Immunotherapies are now providing unprecedented therapeutic benefits across many cancer indications, with the most spectacular advances only in the last 5 years. This presentation will summarise the latest immunotherapy strategies based on antibody-directed delivery of therapeutic payloads. All these strategies rely on careful sculpturing of both the antibody module and the payload to provide a stable, high-affinity and exquisitely-specific cancer therapy. Applications range from the latest 3rd generation drug-loaded antibodies (ADCs) to check-point inhibitors (I/O therapy) to the latest Car-T (active antibody-retargeted T-cells). The antibody delivery modules are usually based on an scFv fragment which has been Bio-Nano-engineered to provide precise structural features and deliver unique pharmacokinetic properties. For the next generation of ADC therapeutics, Avipep designed and produced Diabodies (AvibodiesTM; scFv dimers) with unique surface disulphides for precise loading of either cytotoxic drug payloads (ADC-therapy) or radionuclides (for PET-imaging/ RIT-therapy). With PEGylation, Tag72-targeting diabodies demonstrated remarkable xenograft-tumour uptake >70% ID/g over 24-48hrs with fast blood clearance and low kidney uptake (<10% ID/gm). GMP-manufacture has exceeded 1gm/litre in bacterial fermentation and the diabody is stable for >36 months. A first-in-man Phase-1 Biodistribution (124-I PET imaging) trial in prostate/ovarian cancer was completed in 2016, demonstrating PEG-diabodies delivered high tumour loads in metastatic disease, with no specific uptake in normal tissues, no adverse events nor immunogenicity. Metastases were identified within 1-2 days and tumor-load persisted for 7 days with ideal tumor:blood ratios, AUC and T½ beta of ~48 hrs. The clinical trial validated PEG-diabodies for imaging cancer or for delivery of radioisotopes (RIT) or cytotoxic drug payloads (ADC). Preclinical xenograft evaluation with the latest ADC/RIT therapeutic formulations will be reported.