Pyxis Oncology to Present New Preclinical Data Supporting Development of First-In-Concept ADC Targeting EDB+FN in Tumor Microenvironment at AACR 2025

Rhea-AI Summary

Pyxis Oncology (NASDAQ: PYXS) announced new preclinical data for micvotabart pelidotin (MICVO), their first-in-concept antibody-drug conjugate targeting EDB+FN in the tumor microenvironment. The data will be presented at AACR 2025 in Chicago.

Key highlights include:

• Patient-derived xenograft mouse models showed gene signatures associated with MICVO efficacy
• Combination of MICVO analog with anti-PD-1 therapy demonstrated enhanced tumor regression
• Phase 1 studies showed significant tumor regression across multiple tumor types

The company is advancing MICVO in clinical trials:

• Phase 1 monotherapy expansion for recurrent/metastatic head and neck cancer with preliminary data expected in 2H2025 and 1H2026
• Phase 1/2 combination study with Keytruda® with preliminary data expected in 2H2025

MICVO has received Fast Track Designation from the FDA for treating adult patients with recurrent/metastatic head and neck squamous cell carcinoma after platinum-based chemotherapy and anti-PD-(L)1 therapy.

Positive

• Fast Track Designation received from FDA
• Positive preclinical data showing enhanced tumor regression in combination therapy
• Multiple ongoing clinical trials with data readouts expected in 2025-2026
• Demonstrated significant tumor regression across multiple tumor types in Phase 1

Negative

• Final clinical trial results still pending
• Commercial launch timeline uncertain

Expression data from patient-derived xenograft (PDX) mouse models exposed to micvotabart pelidotin (MICVO) indicate gene signatures associated with efficacy, deepening understanding of MOA and potential patient response

Combination of a mouse analog of MICVO and a mouse anti-PD-1 therapy in a syngeneic model resulted in significantly greater tumor regression than either treatment alone

Company advances MICVO into monotherapy and combination clinical trials with Merck’s anti-PD-1 therapy, Keytruda^® (pembrolizumab), targeting recurrent and metastatic head and neck squamous cell carcinoma; preliminary data expected in 2H2025 and 1H2026

BOSTON, March 25, 2025 (GLOBE NEWSWIRE) -- Pyxis Oncology, Inc. (Nasdaq: PYXS), a clinical-stage company developing next-generation therapeutics for difficult-to-treat cancers, announced today that the Company will present new, positive preclinical data highlighting the potential of micvotabart pelidotin (MICVO, formerly referred to as PYX-201), a first-in-concept antibody-drug conjugate (ADC) that targets EDB+FN, a non-cellular structural component of the tumor extra-cellular matrix. These data will be presented in two poster sessions at the American Association for Cancer Research (AACR) Annual Meeting in Chicago, Illinois, held from April 25 to 30, 2025.

"We are thrilled to present new preclinical data at AACR25 that further elucidate the innovative mechanism of action of MICVO, our first-in-concept EDB+FN targeting ADC, which leverages a unique non-cellular mechanism to drive anti-tumor activity,” said Lara S. Sullivan, M.D., President, Chief Executive Officer and Chief Medical Officer of Pyxis Oncology. “As we advance MICVO both as a monotherapy and in combination with anti-PD-1 therapy in the clinic, we remain confident in our multi-pronged development strategy in recurrent and metastatic head and neck squamous cell carcinoma where we believe altering the extra-cellular matrix may effectively address a main cause of resistance to other therapies.”

In a previous Phase 1 dose escalation study, it was established that MICVO has profound monotherapy effect on multiple tumor types with significant tumor regression. The Company has initiated the Part 2 monotherapy expansion cohorts of the ongoing Phase 1 clinical trial to evaluate MICVO in 2L and 3L recurrent and metastatic head and neck squamous cell carcinoma (R/M HNSCC) patients who have received prior platinum and PD-1 inhibitor therapy, and 2L and 3L R/M HNSCC patients who have received prior EGFRi and PD-1 inhibitor therapy.

Preliminary data from patients who have received prior platinum and PD-1 inhibitor therapy are expected in the second half of 2025 and preliminary data from patients who have received prior EGFRi and PD-1 inhibitor therapy are expected in the first half of 2026. Additionally, the Company initiated a Phase 1/2 combination study of MICVO and Merck’s anti-PD-1 therapy, KEYTRUDA^® (pembrolizumab), in patients with R/M HNSCC and other advanced solid tumors, with the goal of identifying the recommended Phase 2 dose by mid-year 2025 and a readout of preliminary data in the second half of 2025.

MICVO received Fast Track Designation from the U.S. Food and Drug Administration for the treatment of adult patients with R/M HNSCC whose disease has progressed following treatment with platinum-based chemotherapy and an anti-PD-(L)1 therapy.

Presentation details at AACR are listed below, with all times in Central Time (CT):

•	Title: Evaluation of PYX-201, an EDB+FN-targeting ADC, in a comprehensive PDX mini-trial study enables identification of gene signatures associated with anti-tumor activity
		Session Category: Experimental and Molecular Therapeutics Session Title: Therapeutic Approaches to Attack the Tumor Microenvironment Session Date and Time: Monday, April 28, 2025, 2:00 PM – 5:00 PM Location: Poster Section 24 Poster Board Number: 5 Published Abstract Number: 3120
•	Title: The combination of anti-PD1 and a mouse analog of PYX-201, an antibody- drug conjugate targeting the extra-domain B splice variant of fibronectin (EDB+FN), shows greater anti-tumor efficacy than either treatment alone
		Session Category: Experimental and Molecular Therapeutics Session Title: Therapeutic Approaches to Attack the Tumor    Microenvironment Session Date and Time: Monday, April 28, 2025, 2:00 PM – 5:00 PM Location: Poster Section 24 Poster Board Number: 4 Published Abstract Number: 3137

KEYTRUDA^® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

About Pyxis Oncology, Inc.
Pyxis Oncology, Inc. is a clinical stage company focused on defeating difficult-to-treat cancers. The company is efficiently building next generation therapeutics that hold the potential for monotherapy and combination indications. The lead product candidate, micvotabart pelidotin (“MICVO” formerly PYX-201), is an antibody-drug conjugate (ADC) that uniquely targets Extradomain-B Fibronectin (EDB+FN), a non-cellular structural component of the tumor extra-cellular matrix. MICVO has been evaluated in ongoing Phase 1 clinical studies in multiple types of solid tumors with a go-forward development focus on treating patients with recurrent and metastatic head and neck squamous cell carcinoma (R/M HNSCC) based on the strength of the HNSCC signal that emerged. MICVO is designed to generate a multi-pronged attack on difficult-to-treat cancers by directly killing cancer cells, reducing extra-cellular matrix density, inhibiting tumor angiogenesis and mobilizing an anti-tumor immune response. 

To learn more, visit www.pyxisoncology.com or follow us on Twitter and LinkedIn.

Forward-Looking Statements
This press release contains forward-looking statements for the purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995 and other federal securities laws. These statements are often identified by the use of words such as “anticipate,” “believe,” “can,” “continue,” “could,” “estimate,” “expect,” “intend,” “likely,” “may,” “might,” “objective,” “ongoing,” “plan,” “potential,” “predict,” “project,” “should,” “to be,” “will,” “would,” or the negative or plural of these words, or similar expressions or variations, although not all forward-looking statements contain these words. We cannot assure you that the events and circumstances reflected in the forward-looking statements will be achieved or occur and actual results could differ materially from those expressed or implied by these forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those identified herein, and those discussed in the section titled “Risk Factors” set forth in Part II, Item 1A. of the Company’s Annual Report on Form 10-K filed with SEC on March 18, 2025, and our other filings, each of which is on file with the Securities and Exchange Commission. These risks are not exhaustive. New risk factors emerge from time to time, and it is not possible for our management to predict all risk factors, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements. In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date hereof and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain, and investors are cautioned not to unduly rely upon these statements. Except as required by law, we undertake no obligation to update any forward-looking statements to reflect events or circumstances after the date of such statements. 

Pyxis Oncology Contact
Pamela Connealy
CFO and COO
ir@pyxisoncology.com

FAQ

What are the key findings from MICVO's preclinical trials for PYXS stock?

Preclinical data showed positive gene signatures in PDX mouse models and enhanced tumor regression when MICVO was combined with anti-PD-1 therapy compared to individual treatments.

When will Pyxis Oncology (PYXS) release preliminary data for MICVO's Phase 1 trials?

Preliminary data for MICVO monotherapy is expected in 2H2025 and 1H2026, while combination therapy data with Keytruda is expected in 2H2025.

What is the significance of MICVO's Fast Track Designation for PYXS?

The FDA's Fast Track Designation expedites the review process for MICVO in treating recurrent/metastatic head and neck cancer patients who progressed after standard therapies.

How is PYXS's MICVO different from other cancer treatments?

MICVO is a first-in-concept ADC targeting EDB+FN, a non-cellular structural component of tumor extra-cellular matrix, offering a unique mechanism to combat therapy resistance.

What clinical trials is PYXS currently conducting for MICVO?

PYXS is conducting Phase 1 monotherapy expansion trials and a Phase 1/2 combination study with Keytruda for recurrent/metastatic head and neck cancer patients.