Exhibit 10.63











|ACETO Corporation         |                                       | 
|------------------------- | ------------------------------------- | 
|4 Tri Harbor Court        |                                       | 
|Port Washington, NY 11050 | William C. Kennally, III              | 
|Tel: (516) 478-9525       | President and Chief Executive Officer | 
|Fax: (516) 478-9825       |                                       | 
|www.aceto.com             |                                       | 





May 21, 2018



Mr. Steve Rogers

c/o Aceto Corporation

4 Tri Harbor Court

Port Washington, New York 11050



| | Re: | Enhanced Severance Protection
| | --- | -----------------------------



Dear Steve:



We are pleased to inform you that the Company
will provide you with the enhanced severance protection specified below. Capitalized terms used, but not defined herein, shall
have the meanings ascribed thereto in that certain Change in Control Agreement by and between you and the Company dated as of the
28th day of February 2017 (the “Change in Control Agreement”). This letter agreement supersedes and replaces your Enhanced
Severance Protection dated 28th February 2017.



If, prior to a Change in Control, your
employment is terminated by the Company without Cause (other than due to your Disability (as defined below)), in addition to any
Accrued Obligations (which shall be paid to you with ten (10) days of your termination date) and any Other Benefits (such Other
Benefits to be paid or provided in accordance with the terms of the applicable plan, program or policy in effect from time to time),
the Company shall continue to pay your base salary, at the rate then in effect, for the fifteen (15) month period following the
date of termination (the “Severance Period”) as severance (the “Severance.”



“Disability” shall mean your
inability, due to physical or mental illness, injury or incapacity, to substantially perform your duties and responsibilities,
with any legally required reasonable accommodation, for a total of ninety (90) consecutive days or for a total of six (6) months (whether or not
consecutive) within any twelve (12) consecutive months.















Page Two





The Severance shall be in lieu of any severance
payable pursuant to the Company’s Severance Policy, which you shall cease to be eligible to participate in from and after
the date hereof. For the avoidance of doubt, in no event shall you be entitled to receive Severance pursuant to this letter agreement
in the event your employment is terminated on or after the occurrence of a Change in Control (in which case your right to receive
severance, if any, shall be governed by the Change in Control Agreement).



You hereby acknowledge and agree that the
provisions of Section 9 (“Covenants”), Section 10 (“Withholding Taxes”), Section 11 (“Scope of Agreement”)
and Section 12 (“General Provisions”) of the Change in Control Agreement shall apply to this letter agreement and are
hereby expressly incorporated by reference.



Without limitation of Section 12(e) (“Compliance
with Code Section 409A”) of the Change in Control Agreement, (i) each payment of Severance hereunder is intended to be treated
as a separate payment, and (ii) each payment of Severance hereunder that may be excluded from Section 409A of the Code either as
separation pay due to an involuntary “separation from service” or as a short-term deferral will be excluded from Section
409A of the Code to the maximum extent possible. In addition, for purposes hereof and the Change in Control Agreement (which is
hereby amended by this sentence), no Change in Control of the Company shall be deemed to occur unless the Change in Control also
constitutes a “change in control event” under Treasury Regulation Section 1.409A-3(i)(5).



Your
hard work and dedicated service are greatly appreciated.







|ACETO CORPORATION    |                         | 
|-------------------- | ----------------------- | 
|                     |                         | 
|By:                  | /s/ William Kennally    | 
|                     | William Kennally        | 
|                     | Chief Executive Officer | 
|                     |                         | 
|Agreed and Accepted: |                         | 
|                     |                         | 
|/s/ Steve Rogers     |                         | 
|Steve Rogers         |                         |