The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

 Names of Reporting Persons

 Cystic Fibrosis Foundation

 Check the Appropriate Box if a Member of a Group (See Instructions)

 (a) ☐  (b) ☐

 SEC Use Only

 Citizenship or Place of Organization

 Delaware, USA

Number of

Shares  Beneficially 

Owned by

Each

Reporting

Person

With

 Sole Voting Power

 9,330,580 (1)

 Shared Voting Power

 Sole Dispositive Power

 9,330,580 (1)

 Shared Dispositive Power

 Aggregate Amount Beneficially Owned by Each Reporting Person

 9,330,580 (1)

 Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)

 ☐

 Percent of Class Represented by Amount in Row (9)

 15.6% (2)

 Type of Reporting Person (See Instructions)

 CO

Consists of (i) 4,552,315 shares of common stock held by the Reporting Person and (ii) 4,778,265 shares of common stock issuable upon exercise of a warrant exercisable within 60 days held by the Reporting Person. Excludes (i) 21,635 shares of the Issuer’s Series X Non-Voting Convertible Preferred Stock (“Series X Preferred Stock”) held by the Reporting Person and (ii) 10,817,500 shares of common stock issuable upon exercise of a warrant held by the Reporting Person, as the Series X Preferred Stock and such warrant will only become convertible or exercisable, as applicable, following approval by the Issuer’s stockholders. Each share of Series X Preferred Stock is convertible into 1,000 shares of common stock following approval by the Issuer’s stockholders of such conversion, subject to a beneficial ownership limitation.

The percentage ownership was calculated based on (i) 45,979,930 shares of the Issuer’s common stock outstanding as of December 26, 2023 (as reported in the Issuer’s Pre-Effective Amendment No. 1 to Form S-3 Registration Statement as filed by the Issuer with the Securities and Exchange Commission on December 28, 2023) and (ii) 9,164,967 shares of common stock issued to the stockholders of Adaptive Phage Therapeutics, Inc. (“APT”) in connection with the closing of the transactions contemplated by the Agreement and Plan of Merger, by and among the Issuer, BTX Merger Sub I, Inc., BTX Merger Sub II, LLC, and APT, as set forth in the Issuer’s Current Report on Form 8-K filed with the SEC on March 6, 2024, and (iii) 4,778,265 shares of common stock issuable upon exercise of the warrant described in Note 1.

Name of issuer

Address of issuer’s principal executive offices

Name of person filing

Address or principal business office or, if none, residence

Citizenship

Title of class of securities

CUSIP No.

If this statement is filed pursuant to Rules 13d-1(b), or 13d-2(b) or (c), check whether the person filing is a:

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)

(j)

(k)

Ownership

Amount beneficially owned: 9,330,580*

Percent of class: 15.6%**

Number of shares as to which the person has:

Sole power to vote or to direct the vote: 9,330,580*

Shared power to vote or to direct the vote: 0

Sole power to dispose of or to direct the disposition of: 9,330,580*

Shared power to dispose of or to direct the disposition of: 0

Consists of (i) 4,552,315 shares of common stock held by the Reporting Person and (ii) 4,778,265 shares of common stock issuable upon exercise of a warrant exercisable within 60 days held by the Reporting Person. Excludes (i) 21,635 shares of the Issuer’s Series X Non-Voting Convertible Preferred Stock (“Series X Preferred Stock”) held by the Reporting Person and (ii) 10,817,500 shares of common stock issuable upon exercise of a warrant held by the Reporting Person. Each share of Series X Preferred Stock is convertible into 1,000 shares of common stock following approval by the Issuer’s stockholders of such conversion as the Series X Preferred Stock and such warrant will only become convertible or exercisable, as applicable, following approval by the Issuer’s stockholders.

The percentage ownership was calculated based on (i) 45,979,930 shares of the Issuer’s common stock outstanding as of December 26, 2023 (as reported in the Issuer’s Pre-Effective Amendment No. 1 to Form S-3 Registration Statement as filed by the Issuer with the Securities and Exchange Commission on December 28, 2023) and (ii) 9,164,967 shares of common stock issued to the stockholders of Adaptive Phage Therapeutics, Inc. (“APT”) in connection with the closing of the transactions contemplated by the Agreement and Plan of Merger, by and among the Issuer, BTX Merger Sub I, Inc., BTX Merger Sub II, LLC, and APT, as set forth in the Issuer’s Current Report on Form 8-K filed with the SEC on March 6, 2024, and (iii) 4,778,265 shares of common stock issuable upon exercise of a warrant described above.

Ownership of 5 Percent or Less of a Class.

Ownership of More than 5 Percent on Behalf of Another Person.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person.

Identification and Classification of Members of the Group.

Notice of Dissolution of Group.

Certifications.