Eligible participants require histologically confirmed lymphoid malignancies (Parts A/B: CD30+ &ge;1% except cHL/ALCL; Part C: CD30-independent) with specific prior therapy requirements: cHL (&ge;3 lines, anti-PD-1 exposed), PTCL (&ge;2 lines), or ALCL (brentuximab-containing regimens). Key exclusions: >2 brentuximab lines, recent malignancies (<3 years), active CNS disease, allogeneic SCT complications (<100 days/GVHD/CMV reactivation), or significant pulmonary conditions (Grade&ge;2 ILD, steroid-dependent lung disease). ECOG&le;1 and measurable FDG-avid disease (per Lugano criteria) are mandatory.

The safety assessment will track adverse events, laboratory abnormalities, dose modifications, and dose-limiting toxicities (including by dose level) through 30-37 days post-treatment (approximately 1 year). AE reporting will include all medically significant occurrences regardless of causality, with DLT evaluations specifically during the initial 21-day period.

Pharmacokinetic analysis will assess AUC, Cmax, and Tmax through 30-37 days post-treatment (≈1 year), summarized descriptively alongside antidrug antibody incidence. Efficacy endpoints include investigator-assessed ORR (CR+PR), CR rate, and DOR (time from first response to progression/death), all evaluated over ≈1 year using disease-specific criteria.