Erik L Kimble | Search PubMed

PubMed2026

Randomized phase 2 trial of CPX-351 vs. CLAG-M (cladribine, cytarabine, G-CSF, and mitoxantrone) for medically unfit adults with acute myeloid leukemia or other high-grade myeloid neoplasms.

Even with new drugs available, how best to treat unfit adults with acute myeloid leukemia (AML) remains uncertain. In a previous trial in such patients, we found high-dose cytarabine-based therapy with CLAG-M yielded higher response rates but no more toxicity than lower-intensity therapy with dose-attenuated CLAG-M. Here, we conducted a single-institution phase 2 trial (NCT04195945) randomizing 60 adults with untreated AML and medical unfitness with Treatment-Related Mortality (TRM) score of ≥13.1 (68% with ECOG performance status 3-4) 1:1 to standard-dose CPX-351 or CLAG-M. Primary endpoint was 3-month overall survival (OS); key secondary endpoints included overall response rate, rate of measurable residual disease (MRD) negativity, toxicity/mortality rates, and survival estimates. Only CLAG-M met the primary endpoint of ≥63% 3-month OS (70% vs. 60%; P = 0.41), and CLAG-M therapy was associated with a non-significantly higher complete remission (CR) plus CR with incomplete hematologic recovery rate (73% vs. 47%, P = 0.064). Nonetheless, there was no statistically significant difference in relapse-free survival following CLAG-M vs. CPX-351 (median 37.6 vs. 19.9 months; P = 0.80) or OS (median 10.5 vs. 5.8 months; P = 0.76). In patients with proliferative disease, however, OS following CLAG-M was longer (median 18.5 vs. 3.9 months; P = 0.02) suggesting a role for intensive therapy in this patient subset.

Adult↗

PubMed2025

Novel antibodies for identification, selection, and manipulation of T cells expressing Whitlow linker-containing CARs.

BACKGROUND: The translational study of chimeric antigen receptor (CAR) T-cell function, persistence, immunophenotype, and spatial localization after infusion is crucial for understanding factors that influence clinical outcomes. However, research has been limited by a lack of optimized tools to reliably detect CAR-engineered cells. To address this, we developed a novel platform to generate monoclonal antibodies (mAbs) targeting a linker peptide incorporated in single-chain variable fragments (scFvs) of most CAR constructs. METHODS: Using recombinant proteins and scFv linker peptides as immunogens, we generated murine mAbs against the Whitlow linker peptide, capable of binding cells expressing Whitlow linker-containing CARs in both fresh and formalin-fixed paraffin-embedded (FFPE) tissues. We evaluated these antibodies in multiple in vitro translational applications relevant to CAR T-cell research and manufacturing. RESULTS: We identified five unique mAbs reactive against the Whitlow linker and characterized their binding properties and three-dimensional structural conformation. One clone was evaluated in depth, demonstrating comparable capacity to identify CAR T cells in peripheral blood relative to other methods using anti-idiotype antibodies or recombinant CAR-target proteins. In contrast to these reagents, the anti-Whitlow mAb detects cells expressing Whitlow linker-containing CARs with different antigen specificities, including those harboring the widely employed anti-CD19 FMC63-derived scFv as well as other scFvs, such as those targeting B-cell maturation antigen (BCMA) or CD33. Importantly, the anti-Whitlow mAb identified CAR T cells in situ in archival FFPE tissues, and a DNA-barcoded format enabled their spatial characterization and immunophenotyping in highly multiplexed immunohistochemistry. We also assessed the functional consequences of antibody binding on CAR T cells in vitro and demonstrated the feasibility of anti-Whitlow mAb-mediated selective enrichment of CAR-expressing T cells for potential utility in manufacturing workflows. CONCLUSIONS: Anti-Whitlow mAb clones exhibited distinct structural and functional properties that can be leveraged for multiple applications, providing versatile tools for detection, selection and manipulation of a broad range of clinical and preclinical CAR T-cell products.

Humans↗