EXHIBIT 10.15
NYB Holdings Ltd
FORM OF LOCK-UP AGREEMENT
[●], 2026
[Shareholder]
Re:
Lock-Up Agreement for Company Shares
Ladies and Gentlemen:
This letter (this “Letter Agreement”) is being delivered to you in accordance with that certain Business Combination Agreement (as may be amended, restated or supplemented from time to time, the “Business Combination Agreement”) dated October 2, 2025, entered into by and among NYB Holdings Limited, a Cayman Islands exempted company limited by shares (“PubCo”), RF Acquisition Corp II., a Delaware corporation (“SPAC”), NYB Pte. Ltd., a Singapore private company limited by shares (“Amalgamation Sub”) and Nanyang Biologics Pte. Ltd., a Singapore private company limited by shares and a wholly owned subsidiary of PubCo (the “Company”), pursuant to which, among other things, Amalgamation Sub will merge with and into the Company (the “Amalgamation”), with the Company being the surviving entity and becoming a wholly owned subsidiary of PubCo, and PubCo will merge with and into SPAC (the “Merger” and together with the Amalgamation, the “Mergers”), with P
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