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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

 

FORM 8-K

 

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): November 12, 2025

 

Prelude Therapeutics Incorporated

(Exact Name of Registrant as Specified in its Charter)

 

 

 

 

 

 

Delaware

 

001-39527

 

81-1384762

(State or other jurisdiction of
incorporation or organization)

 

(Commission
File Number)

 

(I.R.S. Employer
Identification No.)

 

 

 

175 Innovation Boulevard

Wilmington, Delaware

 

19805

(Address of principal executive offices)

 

(Zip Code)

Registrant’s telephone number, including area code: (302) 467-1280

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

 

 

 

 

 

Title of each class

 

Trading
Symbol(s)

 

Name of each exchange on which registered

Common Stock, $0.0001 par value per share

 

PRLD

 

Nasdaq Global Select Market

 

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐


Item 2.02 Results of Operations and Financial Condition.

 

On November 12, 2025, Prelude Therapeutics Incorporated (the "Company") issued a press release announcing its financial results for the three months ended September 30, 2025. A copy of the press release is attached as Exhibit 99.1 to this Current Report on Form 8-K.

 

 

Item 7.01 Regulation FD Disclosure.

The Company has prepared investor presentation materials with information about the Company, which it intends to use as part of investor presentations. A copy of the investor presentation materials to be used by management for presentations is attached as Exhibit 99.2 to this Current Report on Form 8-K and is incorporated herein by reference.

 

The information in this Current Report on Form 8-K and in Exhibits 99.1 and 99.2 attached hereto is being furnished, but shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (“Exchange Act”), and is not incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended, or the Exchange Act, whether made before or after the date hereof, regardless of any general incorporation language in such filing.

 

 

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

 

 

 

Exhibit
Number

 

Description

99.1

 

Press release issued by Prelude Therapeutics Incorporated regarding its financial results for the three months ended September 30, 2025, dated November 12, 2025.

99.2

 

Presentation

104

 

Cover Page Interactive Data File (embedded within the Inline XBRL Document)

 


SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

 

 

 

 

PRELUDE THERAPEUTICS INCORPORATED

 

 

 

 

 

Date: November 12, 2025

By:

/s/ Bryant Lim

 

 

Bryant Lim

 

 

Chief Legal Officer, Corporate Secretary, and Chief Financial Officer

 


EX-99.1 2 prld-ex99_1.htm EX-99.1 EX-99.1

 

 

 

Exhibit 99.1

img268059179_0.jpg

Prelude Therapeutics Reports Third Quarter 2025 Financial Results and Provides Corporate Update

 

Lead candidate from mutant selective JAK2V617F JH2 inhibitor program advancing with IND filing expected in the first quarter of 2026

 

Lead candidate from oral KAT6A selective degrader program advancing with IND filing expected in mid-2026

 

Preclinical data from JAK2V617F JH2 inhibitor program and CALR-targeted degrader antibody conjugate (DAC) program were both accepted for oral presentations at the American Society of Hematology (ASH) 67th Annual Meeting in December

 

Current cash runway into 2027 based on preliminary estimates

 

Company to host investor conference call and webcast on Wednesday, November 12, 2025 at 8:00 AM EST

 

WILMINGTON, Del., Nov. 12, 2025 (GLOBE NEWSWIRE) – Prelude Therapeutics Incorporated (Nasdaq: PRLD), a precision oncology company, today reported its financial results for third quarter ended September 30, 2025, and provided an update on its pipeline and other corporate developments.

 

“Last week, we announced a number of strategic updates that significantly strengthen and shape our path forward heading into 2026,” stated Kris Vaddi, Ph.D., Chief Executive Officer of Prelude. “We have two promising programs advancing rapidly towards clinical development – our mutant selective JAK2V617F inhibitor program and our highly selective KAT6A degrader program. Both programs target clinically validated mechanisms in disease areas of significant unmet need for patients with clear paths to differentiation in early clinical development.”


Key Pipeline Programs
Mutant selective JAK2V617F JH2 inhibitor program

JAK2V617F is the primary driver mutation responsible for disease progression in the majority of patients living with myeloproliferative neoplasms (MPNs). The mutation impacts approximately 95% of patients with polycythemia vera (PV), 60% of patients with essential thrombocythemia (ET) and 55% of patients with myelofibrosis (MF). Identifying JAK2 JH2 inhibitors that selectively target V617F+ cells has long been a shared goal and challenge for industry. Prelude has discovered novel allosteric inhibitors that bind into the JAK2 JH2 “deep pocket” where the V617F mutation resides. These candidates demonstrate mutant specific inhibition in multiple preclinical models of MPNs.

 


 

 

 

Exhibit 99.1

Prelude believes this approach may have the potential to reduce mutant allele burden, slow or even reverse disease progression, and transform treatment outcomes for MPN patients.

 

The Company has advanced the lead candidate from this program into IND-enabling studies and expects to file an IND and advance into clinical trials in the first half of 2026. The first disclosure of preclinical data from this program has been accepted for oral presentation at the American Society of Hematology (ASH) 67th Annual Meeting taking place in Orlando, FL December 6-9, 2025. The abstract can be found on the ASH 2025 website ASH Annual Meeting & Exposition – Hematology.org.

 

The JAK2V617F inhibitor program is subject to an exclusive option agreement with Incyte announced in November 2025.

 

Highly selective KAT6A oral degrader program

KAT6 is an emerging, clinically-validated target in the treatment of ER+ breast cancer. Prelude discovered and is developing first-in-class, highly potent, highly selective and orally bioavailable KAT6A selective degraders. Prelude believes that selectively degrading KAT6A has the potential for improved efficacy, tolerability and combinability with other agents relative to non-selective inhibitors of KAT6A/B. The Company recently presented preclinical data supporting this hypothesis at the AACR Annual Meeting 2025. The presentation can be found at Publications – Prelude Therapeutics.

 

The Company has selected a development candidate and is on track to file an IND in mid-2026 and initiate a phase 1 dose escalation study in the second half of 2026.

 

Degrader payloads for next generation DACs

Prelude is leveraging our expertise in targeted protein degradation to discover and develop novel degrader payloads for use with next generation DACs. We have developed highly potent SMARCA2/4 and CDK9 degrader payloads optimized for efficacy, tolerability and developability when coupled to a wide range of different antibodies.

 

The Company has amended and expanded the scope of our existing DAC collaboration with AbCellera Biologics. This enables AbCellera to use our degrader payloads on additional undisclosed antibody targets of interest and also enables Prelude to utilize our degrader payloads in licensing arrangements with other potential partners. The Company’s payloads and corresponding payload-linkers are available for licensing to partners to expand the reach of this new technology.

 

We have recently published preclinical data demonstrating that next generation DACs using Prelude degrader payloads have potential for significantly better in vivo efficacy and tolerability compared to traditional cytotoxic ADCs when tested head-to-head in xenograft models. These data can be found at: Publications – Prelude Therapeutics Mutant CALR is a neoantigen presented on the cell surface of malignant myeloid cells but not normal cells and is found in approximately 25-35% of patients with myelofibrosis (MF) and essential thrombocythemia (ET).

 

Mutated calreticulin (mCALR) DAC discovery program

 


 

 

 

Exhibit 99.1

Recently, a mCALR-targeted monoclonal antibody demonstrated robust clinical activity in high-risk ET patients. Prelude is exploring mCALR-targeted DACs using the Company’s proprietary degrader payloads as a differentiated approach for patients with CALR mutations. This early discovery program is wholly owned and controlled by Prelude.

 

The Company presented the first preclinical data from the program at the European Hematology Association 2025 Congress in June. The presentation can be found at Publications – Prelude Therapeutics. Updated preclinical data from this program has been accepted for oral presentation at the American Society of Hematology (ASH) 67th Annual Meeting taking place in Orlando, FL December 6-9, 2025. The abstract can be found on the ASH 2025 website ASH Annual Meeting & Exposition – Hematology.org.

 

Third Quarter 2025 Financial Results 

Cash, Cash Equivalents, Restricted Cash and Marketable Securities:

At September 30, 2025, the Company had cash, cash equivalents, restricted cash and marketable securities totaling $58.2 million. Subsequent to September 30, 2025, the Company received an additional license payment from its expanded collaborative agreement with AbCellera in October 2025 and $60 million from Incyte in November 2025. Based on preliminary estimates, the Company anticipates that its existing cash, cash equivalents, restricted cash and marketable securities will fund Prelude’s operations into 2027.

 

Research and Development (R&D) Expenses:

For the third quarter of 2025, R&D expense decreased to $21.7 million from $29.5 million for the prior year period. Included in the R&D expense for the three months ended September 30, 2025 was $1.4 million of non-cash expense related to stock-based compensation, including employee stock options, compared to $3.4 million for the three months ended September 30, 2024. Along with the decrease in stock-based compensation expense, research and development expenses decreased due to a decrease in expense related to our SMARCA2 clinical trials. Research and development expenses may fluctuate from period to period depending upon the stage of certain projects and the level of preclinical and clinical trial-related activities.

 

General and Administrative (G&A) Expenses:

For the third quarter of 2025, G&A expenses decreased to $5.2 million from $7.7 million for the prior year period. Included in general and administrative expenses for the three months ended September 30, 2025, was $1.0 million of non-cash expense related to stock-based compensation, including employee stock options, compared to $2.5 million for the three months ended September 30, 2024. The decrease in general and administrative expenses was primarily due to a decrease in stock-based compensation due to lower valuation on more recent grants due to the decrease in our stock price.

 

Net Loss:

 


 

 

 

Exhibit 99.1

For the three months ended September 30, 2025, net loss was $19.7 million, or $0.26 per share compared to $32.3 million, or $0.43 per share, for the prior year period. Included in the net loss for the three months ended September 30, 2025, was $2.4 million of non-cash expenses related to the impact of expensing share-based payments, including employee stock options, as compared to $5.9 million for the same period in 2024.

 

Conference Call and Webcast Information

Prelude Therapeutics management team will host a conference call, live webcast with slides and a Q&A on Wednesday, November 12, 2025 at 8:00 AM ET. A live webcast of the presentation will be available at Events & Presentations - Prelude Therapeutics (preludetx.com) A replay of the webcast will be available shortly after the conclusion of the call at Events & Presentations - Prelude Therapeutics (preludetx.com) and archived on the Company’s website for 60 days following the call.

 

About Prelude Therapeutics

Prelude Therapeutics is a leading precision oncology company developing innovative medicines in areas of high unmet need for cancer patients. Our pipeline features JAK2V617F selective inhibitors and highly selective oral KAT6A degraders -- new approaches to clinically validated targets with transformative potential for patients. We are leveraging our expertise in targeted protein degradation to discover and develop next generation degrader antibody conjugates (DACs) with novel payloads. We are on a mission to extend the promise of precision medicine to every cancer patient in need. Our corporate presentation can be found at Events & Presentations - Prelude Therapeutics.. For more information, visit preludetx.com.

 

Cautionary Note Regarding Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995, including, but not limited to, anticipated discovery, preclinical and clinical development activities for Prelude’s product candidates, the potential safety, efficacy, benefits and addressable market for Prelude’s product candidates, the expected timeline for clinical trial results for Prelude’s product candidates, and the sufficiency of Prelude’s cash runway into 2027. All statements other than statements of historical fact are statements that could be deemed forward-looking statements. The words “believes,” “anticipates,” “estimates,” “plans,” “expects,” “intends,” “may,” “could,” “should,” “potential,” “likely,” “projects,” “continue,” “will,” “schedule,” and “would” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These forward-looking statements are predictions based on the Company’s current expectations and projections about future events and various assumptions. Although Prelude believes that the expectations reflected in such forward-looking statements are reasonable, Prelude cannot guarantee future events, results, actions, levels of activity, performance or achievements, and the timing and results of biotechnology development and potential regulatory approval is inherently uncertain. Forward-looking statements are subject to risks and uncertainties that may cause Prelude's actual activities or results to differ significantly from those expressed in any forward-looking statement, including risks and uncertainties related to Prelude's ability to advance its product candidates, the receipt and timing of potential regulatory designations, approvals and commercialization of product candidates, clinical trial sites and our ability to enroll eligible patients, supply chain and manufacturing facilities, Prelude’s ability to maintain and recognize the benefits of certain designations received by product candidates, the timing and results of preclinical and clinical trials, Prelude's ability to fund development activities and achieve development goals, Prelude's ability to protect intellectual property, and other risks and uncertainties described under the heading "Risk Factors" in Prelude’s Annual Report on Form 10-K for the year ended December 31, 2024, its Quarterly Reports on Form 10-Q and other documents that Prelude files from time to time with the Securities and Exchange Commission.

 


 

 

 

Exhibit 99.1

These forward-looking statements speak only as of the date of this press release, and Prelude undertakes no obligation to revise or update any forward-looking statements to reflect events or circumstances after the date hereof, except as may be required by law.

 

 


 

 

 

Exhibit 99.1

PRELUDE THERAPEUTICS INCORPORATED

STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS

(UNAUDITED)

 

 

 

 

 

Three Months Ended September 30,

 

(in thousands, except share and per share data)

 

2025

 

 

2024

 

Revenue

 

$

6,500

 

 

$

3,000

 

 

 

 

 

 

 

 

Operating expenses

 

 

 

 

 

 

Research and development

 

 

21,708

 

 

 

29,457

 

General and administrative

 

 

5,210

 

 

 

7,919

 

Total operating expenses

 

 

26,918

 

 

 

37,376

 

Loss from operations

 

 

(20,418

)

 

 

(34,376

)

Other income, net

 

 

693

 

 

 

2,105

 

Net loss

 

$

(19,725

)

 

$

(32,271

)

Per share information:

 

 

 

 

 

 

Net loss per share of common stock, basic and diluted

 

$

(0.26

)

 

$

(0.43

)

Weighted average common shares outstanding, basic
   and diluted

 

 

76,132,337

 

 

 

75,855,949

 

Comprehensive loss:

 

 

 

 

 

 

Net loss

 

$

(19,725

)

 

$

(32,271

)

Unrealized gain (loss) on marketable securities, net of tax

 

 

3

 

 

 

457

 

Comprehensive loss

 

$

(19,722

)

 

$

(31,814

)

 

 


 

 

 

Exhibit 99.1

PRELUDE THERAPEUTICS INCORPORATED

BALANCE SHEETS

 

(in thousands, except share data)

 

September 30,
2025

 

 

December 31,
2024

 

Assets

 

(unaudited)

 

 

 

 

Current assets:

 

 

 

 

 

 

Cash and cash equivalents

 

$

47,532

 

 

$

12,474

 

Marketable securities

 

 

7,425

 

 

 

121,140

 

Prepaid expenses and other current assets

 

 

3,373

 

 

 

2,281

 

Total current assets

 

 

58,330

 

 

 

135,895

 

Restricted cash

 

 

3,235

 

 

 

4,044

 

Property and equipment, net

 

 

5,531

 

 

 

6,767

 

Operating lease right-of-use asset

 

 

27,549

 

 

 

28,699

 

Other assets

 

 

110

 

 

 

110

 

Total assets

 

$

94,755

 

 

$

175,515

 

Liabilities and stockholders’ equity

 

 

 

 

 

 

Current liabilities:

 

 

 

 

 

 

Accounts payable

 

$

2,533

 

 

$

7,732

 

Accrued expenses and other current liabilities

 

 

12,930

 

 

 

15,209

 

Operating lease liability

 

 

2,727

 

 

 

2,492

 

Finance lease liability

 

 

 

 

 

208

 

Total current liabilities

 

 

18,190

 

 

 

25,641

 

Other liabilities

 

 

2,904

 

 

 

3,090

 

Operating lease liability

 

 

15,127

 

 

 

15,325

 

Total liabilities

 

 

36,221

 

 

 

44,056

 

Commitments (Note 8)

 

 

 

 

 

 

Stockholders’ equity:

 

 

 

 

 

 

Voting common stock, $0.0001 par value: 487,149,741 shares authorized; 43,750,086 and 42,298,859 shares issued and outstanding at September 30, 2025 and December 31, 2024, respectively

 

 

4

 

 

 

4

 

Non-voting common stock, $0.0001 par value: 112,850,259 and 12,850,259 shares authorized at September 30, 2025 and December 31, 2024, respectively; 12,850,259 shares issued and outstanding at both September 30, 2025 and December 31, 2024

 

 

1

 

 

 

1

 

Additional paid-in capital

 

 

725,131

 

 

 

714,982

 

Accumulated other comprehensive income

 

 

2

 

 

 

35

 

Accumulated deficit

 

 

(666,604

)

 

 

(583,563

)

Total stockholders’ equity

 

 

58,534

 

 

 

131,459

 

Total liabilities and stockholders’ equity

 

$

94,755

 

 

$

175,515

 

 

 

Investor Contact:
Robert A. Doody, Jr.
Senior Vice President, Investor Relations

Prelude Therapeutics Incorporated

484.639.7235

rdoody@preludetx.com

 

 


EX-99.2 3 prld-ex99_2.htm EX-99.2

Slide 1

Corporate Presentation November 2025 Exhibit 99.2


Slide 2

This presentation contains “forward-looking” statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995, including, but not limited to, anticipated discovery, preclinical and clinical development activities for Prelude’s product candidates and milestones, the potential safety, efficacy, benefits and addressable market for Prelude Therapeutic Incorporated's (the "Company") product candidates. Any statements contained herein or provided orally that are not statements of historical fact may be deemed to be forward-looking statements. In some cases, you can identify forward-looking statements by such terminology as ‘‘believe,’’ ‘‘may,’’ ‘‘will,’’ ‘‘potentially,’’ ‘‘estimate,’’ ‘‘continue,’’ ‘‘anticipate,’’ ‘‘intend,’’ ‘‘could,’’ ‘‘would,’’ ‘‘project,’’ ‘‘plan,’’ ‘‘expect’’ and similar expressions that convey uncertainty of future events or outcomes, although not all forward-looking statements contain these words. Statements, including forward-looking statements, speak only to the date they are provided (unless an earlier date is indicated).  This presentation shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of securities of the Company in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or other jurisdiction, or pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act of 1933, as amended, and any other applicable securities laws. These forward-looking statements are based on the beliefs of our management as well as assumptions made by and information currently available to us. Although we believe the expectations reflected in such forward-looking statements are reasonable, we can give no assurance that such expectations will prove to be correct. If such assumptions do not fully materialize or prove incorrect, the events or circumstances referred to in the forward-looking statements may not occur. We undertake no obligation to update publicly any forward-looking statements for any reason after the date of this presentation to conform these statements to actual results or to changes in our expectations, except as required by law. Accordingly, readers are cautioned not to place undue reliance on these forward-looking statements.  Additional risks and uncertainties that could affect our business are included under the caption “Risk Factors” in our filings with the Securities and Exchange Commission, including our Annual Report on Form 10-K for the year ended December 31, 2024. Forward Looking Statements & Disclaimers


Slide 3

We are on a mission to extend the promise of precision medicine to every cancer patient in need Select the best modality to precisely target oncogenic mechanisms Strive for first- or best-in-class and anchor to patient unmet need Draw on decades of experience and proven leadership to drive innovation


Slide 4

Kris Vaddi, PhD Chief Executive Officer Andrew Combs, PhD Chief Chemistry Officer Sean Brusky, MBA Chief Business Officer Peggy Scherle, PhD Chief Scientific Officer Bryant Lim, J.D. Chief Financial Officer,Chief Legal Officer, Secretary Dr. Victor Sandor, former CMO at Array BioPharma and current member of our Board of Directors, will serve as a senior medical advisor, providing strategic and operational leadership for our clinical development programs Experienced Leadership Team With Proven Track Records


Slide 5

PROGRAM POTENTIAL INDICATIONS DISCOVERY/LEAD OPT. IND-ENABLING PHASE 1 PROGRAMINTEREST UPCOMING MILESTONES JAK2V617FMutant SelectiveJH2 Inhibitors VF+ myeloproliferative neoplasms (MPNs)(MF, PV, ET) IND Filing Q1 2026 Oral abstract at ASH 2025 KAT6ASelective Degraders ER+ breast cancer, other malignancies Prelude wholly owned IND filing mid-2026 mCALR DAC CALR-mutated MPNs (ET, MF) Prelude wholly owned Oral abstract at ASH 2025 Degrader Payloads for DACs Broad utility across multiple indications . . . Additional Partnerships Prelude’s Pipeline & Discovery Engine  JAK2, janus kinase 2; JH2, JAK2 homology domain 2 (pseudokinase regulatory domain); VF+, V617F mutated; MPNs, myeloproliferative neoplasms; MF, myelofibrosis; PV, polycythemia vera; ET, essential thrombocythemia; ER+, estrogen receptor positive; DAC, degrader antibody conjugate; mCALR = mutated calreticulin1 - Exclusive option agreement with Incyte (announced November 2025) 2 - DAC Discovery Collaboration with AbCellera (announced November 2023, amended and expanded 2H 2025) IND Enabling Discovery Proprietary degrader payloads available for licensing to partners developing next generation DACs 1 2


Slide 6

Our Investment Thesis Centers on Advancing Two Programs – Both Representing Highly Differentiated Approaches to Clinically Validated Targets KAT6AHighly Selective Oral Degraders JAK2V617FMutant Selective Inhibitors First-in-class KAT6A degraders, with absolute selectivity over KAT6B – a differentiated approach against a clinically validated target in ER+ breast cancer with pan-tumor potential in other malignancies Potentially transformative JAK2V617F allosteric JH2 inhibitors with potential to reduce mutant allele burden and modify the course of disease progression in patients with myeloproliferative neoplasms (MPNs)


Slide 7

JAK2V617F is the Primary Driver Mutation Leading to Activated JAK-STAT Signaling, Uncontrolled Proliferation, and Disease Progression in MPNs The JAK-STAT pathway mediates growth factor signaling, most notably: Thrombopoietin receptor for platelet production Erythropoietin receptor for red blood cell production The JAK2V617F mutation leads to growth factor-independent hyperactivation of JAK-STAT pathway and uncontrolled myeloid and erythroid proliferation Inhibition of wildtype JAK2 causes anemia and thrombocytopenia and current JAK inhibitors, like ruxolitinib (Jakafi®), while effective, equally inhibit both WT and V617F-mutated (VF+) JAK2 JAK2 JH2 inhibitors that selectively target VF+ progenitor cells have potential to reduce mutant allele burden, modify disease progression, and transform treatment outcomes for MPN patients Jakafi® is a registered trademark of Incyte Corporation Jakafi® Campbell P.J. and Green A.R. N Engl J Med 2006;355:2452-2466


Slide 8

A JAK2V617F Mutant Selective Inhibitor Could Become a Disease Modifying Option for the Majority of MPN Patients and Represents an Expansive Opportunity Essential Thrombocythemia(ET) Polycythemia Vera(PV) JAK2 V617F Mutated~95% JAK2 V617F Mutated~60% CALRMutated MPL mutation Nonmutated Nonmutated ~78,500 ~142,000 Est. # of U.S. Patients with JAK2V617F Mutation~228,500 Primary Myelofibrosis (PMF) JAK2V617F Mutated~55% CALRMutated MPL mutation Nonmutated ~8,000 Sources: NCI SEER Database (accessed Dec 2024), Leukemia & Lymphoma Society Facts & Figures; F. Passamonte et.al., “Clinical Significance of JAK2 V617F Mutant Allele Burden”; Haematologica 2009 Jan;94(1):7–10


Slide 9

Prelude Scientists Recently Discovered the First Known JAK2 Inhibitors That Bind in the JAK2 JH2 “Deep Pocket” Where the V617F Mutation Resides Prelude JAK2 JH2 Inhibitors Bind into the “Deep Pocket” Adjacent to V617F Mutation Allosteric JH2 Regulatory Domain vs Catalytic Domain


Slide 10

Global sales of ruxolitinib (Jakafi® /Jakavi®) alone grew to over $4.5B in 20241,2 Continuing strong sales growth for ruxolitinib in PV First generation JAK inhibitors have delivered transformative efficacy for MF patients Highly effective at reducing symptoms and spleen size However, toxicities from wild-type activity limit ability to reach maximal efficacy Ruxolitinib is the only JAK inhibitor approved in PV (2L only) and none are approved in ET Prelude’s JAK2V617F mutant selective inhibitors demonstrate: Potent and selective reduction in JAK2V617F cells in vitro compared to WT cells Improved efficacy, reduced toxicity, and rapid reduction of mutant alleles in vivo Potential for transformative efficacy and disease modification in PV, ET and MF JAK2V617F Mutant Selective Inhibitors Are Highly Differentiated From 1st Generation JAK Inhibitors in a Large and Growing Market 1 - Incyte Pharmaceuticals (Q4 2024 Financial Results and Corporate Update Presentation, February 10, 2025); Jakafi is a registered trademark of Incyte2 - Novartis Pharmaceuticals (Full Year 2024 Product Sales, Accessed August 2025; Jakavi is a registered trademark of Novartis 3 - Abstract can be found on the ASH 2025 website: ASH Annual Meeting & Exposition - Hematology.org.  First Public Disclosure of Preclinical Data on Prelude’s JAK2V617F Program Accepted for Oral Presentation at ASH 2025 3


Slide 11

JAK2V617F Program1: Phase 1 Study Design (Illustrative) MPNs 2026 2027 2028 2029 Phase 1b/2 Expansion Phase 1 (MPNs) First Look at Spleen/Symptoms/CHR Mutant Allele Burden Phase 1a Dose Escalation Expansion Cohorts DL(n) (N=3-6) DL1 (N=3-6) DL2 (N=3-6) Expansion ~50 hrPV, hrET & MF at Dose OBJECTIVE CHR rate, Durability (24 week) and Molecular Response Rate (allele burden reduction) Spleen and symptom benefit Data generation in preparation for first registrational trial(s) 1 - Subject to exclusive option agreement with Incyte (announced November 2025) MPNs, myeloproliferative neoplasms; MF, myelofibrosis; hrPV, high risk polycythemia vera; hrET, high risk essential thrombocythemia; CHR, complete hematologic response; DL, dose level


Slide 12

Exclusive option agreement with Incyte (announced November 2025) Option Agreement With Incyte Provides Significant Capital to Further Advance Our JAK2V617F and KAT6A Programs


Slide 13

Our Investment Thesis Centers on Advancing Two Programs – Both Representing Highly Differentiated Approaches to Clinically Validated Targets KAT6AHighly Selective Oral Degraders JAK2V617FMutant Selective Inhibitors First-in-class KAT6A degraders, with absolute selectivity over KAT6B – a differentiated approach against a clinically validated target in ER+ breast cancer with pan-tumor potential in other malignancies Potentially transformative JAK2V617F allosteric JH2 inhibitors with potential to reduce mutant allele burden and modify the course of disease progression in patients with myeloproliferative neoplasms (MPNs)


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KAT6 is a clinically validated mechanism in ER+ breast cancer A KAT6A/B dual inhibitor is now in pivotal phase 3 trials in combination with fulvestrant, after progression on a CDK4/6 inhibitor1 Demonstrated compelling efficacy in post CDK4/6 inhibitor setting in a broad population of ER+ BC1 Clinically relevant safety observations including dysgeusia and grade 3/4 neutropenia are challenging and may limit dosing to maximal benefit in combination with SoC treatments (e.g., CDK4/6 inhibitors)1 Our KAT6A program aims to demonstrate a superior clinical profile Optimal efficacy Lower hematological toxicity Improved combinability profile with other agents (e.g., oral SERDs, AIs, CDK4/6is, PI3Kis) ER+ breast cancer treatment market is projected to reach $42B by 20332 Most common type of breast cancer, representing 70% of all cases 1 - P LoRusso, et. al,, Dose optimization of PF-07248144, a first-in-class KAT6 inhibitor, in patients (pts) with ER+/HER2− metastatic breast cancer (mBC): Results from phase 1 study to support the recommended phase 3 dose (RP3D) ASCO 2025 Annual Meeting, J Clin Oncol 43, 1020(2025) 2 - Vision Research Reports; "Estrogen Receptor Positive Breast Cancer Treatment Market Forecast 2024-2033. ER+ Breast Cancer Treatment Market Size | Companies Prelude’s First-In-Class Oral KAT6A Selective Degraders


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Selectively Degrading KAT6A is a Novel Approach with Potential to Deliver Differentiated Safety and Efficacy Over Non-Selective KAT6A/B Inhibitors Dual Inhibition May Lead to More Bone Marrow Toxicity* KAT6A Amplification and Overexpression in Cancer Leads to Increased Activity 1 3


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Our Lead KAT6A Selective Degrader Development Candidate Prelude Data on File Lead DC is a Potent KAT6A Degrader in Preclinical Models Absolute kinetic selectivity for 6A/6B (>1000-fold) Global proteomics demonstrates selective KAT6A degradation Excellent oral PK across species Compelling in vivo efficacy as monotherapy in multiple models Reduced effect on neutrophils in preclinical models Non-GLP DRF studies complete IND-enabling studies initiated Absolute Degradation Selectivity (KAT6A vs KAT6B) ZR-75 Breast Cancer CDX Model In Vivo Efficacy KAT6A Lead DC KAT6A Lead DC


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Lead DC demonstrates dose-dependent efficacy, driving tumor regressions at low daily oral doses in preclinical models Well-tolerated with no observed body weight loss in preclinical models Human dose of 5-10 mg QD projected to provide required exposure for efficacy Our Lead DC Drives Tumor Regressions in T47-D Model with Significantly Greater Monotherapy Activity than KAT6A/B Inhibitor + Fulvestrant Combination Significant TGI as Monotherapy vs. KAT6A/Bi + fulvestrant Tumor Regressions Observed at Low Doses Prelude Data on File Vehicle Lead DC, 0.3 mg/kg, PO QD Lead DC, 0.3 mg/kg, PO BID Lead DC, 3.0 mg/kg, PO QD Prelude’s KAT6A Lead Degrader DC KAT6A/B Inhibitor + fulvestrant


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KAT6A Selective Degraders Show Potential for Lower Bone Marrow Toxicity in Preclinical Models Compared to KAT6A/B Dual Inhibitors Neutrophils Day 5 Dose Response of CFU-GM Low Dose High Dose High Dose Low Dose KAT6A degrader KAT6A degrader Ex vivo and in vivo studies with KAT6A selective degraders show limited effects on neutrophils in contrast to dual KAT6A/B inhibitors or degraders Prelude Data on File


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Prelude has discovered and developed multiple first-in-class, highly selective KAT6A degraders which demonstrate favorable preclinical results KAT6A degraders show potential to achieve best-in-class efficacy and ability to differentiate on safety and combinability early in clinical development Lead DC has completed dosing in non-GLP studies in rats and dogs On-track to advance to IND filing in mid-2026 Phase 1 start expected 2H 2026 KAT6A Selective Degrader Program Summary


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Prelude is Applying Our Expertise in Targeted Protein Degradation to Advance the Next Generation of Degrader Antibody Conjugates (DACs) Fu, Z., Li, S., Han, S. et al. Sig Transduct Target Ther 7, 93 (2022).  Toxicity & Cross Resistance Efficacy Therapeutic Index Non-selective, Genotoxic Payloads Limited Payload Diversity Broad Chemotherapy Liabilities Emergent Payload Resistance Dual Targeting Tumor-Specific Cell Surface Antigen, and Targeted Degradation of Critical Proteins Expanded Therapeutic Index Overcome Cytotoxic Payload Resistance TargetedDegrader Payloads Traditional ADCs Degrader Antibody Conjugates (DACs) Cytotoxic Chemotherapy DACs, Degrader Antibody Conjugates


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Prelude’s Degrader Payloads: Engineered to Improve Efficacy, Tolerability and Developability Compared to Traditional Cytotoxic Payloads Payload Rationale DAC Properties Prelude Degrader Payload-Linkers Efficacy Tolerability Developability Exceptional Potency (pM) Allows low DAR; Catalytic effect SMARCA2/4 Dual Degraders(VHL- and CRBN- based) CDK9 Degraders Permeable Enable localized bystander effect Non-Permeable Limit off-target toxicity from payload diffusion Highly stable E3 Ligase binder Long t1/2 in vivo; Stable drug substance Prodrug Lower risk of cleavage in plasma High Clearance Rapid clearance in plasma Non-Genotoxic Indications beyond cancer Prelude’s Degrader Payloads Have the Potential to Deliver Novel DACs with Improved Efficacy and Therapeutic Index or


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Mutated Calreticulin (mCALR) Represents a Promising Target for Next Generation DACs Mutant CALR is a neoantigen presented on the cell surface of malignant cells but not normal cells and is found in 25-35% of patients with Myelofibrosis (MF) and ET SMARCA2/4 and CDK9 degraders are both highly active in CALR mutated MPN cell lines and can be used as payloads for mCALR-targeted DACs mCALR-targeted DACs, delivering Prelude’s degrader payloads to disease-initiating clones have the potential to be first-in-class, disease modifying therapies Primary Myelofibrosis (PMF) Essential Thrombocythemia(ET) Polycythemia Vera(PV) JAK2 V617F Mutated~95% MPL mutation MPL mutation Nonmutated Nonmutated mCALR is emerging as a clinically validated target in MPNs with disease modifying potential Nonmutated ~5,000 ~32,500 N/A Est. # of US Pts. with CALR Mutation Sources: NCI SEER Database (accessed Dec 2024), Leukemia & Lymphoma Society Facts & Figures; J.How et. al., Mutant calreticulin in myeloproliferative neoplasms, Blood (2019) 134 (25): 2242–2248 JAK2 V617F Mutated~95% JAK2 V617F Mutated~60% JAK2V617F Mutated~55% CALRMutated ~35% CALRMutated ~25%


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CALR x SMARCA2/4 DACs Demonstrate Robust and Selective Target Degradation and Cytotoxicity in CALR Mutant Cells and Robust Tumor Growth Inhibition In Vivo >68x Ba/F3 CALRins5 Ba/F3 CALRWT 0 .05 0.5 1 10 SMARCA2 0 .05 0.5 1 10 GAPDH SMARCA4 CALR DAC µg/ml Degradation Assay, 48h Anti-proliferation Assay SMARCA2/4 Degrader Robust Tumor Growth Inhibition in vivo Fultang N., et al., EHA2025 Oral Abstract, 12 June 25; Discovery Of First-in-class Precision ADCs Targeting Mutant Calreticulin For The Treatment Of MPNs. (Link) 1 - Abstract now available: ASH Annual Meeting & Exposition - Hematology.org CALR x SMARCA2/4 DAC CALR x SMARCA2/4 DAC CALR x CDK9 DAC Abstract Accepted for Oral Presentation at ASH20251


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Executive Summary Newly disclosed JAK2V617F mutant selective inhibitor program advancing to IND filing in 1Q 2026 1 First-in-class selective KAT6A selective degrader program on track to enter the clinic in 2026 with clear path to differentiation in ER+ breast cancer market Preclinical data from JAK2V617F program and CALR-targeted DAC program both accepted for oral presentations at ASH 2025 in December Cash runway extended into 2027 based on current company projections 1 - Subject of exclusive option agreement with Incyte (announced November 2025)


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Thank YouContact Us: Robert DoodySVP, Investor Relationsrdoody@preludetx.com