Ep183: Sabah Oney on CAR-T Cells Against Solid Tumors

Episode Summary

Executive Summary: Sabah Oney discusses Dispatch Biotherapeutics' strategy to expand CAR-T into solid tumors by using a cancer-selective viral vector to tag tumors with synthetic or redirected antigens, then attacking them with engineered CAR-T cells. The conversation covers the science, safety, manufacturing, team culture, and timeline toward first clinical trials in 2025-2026.

Main Topics: Why Dispatch exists: extending CAR-T beyond blood cancers (Priority: 5/5): Oney explains that CAR-T has been transformative in hematologic malignancies but has not yet solved the vast majority of cancers, motivating a bold attempt to address solid tumors. Two-step therapy: viral tagging plus CAR-T killing (Priority: 5/5): Dispatch’s platform uses a tumor-selective virus to deliver a flare/antigen to cancer cells, then deploys CAR-T cells that recognize and kill only those tagged cells. Program 1: synthetic flare FL1 with reprogrammed CAR-T (Priority: 5/5): The first program introduces a synthetic antigen absent from the human proteome, enabling a wide therapeutic window and a highly engineered CAR-T designed for persistence and potency. Program 2: BCMA redirection plus tumor microenvironment reengineering (Priority: 4/5): The second program uses a known antigen target, BCMA, and focuses on modifying the tumor microenvironment so existing, clinically understood CAR-T biology can work in solid tumors. Safety, dosing, and clinical translation (Priority: 4/5): Oney addresses concerns about toxicity, cytokine release, neurotoxicity, and dosing, emphasizing thoughtful trial design, localized targeting, and prior viral safety data. Manufacturing, scaling, and future access (Priority: 4/5): The company is starting with autologous CAR-T to prove the approach, while planning for future manufacturing evolution, possibly including in vivo CAR-T, to expand access globally. Leadership, culture, and mission-driven execution (Priority: 3/5): Oney describes Dispatch’s lean team, values-based hiring, and the importance of humility, pragmatism, and long-term commitment in building a hard biotech company.

Key Arguments: CAR-T’s success in blood cancers proves the modality can be curative, but solid tumors require solving antigen specificity, antigen homogeneity, and hostile tumor microenvironments. Rather than depending on a naturally tumor-specific antigen, Dispatch uses a virus to place a synthetic or redirected antigen directly onto tumor cells. The viral vector is valuable because it is highly specific to cancer cells and can reach primary and metastatic sites throughout the body. CAR-T cells and the virus create a synergistic feedback loop: virus tags tumor cells, CAR-T kills them, and cell death releases more viral particles to spread tagging. The first program’s synthetic flare is designed to be inert in humans yet highly targetable, creating a large therapeutic window and minimizing off-tumor risk. The second program leverages a validated CAR-T target to reduce clinical uncertainty, but requires microenvironment remodeling for solid-tumor success. Dispatch’s CAR-T engineering aims to increase both effector function and stem-like persistence, overcoming the usual tradeoff between killing power and longevity. Safety is central: the company plans careful dose selection and trial design to reduce risks seen in previous solid-tumor CAR-T attempts. The company is intentionally starting with autologous therapy because it is a proven path and can deliver meaningful impact before future shifts to in vivo manufacturing. A mission-driven culture is essential; Dispatch hires for values first and seeks people motivated by patient impact rather than quick financial exits.

Data Points: Funding raised: $216 million - Dispatch has raised this amount over the past three years. Cancer coverage target: More than 90% of all cancers - The company aims to extend CAR-T to solid tumors of epithelial origin. Team size: About 45 people - Current Dispatch headcount as described by Oney. Planned team size at clinic entry: 50-70 people - Oney expects the company to remain lean by the time it enters the clinic. Time to first IND: Next year (2025) - Expected filing for the first clinical application. Time to second IND: End of 2025 or first half of 2026 - Expected filing for the second program shortly after the first. Clinic entry timeline: 12 to 18 months - Estimated time from the conversation to first clinical entry. Safety experience of virus: More than 250 patients - The viral vector platform has already been used in patients with a favorable safety profile. Specificity advantage: Three orders of magnitude - Virus specificity for cancer cells versus normal cells was described as thousands-fold. CAR-T killing performance in mice: Minuscule doses still produced complete responses - Animal data were presented as highly encouraging in difficult models.

Pivotal Quotes: "we can go after all solid tumors of epithelial origin, which you mentioned is more than 90% of all cancers" — Sabah Oney: Describing the potential reach and significance of Dispatch’s platform "Let's use the strengths of this virus... and then let's go after those cancer cells that have been tagged using the most lytic agent that has ever been developed by humans. A CAR T cell" — Sabah Oney: Explaining the core two-step mechanism of viral tagging followed by CAR-T attack "don't be dogmatic, be pragmatic at everything" — Bob Nelson: Advice Oney says shaped Dispatch’s operating philosophy

Implications: If successful, Dispatch could turn CAR-T into a broadly applicable solid-tumor therapy and reset expectations for cancer immunotherapy. The approach could also influence how future cell therapies are built, manufactured, and scaled.