– Company plans to suspend enrollment in the ongoing milademetan Phase 2 MANTRA-2 basket trial and terminate plans for its Phase 1/2 MANTRA-4 combination trial –

– Evaluation of outcomes from the MANTRA Phase 3 milademetan trial in dedifferentiated liposarcoma (DD LPS) are ongoing with data and findings to be presented at a medical conference in 4Q23 –

– Company continuing to evaluate opportunities for expansion of its pipeline across precision oncology strategies –

– Overall workforce reduction of approximately 65% of the Company's employees; with a transition of Chief Medical Officer (CMO) responsibilities –

– Year-end 2023 cash guidance of $75-80mm, with cash runway to year-end 2026 –

NEWARK, Calif., May 30, 2023 (GLOBE NEWSWIRE) -- Rain Oncology Inc. (NASDAQ:RAIN), (Rain), a clinical stage company developing precision oncology therapeutics today announced an update to its clinical strategy for milademetan, its small molecule inhibitor of the MDM2-p53 complex, to optimize Company resources. The Company is focused on reducing its cash burn with the expectation to extend cash runway to year-end 2026.

"We are working diligently, as additional information continues to come in, to analyze and understand the outcomes in the Phase 3 MANTRA study in DD LPS," said Avanish Vellanki, co-founder and chief executive officer of Rain. "It is imperative we understand those outcomes before allocating further capital to the milademetan program, with corporate expenses to be greatly reduced to maximize optionality for Rain. In the near-term, Rain plans to suspend enrollment in our Phase 2 MANTRA-2 basket trial and terminate plans to initiate the planned Phase 1/2 MANTRA-4 combination trial."

Mr. Vellanki continued, "Rain will make meaningful reductions in our workforce. It was the tremendous effort of our Rain colleagues that allowed us to execute on MANTRA ahead of schedule despite the extreme pressures of the pandemic. I want to sincerely thank every Rain colleague who has been impacted by this realignment. Their contributions have, without a doubt, brought us closer to better understanding the milademetan program, and towards Rain achieving its mission for patients."

The Company thanks Dr. Richard Bryce, MBCHB, MRCGP, MFPM, Rain's CMO, for his tremendous efforts with the MANTRA study, and notes a planned transition from CMO to an ongoing advisory role, with Rain's cofounder, President and chief scientific officer, Dr. Robert Doebele, MD, PhD, to assume the role of CMO.

Strategic Update Summary:

• Continue evaluation of the totality of the pivotal Phase 3 MANTRA data
  • Planned data presentation at a medical conference in 4Q 2023
• Suspend enrollment of additional patients into the MANTRA-2 MDM2 amplified basket study
  • Planned MANTRA-2 clinical update at a medical conference in 4Q 2023
• Terminate plans for the MANTRA-4 clinical study in patients with CDKN2A-loss, p53 wildtype advanced solid tumors
• Evaluate avenues to enhance the pipeline through precision oncology program acquisition
• Streamline internal resources to execute on realigned strategy
  • Reducing full-time employees by approximately 65%, combined with careful workforce management, including employee attrition
  • Transitioning CMO responsibilities from Dr. Richard Bryce to Dr. Robert Doebele
    • Year-end 2023 cash guidance of $75-$80 million, and cash runway to year-end 2026