CLIO-8221 / Hummingbird Biosci, Callio Therapeutics - LARVOL DELTA

Phase 1/2 study of CLIO-8221, a HER2-targeted, dual-payload exatecan and ATR inhibitor antibody-drug conjugate (ADC) in patients with advanced HER2-expressing solid tumors. (ASCO 2026) - P1/2 | "Funded by Callio Therapeutics Clinical Trial Registration Number: NCT07300943 Background: CLIO-8221 is a novel anti-HER2 ADC designed to overcome topoisomerase 1 inhibitor (Topo1i) resistance by incorporating both Topo1i (exatecan) and ataxia telangiectasia and rad3-related protein inhibitor (ATRi; berzosertib) payloads...Trastuzumab deruxtecan (T-DXd) has redefined the treatment paradigm for HER2-expressing breast cancer and is emerging as a frontline treatment option...Antitumor activity, PK, immunogenicity, and biomarkers including HER2 status and ctDNA dynamics will also be evaluated. Enrollment is planned at sites in Australia, US, and China (NCT07300943)."

ADC • Clinical • First-in-human • Metastases • P1/2 data • Ataxia • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Immunology • Movement Disorders • Oncology • Primary Immunodeficiency • Solid Tumor • ATR • HER-2

Callio Therapeutics to Present Phase 1 Trial Design of CLIO-8221, Novel Dual-Payload ADC, at ASCO 2026 (GlobeNewswire) - "The Phase 1 clinical trial recruitment is ongoing in Australia and the United States, and the company plans to activate sites in China."

Clinical protocol • Trial status • Solid Tumor

Development of CLIO-8221: A HER2-targeted multi-payload ADC to address ADC resistance (AACR 2026) - "CLIO-8221 shows in vitro cell killing activity across cell lines with a range of HER2 expression levels and Trastuzumab-DXd (T-Dxd) sensitivities, and drives tumor regressions after a single dose in T-DXd-resistant and refractory xenograft models, with strong durable activity seen at 3 mg/kg. CLIO-8221 is a first-in-class anti-HER2 dual payload ADC that allows targeted delivery of TOP1i and ATRi payloads to HER2 expressing tumors to maximize anti-tumor efficacy, overcome TOP1i resistance, and reduce systemic toxicity. Our findings strongly support the development of CLIO-8221 as a potential therapeutic option for HER2-positive cancers and a phase 1/2 study of CLIO-8221 in patients with advanced solid tumors has been initiated."

ADC • Oncology • Solid Tumor • HER-2

Callio Therapeutics to Present Poster on CLIO-8221, a Novel Dual-Payload Antibody-Drug Conjugate, at AACR 2026 (GlobeNewswire) - "At AACR 2026, Callio Therapeutics will present preclinical data demonstrating that CLIO-8221 provides a wide therapeutic window with strong durable activity, supporting its potential to deliver clinical benefit in patients with tumors resistant to existing Topo1 inhibitor-based ADCs....CLIO-8221 demonstrated potent anti-tumor activity across varying HER2 expression levels and drove tumor regression after a single dose in both trastuzumab deruxtecan-sensitive and -insensitive models. CLIO-8221 has a broad therapeutic window with no toxicological findings observed at doses up to 70 mg/kg in NHP studies."

Preclinical • Solid Tumor

Callio Therapeutics Launches with US$187 Million Series A to Advance Multi-Payload Antibody-Drug Conjugate Platform Through Clinical Proof-of-Concept (PRNewswire) - "Callio Therapeutics...announced its launch with the closing of a $187.0 million Series A financing round. This financing was led by Frazier Life Sciences with significant participation from Jeito Capital alongside other life sciences investors, including Novo Holdings A/S, Omega Funds, ClavystBio, Platanus, Norwest, Pureos Bioventures, SEEDS Capital and EDBI. The newly formed company, with headquarters in Seattle and Singapore, intends to use the proceeds from the Series A financing to achieve clinical proof-of-concept for its HER2-targeted dual-payload ADC and a second undisclosed ADC program."

Financing • Oncology

Callio Therapeutics Doses First Patient in Phase I Clinical Trial of Dual-Payload ADC CLIO-8221 in Advanced HER2-Expressing Solid Tumors (GlobeNewswire) - "The Phase I clinical trial (NCT07300943) is ongoing in Australia and the U.S., with Callio Therapeutics having received IND clearance from the U.S. Food and Drug Administration (FDA) this month. The IND is also under review by the China National Medical Products Administration (NMPA), and the trial is expected to expand to multiple sites in China."

IND • Trial status • Solid Tumor

Study in Advanced Solid Tumor Patients (clinicaltrials.gov) - P1/2 | N=306 | Recruiting | Sponsor: Callio Therapeutics | Not yet recruiting ➔ Recruiting

Enrollment open • Oncology • Solid Tumor

Hummingbird Bioscience Announces Poster Presentation on HMBD-802, Novel Dual-Payload Antibody-Drug Conjugate, at EORTC-NCI-AACR 2024 (GlobeNewswire) - "Hummingbird Bioscience...announced a poster presentation on HMBD-802, a novel first-in-class dual-payload anti-HER2 antibody-drug conjugate, at the 36th EORTC-NCI-AACR symposium (23-25 October 2024)."

Preclinical • Oncology