Onconova Therapeutics Presents Preclinical Data on Narazaciclib at the 17th International Conference on Malignant Lymphoma

Narazaciclib demonstrated significant synergistic anti-cancer activity in multiple in vivo models of mantle cell lymphoma (MCL) when combined with ibrutinib, the current standard-of-care

NEWTOWN, Pa., June 14, 2023 (GLOBE NEWSWIRE) — Onconova Therapeutics, Inc. (NASDAQ: ONTX), (“Onconova” or “the Company”), a clinical-stage biopharmaceutical company focused on discovering and developing novel products for patients with cancer, today presented preclinical data on narazaciclib at the 17^th International Conference on Malignant Lymphoma (ICML), which is taking place in Lugano, Switzerland, through June 17, 2023.

Data from the Josep Carreras Leukaemia Research Institute expanded on a prior presentation at the recent American Association for Cancer Research (AACR) Annual Meeting, showing that narazaciclib’s antitumor activity against mantle cell lymphoma (MCL) cell lines was superior to that of the FDA-approved CDK 4/6 inhibitors palbociclib and ribociclib, and similar to that of the FDA-approved CDK 4/6 inhibitor abemaciclib. Combining narazaciclib with the FDA-approved Bruton’s tyrosine kinase inhibitor ibrutinib led to synergistic increases in antitumor activity against both ibrutinib-sensitive and ibrutinib-resistant MCL cell lines. In addition, treatment with narazaciclib combined with ibrutinib led to significant inhibition of tumor growth and significant reductions in malignant B cell infiltration into the bone marrow in multiple chicken embryo chorioallantoic membrane xenograft models of MCL.

Steven M. Fruchtman, M.D., President and Chief Executive Officer of Onconova, commented, “The data being presented at ICML provide further evidence of narazaciclib’s potential to combine synergistically with a wide range of therapeutic classes, derived from its ability to inhibit CDK 4, 6, and additional kinases involved in cancer cell survival and metastasis. This differentiated kinase inhibitory profile also confers expansive therapeutic potential across a variety of indications and may enable narazaciclib to overcome the efficacy limitations and safety concerns of currently marketed CDK 4/6 inhibitors. Given ibrutinib is the standard-of-care in mantle cell lymphoma, the preclinical results showing narazaciclib improving antitumor responses in combination represents a promising development that speaks to its potential therapeutic utility in this high unmet need indication. We look forward to discussing our data throughout ICML as we continue to evaluate additional opportunities for clinical studies with narazaciclib and advance our ongoing Phase 1/2a combination trial of narazaciclib plus estrogen blockade in endometrial cancer.”

The ICML poster, titled, “Prolonged cell cycle arrest by the CDK 4/6 antagonist narazaciclib restores ibrutinib response in preclinical models of BTKi-resistant mantle cell lymphoma,” is currently available to registered attendees of ICML via the conference’s e-poster gallery. The poster will also be displayed during the in-person poster sessions being held throughout the conference. A copy of the poster will be available on the “Scientific Presentations” section of the Onconova website following the conclusion of the conference.

About Onconova Therapeutics, Inc.

Onconova Therapeutics is a clinical-stage biopharmaceutical company focused on discovering and developing novel products for patients with cancer. The Company has proprietary targeted anti-cancer agents designed to disrupt specific cellular pathways that are important for cancer cell proliferation.

Onconova’s novel, proprietary multi-kinase inhibitor narazaciclib (formerly ON 123300) is being evaluated in a combination trial with estrogen blockade in advanced endometrial cancer. Based on preclinical and clinical studies of CDK 4/6 inhibitors, Onconova is also evaluating opportunities for combination studies with narazaciclib in additional indications.

Onconova’s product candidate rigosertib is being studied in multiple investigator-sponsored studies. These studies include a dose-escalation and expansion Phase 1/2a study of oral rigosertib in combination with nivolumab in patients with KRAS+ non-small cell lung cancer, a Phase 2 program evaluating rigosertib monotherapy in advanced squamous cell carcinoma complicating recessive dystrophic epidermolysis bullosa (RDEB-associated SCC), and a Phase 2 trial evaluating rigosertib in combination with pembrolizumab in patients with metastatic melanoma.

For more information, please visit www.onconova.com.

Forward Looking Statements

Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, Section 21E of the Securities Exchange Act of 1934, as amended, and the Private Securities Litigation Reform Act of 1995, and involve risks and uncertainties. These statements relate to Onconova’s expectations regarding its clinical development and trials, its product candidates, its business and financial position. Onconova has attempted to identify forward-looking statements by terminology including “believes,” “estimates,” “anticipates,” “expects,” “plans,” “intends,” “may,” “could,” “might,” “will,” “should,” “preliminary,” “encouraging,” “approximately” or other words that convey uncertainty of future events or outcomes. Although Onconova believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including the success and timing of Onconova’s clinical trials, investigator-initiated trials and regulatory agency and institutional review board approvals of protocols, Onconova’s collaborations, market conditions and those discussed under the heading “Risk Factors” in Onconova’s most recent Annual Report on Form 10-K and quarterly reports on Form 10-Q. Any forward-looking statements contained in this release speak only as of its date. Onconova undertakes no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events.

Company Contact:
Mark Guerin
Onconova Therapeutics, Inc.
267-759-3680
ir@onconova.us
https://www.onconova.com/contact/

Investor Contact:
Bruce Mackle
LifeSci Advisors, LLC
646-889-1200
bmackle@lifesciadvisors.com