. 🧵 #bcsm 61 of 644 patients had asymptomatic, stable brain mets (30 untreated, 31 previously treated). 24 had measurable intracranial disease. 🙌🏻 Intracranial response: ORR 62.5% vs 37.5%, including a complete response 12-week intracranial disease control 75% vs 50% 🙌🏻 CNS PFS 9.5 vs 2.6 mo, HR 0.27 (95% CI 0.13–0.56). Systemic PFS in the brain mets group: 7.7 vs 3.5 mo, HR 0.37. The signal held in *untreated* brain mets: PFS HR 0.29, OS HR 0.35. That's the group where systemic options matter most. Bottom line: Dato-DXd is a reasonable systemic choice for 1L TNBC with brain mets.
Jason A. Mouabbi MD on SERENA-6
Fantastic news to end the week! 🎉 FDA accelerated approval: camizestrant + CDK4/6i at ESR1 emergence on 1L AI + CDK4/6i (SERENA-6). mPFS 16.0 vs 9.2 mo, HR 0.44. First approval ever driven by ctDNA, not imaging. Molecular progression is now actionable in the US. So happy for https://t.co/uUT2HW2N9S
Jason A. Mouabbi MD on VIKTORIA-1
VIKTORIA-1 PIK3CA-mutant cohort (LBA1008) dropped this morning at #ASCO26. Gedatolisib roughly doubled PFS vs alpelisib + fulvestrant after CDK4/6i progression: • Geda doublet: 11.3 mo • Geda triplet: 11.1 mo • Alpelisib + fulv: 5.6 mo ORR 48.9% (triplet) / 35.7% (doublet) https://t.co/FhvSEI4Yfc
Jason A. Mouabbi MD on NATALEE
Exciting NATALEE update presented today at #ASCO26 (Abstract 501)! New gene expression analysis from the largest biomarker dataset in any adjuvant CDK4/6i trial shows ribociclib + NSAI iDFS benefit is consistent across all PAM50 subtypes (66% LumA, 28% LumB, 3% HER2E, 3%
Jason A. Mouabbi MD’s Most-Engaged Posts in 2026
Their own 2026 posts that fellow physicians reposted most, quoted word for word.
Excited to share our #ESMO26 poster 4260P 🧬 We asked: can reflex liquid NGS add to tissue NGS and tumor-informed ctDNA monitoring? 🧵 #bcsm #ctDNA 50 patients, 10 tumor types (34% breast), 101 plasma samples. Tissue NGS (Altera) + serial ctDNA (Signatera) + reflex liquid NGS. Concordance 🙌🏻: every patient with a tissue-actionable alteration (26/26) had it found in plasma too. Plasma added value 🙌🏻: new relevant or actionable alterations in ~20% of patients. Mostly acquired resistance: 👉🏻ESR1 after AI (switched to a SERD) 👉🏻BRCA2 reversions after PARPi 👉🏻Plus a plasma-only BRAF K601E that guided encorafenib. Tracking: across 45 measurable plasma pairs, the two assays moved in the same direction 96% of the time (ρ = 0.76). But they're NOT interchangeable. In an esophageal case on T-DXd, tumor-informed ctDNA showed a >1-log drop and a sharp rebound, while liquid NGS allele fraction barely moved. 🚨🚨Takeaway: tumor-informed ctDNA tells you *when* to look, and liquid NGS tells you *what* changed. Together they can guide real-time treatment decisions. Grateful to my coauthors @NateraGenetics Come by poster 4260P!
Landmark #OPTIMA trial results presented today at #ASCO2026! Prosigna-guided treatment is non-inferior to chemo + endocrine therapy in high clinical risk ER+ HER2- early breast cancer -> including ~ 1/5 with pN2 (4–9 node+) disease. 2/3 (68%) of clinically high-risk node-positive patients with low ROR safely avoided chemotherapy while maintaining excellent outcomes. Level 1 evidence that changes practice and reduces unnecessary toxicity. Huge congrats to my friend @DrMJELLIS, key contributor since 2006! 👏 #BreastCancer #Prosigna #PrecisionOncology
Industry Payments
CMS Open Payments · 2025 general payments
$84,179 across 66 payments