Callio Therapeutics Wins Best New ADC Drug Developer at the 13th World ADC Awards

Callio Therapeutics Wins Best New ADC Drug Developer at the 13th World ADC Awards, Presents Across Five Sessions at World ADC San Diego
Callio leaders delivered three presentations and two panel discussions on dual-payload ADC resistance, manufacturability, linker design, and the path to next-generation ADCs

SAN DIEGO, SEATTLE and SINGAPORE, Oct. 15, 2026 (GLOBE NEWSWIRE) -- Callio Therapeutics (“Callio” or “the Company”), a global, clinical-stage biotechnology company advancing dual-payload antibody-drug conjugates (ADCs) as the next frontier of rationally designed targeted cancer therapy, today announced it has won Best New ADC Drug Developer at the 13th World ADC Awards. The award was presented at the World ADC Awards Gala on Wednesday evening, October 14, held during World ADC San Diego 2026. Callio also delivered three presentations and two panel discussions at the conference.

Powered by a proprietary platform featuring modular, adaptable linker technology, Callio is actively developing a pipeline of dual-payload ADCs with rationally selected payload combinations designed to overcome treatment resistance in hard-to-treat tumors. CLIO-8221 is the first program from Callio's dual-payload ADC pipeline to enter the clinic, with the first patient dosed in March 2026, approximately one year after the Company's launch.

"We are honored to accept this award, as this recognition reflects what the Callio team has built as we advance dual-payload ADCs for patients whose cancers stop responding to current therapies," said Zachary Hornby, Chief Executive Officer of Callio Therapeutics. "World ADC has emerged as the premier forum for the ADC community to come together and share the latest advancements in the field."  

Callio's Presence at World ADC San Diego 2026

The 17th World ADC San Diego summit brought together more than 1,300 industry attendees from over 400 companies, with seven tracks of end-to-end ADC content from discovery through manufacturing and supply. Callio's leadership and scientific team participated in the following panel discussions and presentations:

Presentation: Harnessing the Promise of Dual-Payload ADCs to Combat Resistance to Traditional ADCs
Presenter: Chris Hassig, PhD, Chief Scientific Officer

Presentation: Leveraging a Modular & Adaptable Linker Design to Evaluate Translation of Rationally Selected Dual-Payload Combinations
Presenter: Alyson Smith, Vice President of Research

Panel Discussion: What's the New Path to the Next Generation of ADCs?
Panelist: Jeremy Sauer, Vice President of Strategy

Panel Discussion: Building the Next Generation of ADC Linkers & Payloads: What Do Innovators Need from Development & Manufacturing Partners?
Panelist: Srinath Thirumalairajan, Executive Director of CMC

Presentation: From Complexity to Manufacturability: Considerations to Rapidly Develop & Manufacture Dual-Payload ADCs
Presenter: Srinath Thirumalairajan, Executive Director of CMC

About Callio Therapeutics

Callio Therapeutics is a clinical-stage biotechnology company that is developing dual-payload antibody-drug conjugates (ADCs) as the next frontier of targeted cancer therapy to address high incidence tumors where better therapies are needed. Its proprietary platform pairs modular, adaptable linker technology with rationally selected synergistic payload combinations designed to block key resistance mechanisms that enable cancer's escape. The Company's lead clinical program, CLIO-8221, is a HER2-targeted dual-payload ADC with potential to prevent and overcome treatment resistance that limits efficacy of current ADCs. Located in San Diego, Seattle, and Singapore, backed by top life science investors, and led by an experienced team with a track record of ADC development and oncology drug approvals, Callio Therapeutics is built to deliver the next generation of dual-payload ADCs and better outcomes for people living with cancer. For more information, visit www.calliotx.com and follow Callio Therapeutics on LinkedIn.

About CLIO-8221

HER2 is a clinically validated target for antibody-drug conjugates (ADCs), with multiple approved therapies demonstrating clinical benefit across tumor types. However, most patients eventually progress on treatment despite their tumors retaining HER2 expression. Mechanistic resistance to cytotoxic payloads has emerged as a key driver of treatment failure. CLIO-8221 is a novel, first-in-class, dual-payload ADC targeting HER2, designed to overcome emergent resistance.

CLIO-8221 delivers two mechanistically complementary payloads, a topoisomerase 1 (Topo1) inhibitor and an ATR inhibitor, directly to HER2-expressing tumors. While Topo1 inhibitors have shown strong clinical activity, activation of the DNA damage response following Topo1 inhibitor-induced replication stress represents a potential major driver of resistance. By simultaneously inhibiting Topo1 and blocking the DNA damage response through ATR inhibition, CLIO-8221 is engineered to overcome payload insensitivity and further sensitize tumors to Topo1 inhibition. Developed using proprietary linker and ADC platform technologies, CLIO-8221 aims to maximize anti-tumor activity while reducing systemic toxicity, offering the potential for deeper and more durable responses in patients with HER2-expressing tumors.

CLIO-8221 is currently being evaluated in an ongoing Phase 1/2, first-in-human, dose-escalation and expansion study in adult patients with metastatic or unresectable HER2-expressing solid tumors, including those who previously received trastuzumab deruxtecan (T-DXd). The first patient was dosed in March 2026, and enrollment is ongoing in Australia and the US, with plans to open the study in China (NCT07300943).

Contacts

Media:
Jeremy Sauer
media@calliotx.com

Ally Stubin – ICR Healthcare
ally.stubin@ICRHealthcare.com
(646) 667-1861

Investors:
ir@calliotx.com

Stephanie Carrington – ICR Healthcare
stephanie.carrington@ICRHealthcare.com
(646) 277-1282