Patients with stage II/III human epidermal growth factor receptor 2 (HER2)???positive or triple-negative breast cancer (TNBC) frequently receive neoadjuvant therapy (NAT). Although pathologic complete response (pCR) correlates with improved outcomes, many non-pCR patients have long-term survival. Circulating tumor-DNA (ctDNA) minimal residual disease (MRD) assessment may provide additional or superior risk stratification.
Pathologic Response Evaluation and Detection in Circulating Tumor-DNA is a prospective, multicenter study evaluating ctDNA as a biomarker of treatment response using a tumor-informed, ultrasensitive (
Of 227 enrolled patients, 220 were evaluable for pCR (48% HER2-positive; 52% TNBC) and 91 patients (41%) had pCR. The primary objective was not met. Although all patients with pCR were ctDNA-negative after NAT, 40% of non-pCR patients were also ctDNA-negative (NPV, 60% [95% CI, 0.50 to 0.69]). However, the prespecified secondary objective was met. Detectable ctDNA after NAT was prognostic for recurrence (hazard ratio [HR], 8.9 [95% CI, 2.4 to 33]; P = .001), independent of pCR. Additionally, detectable ctDNA after surgery identified patients extremely high recurrence risk (HR, 128 [95% CI, 15 to 1,083]; P < .001), while ctDNA-negative patients after surgery had 94% 5-year IDFS.
In HER2-positive breast cancer and TNBC, ctDNA after NAT does not discriminate pCR from non-pCR. However, ctDNA provides markedly superior prognostic stratification, identifying patients with exceptional outcomes and those extreme risk. These findings support ctDNA-guided therapeutic de-escalation and escalation strategies.
Gedatolisib potently targets all four class I PI3K isoforms and mTORC1 and mTORC2 to comprehensively block the PI3K/AKT/mTOR pathway. PFS was 9.3 m in the gedatolisib-triplet group vs 2.0 m in the fulvestrant group (hazard ratio) HR 0.24, and 7.4 m in the gedatolisib-doublet group HR 0.33 v fulvestrant.
This is impressive. However, there is no reported placebo trastuzumab deruxtecan arm, so this is not truly a “no chemotherapy” regimen. It is important to remember that deruxtecan is itself a chemotherapy agent. So, this is really comparing deruxtecan vs taxol or more accurately, a comparison of chemotherapy delivery systems.
The QUIWI study used quizartinib, a FLT3 drug added to standard chemo induction/consolidation in FLT-negative acute myeloid leukemia (AML) patients. There was a meaningful overall survival (OS) improvement across all age and risk groups including the NPM1+ population. They purposefully used a higher dose to achieve what is felt to be off-target TKI activity in familiar pathways of KIT, PDGRF…etc.
This really feels like a first-line practice changer in PD-L1+ MTNBC—the sacituzumab govitecan/pembrolizumab combination delivering a 3.4-month progression-free survival (PFS) improvement and pushing median PFS past 11 months is quite meaningful. Mature overall survival (OS) data will be interesting to see. Remember to watch closely and consider screening for drug-induced interstitial lung disease(ILD).
ASCENT-03 shows that in first-line, PD-1/PD-L1–ineligible advanced TNBC, sacituzumab improves PFS to 9.7 vs 6.9 months and extends median duration of response (DOR) to 12.2 vs 7.2 months, with similar overall response rate (ORR) (48% vs 46%) and immature overall survival (OS) (21.5 vs 20.2 months) Grade ≥3. Adverse events (AEs) were comparable (66% vs 62%), but sacituzumab had more neutropenia and diarrhea, fewer discontinuations (4% vs 12%), and early-cycle infection-related deaths in patients without primary G-CSF. For PD-1/PD-L1–ineligible mTNBC, SG offers more durable control than chemo with manageable myelosuppression — so consider SG first-line and start G-CSF early in higher-risk patients.