Offer Letter, dated October 10, 2017, by and between Harmony Biosciences, LLC and Jeffrey Dayno

Bi-monthly base pay of 16,666.66, which when annualized, is equivalent to a base salary of $400,000 per year.

Participation (pro-rated for the calendar year in which your actual start date occurs) in the Harmony Biosciences, LLC Performance Bonus Plan at up to 50% of your base salary based on Company and individual achievement. Your bonus will be based on your performance meeting established individual goals and objectives to support the growth strategy of the Company, as well as the Company’s overall performance.

Equity in the Company’s parent company, Harmony Biosciences II, Inc. (“Parent”) – 850,000 stock options for Parent common stock equal at an exercise price to the greater of $1.00 and the fair market value per share of common stock as of your start date, to be determined by the Parent’s Board of Directors or its Compensation Committee, if applicable. Your Stock Option Agreement shall provide that these stock options (a) time vest at a rate of 20% per annum on each of the first five (5) anniversaries of your start date (provided that you remain an employee in good standing of the Company as of each such anniversary) and (b) accelerate vest upon a Change in Control (as defined in the Parent’s Equity Incentive Plan) provided that you remain an employee in good standing of the Company on the date of such Change in Control.

In consideration of the money you will leave behind at your current employer for annual bonus and LTI you will receive a sign-on bonus of $150,000 (subject to applicable tax and other withholding), paid to you in two installments. The first will be 50% ($75,000) and paid no later than 12/31/2017. The second will be 50% ($75,000) and paid no later than 12/31/2018. Both payments require that you are an active employee in good standing at the time of payment. If you leave the company for any reason within 12 months after receiving the first payment or 6 months after receiving the second sign-on bonus payment, you must pay back the full pre-tax amount of that payment to Harmony Biosciences.

As a full-time Company employee, you will accrue paid vacation and sick leave. Vacation will accrue at a rate of 1.25 days per month, or 15 days per year.

As a full-time employee of the Company, except as expressly provided for above, you are eligible to participate in the provided Harmony Biosciences, LLC Employee Benefit Plans.

This offer is contingent upon successful completion of Harmony’s pre-employment process.