Exhibit 10.10

August 30, 2013

Mr. John Schmid

11385 Mandrake Point

San Diego, CA 92131

Dear John:

We are pleased to offer you a full-time position with Auspex Pharmaceuticals, Inc. as Chief Financial Officer reporting to the Chief Executive Officer. In this role your compensation will be Two Hundred and Seventy-Five Thousand Dollars ($275,000.00) annually, which will be paid in accordance with Auspex’s normal payroll schedule and will be subject to standard payroll deductions and withholdings.

In addition, you are eligible for a bonus opportunity of thirty percent (30%) of your base salary as determined by the Board of Directors.

In this position, your decisions will directly support the direction and growth of Auspex. Considering the stage of Auspex, it is not possible at this time to fully define all of your duties, so Auspex may modify your role as business needs require. Your role, however, is an important one and will require your full-time attention. As such, you agree not to engage in any other employment, occupation or consulting while employed with Auspex that will conflict with your full time responsibilities to Auspex.

Subject to the approval of the Board of Directors, you will be given the opportunity to purchase 650,000 restricted shares of Auspex’s Common Stock at a price of $0.12 per share (the “Restricted Stock”). The Restricted Stock will be subject to an option of the Company to repurchase such shares at the lesser of (i) the purchase price of the Restricted Stock or (ii) the fair market value of the Restricted Stock at the time of repurchase (the “Repurchase Option”). The Restricted Stock will vest ratably and be released from the Repurchase Option on a monthly basis for 48 consecutive months, measured from the date of purchase of the Restricted Stock, so long as you continue in employment during such time. In addition, you are eligible to participate in all of the employee benefits that Auspex offers to its regular full-time employees subject to the terms and conditions of the applicable policy or plan which may be modified from time to time at Auspex’s discretion. A more detailed explanation of the benefits can be provided to you upon request. The Restricted Stock and the purchase of the Restricted Stock will be governed in all respects by the terms and conditions of the Company’s 2010 Equity Incentive Plan and your restricted stock purchase agreement, which you will be required to sign as a condition of purchasing the Restricted Stock.

Should your employment with the Company be terminated without Cause (as defined below) outside of the Change of Control Protection Period (as defined below) and for reasons other than due to your death or disability, then you shall be entitled to receive severance payments equal to the rate of base salary which you were receiving at the time of such termination during the six (6) month period following the date of your termination (the “Severance Period”). These severance payments shall be conditioned upon you (a) furnishing to the Company an executed release of claims in a form acceptable to the Company (the “Release”) within the applicable time period set forth therein, but in no event later than 45 days following your termination date, and (b) allowing the Release to become effective in accordance with its terms. These severance payments shall be paid during the Severance Period on the same schedule after termination as if you were still employed by the Company, in accordance with the Company’s standard payroll practice and which shall be subject to applicable withholding taxes, provided that any payments scheduled to be made to you prior to the Release effective date shall instead accrue and be paid during the first payroll period that commences thereafter.

Mr. John Schmid

August 30, 2013

Page Two

Should your employment with the Company be terminated without Cause (as defined below) within the Change of Control Protection Period (as defined below) and for reasons other than due to your death or disability, then you shall be entitled to receive severance payments equal to the rate of base salary which you were receiving at the time of such termination during the six (6) month period following the date of your termination (the “Change of Control Severance Period”). These severance payments shall be conditioned upon you (a) furnishing to the Company an executed Release within the applicable time period set forth therein, but in no event later than 45 days following your termination date, and (b) allowing the Release to become effective in accordance with its terms. These severance payments shall be paid during the Change of Control Severance Period on the same schedule after termination as if you were still employed by the Company, in accordance with the Company’s standard payroll practice and which shall be subject to applicable withholding taxes, provided that any payments scheduled to be made to you prior to the Release effective date shall instead accrue and be paid during the first payroll period that commences thereafter.

For the purposes of this offer letter, the terms below shall have the following meanings:

Your severance benefits are intended to be exempt from application of Section 409A of the Internal Revenue Code, and any ambiguities herein shall be interpreted accordingly.

In compliance with federal laws and regulations, you will be required to provide Auspex documentary evidence of your identity and eligibility for employment in the United States as a condition of employment. Such documentation must initially be provided to us within three (3) business days of your date of hire or our employment relationship with you may be terminated.

Mr. John Schmid

August 30, 2013

Page Three

Your employment with Auspex is “at will” which means your employment may be terminated by either you or Auspex at any time with or without cause or advance notice. In connection with this at will relationship, Auspex reserves the right to exercise Its managerial discretion in such areas as assignment of duties, compensation, benefits and discipline.

We will need you to read and sign several documents as a condition of your employment at Auspex. These include:

This letter, along with the Prior Employment Agreements, Confidentiality Agreement, Nondisclosure and Developments Agreement and Arbitration Agreement sets forth the terms and conditions of your employment with Auspex and supersedes any prior representations or agreements including, but not limited to, any representations made during your recruitment, interviews, or pre-employment negotiations, whether written or oral. This letter, including, but not limited to, its at-will employment provision, may not be modified or amended except by a written agreement signed by the Chief Executive Officer and you.

This offer is contingent upon the verification by Auspex of information you have provided to us regarding your qualifications for employment. If you are in agreement with this offer, please indicate your acceptance by signing below and indicate your start date which, based on our discussions, will be September 30, 2013 (or other mutually agreed upon date).

John, we are extremely excited to make you this offer and look forward to having you as part of the Auspex team. We think you will be a very valuable addition to Auspex and will help it to achieve its long-term goals.