Ubi Titer — Weekly Biologics AI Research Digest

Antibody Developability: Bispecifics, Off-Targets, and Clearance

Fri, 10 Jul 2026 16:00:00 GMT

Developability is finally getting measured instead of assumed — bispecific inheritance, proteome-wide off-target screens, and a cheap plate assay that predicts clearance as well as the field's best tools.

High-throughput machine learning-aided antibody discovery for cell surface antigens — A synthetic antibody library engineered specifically for machine learning readout recovered antibodies against targets that a standard screen missed entirely.
Decoding Bispecific Antibody Developability: Design Rules and Predictive Models from a 160-Member Library — A systematic study of 160 bispecific antibodies shows that some developability properties inherit predictably from the parent antibodies, while others only emerge once the two arms are combined.
Degron-independent recruitment of KAT2A expands the target space of CRBN molecular glues — A newly characterized molecular glue degrades a cancer-linked protein by having cereblon grip a surface tyrosine rather than the degron motif every prior cereblon-based glue has relied on.
Predicting antibody self-association with sequence-structure fusion models: the central role of CSI-BLI in early developability screening — A low-cost, high-throughput plate assay for antibody self-association turns out to predict in vivo clearance about as well as the field's leading specialized assays, and can now be predicted directly from sequence.
Off-target reactivity in clinical monoclonal antibodies — A proteome-wide screen of 174 approved and clinical-stage antibodies found that more than a quarter bind at least one unintended human protein, and shows these liabilities can sometimes be engineered away.

Biologics AI Beyond Generation: Selectivity and Formulation

Sat, 04 Jul 2026 16:00:00 GMT

The hard problems in biologics AI aren't just generation anymore — they're ligase selectivity, dual-epitope targeting, and the formulation mechanics behind clinical durability.

Mechanistic dissection of SMARCA2/4 molecular glues reveals programmable switching between DCAF16 and FBXO22 — AbbVie shows that single-atom changes to a molecular glue degrader can reprogram which cellular disposal machinery it recruits — turning ligase choice into a tunable design parameter.
Fully Human Antagonistic Antibodies Targeting FPR2 Through Dual Extracellular-Loop Engagement for Gastric Cancer Therapy — A new antibody blocks a cancer-linked receptor by gripping two separate loops on its surface at once, offering an early proof-of-concept for a target that's historically been hard to drug with antibodies.
Integrated Population Pharmacokinetic Analysis of Intravitreal Aflibercept Drug Products — A population PK analysis across 2,744 patients shows that a widely-used eye biologic's extended dosing interval comes from a genuine formulation effect on ocular clearance, not just from giving a bigger dose.

Targeted Protein Model Adaptation Beats Foundation Models

Sat, 27 Jun 2026 16:00:00 GMT

Targeted adaptation beats foundation models: this week's papers show that narrow, local optimization — in sequence design, PLM fine-tuning, and VHH engineering — consistently outperforms general-purpose approaches in biologics.

Efficient generation of epitope-targeted antibodies with Germinal — Germinal co-optimizes CDR sequence (IgLM) and structure (AlphaFold-Multimer) to design epitope-targeted nanobodies de novo, achieving 4-22% binding success with 43-101 designs tested per target — no starting binder required.
TCR-mimic bispecific nanobody-based T cell engager targeting intracellular tumor antigens for cancer immunotherapy — A VHH-VHH bispecific (TCRm Bi-NbTE) simultaneously engages CD3ε and pMHC-I tumor complexes, redirecting T cells to kill tumor cells via intracellular antigens — with in vivo efficacy in CDX and PDX xenografts.
Efficient inference of non-polyreactive antibody variants dependent on local fine-tuning — Local fine-tuning of a PLM on 240k yeast-display CDR-H3 variants raises polyreactivity prediction success from 0% (base model) to 66.6% — practical demonstration that foundation models need domain adaptation for narrow drug-optimization tasks.
Discovery and optimization of a pH-responsive ultra-long-acting VHH-based growth hormone mimetic — pH-dependent VHH engineering — 227-fold difference in dissociation rate between neutral and acidic pH — extends GH mimetic activity from 6 days to >15 days in rats, achieving ultra-long-acting PK via FcRn recycling logic in a VHH format.
A multi-centre, phase 1a/1b dose escalation and expansion study of the HER2-directed antibody-drug conjugate T-Bren (BL-M07D1) in advanced breast cancer and other solid tumours — T-Bren (BL-M07D1, DAR-8, cathepsin B-cleavable, topo I payload) achieves 81.5% ORR in HER2-positive and 69.5% in HER2-low breast cancer across 253 patients; RP2D 4.4 mg/kg Q3W.
Impact of ASO conjugation and receptor binding affinity on intracellular transport of mono- and bispecific TfR- and CD98-Brainshuttle variants — ASO cargo inverts the TfR1 affinity-transcytosis relationship in Brainshuttles; a bispecific TfR1×CD98hc format rescues BBB delivery by engaging two distinct trafficking pathways simultaneously.

Why Target Expression Fails to Predict ADC Response

Fri, 19 Jun 2026 16:00:00 GMT

Target expression doesn't predict ADC response — two independent papers point to payload sensitivity as the real driver

Dynamic monitoring of antibody drug conjugates targeting TROP2 or HER2 in breast cancer using circulating tumor cells — Prospective cohort (n=35): baseline TROP2/HER2 expression on CTCs does not predict sacituzumab govitecan or T-DXd response. >80% CTC reduction at week 3 does (TROP2: HR 5.15; HER2: HR 6.01). Cross-ADC switching (same TOP1i payload class) rarely produces second-line response — implicating payload resistance.
Telisotuzumab Adizutecan (ABBV-400) in Gastric/Gastroesophageal Junction Adenocarcinoma — ABBV-400 (c-Met ADC, TOP1i payload, DAR 8) in 42 GEA patients: ORR 29%, CBR 71%, DOR 4.2 mo, PFS 4.0 mo, OS 5.8 mo. Responses in c-Met-low patients. Grade ≥3 TEAEs 88%. Independent clinical signal that payload sensitivity — not c-Met expression — drives response.
Biparatopic targeting of IL-23 enables dual-epitope engagement and enhanced neutralization potency — Ustekinumab + guselkumab variable regions combined into biparatopic 1+1 IgG and 2+2 Fab-IgG formats. Picomolar SPR affinities with avidity enhancement; dual-epitope engagement confirmed by bridging SPR and mass photometry. Functional neutralization equivalent to equimolar antibody mixture — a clean engineering framework without synergistic potency gain.
miRNA-Mediated FUT8 Knockdown Enables Complete Afucosylation of Therapeutic Antibodies in CHO Without Titer Loss — RNA Pol II miRNA targeting FUT8 in CHO: >90% afucosylation (HILIC-HPLC), no fucosylated product by intact MS, no titer loss. Beats shRNA (U6 promoter) which causes Dicer saturation → residual fucosylation + reduced titers. Clean solution to the afucosylation-vs-yield tradeoff in antibody manufacturing.

Why Kinetics and Costimulation Beat Maximum Affinity

Fri, 12 Jun 2026 16:00:00 GMT

Kinetic tuning and costimulatory context beat affinity maximization — two papers, two different mechanisms, the same lesson

Combination therapy with a novel CD2-targeted costimulatory bispecific antibody overcomes limitations of CD3 T cell engager treatment for solid tumors — Non-blocking HER2×CD2 bispecific + EpCAM×CD3 TCE: 8/9 complete remissions vs 1/9 with TCE alone. Lower cytokine release than HER2×CD28 approach. Provides costimulation to CD28-negative CD8 T cells.
First-in-Human, Phase I Study of Sigvotatug Vedotin, an Integrin Beta-6–Directed Antibody-Drug Conjugate: Results From Dose Expansion in Advanced Non–Small Cell Lung Cancer — 117 heavily pre-treated NSCLC patients, 19% ORR (29% taxane-naive nonsquamous), 11.3-month median DOR. IB6 expressed in 92% of biopsies. First JCO readout for an IB6-directed ADC.
Discovery and optimization of marstacimab, a human monoclonal antibody targeting tissue factor pathway inhibitor for the treatment of hemophilia A and B — Phage + hybridoma screen → TFPI-blocking mAb optimized to ~5.72 nM affinity for PK (not the tightest binder). Now FDA-approved as Hympavzi. Case study in deliberate affinity de-optimization as a PK lever.
NMR detects clustering and ultra-weak excipient interactions governing monoclonal antibody viscosity in formulation-relevant conditions — NMR + DLS + rheometry at 50–150 mg/mL: arginine/lysine suppress mAb clustering; proline/glycine promote it. Sucrose binds antibody but doesn't reduce viscosity. Mechanistic pipeline for SC formulation decisions.
Endocytic evasion confers resistance to antibody-drug conjugates therapy in cancer — AKR1C1 binds NECTIN4 and blocks AP2M1-dependent clathrin endocytosis; WWP2 exports ADC via extracellular vesicles. High NECTIN4 expression + defective uptake = resistance to enfortumab vedotin. AKR1C1 inhibition restores sensitivity preclinically.

Bispecific ADCs and T-Cell Engagers in Solid Tumors

Fri, 05 Jun 2026 16:00:00 GMT

Bispecific formats — ADCs, TCEs, and targeted delivery — converging on solid tumor antigen heterogeneity as the defining challenge of 2026

Development of Antibody-Drug Conjugates Targeting L1CAM to Treat Metastatic Cancer — ADCs targeting L1CAM — a marker of metastasis-initiating stem cells — achieve complete tumor regression and 100% survival in PDX lung metastasis models at 1 mg/kg with a non-cleavable linker to PNU-159682.
Molecular Design and Preclinical Evaluation of GenSci143, a Novel B7-H3- and PSMA-Directed Bispecific Antibody-Drug Conjugate, for the Treatment of Prostate Cancer — Bispecific ADC simultaneously targeting B7-H3 and PSMA outperforms single-target ADCs in prostate cancer CDX/PDX models by exploiting bystander killing and dual-antigen redundancy against heterogeneous tumors. FDA IND cleared.
A Unified Dataset for Antibody and Nanobody Design Including Sequence, Structure, and Binding Affinity Data — ANDD: 48,683 antibody/nanobody sequences, 24,941 structures, 9,557 affinity values unified from 15 sources — including 30,119 VHH entries. Largest integrated Ab/Nb design dataset with provenance-tracked affinity data.
NbBayesLM: bayesian prediction of nanobody thermostability using protein language model — ESM-2 embeddings + physicochemical Bayesian priors predict nanobody Tm with calibrated confidence intervals. Outperforms point-estimate PLMs and classical feature models. CDR-level attribution identifies instability hotspots.
Adaptive Disorder as the Hallmark of Nanobodies Antigen-Binding Loops — MD simulations show nanobody CDR3 loops are intrinsically disordered in solution — not just flexible. Adaptive disorder enables binding to concave epitopes. CDR1/2 are rigid anchors; CDR3 is a conformationally malleable binding arm.
A trophoblast glycoprotein specific 5T4-Vδ2 bispecific T cell engager recruits Vγ9Vδ2-T cells for tumor-selective cytotoxicity across solid malignancies — VHH-based bispecific T cell engager co-engaging oncofetal antigen 5T4 and Vδ2-TCR kills solid tumor cells in patient-derived 3D models without cytotoxicity against healthy 5T4-expressing tissue.