Calidi Biotherapeutics Presents New Data on Its Differentiated Approach to In Situ T-Cell Engagers Including a New Candidate Targeting TROP-2 at the AACR Annual Meeting in April 2026
Rhea-AI Summary
Calidi Biotherapeutics (NYSE American: CLDI) presented preclinical data at AACR on April 19, 2026, showing its RedTail virotherapy can co-express high levels of an IL-15 superagonist and functional in situ T-cell engagers in the tumor microenvironment. The company named CLD-401 as its lead and expects to file an IND for CLD-401 by end of 2026. Calidi is also developing CLD-501 targeting TROP2 and exploring EGFR, EpCAM, and Nectin-4 targets.
Positive
- RedTail co-expresses IL-15 SA and T-cell engagers in situ
- Company expects to file IND for CLD-401 by end of 2026
- CLD-501 targets TROP2 while limiting off-tumor exposure
Negative
- No human clinical data presented; findings are preclinical
- T-cell engagers historically failed in solid tumors due to TME
Key Figures
Market Reality Check
Peers on Argus
CLDI was modestly lower by 0.79% while sector peers showed mixed momentum: some names like APRE and CELZ appeared in scanners with notable moves, and 3 of 4 momentum peers (APRE, CELZ, GLMD) were down, suggesting broader biotech pressure alongside company-specific AACR news.
Historical Context
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Apr 14 | Conference presentation | Positive | -4.4% | IOVC talk on RedTail systemic delivery and CLD-401/CLD-501 progress. |
| Apr 07 | Conference preview | Positive | -1.3% | ASGCT preclinical RedTail data and IND timing for CLD-401. |
| Apr 02 | AACR CLD-401 data | Positive | -2.7% | AACR preclinical update on CLD-401 IL-15 SA tumor-restricted expression. |
| Apr 01 | AACR T-cell engager | Positive | +1.6% | AACR preview on in situ T-cell engagers and TROP2 candidate. |
| Mar 27 | Earnings and update | Negative | -11.7% | Q4/FY25 loss, low cash, and financing plus development updates. |
Recent platform and conference announcements often coincided with negative next-day moves, while the earnings release with larger loss also saw a sharp decline, showing a tendency for weak or contrarian price reactions to news.
Over the last month, Calidi has repeatedly highlighted its RedTail virotherapy platform and lead asset CLD-401 across multiple conferences (AACR, ASGCT, IOVC), consistently signaling an IND by end of 2026. A prior AACR preview on Apr 1 drew a modest +1.59% move, but subsequent similar updates on Apr 2, 7, and 14 saw declines. The Mar 27 earnings release, noting a $25.6M 2025 net loss, also triggered an -11.67% reaction, underscoring sensitivity to financial strain alongside scientific progress.
Market Pulse Summary
This announcement highlights new AACR data on Calidi’s RedTail virotherapy platform and its in situ T‑cell engager strategy, including CLD‑401 and a TROP2‑targeting CLD‑501 candidate, with an IND expected by the end of 2026. It builds on a series of recent conference previews emphasizing tumor‑restricted cytokine and engager expression. Against a backdrop of prior losses and recent financings, key watch points remain progress toward IND submission, partnering activity, and future clinical readouts.
Key Terms
tumor microenvironment medical
t-cell engagers medical
virotherapy medical
il-15 superagonist medical
trop2 medical
epcam medical
nectin-4 medical
AI-generated analysis. Not financial advice.
SAN DIEGO, April 20, 2026 (GLOBE NEWSWIRE) -- Calidi Biotherapeutics, Inc. (NYSE American: CLDI) (“Calidi” or the “Company”), a biotechnology company pioneering the development of targeted genetic medicines, presented new data at the American Association of Cancer Research (AACR) annual meeting in San Diego, California on April 19, 2026. The Company demonstrated new data on its approach of simultaneously activating T-cells while inducing the expression of T-cell engagers specifically in situ in the tumor microenvironment (“TME”). The poster is available here.
RedTail is Calidi’s systemically delivered virotherapy platform designed to selectively target tumors, remodel the TME, and enable high-level expression of therapeutic genetic payloads directly at the tumor site while limiting peripheral exposure. CLD-401, the lead candidate derived from the RedTail platform, is engineered to express high levels of IL-15 superagonist (“IL-15 SA”), a known CD8⁺ T-cell, NK cell, and gamma delta (γδ) T-cell activator, in the TME. The Company expects to file an IND for CLD-401 by the end of 2026.
Data presented at the AACR meeting showcased RedTail viruses that can express both a functional T-cell engager, capable of binding targeted solid tumor cells, and IL-15 SA at high concentrations, allowing for simultaneous T-cell activation and high expression in situ of a T-cell engager. T-cell engagers have shown exceptional efficacy in hematological malignancies but have failed to show clinical benefit in solid tumors where the TME inhibits immune cell infiltration and T-cell activity. By remodeling the TME and driving T-cell activation in concert with expression of a T-cell engager, RedTail is designed to overcome these historical limitations.
The Company is developing CLD-501, a lead candidate targeting TROP2, a cell-surface glycoprotein. TROP2 expression in normal tissue and the high potential for off-tumor / on-target toxicity has made it a difficult target for T-cell engagers. The RedTail approach confines expression of the T-cell engager to the TME, limiting off-tumor interactions. The Company is pursuing additional T-cell engager targets like EGFR, EpCAM, and Nectin-4.
“Data presented at AACR show the advances we have made with the RedTail platform, our first lead, CLD-401, and our progress in addressing a central challenge in immuno-oncology: how to deliver tumor-specific T-cell engagers effectively in solid tumors” said Eric Poma, PhD, Chief Executive Officer of Calidi. “We believe RedTail represents a major breakthrough in the ability to deliver genetic payloads, including in situ T-cell engagers in a targeted fashion to distal sites of disease through systemic administration.”
“The data we presented at AACR highlight the ability of the RedTail platform to functionally overexpress complex biologics including cytokines and T-cell engagers, and profoundly alter the tumor microenvironment” said Antonio F. Santidrian, PhD, Chief Scientific Officer and Head of Technical Operations at Calidi. “This tumor-restricted approach enables targeting of antigens such as TROP2, something that has not been effectively accomplished with existing T-cell engager therapies.
The Company continues to expand the functionality of the RedTail platform and is also actively pursuing strategic partnerships to accelerate clinical development and broaden the impact of its RedTail platform.
About Calidi
Calidi Biotherapeutics (NYSE American: CLDI) is a biotechnology company pioneering the development of targeted therapies with the potential to deliver genetic medicines to distal sites of disease. The company’s proprietary RedTail platform features an engineered enveloped oncolytic virus designed for systemic delivery and targeting of metastatic sites. This advanced enveloped technology is intended to shield the virus from immune clearance, allowing virotherapy to effectively reach tumor sites, induce tumor lysis, and deliver potent genetic medicine(s) to metastatic locations.
CLD-401, the lead candidate from the RedTail platform, currently in IND-enabling studies, targets non-small cell lung cancer, head and neck cancer, and other tumor types with high unmet medical need. Calidi continues to advance its pipeline utilizing the RedTail platform including its novel approach to incorporate in situ T-cell engagers in solid tumors.
Calidi Biotherapeutics is headquartered in San Diego, California. For more information, please visit www.calidibio.com or view Calidi’s Corporate Presentation here.
Forward-Looking Statements
This press release may contain forward-looking statements for purposes of the “safe harbor” provisions under the United States Private Securities Litigation Reform Act of 1995. Terms such as “anticipates,” “believe,” “continue,” “could,” “estimate,” “expect,” “intends,” “may,” “might,” “plan,” “possible,” “potential,” “predicts,” “project,” “should,” “towards,” “would” as well as similar terms, are forward-looking in nature, but the absence of these words does not mean that a statement is not forward-looking. These forward-looking statements include, but are not limited to, statements concerning key milestones, including certain pre-clinical data, planned clinical trials, and statements relating to the safety and efficacy of Calidi’s therapeutic candidates in development. Any forward-looking statements contained in this discussion are based on Calidi’s current expectations and beliefs concerning future developments and their potential effects and are subject to multiple risks and uncertainties that could cause actual results to differ materially and adversely from those set forth or implied in such forward-looking statements. These risks and uncertainties include, but are not limited to, the risk that Calidi is not able to raise sufficient capital to support its current and anticipated clinical trials, the risk that early results of clinical trials do not necessarily predict final results and that one or more of the clinical outcomes may materially change following more comprehensive review of the data, and as more patient data becomes available, the risk that Calidi may not receive FDA approval for some or all of its therapeutic candidates. Other risks and uncertainties are set forth in the section entitled “Risk Factors” and “Cautionary Note Regarding Forward-Looking Statements” in the Company’s annual report filed with the SEC on Form 10-K on March 27, 2026, as may be amended or supplemented by other reports we file with the SEC from time to time. We disclaim any obligation to update any forward-looking statement to reflect events or circumstances after the date of this press release or to reflect the occurrence of unanticipated events.
For Investors:
Dave Gentry, CEO
RedChip Companies, Inc.
1-407-644-4256
CLDI@redchip.com
