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Margaret Gatti-Mays, MD MPH

@drgattimays.bsky.social

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Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · Jan 9

Looking for your first faculty position? Or perhaps new start? THE Ohio State University Comprehensive Cancer Center (Columbus, OH) is hiring in several #MedOnc sections - GI, Thoracic, Breast, Neuroendocrine, cutaneous. #AcademicJobs #OSUCCC @osucccjames.bsky.social @christianrolfo.bsky.social

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Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

Reference(s)

Andre F, et al. N Engl J Med. 2019 May 16;380(20):1929-1940.
Rodon J, et al. Breast Cancer Res. 2024 Mar 4;26(1):36.
FDA prescribing information, alpelisib. Updated 1/18/2024.
Llombart-Cussac A, et al. EClinicalMedicine. 2024 Apr 11:71:102520.

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

Metformin prophylaxis can be considered for patients at elevated risk; the METALLICA study4 demonstrated a decreased incidence and severity of alpelisib-related hyperglycemia with metformin, though this was accompanied by increased gastrointestinal AEs (nausea, vomiting, and diarrhea).

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

The prescribing information for alpelisib3 recommends obtaining FPG and HbA1c at baseline, then monitoring FPG at least weekly for the first 2 weeks and then monthly thereafter; HbA1c should be rechecked every 3 months.

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

Answer: D. All of the above

Rationale: Hyperglycemia is the most common and clinically significant grade ≥3 adverse event associated with alpelisib, observed in 37% of patients in SOLAR-1.1 This pt has multiple risk factors for severe hyperglycemia: obesity (BMI ≥30 kg/m2), age ≥75, and high HbA1c

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

A. Monitor labs QW x 2, then monthly
B. A1C at baseline, then every 3 months
C. Consider metformin premedication
D. All of the above

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

🧐 A 75yo ♀️w/ ER+/HER2- PIK3CA+ mBC is starting 2L therapy with alpelisib + fulvestrant. Baseline A1C is 6.1 and BMI is 33. What steps can limit risk for severe hyperglycemia❓

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

References
1. Turner NC, et al. N Engl J Med. 2023 Jun 1;388(22):2058-2070.
2. Baselga J, et al. N Engl J Med. 2012 Feb 9;366(6):520-9.
3. Bidard F-C, et al. J Clin Oncol. 2022 Oct 1;40(28):3246-3256.
4. NCCN Guidelines. Breast Cancer. Version 4.2025. Issued 5/17/2025.

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

Combining mTOR inhibitor everolimus with fulvestrant offers inferior specificity and efficacy vs AKT inh in AKT-mutant disease (BOLERO-2).2 Elacestrant, an oral SERD, is indicated for ESR1-mut (EMERALD);3 chemotherapy should be reserved for endocrine-refractory in the absence of targetable mut.

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

In the CAPItello-291 trial of pts with progression on/after AI + CDK4/6i, addition of the AKT inhibitor capivasertib to fulvestrant sig improved median PFS (7.2 vs 3.6 months overall; HR=0.60, P <.001), with strongest benefit in tumors w/ AKT- alterations (7.3 vs 3.1 months; HR=0.50, P <.001).1

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

Answer: B. Capivasertib + fulvestrant
Rationale: Alterations in the PI3K/AKT/PTEN pathway promote endocrine resistance and tumor proliferation in HR+/HER2– mBC.

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

🤔What 2L Tx would you offer a 45yo♀️w/ ER+/HER2- mBC and an AKT mutation on 🧪liquid biopsy after progression at cycle 47 of ribociclib ➕ AI/OFS❓

Capecitabine monotherapy
Capivasertib + fulvestrant
Elacestrant monotherapy
Everolimus + fulvestrant

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

#PostTest Q1️⃣ #TumorBoardTuesday
👉🏽#CME Eval 🔗 integrityce.com/TBTeval24
👉🏽ALL CME🔗 integrityce.com/TBT2024

2024 Tumor Board Tuesday Evaluation

Take this survey powered by surveymonkey.com. Create your own surveys for free.

integrityce.com

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

OlympiAD. Robson et al. NEJM. 2017
DESTINY-Breast04. Modi et al. NEJM. 2022.
TROPiCS-02. Rugo et al. JCO. 2022.
TROPION-Breast01. Bardia et al. JCO. 2024.

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

References (in order from top to bottom):
CAPItello-291. Turner et al. NEJM. 2023.
SOLAR-1. Andre et al. NEJM. 2019.
EMERALD. Bidard et al. JCO. 2022.
EMBER-3. Jhavari et al. NEJM. 2025
PrE0102. Kornblum et al. JCO. 2018
BOLERO-2. Baselga et al. NEJM. 2012.
MAINTAIN. Kalinsky et al. JCO. 2023.

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

Current SOC options for 2L metastatic ER+ breast cancer #OptionsAreGood

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

18/18 #TumorBoardTuesday
👩🏻‍🏫Mini Tweetorial 12🏫

🔊Take home points 🔊:
✅ Liquid biopsy recommended at progression on 1L to screen for mutations
✅ 2L options have mPFS 5-11 months, some with OS benefit
✅ Optimal sequence unknown at this time, likely depends in part on patient factors

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

📎A Phase 3, Randomized, Open-label Study Comparing Efficacy and Safety of Sacituzumab Tirumotecan (Sac-TMT, MK-2870) as a Monotherapy and in Combination With Pembro (MK-3475) Vs Physician's Choice in Previously Untreated Locally Recurrent Unresectable or Metastatic TNBC, PD-L1 CPS <10 (TroFuse-011)

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

📎An Open-label, Randomized, Phase 3 Study to Evaluate Patritumab Deruxtecan Monotherapy Versus Treatment of Physician's Choice in Hormone Receptor-positive, HER2-negative Unresectable Locally Advanced or Metastatic Breast Cancer (HERTHENA-Breast04)

ClinicalTrials.gov

clinicaltrials.gov

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

2️⃣ TroFuse-011 (NCT06841354)
💊 Sacituzumab tirumotecan vs physician’s choice chemo
💉 Trop-2 directed ADC
👆 Primary endpoints: PFS and OS

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

17/18 #TumorBoardTuesday
👩🏻‍🏫Mini Tweetorial 11🏫

Ongoing trials in the HR+/HER2- space…

1️⃣ HERTHENA-Breast04 (NCT07060807)
💊 Patritumab deruxtecan (HER3-DXd) vs physician’s choice chemo
💉 ADC of HER3 mAb linked to topoisomerase I payload
👆Primary endpoints: PFS and OS

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

📎Modi et al. Trastuzumab Deruxtecan in Previously Treated HER2-Low Advanced Breast Cancer. NEJM. 2022.

Link to trial: www.nejm.org/doi/full/10....

Trastuzumab Deruxtecan in Previously Treated HER2-Low Advanced Breast Cancer | NEJM

Among breast cancers without human epidermal growth factor receptor 2 (HER2) amplification, overexpression, or both, a large proportion express low levels of HER2 that may be targetable. Currently ...

www.nejm.org

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

DB-04 Con't

💊 T-DXd: antibody-drug conjugate (ADC) of humanized anti-HER2 mAb linked to topoisomerase I inhibitor
⬆️ mPFS 10.1 months in ER+/HER-low with T-DXd vs mPFS 5.4 doc’s choice
⬆️ mOS 23.9mon in ER+/HER2-low vs mOS 17.5 doc’s choice

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

16/18 #TumorBoardTuesday
👩🏻‍🏫Mini Tweetorial 10🏫

DESTINY-Breast04
👩‍🦳 2L metastatic HER2- low BC
✅ Included both ER+ and ER-; HER2-low breakdown: IHC1+ = 58% and IHC2+ = 42%
💊 Trastuzumab deruxtecan (T-DXd) vs physician’s choice chemo (capecitabine, eribulin, gemcitabine, paclitaxel or nab-paclitaxel)

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

📎 DESTINY-Breast04. Modi et al. NEJM. 2022

Link to article: www.nejm.org/doi/full/10....

Trastuzumab Deruxtecan in Previously Treated HER2-Low Advanced Breast Cancer | NEJM

www.nejm.org

Margaret Gatti-Mays, MD MPH @drgattimays.bsky.social · 3h

What is HER2 low breast cancer?
👉 HER2 IHC 1+ or IHC 2+ with neg FISH
🔬Recent review showed that among all patients 35.2% are HER2-low
🔎HR+ patients, 39.8% are HER2-low expressing
🔎HR- patients, 22.5% are HER2-low expressing
🚫Clinical data - probably not a separate subtype but data is immature