R&D expenses were $14.7 million and $40.8 million for the three months and year ended December 31, 2021, respectively, as compared to $4.2 million and $15.4 million for the same periods in 2020, respectively. The increases were primarily driven by the ongoing Phase 3 pivotal trial in dedifferentiated liposarcoma (MANTRA) and Phase 2 tumor-agnostic basket trial (MANTRA-2), as well as personnel costs. Non-cash stock-based compensation expenses included in R&D expenses were approximately $1.1 million and $2.5 million in the three months and year ended December 31, 2021, respectively, as compared to $0.2 million and $0.6 million in the same periods in 2020, respectively.
General and administrative (G&A) expenses were $3.4 million and $10.7 million for the three months and year ended December 31, 2021, respectively, as compared to $1.3 million and $3.6 million for the same periods in 2020, respectively. The increases were primarily due to higher costs associated with Rain becoming a public company, including the costs of director and officer insurance, personnel, legal, outside consulting, and accounting and audit fees. Non-cash stock-based compensation expense included in G&A expenses were approximately $0.2 million and $0.6 million for the three months and year ended December 31, 2021, respectively, as compared to $0.1 million and $0.3 million for the same periods in 2020, respectively.
Total non-cash stock-based compensation expenses were approximately $1.3 million and $3.1 million for the three months and year ended December 31, 2021, respectively, as compared to $0.3 million and $0.9 million for the same periods in 2020, respectively.
As of December 31, 2021, Rain had $140.2 million in cash, cash equivalents and short-term investments. Rain anticipates that its year-end cash position will provide runway into the first half of 2024, including completion of all its ongoing and planned clinical trials with an ample cash cushion for the Phase 3 MANTRA trial in liposarcoma.
As of December 31, 2021, Rain had approximately 26.5 million shares of common stock outstanding.
Fourth Quarter 2021 Results Conference Call and Webcast Details
The management of Rain Therapeutics will host a conference call and webcast for the investment community today, March 3, 2022 at 1:30 pm PT (4:30 pm ET). A live webcast may be accessed here: https://edge.media-server.com/mmc/p/c4ut4zai. The conference call can be accessed by dialing (833) 562-0127. The passcode for the conference call is 4729972.
Replay of the call will be available by visiting the “Events” section of the Rain website after the conclusion of the presentation and will be archived on the Rain website for 30 days.
About Milademetan
Milademetan (also known as RAIN-32) is a small molecule, oral inhibitor of MDM2, which is oncogenic in numerous cancers. Milademetan has already demonstrated antitumor activity in an MDM2-amplified subtype of liposarcoma (LPS) and other solid tumors in a Phase 1 clinical trial, supported by a rationally-designed dosing schedule to mitigate safety concerns and widen the therapeutic window of MDM2 inhibition. Milademetan is being evaluated in an ongoing Phase 3 clinical trial in patients with LPS (MANTRA), as well as a Phase 2 tumor-agnostic basket trial in certain solid tumors (MANTRA-2). Rain anticipates commencing a Phase 2 clinical trial of milademetan (MANTRA-3), for the treatment of patients with wildtype p53 Merkel cell carcinoma who are also refractory to immune checkpoint inhibition (ICI), in the second half of 2022, as well as a Phase 1 clinical trial to evaluate the safety, tolerability and efficacy of milademetan in combination with Roche’s atezolizumab in patients with loss of cyclin-dependent kinase inhibitor 2A (CDKN2A) and wildtype p53 advanced solid tumors (MANTRA-4), in the second half of 2022. Milademetan has received Orphan Drug Designation from the U.S. Food and Drug Administration (FDA) for patients with LPS.
