Oncternal Therapeutics to Present Cirmtuzumab Clinical Data Updates at 2019 ASH Annual Meeting and San Antonio Breast Cancer Symposium

Oncternal Therapeutics, Inc. (Nasdaq: ONCT), a clinical-stage biopharmaceutical company focused on the development of novel oncology therapies, today announced that clinical data updates for cirmtuzumab, its investigational anti-ROR1 monoclonal antibody, will be presented at upcoming medical conferences.

Interim data from the ongoing Phase 1/2 clinical study of cirmtuzumab in combination with ibrutinib in patients with chronic lymphocytic leukemia (CLL) or mantle cell lymphoma (MCL) will be presented at the American Society of Hematology (ASH) Annual Meeting that will be held December 7-10, 2019, in Orlando, FL.

• Abstract: Cirmtuzumab, a ROR1 Targeted mAb, Reverses Cancer Stemness, and Its Combination with Ibrutinib Is Safe and Effective: Planned Analysis of the CIRLL Phase 1/2 Trial for CLL and MCL (abstract #1755)
• Session Name: 642. CLL: Therapy, excluding Transplantation: Poster I
• Session Date: Saturday, December 7, 2019
• Session Time: 5:30 PM - 7:30 PM
• Location: Hall B, Level 2 (Orange County Convention Center)

Initial data from the ongoing, investigator-sponsored Phase 1 clinical study of cirmtuzumab in combination with paclitaxel in patients with Her2 negative, metastatic or locally advanced unresectable breast cancer will be presented at the San Antonio Breast Cancer Symposium (SABCS) that will be held December 10-14, 2019, in San Antonio, TX.

• Abstract: Phase 1b Trial of Cirmtuzumab and Paclitaxel for Locally Advanced, Unresectable and Metastatic Breast Cancer
• Session Name: PS3. Poster Session 3
• Session Date: Thursday, December 12, 2019
• Session Time: 5:00 PM - 7:00 PM
• Location: Hall 1 (Henry B. Gonzalez Convention Center)

About Cirmtuzumab

Cirmtuzumab is an investigational, potentially first-in-class monoclonal antibody targeting ROR1, or Receptor tyrosine kinase-like Orphan Receptor 1. Cirmtuzumab is currently being evaluated in a Phase 1/2 clinical trial in combination with ibrutinib for the treatment of CLL and MCL, in a collaboration with the University of California San Diego School of Medicine and the California Institute for Regenerative Medicine (CIRM). In addition, an investigator-initiated Phase 1 clinical trial of cirmtuzumab in combination with paclitaxel for women with metastatic breast cancer is being conducted at the UC San Diego School of Medicine. CIRM has also provided funding to support development programs for cirmtuzumab and a CAR-T therapy that targets ROR1, which is currently in preclinical development as a potential treatment for hematologic cancers and solid tumors.

ROR1 is a potentially attractive target for cancer therapy because it is an oncofetal antigen ? a protein that confers a survival and fitness advantage when reactivated and expressed by tumor cells. When expressed by hematologic malignancies such as CLL and MCL, ROR1 acts as a receptor for the tumor growth factor Wnt5a. Researchers at the UC San Diego School of Medicine discovered that targeting a critical epitope on ROR1 was key to inhibiting Wnt5a activation, specifically targeting ROR1 expressing tumors. This led to the development of cirmtuzumab that binds this critical epitope of ROR1, which is highly expressed on many different cancers but not on normal tissues. Preclinical data showed that when cirmtuzumab bound to ROR1, it blocked Wnt5a signaling, inhibited tumor cell proliferation, migration and survival, and induced differentiation of the tumor cells. Cirmtuzumab is in clinical development and has not been approved by the U.S. Food and Drug Administration for any indication.

About Oncternal Therapeutics

Oncternal Therapeutics is a clinical-stage biopharmaceutical company focused on the development of novel oncology therapies for the treatment of cancers with critical unmet medical need. Oncternal focuses drug development on promising yet untapped biological pathways implicated in cancer generation or progression. The pipeline includes cirmtuzumab, an investigational monoclonal antibody designed to inhibit the ROR1 pathway, a type I tyrosine kinase-like orphan receptor, that is being evaluated in a Phase 1/2 clinical trial in combination with ibrutinib for the treatment of chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), and TK216, an investigational targeted small-molecule inhibitor of the E26 transformation specific (ETS) family of oncoproteins, that is being evaluated in a Phase 1 clinical trial for patients with Ewing sarcoma alone and in combination with vincristine chemotherapy. In addition, Oncternal has a program to develop a CAR-T therapy that targets ROR1, which is currently in preclinical development as a potential treatment for hematologic cancers and solid tumors. More information is available at www.oncternal.com.

Forward-Looking Information

Oncternal cautions you that statements included in this press release that are not a description of historical facts are forward-looking statements. In some cases, you can identify forward-looking statements by terms such as "may," "will," "should," "expect," "plan," "anticipate," "could," "intend," "target," "project," "contemplates," "believes," "estimates," "predicts," "potential" or "continue" or the negatives of these terms or other similar expressions. These statements are based on the Company's current beliefs and expectations. Forward looking statements include statements regarding the safety, efficacy or ability of cirmtuzumab to reverse cancer stemness. The inclusion of forward-looking statements should not be regarded as a representation by Oncternal that any of its plans will be achieved. Actual results may differ from those set forth in this release due to the risks and uncertainties inherent in Oncternal's business, including, without limitation: uncertainties associated with the clinical development and process for obtaining regulatory approval of cirmtuzumab and Oncternal's other product candidates, including potential delays in the commencement, enrollment and completion of clinical trials; the Company's dependence on the success of cirmtuzumab and its other product development programs; the risk that interim results of a clinical trial do not necessarily predict final results and that one or more of the clinical outcomes may materially change as patient enrollment continues, following more comprehensive reviews of the data, and as more patient data become available; the risk that unforeseen adverse reactions or side effects may occur in the course of developing and testing product candidates such as cirmtuzumab and Oncternal's other product candidates; the Company's limited operating history and the fact that it has incurred significant losses, and expects to continue to incur significant losses for the foreseeable future; risks related to the inability of Oncternal to obtain sufficient additional capital to continue to advance the development of cirmtuzumab and its other product candidates; and other risks described in the Company's prior press releases as well as in public periodic filings with the U.S. Securities & Exchange Commission. All forward-looking statements in this press release are current only as of the date hereof and, except as required by applicable law, Oncternal undertakes no obligation to revise or update any forward-looking statement, or to make any other forward-looking statements, whether as a result of new information, future events or otherwise. All forward-looking statements are qualified in their entirety by this cautionary statement. This caution is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.