Exhibit (a)(1)(E)
        
          Offer to Purchase
          
          All Outstanding Shares of Common Stock of
          
          BIODELIVERY SCIENCES INTERNATIONAL, INC.
          
          at
          
          $5.60 per share, in cash
          
          Pursuant to the Offer to Purchase dated February 18, 2022 by
          
          BRISTOL ACQUISITION COMPANY INC.
          
          a Wholly Owned Subsidiary of
          
          COLLEGIUM PHARMACEUTICAL, INC. 
        
        
          
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                THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT THE END OF THE DAY, 
                ONE MINUTE FOLLOWING 11:59 P.M., EASTERN TIME, ON MARCH 18, 2022,
 UNLESS THE OFFER IS EXTENDED OR EARLIER TERMINATED
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          February 18, 2022
        
          To Our Clients: 
        
        
          Enclosed for your consideration are the Offer to Purchase, dated February 18, 2022 (the “Offer to Purchase”), and the related Letter of Transmittal in connection with the offer by Bristol Acquisition Company Inc., a Delaware corporation (“Purchaser”) and wholly owned subsidiary of Collegium Pharmaceutical, Inc., a Virginia corporation (“Collegium”), to purchase all of the issued and outstanding shares of common stock, par value $0.001 per share (the “Shares”), of BioDelivery Sciences International, Inc., a Delaware corporation (“BDSI”), in exchange for $5.60 per share, in cash, upon the terms and subject to the conditions of the Offer to Purchase and the related Letter of Transmittal (which, together with the Offer to Purchase, as they may be amended or supplemented from time to time, collectively constitute the “Offer”). 
        
        
          THE BOARD OF DIRECTORS OF BDSI RECOMMENDS THAT YOU TENDER ALL OF YOUR SHARES IN THE OFFER. 
        
        
          We or our nominees are the holder of record of Shares held for your account. A tender of such Shares can be made only by us as the holder of record and pursuant to your instructions. The Letter of Transmittal is furnished to you for your information only and cannot be used by you to tender Shares held by us for your account. 
        
        
          We request instructions as to whether you wish us to tender any or all of the Shares held by us for your account, upon the terms and subject to the conditions set forth in the enclosed Offer to Purchase and the Letter of Transmittal. 
        
        
          Please note carefully the following: 
        
        
          1. The offer price for the Offer is $5.60 per share, in cash. 
        
        
          2. The Offer is being made for all issued and outstanding Shares. 
        
        
          3. The Offer is being made pursuant to an Agreement and Plan of Merger, dated February 14, 2022 (as it may be amended from time to time, the “Merger Agreement”), by and among Collegium, Purchaser and BDSI. The Merger Agreement provides, among other things, that following the consummation of the Offer and provided that there are no legal restraints preventing or prohibiting the Merger, Purchaser will be merged with and into BDSI pursuant to Section 251(h) of the General Corporation Law of the State of Delaware, as amended (the “DGCL”), with BDSI continuing as the surviving corporation and becoming a wholly owned subsidiary of Collegium (the “Merger”). 
        
        
          4. The board of directors of BDSI, among other things, has unanimously (i) approved, adopted and declared advisable the Merger Agreement and the transactions contemplated thereby, including the Offer and the Merger (together, the “Transactions”), (ii) determined that the Transactions, including