Elysium Therapeutics is advancing its Synthetic Opioid Overdose Prevention and Reversal (SOOPR) program to address fentanyl rebound, a phenomenon where existing opioid antagonists lose effect before the opioid is fully metabolized, leading to re-narcotization and fatal overdoses. The company is developing a longer-acting rescue agent to improve survival outcomes. Expansion plans include collaboration deals and funding to accelerate development amidst enduring opioid crisis concerns.