Budigalimab

Overview

Budigalimab (ABBV-181; PR-1648817) is an investigational, humanized IgG1 monoclonal antibody that targets PD‑1. Early-phase clinical development has included monotherapy and combinations across advanced solid tumors. Phase 1 monotherapy expansion cohorts in head and neck squamous cell carcinoma (HNSCC) and non–small cell lung cancer (NSCLC) reported objective responses and a safety profile consistent with approved PD‑1 inhibitors. Ongoing studies are evaluating combinations, notably with the anti–GARP–TGF‑β1 antibody livmoniplimab (ABBV‑151) in hepatocellular carcinoma (HCC). (link.springer.com)

Mechanism of action

Budigalimab binds PD‑1 and blocks interaction with its ligands PD‑L1 and PD‑L2, restoring T‑cell activity. It is an engineered IgG1 with L234A/L235A (LALA) Fc mutations to minimize Fcγ receptor engagement and effector function, functioning as a pure antagonist. Pharmacodynamic assessments demonstrate rapid and sustained saturation of peripheral PD‑1–positive T cells at clinically explored doses. (link.springer.com)

Efficacy

• Monotherapy (Phase 1 expansion, NCT03000257): In 81 PD‑1/PD‑L1‑naïve patients (HNSCC n=41; NSCLC n=40) treated at 250 mg Q2W or 500 mg Q4W, objective response rates (ORR) were 13% (90% CI, 5.1–24.5) in HNSCC and 19% (90% CI, 9.2–32.6) in NSCLC; median progression‑free survival was 3.6 months (95% CI, 1.7–4.7) and 1.9 months (95% CI, 1.7–3.7), respectively. Responses included one complete response in NSCLC. (link.springer.com)

• Combination signals (early-phase): In a phase 1 program of livmoniplimab (ABBV‑151) plus budigalimab, an HCC cohort (post first‑line, PD‑1/PD‑L1‑naïve) reported ORR 42% (5/12) in meeting abstracts, prompting randomized phase 2 and a phase 2/3 study versus STRIDE (tremelimumab + durvalumab). Detailed peer‑reviewed efficacy for this combination is pending. (ascopubs.org)

Safety

• Class‑consistent profile: In the phase 1 HNSCC/NSCLC expansion, the most frequent grade ≥3 treatment‑emergent adverse event was anemia (HNSCC 22%; NSCLC 13%); no treatment‑related deaths were reported. Immune‑related AEs commonly included hypothyroidism, diarrhea, hyperthyroidism, pruritus, and rash. Overall, safety was considered similar to other PD‑1 inhibitors. (link.springer.com)

• Dose finding and broader phase 1 experience: Across dose‑escalation and multihistology expansion cohorts, immune‑related AEs occurred in 18.6% (11/59) of patients, with grade ≥3 in 1.7% (1/59). Exposure–safety analyses did not show an exposure‑response relationship and supported flat dosing regimens. (pubmed.ncbi.nlm.nih.gov)

Dosing and pharmacokinetics (investigational)

Population PK/PD modeling and clinical data support flat dosing regimens of 250 mg every 2 weeks, 375 mg every 3 weeks, or 500 mg every 4 weeks, providing comparable exposure and sustained PD‑1 receptor saturation. PK is approximately dose‑proportional in the studied range. (ascpt.onlinelibrary.wiley.com)

Development status and selected trials

• Monotherapy and combinations in advanced solid tumors, including with venetoclax or rovalpituzumab tesirine in the first‑in‑human study (NCT03000257; phase 1 completed March 29, 2022). (cdek.pharmacy.purdue.edu)
• Ongoing combination development with livmoniplimab in HCC (phase 2 and phase 2/3 programs; NCT06109272). (ascopubs.org)

Further reading

• First‑in‑human phase 1 expansion in HNSCC and NSCLC (open access): Cancer Immunology, Immunotherapy, 2022. (link.springer.com)
• Model‑informed dosing and phase 1 results: Clinical and Translational Science, 2021. (ascpt.onlinelibrary.wiley.com)
• PubMed record of the CTS article (quick summary/metadata). (pubmed.ncbi.nlm.nih.gov)
• ASCO 2024 meeting abstracts on livmoniplimab + budigalimab in HCC (phase 2 and phase 2/3 designs; early activity signal noted in phase 1). (ascopubs.org)
• AbbVie pipeline overview for mechanism and program context. (abbviescience.com)

Notes: Budigalimab remains investigational; no regulatory approvals as of October 7, 2025. Reported combination outcomes outside of peer‑reviewed publications are primarily from conference abstracts and should be interpreted cautiously pending full reports. (ascopubs.org)

Last updated: Oct 2025