Phase II chemotherapy-free, pCR-guided (response-adapted) trastuzumab + pertuzumab in early HER2+ breast cancer. 59.6% pCR with concurrent Annals of Oncology publication at ESMO Breast 2026.
Discover KOL Sentiment on PHERGain-2 →Design - Phase II MedSIR investigator-initiated, response-adapted (PET/pCR-guided) chemotherapy-free neoadjuvant trastuzumab + pertuzumab, with escalation to T-DM1 in non-responders, in HER2+ early breast cancer (NCT04733118).
pCR - 59.6% pathologic complete response overall, with a concurrent Annals of Oncology publication at ESMO Breast 2026.
Safety - Treatment-related adverse events of any grade in 86.6%; grade >=3 in 5.6%; serious AEs in 6.1%; one patient (0.3%) died from T-DM1-related pneumonitis - underscoring that de-escalation still requires careful monitoring.
Strategy - Chemotherapy-free, response-adapted de-escalation - follow-on to the original PHERGain trial.
Regulatory - Investigational strategy; not FDA approved. Component agents are individually approved in HER2+ breast cancer.
Sponsor / drugs - MedSIR; trastuzumab (Herceptin) + pertuzumab (Perjeta), escalation to T-DM1 (Kadcyla).
Compiled and reviewed by the KOL Pulse research team, led by Brian Shields, Founder, KOL Pulse. Last updated July 21, 2026.
Trial slides shared by KOLs at ESMO Breast 2026 (#ESMOBreast26). Click any image to expand. OCR text extracted via AWS Textract.
[Slide 1] Content of this presentation is copyright and responsibility of the author. Permission is required for re-use. PHERGain-2 Study Design TREATMENT Key eligibility criteria Cohort A pCR Patients 2 18 years Histologically confirmed ypTO/is HP (±ET) x10 invasive carcinoma of ypNO the breast Primary Endpoints No prior treatment for At screening: Cohort B Central breast cancer HP (±ET) HER2 IHC 3+* x8 Breast MRI Surgery ypN0(i+) HER2 status T-DM1 (±ET) (1) >10% HRQoL ypN0(mol+) EoS & ypN1mi x10 decline rate Node-negative status Tumor size 5-30 mm MRI imaging (2) 3y-RFI rate (MRI) Cohort C ECOG PS 0/1 ChT' T-DM1 LVEF >55% ypN1-N3 (+ET) Adequate organ function HP: 600 mg H plus 1200 mg P loading x10 dose, then 600 mg H plus 600 mg P Physician's choice chemotherapy was allowed maintenance dose q3w before adjuvant T-DM1 T-DM1: 3.6 mg/kg of body weight q3w ET up to 5 years and radiotherapy as per Follow-up* HR status and institutional practices PROs assessments: Baseline D1C1-C8 <14d pre-op Adj D1C1 FU q3m x2y FU q6m x3y Annual to EOS "According to the 2018 American Society of Clinical Oncology/College of American Pathologists criteria. TAII patients who were hormonal receptor-positive received ET concomitantly with HP or T-DM1. ET was sex- and menopausal status-based premenopausal and perimenopausal women receive ovanan function suppression plus tamoxifen (20 mg/day orally) or letrozole (2.5 mg/day orally); postmenopausal women receive letrozole (2.5 mg/day orally): and men receive tamoxifen (20 mg/day orally). *All patients must be followed up for 5 years from when the last patient has completed surgery (EoS), even if the assigned treatment is discontinued permanently ChT, chemotherapy, ECOG PS, Eastern Cooperative Oncology Group performance status; d, day, EoS, end of study, ET, endocrine therapy, FU, follow-up; HER2, human epidermal growth factor receptor 2; HP, trastuzumab and pertuzumab; HRQoL. health related quality of life; IHC, immunohistochemistry, LVEF, left ventricular ejection fraction; m, month; MRI, magnetic resonance imaging pCR pathological complete response; PRO, patient-reported outcomes; RFI, recurrence-free survival; q3w, every three weeks; y. year --- [Slide 2] Baseline Characteristics N = 396 N = 396 Patient baseline characteristics Primary tumor baseline characteristics n (%) n (%) Age; Median (range) (years) 55 (24-85) Median tumor size (mm, Min; Max) 18 (7-30) Sex T stage1, mm Woman 394 (99.5) T1b/T1c: >5 to <20 244 (61.6) T2: >20 to <30 Menopausal status 152 (38.4) Postmenopausal 235 (59.3) Histologic grade Gx* 57 (14.4) Premenopausal 159 (40.2) G1 21 (5.3) Not available 2 (0.5) G2 185 (46.7) ECOG performance status G3 133 (33.6) 0 382 (96.5) HER2 IHC 3+ 396 (100) 1 14 (3.5) Hormonal receptor status Multifocal or multicentric breast cancer 15 (3.8) Negative 108 (27.3) ECOG PS, Eastern Cooperative Oncology Group performance status; HER2, human epidermal growth factor receptor 2; Positive 288 (72.7) IHC, immunohistochemistry Tumor staging was assessed as per American Joint Committee on Cancer staging manual, 8th edition "Differentiation status could not be assessed *All patients who were hormonal receptor-positive received ET concomitantly with HP or T-DM1. ET was sex- and menopausal status-based premenopausal and perimenopausal women receive ovanan function suppression plus tamoxifen (20 mg/day orally) or letrozole (2.5 mg/day orally); postmenopausal women receive letrozole (25 mg/day orally); and men receive tamoxifen (20 Dr. Antonio Llombart-Cussac mg/day orally). Content of this presentation is copyright and responsibility of the author. Permission is required for re-use n (%), number of patients (percentage based on N); N, Number of patients ESMO --- [Slide 3] Primary safety endpoint: >10% HRQoL decline rate at one year ≥10% HRQoL decline rate Patient-reported outcomes N = 396 ; n (%) Completion rate at baseline 391 (98.7) 42.8% 95% CI 36.9-48.8 Baseline HRQoL score, mean (95% CI) 78.6 (76.8-8 0.5) Completion rate at 1 year 360 (90.9) HR positive: 45.2% (95% CI 38.3-52.3) Fisher's exact test 1-year HRQoL score, mean (95% CI) 69.6 (67.5-71.8) HR negative: 36.1% (95% CI 25.4-47.9) p 0.11 n (%), number of patients (percentage based on N); N, Number of patients. Patient reported outcomes were analyzed on patients who received at least one dose of study treatment and completed baseline and at least one follow-up questionnaire 1. year post-neoadjuvant treatment Patients without a >10% decline at one year who discontinued the study due to disease progression, toxicity or death within the first year after starting neoadjuvant treatment were considered events Dr. Antonio Llombart-Cussac Content of this presentation is copyright and responsibility of the author Permission is required for re-use ESMO CI, confidence interval; HR, hormone receptor, HRQoL, health-related quality of life --- [Slide 4] Secondary endpoint: pCR rate by HR status and tumor size Median (range) T1 tumor size: 16mm (7-20) Median (range) T2 tumor size: 23.5mm (21-30) 100 pCR rate 100 100 59.6% 63.0% 59.6% 95% CI 54.6-64.4 95% CI 53.1-72.1 95% CI 53.3-65.7 80 80 80 59.6% 58.3% Pathological complete response (%) 95% CI 51.0-67.7 95% CI 52.4-64.1 60 60 60 40 40 40 236 / 396 68 / 108 168 / 288 152/255 20 84 141 20 20 0 0 0 All participants HR- HR+ T1 T2 Fisher's exact test Fisher's exact test p=0.42 P 1.00 Dr. Antonio Liombart-Cussac Content of this presentation is copyright and responsibility of the author Permission is required for re-use. ESMO CI, confidence interval; HR, hormone receptor, pCR pathological complete response
[Slide 1] 2140: pCR-guided strategy with HP & T-DM1 in PHERGain-2 Lombert-Cussac et al De-escalate therapy for low risk/HER2 strongly + TREATMENT N=236 Key eligibility criteria Cohort A PCR 59.6% pCR rate (95% CI 54.6-64.4) Patients 19 yours ypToM HP (BET) Histologically sentemed N10 investive cancinoma of N=396 ypMo Varied by HR status: 63% HR-; 58.3% HR+ the No proor treatment for At screening Central breast cancet HP (BET) HER2 education Bread Cohort B Surgery Primary Endpoints No variation in pCR by tumor size HER2 INC " *8 ypND(mol+) T-DM1 (eET) .... EoS & *10 Node-megative status (1) >10% HRQoL Tumor size 5-30 mm MR) maging decline rate Greater decline in HRQoL in arm B and C than arm A (MR) Cohort c ECOG DT Chi T-OM1 (2) 3y-RF rate LVEF #55% YPN1-N3 N3 (#ET) Main toxicity diarrhea and fatigue Adequate organ function NP 600 mg M plus 1200 mg P loading #10 N-7 dose, then 600 mg plus 600 mg P Physician's child thematheripy - slowed One death due to pneumonitis with T-DM1 maintenance dose q3w before adjuvant 1-CM T-DM1 3.6 mgkg of body weight (3w ET up 105 years and radiotherapy as per Folow-up HR status and institutional practices PROs assessments: Baseline D1C1-C8 $144 pre-op Adj D1C1 FU q3m *2y FU q6m *3y Annual to EOS Conclusions The trial met its primary endpoint of HRQOL PHERGain-2: pCR-adapted de-escalation with HP and T-DM1 in highly High pCR rate even though 3/4 of patients had HR+ selected patients with HER2+ IHC 3+, N- EBC disease Primary endpoints safety and relapse free interval Await 3-year RFI 34 pts dropped out after surgery Median FU: 15.1 months (0.49-36.1); 73% HR+ This data suggests that up to 60% of patients with CS with CamScanner Scanned 5. Rugo, MD node negative strongly HER2+ EBC could potentially be cured with antibody therapy alone Content of this presentation is copyright and responsibility of the author Permission is required for re-use ESMO
[Slide 1] KOL Pulse / Conference Intelligence ESMO Breast 2026 Live Coverage Berlin, Germany . May 6 - 8, 2026 256 Tweets . 57 KOLs . 46.6K Impressions KOL Social Media Perspectives Top Discussion Leaders
[Slide 1] PHERGain-2 Study Design TREATMENT Cohort A Key eligibility criteria pCR Patients ≥ 18 years ypTO/is HP (±ET) Histologically confirmed x10 ypNO invasive carcinoma of Primary Endpoints the breast At screening: Cohort B No prior treatment for Central breast cancer HER2 IHC 3+* Breast MRI ypN0(i+) HP (±ET) HER2 status Surgery (1) ≥10% HRQoL ypN0(mol+) T-DM1 (±ET) EoS x8 x10 decline rate & ypN1mi Node-negative status MRI imaging (2) 3y-RFI rate Tumor size 5-30 mm (MRI) Cohort C ECOG PS 0/1 ChT' + T-DM1 LVEF >55% ypN1-N3 (±ET) x10 Adequate organ function HP: 600 mg H plus 1200 mg P loading dose, then 600 mg H plus 600 mg P Physician's choice chemotherapy was allowed maintenance dose q3w before adjuvant T-DM1 T-DM1: 3.6 mg/kg of body weight q3w ET up to 5 years and radiotherapy as per Follow-up" HR status and institutional practices PROs assessments: Baseline D1C1-C8 ≤14d pre-op Adj D1C1 FU q3m x2y FU q6m x3y Annual to EOS --- [Slide 2] Conclusion PHERGain-2 suggests maintenance of HRQoL over one year of treatment, although interpretation is limited by treatment heterogeneity and lack of a direct comparator Patients without pCR experienced greater HRQoL deterioration, likely reflecting treatment escalation (T-DM1 ± chemotherapy) The pCR rate of 59.6% observed with this chemotherapy-free strategy is encouraging, particularly in a population including HR-positive disease The safety profile was consistent with known effects of trastuzumab/pertuzumab and T-DM1 Pending mature efficacy outcomes (3-year RFI), this response-adapted, chemotherapy-free, strategy appears clinically feasible and may support treatment individualization in selected low-risk patients
[Slide 1] Content of this presentation is copyright and responsibility of the author. Permission is required for re-use. PHERGain-2 Study Design TREATMENT Key eligibility criteria Cohort A pCR Patients 2 18 years Histologically confirmed ypTO/is HP (±ET) x10 invasive carcinoma of ypNO the breast Primary Endpoints No prior treatment for At screening: Cohort B Central breast cancer HP (±ET) HER2 IHC 3+* x8 Breast MRI Surgery ypN0(i+) HER2 status T-DM1 (±ET) (1) >10% HRQoL ypN0(mol+) EoS & ypN1mi x10 decline rate Node-negative status Tumor size 5-30 mm MRI imaging (2) 3y-RFI rate (MRI) Cohort C ECOG PS 0/1 ChT' T-DM1 LVEF >55% ypN1-N3 (+ET) Adequate organ function HP: 600 mg H plus 1200 mg P loading x10 dose, then 600 mg H plus 600 mg P Physician's choice chemotherapy was allowed maintenance dose q3w before adjuvant T-DM1 T-DM1: 3.6 mg/kg of body weight q3w ET up to 5 years and radiotherapy as per Follow-up* HR status and institutional practices PROs assessments: Baseline D1C1-C8 <14d pre-op Adj D1C1 FU q3m x2y FU q6m x3y Annual to EOS "According to the 2018 American Society of Clinical Oncology/College of American Pathologists criteria. TAII patients who were hormonal receptor-positive received ET concomitantly with HP or T-DM1. ET was sex- and menopausal status-based premenopausal and perimenopausal women receive ovanan function suppression plus tamoxifen (20 mg/day orally) or letrozole (2.5 mg/day orally); postmenopausal women receive letrozole (2.5 mg/day orally): and men receive tamoxifen (20 mg/day orally). *All patients must be followed up for 5 years from when the last patient has completed surgery (EoS), even if the assigned treatment is discontinued permanently ChT, chemotherapy, ECOG PS, Eastern Cooperative Oncology Group performance status; d, day, EoS, end of study, ET, endocrine therapy, FU, follow-up; HER2, human epidermal growth factor receptor 2; HP, trastuzumab and pertuzumab; HRQoL. health related quality of life; IHC, immunohistochemistry, LVEF, left ventricular ejection fraction; m, month; MRI, magnetic resonance imaging pCR pathological complete response; PRO, patient-reported outcomes; RFI, recurrence-free survival; q3w, every three weeks; y. year --- [Slide 2] Primary safety endpoint: >10% HRQoL decline rate at one year ≥10% HRQoL decline rate Patient-reported outcomes N = 396 ; n (%) Completion rate at baseline 391 (98.7) 42.8% 95% CI 36.9-48.8 Baseline HRQoL score, mean (95% CI) 78.6 (76.8-8 0.5) Completion rate at 1 year 360 (90.9) HR positive: 45.2% (95% CI 38.3-52.3) Fisher's exact test 1-year HRQoL score, mean (95% CI) 69.6 (67.5-71.8) HR negative: 36.1% (95% CI 25.4-47.9) p 0.11 n (%), number of patients (percentage based on N); N, Number of patients. Patient reported outcomes were analyzed on patients who received at least one dose of study treatment and completed baseline and at least one follow-up questionnaire 1. year post-neoadjuvant treatment Patients without a >10% decline at one year who discontinued the study due to disease progression, toxicity or death within the first year after starting neoadjuvant treatment were considered events Dr. Antonio Llombart-Cussac Content of this presentation is copyright and responsibility of the author Permission is required for re-use ESMO CI, confidence interval; HR, hormone receptor, HRQoL, health-related quality of life --- [Slide 3] Secondary endpoint: pCR rate by HR status and tumor size Median (range) T1 tumor size: 16mm (7-20) Median (range) T2 tumor size: 23.5mm (21-30) 100 pCR rate 100 100 59.6% 63.0% 59.6% 95% CI 54.6-64.4 95% CI 53.1-72.1 95% CI 53.3-65.7 80 80 80 59.6% 58.3% Pathological complete response (%) 95% CI 51.0-67.7 95% CI 52.4-64.1 60 60 60 40 40 40 236 / 396 68 / 108 168 / 288 152/255 20 84 141 20 20 0 0 0 All participants HR- HR+ T1 T2 Fisher's exact test Fisher's exact test p=0.42 P 1.00 Dr. Antonio Liombart-Cussac Content of this presentation is copyright and responsibility of the author Permission is required for re-use. ESMO CI, confidence interval; HR, hormone receptor, pCR pathological complete response --- [Slide 4] Conclusion PHERGain-2 suggests maintenance of HRQoL over one year of treatment, although interpretation is limited by treatment heterogeneity and lack of a direct comparator Patients without pCR experienced greater HRQoL deterioration, likely reflecting treatment escalation (T-DM1 ± chemotherapy) The pCR rate of 59.6% observed with this chemotherapy-free strategy is encouraging, particularly in a population including HR-positive disease The safety profile was consistent with known effects of trastuzumab/pertuzumab. and T-DM1 Pending mature efficacy outcomes (3-year RFI), this response-adapted, chemotherapy-free, strategy appears clinically feasible and may support treatment individualization in selected low-risk patients Dr. Antonio Llombart Cussac Content of this presentation is copyright and responsibility of the author Permission is required for re-use ESMD
[Slide 1] 2026 ESMO BREAST CANCER Annual Congress Chemotherapy-free, pathological complete response (pCR)-guided strategy with trastuzumab-pertuzumab. (HP) and T-DM1 in HER2+ early breast cancer (EBC): PHERGain-2 Laia Garrigós, Manuel Ruiz-Borrego, José Manuel Pérez-Garcia, Angel Guerrero-Zotano, Alfonso Cortés- Salgado, Sherko Kümmel, Marco Colleoni, Cristina Reboredo-Rendo, Begoña Bermejo, Isabel Blancas, Joaquin Gavila, Alessandra Fabi, Olalla Ballesteros, Griselda Martrat, Simona lacobucci, Olga Boix, Pau Berenguer-Molins, Daniel Alcalá-López, Javier Cortés, Antonio Llombart-Cussac May 6, 2026 --- [Slide 2] Content of this presentation is copyright and responsibility of the author Permission is required for re-use. PHERGain-2 Study Design TREATMENT Cohort A Key eligibility criteria pCRt Patients ≥ 18 years ypTO/is HP (±ET) Histologically confirmed x10 invasive carcinoma of ypNO the breast Primary Endpoints At screening: Cohort B No prior treatment for Central HP (±ET) Breast MRI ypN0(i+) breast cancer HER2 status Surgery (1) >10% HRQoL ypN0(mol+) T-DM1 (±ET) EoS HER2 IHC 3+* x8 & ypN1mi x10 decline rate Node-negative status MRI imaging Tumor size 5-30 mm (2) 3y-RFI rate (MRI) Cohort C ECOG PS 0/1 ChT + T-DM1 LVEF >55% ypN1-N3 (±ET) Adequate organ function x10 HP: 600 mg H plus 1200 mg P loading dose, then 600 mg H plus 600 mg P Physician's choice chemotherapy was allowed maintenance dose q3w before adjuvant T-DM1 T-DM1: 3.6 mg/kg of body weight q3w ET up to 5 years and radiotherapy as per Follow-up® HR status and institutional practices PROs assessments: Baseline D1C1-C8 <14d pre-op Adj D1C1 FU q3m x2y FU q6m x3y Annual to EOS "According to the 2018 American Society of Clinical Oncology/College of American Pathologists criteria. TAll patients who were hormonal receptor-positive received ET concomitantly with HP or T-DM1. ET was sex- and menopausal status-based: premenopausal and perimenopausal women receive ovarian function suppression plus tamoxifen (20 mg/day orally) or letrozole (2.5 mg/day orally); postmenopausal women receive letrozole (2.5 mg/day orally); and men receive tamoxifen (20 mg/day orally). "All patients must be followed up for 5 years from when the last patient has completed surgery (EoS), even if the assigned treatment is discontinued permanently. ChT, chemotherapy; ECOG PS, Eastern Cooperative Oncology Group performance status; d, day, EoS, end of study, ET, endocrine therapy, FU, follow-up; HER2, human epidermal growth factor receptor 2; HP, trastuzumab and pertuzumab; HRQoL, health related quality life; IHC, immunohistochemistry; LVEF, left ventricular ejection fraction; m, month; MRI, magnetic resonance imaging: pCR pathological complete response; PRO, patient-reported outcomes; RFI, recurrence-free survival; q3w, every three weeks; Y. year --- [Slide 3] Secondary endpoint: overall pCR rate 100 pCR rate Patients Undergoing Surgery 59.6% N 391 80 95% CI 54.6-64.4 Cohort B Cohort A Cohort C pCR ypN1-N3 ypN0(mol+), ypN1mi N = 236 N = 148 Pathological complete response (%) 60 ypN0(i+), I N=7 40 236/396 20 Adjuvant Therapy 0 At data cutoff, all patients were receiving the protocol-specified treatment for their assigned cohort All participants In Cohort C, two patients received chempotherapy + T-DM1 Dr. Antonio Llombart-Cussac Content of this presentation is copyright and responsibility of the author. Permission is required for re-use. ESMD CI, confidence interval; pCR, pathological complete response --- [Slide 4] Secondary endpoint: pCR rate by HR status and tumor size Median (range) T1 tumor size: 16mm (7-20) Median (range) T2 tumor size: 23.5mm (21-30) 100 pCR rate 100 100 59.6% 63.0% 59.6% 95% CI 54.6-64.4 95% CI 53.1-72.1 95% CI 53.3-65.7 80 80 80 59.6% 58.3% Pathological complete response (%) 95% CI 51.0-67.7 95% CI 52.4-64.1 60 60 60 I 40 40 40 236 / 396 68 / 108 168 / 288 152/255 84 / 141 20 20 20 0 0 0 All participants HR- HR+ T1 T2 Fisher's exact test Fisher's exact test P 0.42 p=1.00 Dr. Antonio Llombart-Cussac Content of this presentation is copyright and responsibility of the author. Permission is required for re-use. ESMO CI, confidence interval; HR, hormone receptor, pCR pathological complete response
PHERGain-2 is an international, multicentre, open-label Phase II trial evaluating a chemotherapy-free, pCR-guided treatment strategy using trastuzumab-pertuzumab (HP) and T-DM1 in patients with HER2-positive (IHC 3+), node-negative, small (5–30 mm) early breast cancer. Presented at ESMO Breast Cancer 2026 with concurrent publication in Annals of Oncology, the trial enrolled 396 patients across 47 centres in Spain, Italy, Denmark, Hungary, Poland, and Bulgaria. The strategy: all patients received 8 cycles of neoadjuvant trastuzumab + pertuzumab; adjuvant therapy was adapted by pathological response (pCR continued HP; residual disease escalated to T-DM1).
Population: 396 patients with untreated, centrally confirmed HER2-positive (IHC 3+), node-negative, early breast cancer. Tumours 5–30 mm by central MRI. Median tumour size 18 mm; 72.7% HR+; 61.6% T1; 391 (98.7%) underwent surgery.
Interventions: Neoadjuvant: 8 cycles trastuzumab + pertuzumab (subcutaneous, every 3 weeks). Adjuvant by response: Cohort A (n=236, pCR) — HP to complete 18 cycles; Cohort B (n=148, residual invasive disease or ITC/micromets) — T-DM1 ×10 cycles; Cohort C (n=7, ypN1-3) — optional adjuvant chemo before T-DM1.
Endpoints: Co-primary: 1-year HRQoL decline (≥10% EORTC QLQ-C30 global) and 3-year recurrence-free interval. Secondary: pCR rate, safety, biomarker analyses (ctDNA).
pCR was achieved in 236 patients (59.6%) following chemotherapy-free neoadjuvant trastuzumab-pertuzumab. By HR status: 63.0% pCR in HR-negative, 58.3% in HR-positive (no significant difference). By tumour size: 59.6% in both T1 and T2. At 1 year, ≥10% HRQoL decline occurred in 154/360 (42.8%) — significantly lower among pCR patients (37.3%) than non-pCR T-DM1 cohort (51.9%). The 3-year recurrence-free interval primary endpoint remains immature.
Treatment-related adverse events of any grade reported in 86.6% of patients; grade ≥3 in 5.6%; serious AEs in 6.1%. One patient (0.3%) died from T-DM1-related pneumonitis, underscoring that de-escalation strategies still require careful monitoring when ADCs are deployed. Only 2 patients (0.5%) discontinued for disease progression.
Rishabh Jain summarized PHERGain-2 as testing “a pCR-guided strategy with HP ± T-DM1,” with key findings “pCR: 59.6%,” “Similar across HR+ / HR-,” and “HRQoL maintained,” while flagging that “3-year RFI still immature.” Aya Mohamed framed the result as “Chemotherapy Free Dual HER2 Blockade Achieves ~60% pCR with Preserved HRQoL—Operationalizing a De-escalation, ‘Minimum Effective Treatment’ Strategy in Low Risk HER2+ Early #BreastCancer.” The OCR-confirmed conclusions slide from presenter Antonio Llombart-Cussac characterizes the chemotherapy-free strategy as encouraging in a population that includes HR-positive disease, with mature efficacy outcomes (3-year RFI) still pending. The central caveat remains: this response-adapted approach may support treatment individualization in selected low-risk patients only once the recurrence endpoint matures.
PHERGain-2 (NCT04733118) is a Phase II investigator-initiated trial run by MedSIR that tests a chemotherapy-free, response-adapted (PET and pathologic-complete-response-guided) neoadjuvant strategy of dual HER2 blockade - trastuzumab plus pertuzumab - in HER2-positive early breast cancer, with escalation to T-DM1 for patients who do not respond. It is a follow-on to the original PHERGain trial.
PHERGain-2 reported a pathologic complete response rate of 59.6% with the chemotherapy-free, response-adapted strategy, with a concurrent publication in Annals of Oncology at ESMO Breast 2026. The result supports further evaluation of chemotherapy de-escalation in selected HER2-positive early breast cancer, while highlighting that some patients still require escalation.
No. The PHERGain-2 chemotherapy-free, response-adapted strategy is investigational and not FDA approved. The individual drugs it uses - trastuzumab, pertuzumab, and T-DM1 (used for escalation in non-responders) - are each separately FDA-approved in HER2-positive breast cancer.
Treatment-related adverse events of any grade were reported in 86.6% of patients, grade 3 or higher in 5.6%, and serious adverse events in 6.1%. Notably, one patient (0.3%) died from T-DM1-related pneumonitis, underscoring that de-escalation strategies still require careful patient monitoring.
PHERGain-2 is a follow-on to the original PHERGain trial and extends the response-adapted, chemotherapy-free de-escalation concept in HER2-positive early breast cancer. Both use PET and pathologic response to guide whether patients can avoid chemotherapy, with PHERGain-2 reporting its results at ESMO Breast 2026 alongside an Annals of Oncology publication.
| Handle | Name | Sentiment | Tweet (excerpt) | Imp. |
|---|---|---|---|---|
| @PTarantinoMD | Paolo Tarantino | Neutral | PHERGain-2: large phase 2 trial in selected patients with small (5-30 mm), HER2 IHC 3+ tumors, shows mostly preserved Qo… | 326 |
| @ErikaHamilton9 | Erika Hamilton, MD, FASCO | Neutral | #PHERGain2 took Node neg, <3 cm rumors IHC 3+ tumor's and have HP +/- ET x8 and took to surgery. 59.6% pCR rate. 🎯 up… | 260 |
| @KolPulseAI | KOL Pulse AI | Neutral | KOL Updates #ESMOBreast26 Day 2 — Berlin 🔥 TRAIN-4: 73% pCR chemo-free HER2+ neoadj 🔥 PHERGain-2 published in Annals of … | 210 |
| @UOzkerim | Uğur Özkerim | Neutral | 🧬 PHERGain-2 continues to challenge the “chemotherapy for all” paradigm in HER2+ early breast cancer. 🔥A response-adapt… | 109 |