30-Second Takeaway
- CDK4/6 plus endocrine therapy continues to deepen responses after endocrine progression in HR+/HER2- breast cancer with expected toxicity.
- First-line zolbetuximab plus chemoimmunotherapy shows high activity in CLDN18.2-high metastatic gastric/GEJ adenocarcinoma, warranting randomized confirmation.
- Adding PD-1 blockade to neoadjuvant chemoradiotherapy improves pCR in pMMR rectal cancer without increasing high-grade toxicity.
- CT-derived thymic health and baseline ctDNA levels emerge as practical host- and disease-focused biomarkers to refine immunotherapy and mCRPC risk stratification.
- New ADCs and T-cell–engaging strategies (SHR-A1811, tarlatamab) demonstrate durable activity but require careful toxicity monitoring.
Week ending March 21, 2026
Targeted combinations, immunotherapy biomarkers, and novel agents reshape advanced solid tumor management
Bireociclib plus fulvestrant prolongs PFS after endocrine progression in HR+/HER2- advanced breast cancer
In BRIGHT-2, bireociclib plus fulvestrant roughly doubled median PFS versus fulvestrant alone (14.7 vs 7.3 months; HR 0.54). Objective response rate was markedly higher with bireociclib (45.6% vs 14.9%), and responses were more durable. Benefit was consistent across subgroups defined by menopausal status, sites of metastasis, prior therapy, and common genomic alterations. Toxicity was manageable and aligned with known CDK4/6 inhibitor profiles, with early-onset diarrhea potentially marking greater benefit.
Zolbetuximab plus mFOLFOX6 and nivolumab yields high responses in CLDN18.2-positive metastatic gastric/GEJ cancer
In ILUSTRO cohort 4, first-line zolbetuximab plus mFOLFOX6 and nivolumab achieved a median PFS of 14.8 months overall. Patients with CLDN18.2-high tumors had an estimated median PFS of 18.0 months, suggesting greater benefit in strongly expressing disease. Objective response rate in measurable disease reached 62.1% overall and 68.1% in CLDN18.2-high tumors. Nausea and decreased appetite were the most frequent adverse events, supporting feasibility of randomized phase 3 evaluation.
PD-1 blockade added to neoadjuvant chemoradiotherapy increases pCR in pMMR rectal cancer
This meta-analysis pooled six randomized trials (n=935) comparing nCRT plus PD-1 inhibitors versus nCRT alone in pMMR non-metastatic rectal cancer. PD-1 addition significantly increased pathological complete response (RR 1.79; 95% CI 1.34-2.40). Clinical complete response trended higher but was not definitive (RR 1.67; 95% CI 0.89-3.13). There were no significant differences in R0 resection, sphincter preservation, grade ≥3 neoadjuvant toxicity, or major surgical morbidity. Short-course radiotherapy combinations appeared to derive greater pCR benefit, supporting further phase III regimen optimization.
CT-based thymic health predicts immune checkpoint inhibitor outcomes across multiple cancers
A deep-learning model quantified thymic health on routine CT scans in 3,476 patients receiving immune checkpoint inhibitors. Higher thymic health in NSCLC was associated with lower risks of progression and all-cause mortality, independent of PD-L1 and tumor mutation burden. In the TRACERx lung cohort, thymic health correlated with T-cell receptor diversity, T-cell receptor excision circles, and immune signaling pathways. Associations extended to melanoma, breast, and renal cancers, suggesting a tumor-agnostic host biomarker for immunotherapy stratification and timing.
References
Numbered in order of appearance. Click any reference to view details.
Additional Reads
Optional additional studies from this edition.