RAIN Rain Oncology Inc

Rain Therapeutics Inc. (NasdaqGS: RAIN) (“Rain”), a late-stage company developing precision oncology therapeutics, today announced non-clinical data on its oral mouse double minute 2 (“MDM2”) inhibitor, milademetan (RAIN-32), presented at the IASLC 2021 World Conference on Lung Cancer (#WCLC21) hosted by the International Association for the Study of Lung Cancer and held virtually September 8-14, 2021.

Key findings from Rain’s poster presentation include:

• Milademetan treatment showed differential sensitivity in mesothelioma models with cyclin dependent kinase inhibitor 2A (CDKN2A) loss and wild-type p53 compared to p53 deficient models.
• Milademetan treatment increased p53 protein levels in the MDM2 inhibitor-sensitive cell lines, demonstrating target engagement and a p53-mediated mechanism of action.
• Oral milademetan significantly reduced the growth of multiple MDM2 inhibitor-sensitive MPM xenografts.

“MPM is an attractive target for MDM2 inhibition given the genetic profile of simultaneous low p53 mutation rate and high rate of CDKN2A loss via genetic deletion and other mechanisms,” said Robert Doebele, M.D., Ph.D., co-founder and chief scientific officer of Rain. “There is an unmet medical need in MPM patients after progressing on anti-PD1-based immunotherapies or cytotoxic agents, and this provides a potential opportunity for a targeted therapeutic strategy with milademetan in this setting.”

A copy of the presentation will be available by visiting the “Events & Presentations” section of the Rain website after the conclusion of the conference and will be archived on the Rain website for 30 days.

About Milademetan Milademetan is a small molecule, oral inhibitor of MDM2, which is oncogenic in numerous cancers. Milademetan has already demonstrated meaningful antitumor activity in an MDM2-amplified subtype of liposarcoma (“LPS”) and other solid tumors in a Phase 1 clinical trial, validating a rationally-designed dosing schedule to mitigate safety concerns and widen the therapeutic window of MDM2 inhibition. In addition to the ongoing Phase 3 clinical trial evaluating milademetan in patients with LPS, Rain Therapeutics anticipates commencing a Phase 2 tumor-agnostic basket trial in certain solid tumors in the second half of 2021 and a Phase 2 trial in intimal sarcoma by early 2022. Milademetan has received U.S. Food and Drug Administration Orphan Drug Designation for patients with LPS.

About Rain Therapeutics Inc.Rain Therapeutics Inc. is a late-stage precision oncology company developing therapies that target oncogenic drivers for which it is able to genetically select patients it believes will most likely benefit. This approach includes using a tumor-agnostic strategy to select patients based on their tumors’ underlying genetics rather than histology. Rain’s lead product candidate, milademetan, is a small molecule, oral inhibitor of MDM2, which is oncogenic in numerous cancers. In addition to milademetan, Rain is also developing a preclinical program that is focused on inducing synthetic lethality in cancer cells by inhibiting RAD52.

Forward Looking StatementsStatements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements include statements regarding, among other things, the results, conduct, progress and timing of Rain’s ongoing and planned trials for milademetan, the opportunity for milademetan in MPM patients and the sensitivity and efficacy of milademetan. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Words such as “plans,” “will,” “anticipates,” “goal,” “potential” and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based upon Rain’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. Actual results could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, which include, without limitation, risks and uncertainties associated with Rain’s business in general, our substantial dependence on the success of its lead product candidate, lack of success in its clinical trials, difficulties in enrolling patients, competition from competing products, the impact of the COVID-19 pandemic, and the other risks and uncertainties described in Rain’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2021 and subsequent filings with the Securities and Exchange Commission. All forward-looking statements contained in this press release speak only as of the date on which they were made and are based on management’s assumptions and estimates as of such date. Rain undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made, except as required by law.

Media ContactJordyn TemperatoLifeSci Communications+1.646.876.5196jtemperato@lifescicomms.com