BioNTech and partner OncoC4 reported Phase 3 survival data for an anti‑CTLA‑4 antibody in lung cancer that more than halved the risk of death, delivering a significant efficacy signal. Subsequent analyses and regulatory reviews, however, flagged a challenging tolerability profile with immune‑related adverse events that complicate the drug's clinical utility and commercial positioning. Analysts noted the efficacy is compelling but cautioned that toxicity management will be central to labeling, uptake and potential combination strategies.