LeonaBio Inc. Announces 500th ELAINE‑3 Enrollment; Series A Warrants Now Exercisable

What Happened

• On August 26, 2026, LeonaBio, Inc. (LONA) filed a Form 8‑K (Item 8.01) announcing that it enrolled the 500th subject in its Phase 3 ELAINE‑3 trial (NCT05696626) of lasofoxifene plus abemaciclib for ER+/HER2‑, ESR1‑mutated metastatic breast cancer following progression on aromatase inhibitors and CDK4/6 inhibitors.
• The 8‑K also confirms that this filing constitutes the public announcement that triggers the eligibility for holders to exercise certain Series A Common Warrants issued in the Company’s December 2025 private placement.

Key Details

• Enrollment milestone: 500th subject in ELAINE‑3 announced on August 26, 2026.
• Series A Common Warrants: 23,031,494 warrants were issued in the December 2025 private placement.
• Exercise terms: $6.35 per share cash exercise price (cashless net exercise if resale registration unavailable). Warrants become exercisable after the defined initial exercise date (established by the filing) and will remain exercisable for 30 days thereafter, with the latest possible termination no later than November 30, 2026.
• Potential proceeds: If all Series A Common Warrants are exercised for cash, the Company would receive approximately $146.2 million.

Why It Matters

• The 500th enrollment is a key Phase 3 milestone that advances LeonaBio’s development program and satisfied the filing condition that makes the Series A warrants exercisable.
• Exercising the warrants could provide up to ~$146.2M in additional capital — important for funding operations or development — but exercise may be cashless if resale registration is unavailable, which would reduce or eliminate cash proceeds and dilute existing shareholders.
• Investors should note the timing window for exercise (initial exercise date triggered by this announcement and a limited 30‑day exercise period thereafter, no later than Nov 30, 2026) and the forward‑looking risk disclosures in the filing.