tm2516065-1_sctot_DIV_21-exha1b - none

Exhibit (a)(1)(B)

Letter of Transmittal
to Tender Shares of Common Stock of
Regulus Therapeutics Inc.
at
$7.00 per share in cash, plus one contingent value right per share representing the right to receive
one contingent payment of $7.00 in cash upon the achievement of a specified milestone
Pursuant to the Offer to Purchase dated May 27, 2025
by
Redwood Merger Sub Inc.
an indirect wholly owned subsidiary of
Novartis AG

THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT ONE MINUTE PAST 11:59 P.M.,
NEW YORK CITY TIME, ON JUNE 24, 2025, UNLESS THE OFFER IS EXTENDED
OR EARLIER TERMINATED.

The Depositary for the Offer is:

Method of delivery of the certificate(s) is at the option and risk of the owner thereof. See Instruction 2. Mail or deliver this Letter of Transmittal, together with the certificate(s) representing your shares, to:

	If delivering by mail:			If delivering by express mail or other expedited mail service:
	Computershare Trust Company, N.A. c/o Voluntary Corporate Actions P.O. Box 43011 Providence, Rhode Island 02940-3011			Computershare Trust Company, N.A. c/o Voluntary Corporate Actions 150 Royall Street, Suite V Canton, Massachusetts 02021

DESCRIPTION OF SHARES TENDERED

Name(s) and Address(es) of Registered Owner(s)
(If blank, please fill in exactly as name(s) appear(s)
on share certificate(s))

Shares Tendered (attach additional list if necessary)

Certificated Shares*

Book Entry Shares**

Certificate
Number(s)

Total Number
of Shares
Represented
by
Certificates

Number of
Shares
Represented by
Certificate(s)
Tendered

Number of
Shares
Held in Book-
Entry Form
Tendered

Total Shares

Unless otherwise indicated, it will be assumed that all shares of common stock represented by certificates described above are being tendered hereby. See Instruction 4.

Unless otherwise indicated, it will be assumed that all shares of common stock held in book-entry form are being tendered hereby.

The instructions accompanying this Letter of Transmittal should be read carefully before this Letter of Transmittal is completed.

Delivery of this Letter of Transmittal to an address other than as set forth above for the Depositary will not constitute valid delivery. You must sign this Letter of Transmittal in the appropriate space provided below, with signature guarantee, and complete the IRS Form W-9 set forth below or provide the appropriate IRS Form W-8, if required.

All questions regarding the Offer should be directed to the Information Agent, Innisfree M&A Incorporated, at (877) 800-5186 (toll-free from the United States or Canada) or +1 (412) 232-3651 (from outside of the United States or Canada) for assistance. Banks and brokers may call collect at (212) 750-5833 or the address set forth on the back page of the Offer to Purchase. If you would like additional copies of this Letter of Transmittal or any of the other offering documents, you should contact the Information Agent, at the number above.

The Offer is not being made to stockholders in any jurisdiction where it would be illegal to do so. We are not aware of any jurisdiction in which the making of the Offer or the acceptance thereof would be prohibited by securities, blue sky or other valid laws of such jurisdiction. If we become aware of any U.S. state in which the making of the Offer or the acceptance of Shares pursuant thereto would not be in compliance with an administrative or judicial action taken pursuant to a U.S. state statute, we will make a good faith effort to comply with any such law. If, after such good faith effort, we cannot comply with any such law, the Offer will not be made to (nor will tenders be accepted from or on behalf of) the holders of Shares in such state.

This Letter of Transmittal is being delivered to you in connection with the offer by Redwood Merger Sub Inc., a Delaware corporation (“Purchaser”) and an indirect wholly owned subsidiary of Novartis AG, a company limited by shares (Aktiengesellschafl) incorporated under the laws of Switzerland (“Parent”), to purchase all of the outstanding shares of common stock, par value $0.001 per share (the “Shares”), of Regulus Therapeutics Inc., a Delaware corporation (“Regulus”), in exchange for (i) $7.00 in cash per Share, subject to any applicable withholding and without interest thereon, plus one contingent value right per Share, representing the right to receive one contingent payment of $7.00 in cash, subject to any applicable withholding and without interest thereon, upon the achievement of the milestone specified in, and on the other terms and subject to the other conditions set forth in, the CVR Agreement to be entered into between Parent and a rights agent. The Offer expires one minute past 11:59 p.m., New York City Time, on June 24, 2025, unless the Offer is extended or earlier terminated as permitted by the Agreement and Plan of Merger, dated as of April 29, 2025 (as it may be amended, supplemented or otherwise modified from time to time), among Parent, Purchaser and Regulus (such time, the “Expiration Time”).

You should use this Letter of Transmittal to deliver to Computershare Trust Company, N.A. (the “Depositary”) Shares represented by stock certificates, or held in book-entry form on the books of Regulus, or its stock transfer agent, for tender. If you are delivering your Shares by book-entry transfer to an account maintained by the Depositary at The Depository Trust Company (“DTC”), you must use an Agent’s Message (as defined in Instruction 2 below). In this Letter of Transmittal, stockholders who deliver certificates representing their Shares are referred to as “Certificate Stockholders.” Delivery of documents to DTC will not constitute delivery to the Depositary.

If any certificate representing any Shares you are tendering with this Letter of Transmittal has been lost, stolen, destroyed or mutilated, you should contact Regulus’ stock transfer agent, Computershare Trust Company, N.A. (the “Transfer Agent”) at (800) 962-4284 (toll free in the United States) regarding the requirements for replacement. You will be required to make an affidavit of fact and may be required to post a bond to secure against the risk that such certificates may be subsequently recirculated. You are urged to contact the Transfer Agent immediately in order to receive further instructions, for a determination of whether you will need to post a bond and to permit timely processing of this documentation. See Instruction 10.

Holders of outstanding Shares, whose certificates for such Shares are not immediately available or who cannot deliver such certificates and all other required documents to the Depositary at or prior to the Expiration Time or who cannot complete the procedure for book-entry transfer at or prior to the Expiration Time, may only tender their Shares according to the guaranteed delivery procedure set forth in Section 3 of the Offer to Purchase. See Instruction 2.

Ladies and Gentlemen:

The undersigned hereby tenders to Redwood Merger Sub Inc., a Delaware corporation (“Purchaser”) and an indirect wholly owned subsidiary of Novartis AG, a company limited by shares (Aktiengesellschafl) incorporated under the laws of Switzerland (“Parent”), the above-described shares of common stock, par value $0.001 per share (the “Shares”), of Regulus Therapeutics Inc., a Delaware corporation (“Regulus”), pursuant to Purchaser’s offer to purchase all of the outstanding Shares, in exchange for (i) $7.00 in cash per Share, subject to any applicable withholding and without interest thereon (the “Closing Amount”), plus one contingent value right (each, a “CVR”) per Share, representing the right to receive one contingent payment of $7.00 in cash (the Closing Amount and one CVR, collectively, or any greater amount per Share that may be paid pursuant to the Offer, being hereinafter referred to as the “Offer Price”), subject to any applicable withholding and without interest thereon, upon the achievement of the milestone specified in, and on the other terms and subject to the other conditions set forth in, the CVR Agreement to be entered into between Parent and a rights agent as of or prior to the date and time of the irrevocable acceptance for payment by Purchaser of the Shares that have been validly tendered and not validly withdrawn pursuant to and subject to the conditions of the Offer (as defined below). Such offer is being made upon the terms and subject to the conditions set forth in the Offer to Purchase (as it may be amended, supplemented or otherwise modified from time to time, the “Offer to Purchase”) and in this Letter of Transmittal (as it may be amended, supplemented or otherwise modified from time to time, the “Letter of Transmittal”) which, together with the Offer to Purchase, collectively constitute the “Offer.” The Offer expires at the Expiration Time. “Expiration Date” means one minute past 11:59 p.m., New York City time, on June 24, 2025, unless the Offer is otherwise extended or earlier terminated.

Upon the terms and subject to the conditions of the Offer (including, if the Offer is extended or amended, the terms and conditions of such extension or amendment), subject to, and effective upon, acceptance for payment of the Shares validly tendered herewith and not validly withdrawn prior to the Expiration Time in accordance with the terms of the Offer, the undersigned hereby sells, assigns and transfers to, or upon the order of, Purchaser, all right, title and interest in and to all of the Shares being tendered hereby and any and all dividends, distributions, rights, other Shares or other securities issued or issuable in respect of such Shares on or after the date of the Merger Agreement (collectively, “Distributions”). In addition, the undersigned hereby irrevocably appoints Purchaser as the true and lawful agent and attorney-in-fact and proxy of the undersigned with respect to such Shares and any and all Distributions with full power of substitution (such proxies and power of attorney being deemed to be an irrevocable power coupled with an interest in the tendered Shares and any Distributions) to the full extent of such stockholder’s rights with respect to such Shares and any Distributions (a) to deliver certificates representing such Shares (the “Share Certificates”) and any and all Distributions, or transfer of ownership of such Shares and any and all Distributions on the account books maintained by The Depository Trust Company (“DTC”), together, in either such case, with all accompanying evidence of transfer and authenticity, to or upon the order of Purchaser, (b) to present such Shares and any and all Distributions for transfer on the books of Regulus and (c) to receive all benefits and otherwise exercise all rights of beneficial ownership of such Shares and any Distributions, all upon the terms and subject to the conditions of the Offer.

By executing this Letter of Transmittal (or taking action resulting in the delivery of an Agent’s Message), the undersigned hereby irrevocably appoints each of the designees of Purchaser the attorneys-in-fact and proxies of the undersigned, each with full power of substitution, to the full extent of such stockholder’s rights with respect to the Shares tendered hereby and not validly withdrawn which have been accepted for payment and with respect to any and all Distributions. The designees of Purchaser will, with respect to such Shares and Distributions, be empowered to exercise all voting and any other rights of such stockholder, as they, in their sole discretion, may deem proper at any annual, special, adjourned or postponed meeting of Regulus’ stockholders, by written consent in lieu of any such meeting or otherwise as such designee, in its, his or her sole discretion, deems proper with respect to all Shares and any and all Distributions. This proxy and power of attorney will be irrevocable and coupled with an interest in the tendered Shares and any and all Distributions. Such appointment is effective when, and only to the extent that, Purchaser accepts the Shares tendered with this Letter of Transmittal for payment pursuant to the Offer. Upon the effectiveness of such appointment, without further action, all prior powers of attorney, proxies and consents given by the undersigned with respect to such Shares and any and all associated Distributions (other than prior powers of attorney, proxies or consent given by the undersigned to Purchaser) will be revoked, and no

subsequent powers of attorney, proxies, consents or revocations (other than powers of attorney, proxies, consents or revocations given to Purchaser) may be given (and, if given, will not be deemed effective).

Purchaser reserves the right to require that, in order for Shares to be deemed validly tendered, immediately upon Purchaser’s acceptance for payment of such Shares, Purchaser must be able to exercise full voting, consent and other rights, to the extent permitted under applicable law, with respect to such Shares and any and all Distributions, including voting at any meeting of stockholders or executing a written consent concerning any matter.

The undersigned hereby represents and warrants that the undersigned has full power and authority to tender, sell, assign and transfer any and all of the Shares tendered hereby and any and all Distributions and, when the same are accepted for payment by Purchaser, Purchaser will acquire good, marketable and unencumbered title thereto, free and clear of all liens, restrictions, charges and encumbrances, and that the same will not be subject to any adverse claim. The undersigned hereby represents and warrants that the undersigned is the registered owner of the Shares, or the Share Certificate(s) have been endorsed to the undersigned in blank, or the undersigned is a participant in DTC whose name appears on a security position listing as the owner of the Shares. The undersigned will, upon request, execute and deliver any additional documents deemed by the Depositary or Purchaser to be necessary or desirable to complete the sale, assignment and transfer of any and all of the Shares tendered hereby and any and all Distributions. In addition, the undersigned will promptly remit and transfer to the Depositary for the account of Purchaser any and all Distributions in respect of any and all of the Shares tendered hereby, accompanied by appropriate documentation of transfer and, pending such remittance and transfer or appropriate assurance thereof, Purchaser will be entitled to all rights and privileges as owner of any such Distributions and may withhold the entire Offer Price or deduct from such Offer Price the amount or value thereof, as determined by Purchaser in its sole discretion.

It is understood that the undersigned will not receive payment for the Shares unless and until the Shares are accepted for payment and until the Share Certificate(s) owned by the undersigned are received by the Depositary at the address set forth above, together with such additional documents as the Depositary may require, or, in the case of Shares held in book-entry form, ownership of Shares is validly transferred on the account books maintained by DTC, and until the same are processed for payment by the Depositary.

It is understood that the method of delivery of the Shares, the Share Certificate(s) and all other required documents (including delivery through DTC) is at the option and risk of the undersigned and that the risk of loss of such Shares, Share Certificate(s) and other documents will pass only after the Depositary has actually received the Shares or Share Certificate(s) (including, in the case of a book-entry transfer, by Book-Entry Confirmation (as defined below)). If delivery is by mail, it is recommended that all such documents be sent by properly insured registered mail with return receipt requested. In all cases, sufficient time should be allowed to ensure timely delivery.

All authority conferred or agreed to be conferred pursuant to this Letter of Transmittal will not be affected by, and will survive, the death or incapacity of the undersigned and any obligation of the undersigned hereunder will be binding upon the heirs, executors, administrators, trustees in bankruptcy, personal representatives, successors and assigns of the undersigned. Except upon the terms and subject to the conditions of the Offer, this tender is irrevocable.

The undersigned understands that the acceptance for payment by Purchaser of Shares tendered pursuant to one of the procedures described in Section 3 of the Offer to Purchase and in the instructions hereto will constitute a binding agreement between the undersigned and Purchaser upon the terms and subject to the conditions of the Offer. The undersigned recognizes that under certain circumstances, upon the terms and subject to the conditions of the Offer, Purchaser may not be required to accept for payment any of the Shares tendered hereby. Without limiting the foregoing, if the Offer Price is amended in accordance with the terms of the Agreement and Plan of Merger, dated as of April 29, 2025 (as it may be amended, supplemented or otherwise modified from time to time, the “Merger Agreement”), among Parent, Purchaser and Regulus pursuant to which the Offer is being made, the price to be paid to the undersigned will be the amended price notwithstanding the fact that a different price is stated in this Letter of Transmittal.

Unless otherwise indicated herein under “Special Payment Instructions,” please issue the check for the Offer Price in the name(s) of, and/or return any Share Certificates representing Shares not validly tendered

or accepted for payment to, the registered owner(s) appearing under “Description of Shares Tendered.” Similarly, unless otherwise indicated under “Special Delivery Instructions,” please mail the check for the Offer Price and/or return any Share Certificates representing Shares not validly tendered or accepted for payment (and accompanying documents, as appropriate) to the address(es) of the registered owner(s) appearing under “Description of Shares Tendered.”

In the event that both the Special Delivery Instructions and the Special Payment Instructions are completed, please issue the check for the Offer Price and/or issue any Share Certificates representing Shares not validly tendered or accepted for payment (and any accompanying documents, as appropriate) in the name of, and deliver such check and/or return such Share Certificates (and any accompanying documents, as appropriate) to, the person or persons so indicated. Unless otherwise indicated herein in the box titled “Special Payment Instructions,” please credit any Shares validly tendered hereby or by an Agent’s Message and delivered by book-entry transfer, but which are not purchased, by crediting the account at DTC designated above. The undersigned recognizes that Purchaser has no obligation pursuant to the Special Payment Instructions to transfer any Shares from the name of the registered owner thereof if Purchaser does not accept for payment any of the Shares so validly tendered.

		SPECIAL PAYMENT INSTRUCTIONS (See Instructions 1, 4, 5, and 7)
		To be completed ONLY if Share Certificate(s) not validly tendered or not accepted for payment and/or the check for the Offer Price in consideration of Shares validly tendered and accepted for payment are to be issued in the name of someone other than the undersigned or if Shares validly tendered by book-entry transfer which are not accepted for payment are to be returned by credit to an account maintained at DTC other than that designated above.
		Issue: ☐ Check and/or ☐ Shares to:
		Name			(Please Print)
		Address
		(Include Zip Code)

		(Tax Identification or Social Security Number) (Please additionally complete IRS Form W-9 (attached) or the applicable IRS Form W-8, available at irs.gov)
		☐ Credit Shares tendered by book-entry transfer that are not accepted for payment to the DTC account set forth below.
		(DTC Account Number)

		SPECIAL DELIVERY INSTRUCTIONS (See Instructions 1, 4, 5, and 7)
		To be completed ONLY if Share Certificate(s) not validly tendered or not accepted for payment and/or the check for the Offer Price of Shares validly tendered and accepted for payment are to be sent to someone other than the undersigned or to the undersigned at an address other than that shown in the box titled “Description of Shares Tendered” above.
		Deliver: ☐ Check and/or ☐ Shares to:
		Name			(Please Print)
		Address
		(Include Zip Code)

IMPORTANT- SIGN HERE

Signature(s) of Stockholder(s):

Dated: , 2025

(Must be signed by registered owner(s) exactly as name(s) appear(s) on Share Certificate(s) or on a security position listing or by person(s) authorized to become registered holder(s) by certificates and documents transmitted herewith. If signature is by trustees, executors, administrators, guardians, attorneys-in-fact, officers of a corporation or others acting in a fiduciary or representative capacity, please set forth full title and see Instruction 5. For information concerning signature guarantees, see Instruction 1.)

	Name(s):			(Please Print)
	Capacity (Full Title):
	Address:			(Include Zip Code)
	Area Code and Telephone Number:
	Tax Identification or Social Security No.:

(Please additionally complete IRS Form W-9 (attached) or the applicable IRS Form W-8, available at irs.gov)

GUARANTEE OF SIGNATURE(S)
(For use by Eligible Institutions only;
see Instructions 1 and 5)

	Name of Firm:
	Address:			(Include Zip Code)
	Authorized Signature:
	Name:			(Please Print)
	Area Code and Telephone Number Dated: , 2025

Place medallion guarantee in space below:

INSTRUCTIONS

Forming Part of the Terms and Conditions of the Offer

1. Guarantee of Signatures for Shares. No signature guarantee is required on this Letter of Transmittal (a) if this Letter of Transmittal is signed by the registered holder(s) (which term, for purposes of this Section 1, includes any participant in DTC’s systems whose name appears on a security position listing as the owner of the Shares) of the Shares tendered therewith, unless such holder or holders have completed either the box entitled “Special Delivery Instructions” or the box entitled “Special Payment Instructions” on the cover of this Letter of Transmittal or (b) if the Shares are tendered for the account of a financial institution (including most commercial banks, savings and loan associations and brokerage houses) that is a member in good standing of the Security Transfer Agents Medallion Program or any other “eligible guarantor institution,” as such term is defined in Rule 17Ad-15 of the Exchange Act (each an “Eligible Institution” and collectively “Eligible Institutions”) (for example, the Security Transfer Agents Medallion Program, the New York Stock Exchange Medallion Signature Program and the Stock Exchanges Medallion Program). In all other cases, all signatures on this Letter of Transmittal must be guaranteed by an Eligible Institution. See Instruction 5.

2. Delivery of Letter of Transmittal and Certificates or Book-Entry Confirmations. This Letter of Transmittal is to be completed by stockholders if Share Certificates are to be forwarded herewith. If Shares represented by Share Certificates are being tendered, such Share Certificates, as well as this Letter of Transmittal properly completed and duly executed with any required signature guarantees, and any other documents required by this Letter of Transmittal, must be received by the Depositary at its address set forth herein on or prior to the Expiration Date. If Shares are to be tendered by book-entry transfer, the procedures for tender by book-entry transfer set forth in Section 3 of the Offer to Purchase must be followed, and an Agent’s Message and confirmation of a book-entry transfer into the Depositary’s account at DTC of Shares tendered by book-entry transfer (such a confirmation, a “Book-Entry Confirmation”) must be received by the Depositary on or prior to the Expiration Date.

The term “Agent’s Message” means a message, transmitted through electronic means by DTC in accordance with the normal procedures of DTC to, and received by, the Depositary and forming part of a Book-Entry Confirmation, that states that DTC has received an express acknowledgment from the participant in DTC tendering the Shares that are the subject of such Book-Entry Confirmation that such participant has received and agrees to be bound by the terms of, this Letter of Transmittal, and that Purchaser may enforce such agreement against such participant. The term “Agent’s Message” also includes any hard copy printout evidencing such message generated by a computer terminal maintained at the Depositary’s office.

Stockholders whose certificates for Shares are not immediately available or stockholders who cannot deliver their certificates and all other required documents to the Depositary by the Expiration Time or who cannot comply with the procedures for book-entry transfer by the Expiration Time may tender their Shares by completing a Notice of Guaranteed Delivery pursuant to the guaranteed delivery procedure set forth in Section 3 of the Offer to Purchase. Under the guaranteed delivery procedure:

•

a properly completed and duly executed Notice of Guaranteed Delivery substantially in the form provided by Purchaser with the Offer to Purchase must be received by the Depositary by the Expiration Time; and

•

the certificates for all tendered Shares (or a confirmation of a book-entry transfer of such Shares into the Depositary’s account at the Book-Entry Transfer Facility), as well as a properly completed and duly executed Letter of Transmittal (or a manually signed facsimile thereof) with any required signature guarantee (or an Agent’s Message) and any other documents required by this Letter of Transmittal, must be received by the Depositary within one Nasdaq Stock Market trading day after the date of execution of such Notice of Guaranteed Delivery, all as provided in Section 3 of the Offer to Purchase.

The method of delivery of the Shares (or Share Certificates), this Letter of Transmittal and all other required documents, including delivery through DTC, is at the election and risk of the tendering stockholder. Delivery of the Shares (or Share Certificates), this Letter of Transmittal and all other required documents will be deemed made, and risk of loss thereof will pass, only when they are actually received by the Depositary

(including, in the case of a book-entry transfer of Shares, by Book-Entry Confirmation with respect to such Shares). If such delivery is by mail, it is recommended that the Shares (or Share Certificates), this Letter of Transmittal and all other required documents be sent by properly insured registered mail with return receipt requested. In all cases, sufficient time should be allowed to ensure timely delivery.

No alternative, conditional or contingent tenders will be accepted and no fractional Shares will be purchased. All tendering stockholders, by execution of this Letter of Transmittal, waive any right to receive any notice of the acceptance of their Shares for payment.

All questions as to validity, form and eligibility (including time of receipt) of the surrender of any Share Certificate hereunder, including questions as to the proper completion or execution of any Letter of Transmittal or other required documents and as to the proper form for transfer of any certificate of Shares, will be determined by Purchaser in its sole and absolute discretion (which may be delegated in whole or in part to the Depositary), which determination will be final and binding, subject to any judgment of any court of competent jurisdiction. Purchaser reserves the absolute right to reject any and all tenders determined by it not to be in proper form or the acceptance for payment of or payment for which may be unlawful. Purchaser also reserves the absolute right to waive any defect or irregularity in the surrender of any Shares or Share Certificate(s) whether or not similar defects or irregularities are waived in the case of any other stockholder. A surrender will not be deemed to have been validly made until all defects and irregularities have been cured or waived.

3. Inadequate Space. If the space provided on the cover page to this Letter of Transmittal is inadequate, the certificate numbers and/or the number of Shares should be listed on a separate schedule attached hereto and separately signed on each page thereof in the same manner as this Letter of Transmittal is signed.

4. Partial Tenders. Unless otherwise indicated, it will be considered that all Shares represented by a certificate(s) delivered with the Letter of Transmittal or held in the account in book-entry form are to be tendered. If fewer than all of the Shares represented by any certificate delivered to the Depositary are to be tendered, fill in the number of Shares which are to be tendered in the area entitled “Shares Tendered.” In such case, a new certificate for the remainder of the Shares represented by the old certificate will be issued and sent to the person(s) signing this Letter of Transmittal, unless otherwise provided in the appropriate box on this Letter of Transmittal, as promptly as practicable following the expiration or termination of the Offer.

5. Signatures on Letter of Transmittal; Stock Powers and Endorsements. If this Letter of Transmittal is signed by the registered owner(s) of the Shares tendered hereby, the signature(s) must correspond with the name(s) as written on the face of the Share Certificate(s) without alteration or any other change whatsoever.

If any Shares tendered hereby are owned of record by two or more joint owners, all such owners must sign this Letter of Transmittal.

If any tendered Shares are registered in the names of different holder(s), it will be necessary to complete, sign and submit as many separate Letters of Transmittal as there are different registrations of such Shares.

If this Letter of Transmittal or any certificates or stock powers are signed by trustees, executors, administrators, guardians, attorneys-in-fact, officers of corporations or others acting in a fiduciary or representative capacity, such persons should so indicate when signing, and proper evidence satisfactory to Purchaser of their authority so to act must be submitted.

If this Letter of Transmittal is signed by the registered owner(s) of the Shares listed and transmitted hereby, no endorsements of Share Certificates or separate stock powers are required unless payment is to be made to, or Share Certificates representing Shares not tendered or accepted for payment are to be issued in the name of, a person other than the registered owner(s), in which case the Share Certificates representing the Shares tendered by this Letter of Transmittal must be endorsed or accompanied by appropriate stock powers, in either case, signed exactly as the name(s) of the registered owner(s) or holder(s) appear(s) on the Share Certificates. Signatures on such Share Certificates or stock powers must be guaranteed by an Eligible Institution.

If this Letter of Transmittal is signed by a person other than the registered owner(s) of the Share(s) listed, the Share Certificate(s) must be endorsed or accompanied by the appropriate stock powers, in either case, signed exactly as the name or names of the registered owner(s) or holder(s) appear(s) on the Share Certificate(s). Signatures on such Share Certificates or stock powers must be guaranteed by an Eligible Institution.

6. Transfer Taxes. Except as otherwise provided in this Instruction 6, all transfer taxes with respect to the transfer and sale of Shares contemplated hereby will be paid or caused to be paid by Purchaser. If payment of the Offer Price is to be made to, or (in the circumstances permitted hereby) if Share Certificates not validly tendered or accepted for payment are to be registered in the name of, any person other than the registered owner(s), or if tendered Share Certificates are registered in the name of any person other than the person signing this Letter of Transmittal, the amount of any transfer taxes whether imposed on the registered owner(s) or such person payable on account of the transfer to such person will be deducted from the Offer Price unless satisfactory evidence of the payment of such taxes, or exemption therefrom, is submitted.

7. Special Payment and Delivery Instructions. If a check for the Offer Price is to be issued, and/or Share Certificates representing Shares not validly tendered or accepted for payment are to be issued or returned to, a person other than the signer(s) of this Letter of Transmittal or to an address other than that shown in the box titled “Description of Shares Tendered” above, the appropriate boxes on this Letter of Transmittal should be completed. Stockholders delivering Shares tendered hereby or by Agent’s Message by book-entry transfer may request that Shares not purchased be credited to an account maintained at DTC as such stockholder may designate in the box titled “Special Payment Instructions” herein. If no such instructions are given, all such Shares not purchased will be returned by crediting the same account at DTC as the account from which such Shares were delivered.

8. Requests for Assistance or Additional Copies. Questions or requests for assistance may be directed to Innisfree M&A Incorporated (the “Information Agent”) at its address and telephone number set forth below or to your broker, dealer, commercial bank or trust company. Additional copies of the Offer to Purchase, this Letter of Transmittal and other tender offer materials may be obtained from the Information Agent as set forth below, and will be furnished at Purchaser’s expense.

9. U.S. Federal Backup Withholding. Under U.S. federal income tax laws, the Depositary will be required to withhold a portion of the amount of any payments made to certain stockholders (or other payees) pursuant to the Offer, as applicable. To avoid backup withholding, each tendering stockholder (or other payee) that is or is treated as a United States person (for U.S. federal income tax purposes) and that does not otherwise establish an exemption from U.S. federal backup withholding must complete and return the attached Internal Revenue Service (“IRS”) Form W-9, certifying that such stockholder (or other payee) is a United States person, that the taxpayer identification number (“TIN”) provided is correct, and that such stockholder (or other payee) is not subject to backup withholding. If such stockholder (or other payee) is a U.S. individual, the TIN is such stockholder’s (or other payee’s) social security number.

Certain stockholders and other payees (including, among others, corporations, non-resident foreign individuals and foreign entities) are not subject to these backup withholding and reporting requirements. To avoid backup withholding, exempt U.S. persons should furnish their TIN and indicate their exempt status on IRS Form W-9 and sign, date and return the IRS Form W-9 to the Depositary. A tendering stockholder (or other payee) that is a foreign individual or a foreign entity should complete, sign, and submit to the Depositary the appropriate IRS Form W-8 attesting to such stockholder’s (or payee’s) foreign status or should otherwise establish an exemption. The appropriate IRS Form W-8 may be downloaded from the Internal Revenue Service’s website at the following address: http://www.irs.gov. Failure to complete the IRS Form W-9 or the appropriate IRS Form W-8 will not, by itself, cause Shares to be deemed invalidly tendered, but may require the Depositary to withhold a portion of the amount of any payments made of the Offer Price pursuant to the Offer. Tendering stockholders (or other payees) should consult their tax advisors as to any qualification for exemption from backup withholding, and the procedure for obtaining the exemption.

If backup withholding of U.S. federal income tax on payments for Shares made in the Offer or under the Merger Agreement applies, the Depositary is required to withhold 24% of any payments of the Offer Price made to the stockholder (or other payee). Backup withholding is not an additional tax. Any

amounts withheld under the backup withholding rules may be refunded or credited against a stockholder’s U.S. federal income tax liability, if any; provided that such stockholder timely furnishes the required information to the IRS.

Note: Failure to complete and return the IRS Form W-9 (or appropriate IRS Form W-8, as applicable) may result in backup withholding of a portion of any payments made to you pursuant to the Offer.

10. Lost, Destroyed, Mutilated or Stolen Share Certificates. If any Share Certificate has been lost, destroyed, mutilated or stolen, the stockholder should promptly notify the Transfer Agent, at (800) 962-4284 (toll free in the United States). The stockholder will then be instructed as to the steps that must be taken in order to replace the Share Certificate. This Letter of Transmittal and related documents cannot be processed until the procedures for replacing lost, mutilated, destroyed or stolen Share Certificates have been followed.

11. Waiver of Conditions. Parent and Purchaser expressly reserve the right to waive any of the Offer Conditions, to make any change in the terms of or conditions to the Offer in a manner consistent with the terms of the Merger Agreement or to increase the Offer Price, provided that, without the prior written consent of Regulus, Parent and Purchaser may not (and Parent will not permit Purchaser to):

•

waive or modify the (i) Minimum Condition, (ii) Illegality Condition, (iii) Antitrust Condition, or (iv) Termination Condition (each as defined in the Offer to Purchase);

•

change the form of consideration to be paid in the Offer;

•

decrease the Offer Price or the number of Shares sought in the Offer;

•

extend the Offer or the Expiration Time, except as described in the Offer to Purchase;

•

impose conditions or requirements on the Offer other than the Offer Conditions (as defined in the Offer to Purchase);

•

amend or modify any term or condition of the Offer in any manner that is (or reasonably would be expected to be) adverse to Regulus’ stockholders; or

•

make any change in terms of or conditions to the Offer in a manner that would, individually or in the aggregate, prevent or materially delay the consummation of the Offer or prevent, materially delay or materially impair the ability of Parent or Purchaser to consummate the Offer or the Merger by the Termination Date (as defined in the Offer to Purchase).

Important: This Letter of Transmittal or an Agent’s Message, together with Share Certificate(s) or Book-Entry Confirmation and all other required documents, must be received by the Depositary on or prior to the Expiration Date, or the tendering stockholder must comply with the procedures for guaranteed delivery.

The Depositary for the Offer is:

	If delivering by mail:			If delivering by express mail or other expedited mail service:
	Computershare Trust Company, N.A. c/o Voluntary Corporate Actions P.O. Box 43011 Providence, Rhode Island 02940-3011			Computershare Trust Company, N.A. c/o Voluntary Corporate Actions 150 Royall Street, Suite V Canton, Massachusetts 02021

DELIVERY OF THIS LETTER OF TRANSMITTAL TO AN ADDRESS OTHER THAN AS SET FORTH ABOVE WILL NOT CONSTITUTE A VALID DELIVERY TO THE DEPOSITARY.

Any questions or requests for assistance may be directed to the Information Agent at its telephone number and location listed below. Requests for additional copies of the Offer to Purchase and this Letter of Transmittal may be directed to the Information Agent at its telephone number and location listed below. You may also contact your broker, dealer, commercial bank or trust company or other nominee for assistance concerning the Offer.

The Information Agent for the Offer is:

Innisfree M&A Incorporated
501 Madison Avenue, 20th floor
New York, New York 10022
Stockholders may call: (877) 800-5186 (toll-free from the United States or Canada) or
+1 (412) 232-3651 (from outside of the United States or Canada)
Banks and Brokers may call collect: (212) 750-5833

	Name of Tendering Stockholder:
	Window Ticket Number (if any) or DTC Participant Number:
	Date of Execution of Notice of Guaranteed Delivery
	Name of Institution which Guaranteed Delivery

	Name of Tendering Institution:
	DTC Participant Number:
	Transaction Code Number: