8-K
Cabaletta Bio, Inc. (CABA)
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
August 18, 2021
Date of Report (Date of earliest event reported)
CABALETTA BIO, INC.
(Exact name of Registrant as Specified in its Charter)
| Delaware | 001-39103 | 82-1685768 |
|---|---|---|
| (State or other jurisdiction<br> <br>of incorporation) | (Commission<br> <br>File Number) | (I.R.S. Employer<br> <br>Identification No.) |
| 2929 Arch Street, Suite 600,<br> <br>Philadelphia, PA | 19104 | |
| --- | --- | |
| (Address of principal executive offices) | (Zip Code) |
(267) 759-3100
(Registrant’s telephone number, including area code)
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<br> <br>Symbol(s) | Name of Each Exchange<br> <br>on Which Registered |
|---|---|---|
| Common Stock, par value $0.00001 per share | CABA | The 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 7.01 | Regulation FD Disclosure. |
|---|
On August 18, 2021, Cabaletta Bio, Inc. (the “Company”) posted to the “Investors & Media” section of the Company’s website at www.cabalettabio.com an updated corporate presentation providing a corporate overview and updated development plan (the “Corporate Presentation”). A copy of the Corporate Presentation is attached hereto as Exhibit 99.1 and is incorporated by reference into this Item 7.01 of this Current Report on Form 8-K.
The information contained in Item 7.01 of this Current Report on Form 8-K is being furnished and shall not be deemed to be “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section and shall not be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.
| Item 8.01 | Other Events. |
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On August 18, 2021, the Company issued a press release announcing clinical data from the second dose cohort in its ongoing DesCAARTes^™^ Phase 1 clinical trial of DSG3-CAART for the treatment of patients with mucosal-dominant pemphigus vulgaris. A copy of the full text of the press release referenced above is filed as Exhibit 99.2 to this Current Report on Form 8-K and is incorporated herein by reference into this Item 8.01 of this Current Report on Form 8-K.
| Item 9.01. | Financial Statements and Exhibits. |
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(d) Exhibits
| 99.1 | Cabaletta Bio, Inc. Corporate Presentation, dated August 18, 2021, furnished herewith. |
|---|---|
| 99.2 | Press Release issued by the registrant on August 18, 2021. |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL Document). |
SIGNATURE
Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized.
| CABALETTA BIO, INC. | ||
|---|---|---|
| Date: August 18, 2021 | By: | /s/ Steven Nichtberger |
| Steven Nichtberger, M.D. | ||
| President and Chief Executive Officer |
EX-99.1
Corporate Presentation August 2021 Exhibit 99.1
Disclaimer The following presentation, including any printed or electronic copy of these slides, the talks given by the presenters, the information communicated during any delivery of the presentation and any question and answer session and any document or material distributed at or in connection with the presentation (collectively, the “Presentation”) has been prepared by Cabaletta Bio, Inc. (“we,” “us,” “our,” “Cabaletta” or the “Company”) and is made for informational purposes only. This Presentation does not purport to be a prospectus, to be complete or to contain all of the information you may desire. Statements contained herein are made as of the date of this Presentation unless stated otherwise, and this Presentation shall not under any circumstances create an implication that the information contained herein is correct as of any time after such date or that information will be updated or revised to reflect information that subsequently becomes available or changes occurring after the date hereof. This Presentation may contain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995 relating to our business, operations, and financial conditions, and include, but are not limited to, express or implied statements regarding our current beliefs, expectations and assumptions regarding: our business, future plans and strategies for our CAR T technology and CABA platform; the therapeutic potential and clinical benefits of our product candidates; our ability to successfully complete our preclinical and clinical studies for our product candidates, including our ongoing Phase 1 DesCAARTesTM trial, MuSK-CAART study and other discovery programs; our ability to obtain and maintain regulatory approval of our product candidates, including our planned IND submission for our MuSK-CAART program; the further expansion and development of our modular CABA platform across a range of autoimmune diseases; our ability to contract with third-party suppliers and manufacturers and further develop our internal manufacturing strategy, capabilities and facilities; our potential commercial opportunities, including value and addressable market, for our product candidates; our expectations regarding our use of capital and other financial results during 2021; and our ability to fund operations for at least the next 12 months. Words such as, but not limited to, “look forward to,” “believe,” “expect,” “anticipate,” “estimate,” “intend,” “plan,” “would,” “should” and “could,” and similar expressions or words, identify forward-looking statements. Various risks, uncertainties and assumptions could cause actual results to differ materially from those anticipated or implied in our forward-looking statements. Such risks and uncertainties include, but are not limited to, risks related to the success, cost, and timing of our product candidate development activities and preclinical studies and clinical trials, risks related to our ability to protect and maintain our intellectual property position, risks related to our relationship with third parties, uncertainties related to regulatory agencies’ evaluation of regulatory filings and other information related to our product candidates, the risk that any one or more of our product candidates will not be successfully developed and commercialized, the risk that the results of preclinical studies or clinical studies will not be productive of future results in connection with future studies, the impact of COVID-19 on the timing, progress, interpretability of data, and results of ongoing or planned clinical trials and risks relating to as a result of extraordinary events or circumstances such as the COVID-19 pandemic, and any business interruptions to our operations or to those of our clinical sites, manufacturers, suppliers, or other vendors resulting from the COVID-19 pandemic or similar public health crisis. New risks and uncertainties may emerge from time to time, and it is not possible to predict all risks and uncertainties. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise. 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. Accordingly, you are cautioned not to place undue reliance on these forward-looking statements. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements. For a discussion of these and other risks and uncertainties, and other important factors, any of which could cause our actual results to differ materially from those contained in the forward-looking statements, see the section entitled "Risk Factors" in our 2020 annual report on Form 10-K, as well as discussions of potential risks, uncertainties, and other important factors in our other filings with the Securities and Exchange Commission. Certain information contained in this Presentation relates to or is based on studies, publications, surveys and other data obtained from third-party sources and the Company’s own internal estimates and research. While the Company believes these third-party sources to be reliable as of the date of this Presentation, it has not independently verified, and makes no representation as to the adequacy, fairness, accuracy or completeness of, any information obtained from third-party sources. The Company is the owner of various trademarks, trade names and service marks. Certain other trademarks, trade names and service marks appearing in this Presentation are the property of third parties. Solely for convenience, the trademarks and trade names in this Presentation are referred to without the ® and TM symbols, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto.
Develop and launch the first curative targeted cellular therapies for patients with autoimmune diseases
Cabaletta overview * 20M, 100M & 500M refers to the number of DSG3-CAART cells infused for patients in dosing cohorts 1-3, in millions. As of August 17, 2021. Assumes no dose-limiting toxicities are observed during cohort and uninterrupted enrollment occurs in the trial. Includes five disclosed product candidates and two undisclosed pipeline disease targets in our pipeline. Developing highly specific CAAR T products to treat B cell-mediated autoimmune diseases Where there is a biologic opportunity for deep and durable, perhaps curative, responses Leveraging a clinically validated CAR T product design and manufacturing process through Penn alliance DesCAARTesTM trial enrolling patients with mucosal pemphigus vulgaris (mPV) at 500M cell dose No DLTs or clinically relevant AEs observed to date1 in all 6 patients following completion of first 2 dose cohorts (20M & 100M cells) DSG3-CAART persistence observed via qPCR in all 6 patients within the first 2 dose cohorts during the first 28 days following infusion Without lymphodepletion and in presence of circulating anti-DSG3 antibodies Potential to report biologic activity data (20M & 100M) and safety data (500M cells) this year2 Preclinical pipeline led by MuSK-CAART for myasthenia gravis – IND filing planned in 2H21 PLA2R-CAART pre-IND interaction with FDA anticipated in 2H21 for PLA2R positive primary membranous nephropathy patients Product portfolio3 currently targeting diseases that affect over 80,000 patients in the US Cash runway through at least 4Q22 with $103M in cash and investments as of June 30, 2021
Our scientific platform leverages clinically validated CAR T technology CAR T Therapy Chimeric Antigen Receptor T cell Kymriah CAAR T product candidates are designed for selective and specific elimination of the pathogenic B cells CAAR T Therapy Chimeric AutoAntibody Receptor T cell CABA CAAR T CD137 (4-1BB) Costimulatory Domain CD3-Zeta Signaling Domain HEALTHY B CELL
Foundational CAR T technology clinically validated in treating B cell-mediated cancers Cabaletta: Advancing targeted cell therapy to autoimmunity Marketed Pivotal Clinical Preclinical / Discovery Oncology B Cell-Mediated Allo/Autoimmune Diseases CAR-T / CAAR-T T-reg, NK, TCR, RBC, macrophage, TIL (7 programs under development)
Biologic opportunity for cure or treatment may be possible in dozens of B-cell mediated autoimmune diseases* CABA platform may apply across a range of autoimmune diseases Pemphigus Vulgaris1,2,3 Pemphigus Foliaceus1,2,3 Epidermolysis Bullosa Acquisita3 Bullous Pemphigoid1,2,3 Lupus Nephritis3,4 Membranous Nephropathy1,2,3 Goodpasture’s Syndrome1,2,3,4 Myasthenia Gravis1,2,3,5 Neuromyelitis Optica3 Chronic Inflammatory Demyelinating Polyneuropathy1.2 Anti-NMDAR Encephalitis3 Lambert-Eaton Syndrome5 Immune Thrombocytopenic Purpura3 Thrombotic Thrombocytopenic Purpura1,2,3 Antiphospholipid Syndrome4,5 Autoimmune Hemolytic Anemia3 Rheumatoid Arthritis2,3,4 Systemic lupus erythematosus3,4,5 ANCA-Associated Vasculitis3,4,5 Myositis5 Type 1 Diabetes3 Graves’ Disease3,5 Hashimoto’s Disease5 * Illustrative list of diseases where biologic opportunity for cure or treatment may be possible. Koneczny, Inga. "Update on IgG4-mediated autoimmune diseases: new insights and new family members." Autoimmunity Reviews (2020): 102646. Huijbers, Maartje G., et al. "IgG4-mediated autoimmune diseases: a niche of antibody-mediated disorders." Annals of the New York Academy of Sciences 1413.1 (2018): 92. Ludwig, Ralf J., et al. "Mechanisms of autoantibody-induced pathology." Frontiers in immunology 8 (2017): 603. Suurmond, Jolien, and Betty Diamond. "Autoantibodies in systemic autoimmune diseases: specificity and pathogenicity." The Journal of clinical investigation 125.6 (2015): 2194-2202. Xiao, Ze Xiu, Joseph S. Miller, and Song Guo Zheng. "An updated advance of autoantibodies in autoimmune diseases." Autoimmunity Reviews (2020): 102743. Dermatology Nephrology Neurology Hematology Rheumatology Endocrinology
Technology foundation designed to enable a portfolio of programs targeting B cell-mediated diseases Modular platform with “plug-and-play” architecture Clinically validated engineered T cell platform is the foundational technology PLA2R-CAART PLA2R+ membranous nephropathy DSG3-CAART Mucosal pemphigus vulgaris MuSK-CAART MuSK+ myasthenia gravis DSG3/1-CAART Mucocutaneous pemphigus vulgaris Swapping the extracellular domain, or autoantigen, creates new product candidates FVIII-CAART Hemophilia A with FVIII inhibitors
Epitope mapping to determine regions targeted by autoantibodies Optimize CAAR construct / design with the goal of selectively ablating reactive B cells Preclinical in vitro and in vivo testing to evaluate efficacy and safety Scientific, clinical and commercial assessment to inform product candidate development Vector & Clinical Cell manufacturing Clinical trials CABA (Cabaletta Approach for Selective B cell Ablation) platform
Therapeutic Area Indication Program Discovery2 Preclinical Phase 1 Phase 2/3 Dermatology Mucosal Pemphigus Vulgaris DSG3-CAART Mucocutaneous Pemphigus Vulgaris DSG3/1-CAART Neurology MuSK Myasthenia Gravis MuSK-CAART Nephrology PLA2R Membranous Nephropathy PLA2R-CAART Hematology Hemophilia A w/ FVIII Alloantibodies FVIII-CAART Pipeline1 includes multiple disease targets where cure is possible Two additional undisclosed disease targets added to our pipeline portfolio through expansion of our Sponsored Research Agreement with the University of Pennsylvania are not shown. In our discovery stage, we perform epitope mapping and optimize CAAR construct and design. Current pipeline includes 7 programs targeting diseases affecting >80,000 patients in the US
Data from the DesCAARTes™ trial provides read-through to pipeline Clinical data Biologic Activity Indicators Manufacturing Strong operating partnership with Penn CVPF manufacturing organization Use of validated process from CAR T experience at Penn helps mitigate risk 100% success rate for DesCAARTes™ trial manufacturing to date1 No DLTs or any clinically relevant toxicities observed to date1 in all 6 patients DSG3-CAART persistence via qPCR in all patients during 28 days post infusion Without lymphodepletion, but in presence of circulating anti-DSG3 antibodies Potential to report biologic activity (20M & 100M) and 28-day safety data (500M) in 4Q21 We are evaluating: Persistence of DSG3-CAART detected via qPCR Change in level of DSG3 antibodies (targeting persistent reduction) Reduced mPV therapy and absence of new systemic rescue therapy Change in disease activity based on clinically validated scales (e.g. PDAI, ODSS) As of August 17, 2021. Data expected within 6 months of completion for each cohort
DSG3-CAART for patients with mucosal pemphigus vulgaris
DSG3 antibodies are widely considered to be necessary and sufficient to cause PV1 PV is an optimal lead indication for CAAR T therapy Spindler, Volker, et al. "Mechanisms causing loss of keratinocyte cohesion in pemphigus." Journal of Investigative Dermatology 138.1 (2018): 32-37. Schmidt, Enno, et al. "Novel ELISA systems for antibodies to desmoglein 1 and 3." Experimental dermatology 19.5 (2010): 458-463. Joly, Pascal, et al. "First-line rituximab combined with short-term prednisone versus prednisone alone for the treatment of pemphigus (Ritux 3): a prospective, multicentre, parallel-group, open-label randomised trial." The Lancet 389.10083 (2017): 2031-2040. Mouquet, Hugo, et al. "B-cell depletion immunotherapy in pemphigus: effects on cellular and humoral immune responses." Journal of Investigative Dermatology 128.12 (2008): 2859-2869. Hammers, Christoph M., et al. "Persistence of anti-desmoglein 3 IgG+ B-cell clones in pemphigus patients over years." Journal of Investigative Dermatology 135.3 (2015): 742-749. Ohyama, Bungo, et al. "Epitope spreading is rarely found in pemphigus vulgaris by large-scale longitudinal study using desmoglein 2–based swapped molecules." Journal of investigative dermatology 132.4 (2012): 1158-1168. Ellebrecht, Christoph T., et al. "Reengineering chimeric antigen receptor T cells for targeted therapy of autoimmune disease." Science 353.6295 (2016): 179-184. Serum anti-DSG3 antibodies are 98 - 100% sensitive and specific2 1 The DSG3 CAAR has published animal model proof-of-concept validation7 5 Depletion of B cells by rituximab3 or antibody by plasmapheresis transiently improves clinical disease 2 The B cell repertoire and antigenic epitopes on DSG1/3 are well understood6, and formed the basis for DSG3 and DSG1 CAAR designs 4 Incomplete B cell depletion by rituximab leads to PV recurrences, with identical disease-causing B cell clones4,5 3 anti- dsg
Current treatments require broad immunosuppression associated with safety risks and transient efficacy Overview of Pemphigus Vulgaris Image credit: D@nderm. http://www.vgrd.org/archive/cases/2004/pv/DSCN4996%20copy.JPG Joly, Pascal, et al. "First-line rituximab combined with short-term prednisone versus prednisone alone for the treatment of pemphigus (Ritux 3): a prospective, multicentre, parallel-group, open-label randomised trial." The Lancet 389.10083 (2017): 2031-2040. Werth, Victoria P., et al. "Rituximab versus Mycophenolate Mofetil in Patients with Pemphigus Vulgaris." New England Journal of Medicine (2021). Rituximab label, 08/2020 revision. Kushner, Carolyn J., et al. "Factors Associated With Complete Remission After Rituximab Therapy for Pemphigus." JAMA dermatology (2019). Tony, Hans-Peter, et al. "Safety and clinical outcomes of rituximab therapy in patients with different autoimmune diseases: experience from a national registry (GRAID)." Arthritis research & therapy 13.3 (2011): 1-14. Current Treatment Landscape Broad immunosuppression3,6 Modestly effective Poorly tolerated Rituximab plus steroids (~3,500 mg/yr)4 Response: ~40% of patients achieved a 16-week period with no lesions or medicines during 1 yr4,5 22% annual serious adverse event (SAE) rate4 4-9%3,4,5 annual risk of severe infection in PV Real world data indicate: Transient remission ~ 70% CROT6: ~30% relapse in 1 year6 >50% relapse within 2 years6 ~30% never achieve CROT6 ~1.9% lifetime risk of fatal infection7 CROT = 8+ weeks without lesions while off systemic therapy http://www.danderm-pdv.is.kkh.dk/atlas/3-157.html http://www.dermis.net/bilder/CD008/550px/img0042.jpg Mucosal PV1 25% of U.S. pemphigus vulgaris Mucocutaneous PV2 75% of U.S. pemphigus vulgaris Associated Antibody Anti-DSG3 Anti-DSG3 + Anti-DSG1 Clinical Signs Painful blisters of the mucous membranes (mouth, nose, larynx, esophagus, eyes, genitalia, rectum) Blisters on orifices and skin US Disease Prevalence 3,250 to 4,750 9,750 to 14,250
Inclusion of all disease-relevant epitopes enables a ‘one-size-fits-all’ approach for patients with mPV DSG3-CAART is designed to bind all known pathogenic autoantibodies Ohyama, Bungo, et al. "Epitope spreading is rarely found in pemphigus vulgaris by large-scale longitudinal study using desmoglein 2–based swapped molecules." Journal of investigative dermatology 132.4 (2012): 1158-1168. Antibodies that target the specific extracellular domain are shown below each extracellular domain. EC5 directed antibodies are not known to be pathogenic DSG3-CAART Costimulatory Domains anti-EC4 P2C1, P5D4, P5B6, P3A6, P5E4 2 anti-EC3 AK18 2 anti-EC2 PVB28, AK19 2 anti-EC1 AK23, Px43, Px44, 6G2C11, F779 2 EC1 EC2 EC3 EC4 Transmembrane Domain Cytoplasmic tail % of PV sera targeting each domain1 91% 71% 51% 19% 12% EC5 EC1 EC2 EC3 EC4 CD137 CD3z DSG3 Protein
Tolerability Target Engagement No evidence of toxicity at clinically relevant doses with selective and specific target engagement DSG3-CAART preclinical data1,2 INDICATOR RESULTS In vitro off-target toxicity No specific cytotoxicity at clinically relevant cell numbers vs FcgR-expressing cells No confirmed interactions with human membrane proteins In vivo off-target toxicity No off-target effects detected at clinically relevant doses Anti-DSG3 autoantibody titer Serologic ‘remission’ – dose-dependent elimination of anti-DSG3 B cells and antibodies CAAR T cell engraftment Dose-dependent increase in CAAR-positive cells observed via flow cytometry Tissue blistering Histologic ‘remission’ – no blistering of oral mucosa Anti-DSG3 hybridoma outgrowth Significantly delayed outgrowth despite soluble anti-DSG antibodies Ellebrecht, Christoph T., et al. "Reengineering chimeric antigen receptor T cells for targeted therapy of autoimmune disease." Science 353.6295 (2016): 179-184. 2. Lee, Jinmin, et al. "Antigen-specific B-cell depletion for precision therapy of mucosal pemphigus vulgaris." The Journal of Clinical Investigation (2020).
Phase 1 clinical trial in mucosal-dominant PV (mPV) patients DesCAARTes™: FDA has requested, and the Company has agreed, that we will share data from part A to inform a discussion on the optimal design of part C. According to FDA advice, the submission of part A data is not gating to planned enrollment in part B. Study Endpoint & Objectives Primary Endpoint: Adverse Events, including Dose Limiting Toxicity (DLT) DLTs include any grade 3 or 4 CRS or neurotoxicity, or any grade 2 CRS or neurotoxicity that failed to improve to ≤ Grade 1 or baseline within 7 days Secondary Objectives: DSG3 ELISA titer changes, CAAR T expansion/persistence, change in PDAI, rate of/time to/duration of remission, manufacturing success rate Open-label study to determine the maximum tolerated dose & fractionation of DSG3-CAART Part Cohort # Subjects A – Dose Escalation Fractionated infusion at increasing dose levels A1-A4 3 (+3) per cohort B – Dose Consolidation Consolidating selected dose fractions into a single infusion B1-B2 3 (+3) per cohort C – Expansion1 Expanded subject enrollment at final selected dose C ~12 Total ~30 (+18) Age: ≥18 Inadequately managed by standard immunosuppressive therapies Confirmed diagnosis Active disease Anti-DSG3 antibody positive Rituximab recently administered Prednisone > 0.25mg/kg/day Other autoimmune disorder requiring immunosuppressive therapies Recent investigational treatment ALC < 1,000 at screening Major Inclusion Criteria Major Exclusion Criteria SCREENING MONITORING (2-4 WEEKS) TREATMENT (~1 WEEK) Next Patient MANUFACTURING TREATMENT (~1 WEEK)
Safety assessed acutely, at 28 days and at 3 months, with data on biologic activity within 6 months DesCAARTes™ clinical trial assessments and timeframes * Clearance of 28-day observation window without DLTs required to initiate next dosing cohort. This information represents data that we believe can be used to inform potential efficacy endpoints in future clinical development. Spindler, Volker, et al. "Mechanisms causing loss of keratinocyte cohesion in pemphigus." Journal of Investigative Dermatology 138.1 (2018): 32-37. Up to Wk -18 Wk -18 to -1 Day -7 to -3 Pre-infusion visit 3 Years Efficacy 15 Years Long-term follow-up 3 Months Primary safety endpoint 8-10 weeks from screening to infusion DSG3-CAART INFUSION Day 28 safety data Infusion of DSG3-CAART in context of circulating soluble Ab Other safety measures CRS / neurotoxicity Other adverse events Early evaluations of efficacy includes1: Persistence of DSG3-CAART detected via qPCR Change in level of DSG3 antibodies (targeting persistent reduction) Reduced mPV therapy and absence of new systemic rescue therapy Change in disease activity based on clinically validated scales e.g. PDAI, ODSS Primary safety endpoint at 3 months Potential for disease flare during planned steroid taper DLT observation window* 6 Months Biologic Activity Data Data expected within 6 months of completion for each cohort Day 28 Day 8 Acute safety data
DSG3-CAART persistence observed via qPCR across cohorts No DLTs observed to date in 1st or 2nd cohorts of DesCAARTes™ trial As of August 17, 2021. No clinically meaningful adverse events in any subject to date1, enabling progression to cohort A3 with dose of 500M cells COHORT A1: 3 patients received fractionated dose of 20M cells COHORT A2: 3 patients received fractionated dose of 100M cells Up to Wk -18 Wk -18 to -1 Day -7 to -3 Pre-infusion visit Day 8 Acute safety data 8-10 weeks from screening to infusion DSG3-CAART INFUSION Day 28 DLT observation window 3 Months Primary safety endpoint 6 Months Biologic Activity Data
100% success rate for manufacturing of DSG3-CAART cells in DesCAARTes™ trial to date1 Manufactured DSG3-CAART cells exhibit target elimination in vitro Manufacturing partnership with Penn is delivering necessary quality & capacity for the clinical trial requirements 2.5:1 1.25:1 0.625:1 0:1 (Target cells only) Samples run in triplicate 1 × 105 target cells per well Effector:Target Ratio DSG3-CAART cells successfully engage & eliminate DSG3 antibody expressing target cells in vitro As of August 17, 2021.
Dose of CAART cells 2 CAART cell expansion post-infusion 3 Circulating antibody titer 4 Range of strategies to consider for targeted cell therapy approaches in patients with autoimmune diseases Potential drivers of biologic activity in autoimmune disease Target cell population 0.1-1% of B cells are DSG3+ Many options exist to optimize product and patient profiles 1 Phenotype of CAART cells 6 Healthy B cell Pathogenic autoreactive B cell CAART cell 5 Number of CAARs on each T cell surface
Expanding relationships with patient advocacy organizations Growing clinical site network with high investigator engagement Rapid cadence of trial recruitment may enable enrollment & dosing of first 4 cohorts by end of 20211 Accelerating timelines for DesCAARTes™ trial Assumes no dose-limiting toxicities are observed during cohort and uninterrupted enrollment occurs in the trial. Number of transduced cells. Opportunities to accelerate development ORPHAN DRUG FAST TRACK Milestone 1Q 2021 2Q 2021 3Q 2021 4Q 2021 1Q 2022 DSG3-CAART: DesCAARTes™ Data 1st cohort (20M)2 2nd cohort (100M)2 3rd cohort1 (500M)2 4th cohort1(2.5B)2 28-Day Safety Biologic Activity Accelerating development & learnings from DesCAARTes™ trial to inform MuSK-CAART & future programs COMPLETED
DSG3/1 CAARs designed for mcPV DSG3 and DSG1 autoantibodies Most severe and common form of PV (~75%) Mucosal blistering, plus skin erosion and blistering Managed with immune suppression, similar to mPV High risk of relapse Potential for hospitalizations and fatal infections Plan to submit an IND after review of DSG3-CAART safety and biologic activity data with FDA DSG3/1 CAART for mucocutaneous PV (mcPV) Ohyama, Bungo, et al. "Epitope spreading is rarely found in pemphigus vulgaris by large-scale longitudinal study using desmoglein 2–based swapped molecules." Journal of investigative dermatology 132.4 (2012): 1158-1168. As presented at the 2018 International Investigative Dermatology conference. DSG1-CAART and DSG3-CAART both demonstrated specific cytotoxicity in vitro2 Together, DSG1-CAART and DSG3-CAART demonstrated cytotoxicity towards anti-DSG3 and anti-DSG1 B cells EC1 EC2 EC3 EC4 Transmembrane Domain Cytoplasmic tail % of PV sera targeting each domain1 98% 26% 9% 4% 7% EC5 EC1 EC2 EC3 EC4 CD137 CD3z DSG1 DSG1 CAAR
MuSK-CAART for patients with MuSK myasthenia gravis
6.0 - 7.5% All known extracellular domains can be included in the CAAR design High unmet need in MuSK myasthenia gravis; a valuable CAAR target Hain, Berit, et al. "Successful treatment of MuSK antibody–positive myasthenia gravis with rituximab." Muscle & Nerve: Official Journal of the American Association of Electrodiagnostic Medicine 33.4 (2006): 575-580. Illa, Isabel, et al. "Sustained response to Rituximab in anti-AChR and anti-MuSK positive Myasthenia Gravis patients." Journal of neuroimmunology 201 (2008): 90-94. Jiang, Ruoyi, et al. "Single-cell repertoire tracing identifies rituximab-resistant B cells during myasthenia gravis relapses." JCI insight 5.14 (2020). AChR MG Early Onset Age <50 ; F>M AChR MG Late Onset Age >50 ; M>F MuSK MG Seronegative MG Low affinity AChR, LRP4 Total US MG Prevalence: 50,000 to 80,000 patients Typically more severe Limited treatment options Early onset – 7:1 females MuSK has similar modular structure and size as DSG3 lg1 lg2 lg3 Fz Autoantibody titers drop after rituximab1,2 Pathogenic B cells are incompletely eliminated by rituximab and persist during relapse3 1 Similarities to pemphigus support clinical potential of CAAR T in MuSK MG 2
Additional in vitro studies demonstrated no confirmed off-target toxicity observed with MuSK-CAART to date MuSK-CAART showed in vitro selective & specific target engagement1 https://cabalettabio.com/technology/posters-publications. NTD = non transduced T cell control against the same target cells Target cells are the pre B cell line, Nalm-6, genetically modified to express anti-MuSK antibodies specific for one of the MuSK domains, Ig1, Ig2, Ig3, or Fz MuSK-CAART Ig1 Ig2 Ig3 Fz MuSK-CAART observed to be specific for anti-MuSK antibody expressing cells in vitro No off-target toxicity observed in vitro ~6,000 human membrane proteins evaluated No on-target toxicity observed in vitro Cellular assays to evaluate cytotoxicity against native ligand LRP4 MuSK-CAART program on track for IND filing in 2H 2021 MuSK-CAART cytotoxicity vs all epitopes tested3 Pro-inflammatory cytokine production3 2 2
MuSK-CAART eliminated anti-MuSK target cells2 in an animal model where CART19 cells were a positive control MuSK-CAART demonstrated specific in vivo target engagement1 https://cabalettabio.com/technology/posters-publications. Target cells represent a B cell tumor line (CD19 positive) that has been modified to express the anti-MuSK antibody. MuSK CAAR CART19 DSG3 EC1-3 Day 1 Day 3 Day 5 Day 7 Day 13 5.0e4 2.0e6 (Radiance) 3.0e5 2.0e6 . . . NTD Positive control Negative control Negative control CART19 MuSK-CAART DSG3 EC1-3 NTD
PLA2R-CAART for patients with PLA2R-associated membranous nephropathy
Primary MN is an immune-mediated kidney disease with anti-PLA2R antibodies in ~75% of patients Preclinical stage CAART program in membranous nephropathy PLA2R+ MN is attractive for CAAR development Single pass transmembrane protein with distinct immunogenic regions Epitopes are well-defined IgG4-dominant disease, similar to PV and MuSK MG Membranous nephropathy (MN) is a type of glomerular disease that causes nephrotic syndrome and may lead to kidney failure Accumulating evidence of a correlation between PLA2R antibodies and disease activity, remission and relapse in primary MN PLA2R autoantibody levels routinely used as diagnostic and prognostic markers Autoantibody titer shown to precede and rise rapidly before clinical manifestations Co-localization of antigen & PLA2R antibodies at site of damage in kidney 1 2 3 Request for pre-IND interaction submitted to FDA; anticipate interaction to be conducted in 2H21
Opportunity to develop antigen-targeted therapy to address significant unmet need Changing treatment paradigm highlights the role of B cells in disease High unmet need despite B cell-depleting therapies Rituximab increasing 1st line for medium to high-risk pts 1/3 cure; 1/3 relapse; 1/3 fail1 Relapse of nephrotic syndrome occurs within 2-4 years Preceded by return of B cells & PLA2R autoantibodies Patients with higher anti-PLA2R levels at baseline and with epitope spreading less likely to respond to rituximab Up to 30% of diagnosed patients develop ESRD PLA2R antibody levels correlate with proteinuria, a commonly used surrogate endpoint Anti-PLA2R levels Proteinuria MENTOR trial results: Antibody levels & proteinuria by group in patients with complete or partial remission at month 24 Accelerated rituximab clearance secondary to renal damage in patients with MN thought to be a major driver of limited drug effect.
Potential addressable market for PLA2R-CAART Confidential Eligible population prevalence of ~4,000 to 8,000 patients & annual incidence of ~700 to 1,400 patients ~3,300 ~2,475 ~1,860 ~1,400 Rituximab-eligible 700 patients Relapsed/ refractory to rituximab ~20,000 ~15,000 ~11,000 ~8,000 Rituximab-eligible ~4,000 patients Relapsed/ refractory to rituximab Membranous nephropathy Primary MN (75%) PLA2R autoantibodies (70-80%) Medium to high risk (~75%) Rituximab outcomes Remission in 1-2 years in ~70% of patients ~33% of responders relapse within 2-4 years U.S. Prevalence U.S. Annual Incidence
Manufacturing
Three-stage approach allows for efficient allocation of capital while leveraging experienced partners Manufacturing strategy Penn-sponsored CD19 CAR IND CMC data has been cross-referenced in DSG3-CAART IND to provide additional data reflecting alignment. Stage 3: Cabaletta Facility Commercialization & Scale-Up Data-gated investment Stage 1: Penn DSG3-CAART Phase 11 Stage 2: CDMOs & CABA Process MuSK-CAART Phase 1 Cell processing capacity secured through Penn partnership SOPs previously used to develop an FDA approved product Clinical vector validated CDMOs for vector and cell processing with commercial support capabilities Leasing and build out Cabaletta-owned manufacturing facility 2021 – 2019 –
Utilizing a clinically validated CART19 cell manufacturing process mitigates risks Cross referenced Penn CART19 IND including CMC process1 Penn process, not Novartis process, avoiding Kymriah release challenges2 Engineering runs have demonstrated efficient manufacture of DSG3-CAART cells from PV patients3 Multiple runs contractually secured each month at Penn Subject to future COVID-19 impact DSG3 vector supply validated and secured Vector production and cell processing are key risks mitigated by strategy, partnership, process and people Parallel steps in manufacturing process1 for CAR T vs CAAR T Penn-sponsored CD19 CAR IND CMC data has been cross-referenced in DSG3-CAART IND to provide additional data. Manufacturing challenges were due to release specifications: https://www.biopharmadive.com/news/novartis-hits-car-t-manufacturing-snag-as-kymriah-sales-disappoint/528202/. T cells isolated from patients with a range of treatment regimens of low to high intensity were tested; the highest intensity regimen and patients with ALC<1000 cells/uL expanded less well and will be excluded from the trial design. Vector Production T Cell Activation Transduction CAAR T Expansion Concentration, Washing and Formulation Apheresis Collection of T cells
Corporate Summary
SCIENTIFIC ADVISORY BOARD Leadership team Aimee Payne, M.D., Ph.D. Co-Founder and Co-Chair Michael C. Milone, M.D., Ph.D. Co-Founder and Co-Chair Jay Siegel, M.D. LEADERSHIP TEAM Steven Nichtberger, M.D. President, CEO & Chairman Anup Marda Chief Financial Officer Arun Das, M.D. Executive Director BD Gwendolyn Binder, Ph.D. EVP Science & Technology David J. Chang, M.D., M.P.H. Chief Medical Officer Martha O’Connor Chief HR Officer Iain McInnes, PhD, FRCP, FRSE, FMedSci Carl June, M.D. Brian Daniels, M.D.
Cabaletta today Leveraging a clinically validated CAR T platform as a novel approach to treating autoimmune diseases aiming to provide: Deep and durable responses, potentially cures, for autoimmune patients and An exceptional safety profile, based on Highly specific, targeted therapy designed to eliminate only pathogenic B cells Multiple potential near-term clinical data catalysts with potential pipeline read-through Safety, biologic activity data, clinical responses Expanding network of academic & industry partners to enhance platform
Anticipated near-term milestones Milestone 1Q 2021 2Q 2021 3Q 2021 4Q 2021 1Q 2022 DSG3-CAART: DesCAARTes™ Data 1st cohort (20M)2 2nd cohort (100M)2 3rd cohort1 (500M)2 4th cohort1 (2.5B)2 MuSK-CAART Validate manufacturing process with CMO partner MuSK-CAART IND filing PLA2R-CAART Pre-IND interaction with FDA 28-Day Safety Biologic Activity Assumes no dose-limiting toxicities are observed during cohort and uninterrupted enrollment occurs in the trial. Number of transduced cells. COMPLETED
Corporate Presentation AUGUST 2021
EX-99.2
Exhibit 99.2
Cabaletta Bio Reports Clinical Data from the Second Dose Cohort in DesCAARTes^™^ Trial in Patients with mPV
• No dose-limitingtoxicities (DLTs) or clinically relevant adverse events observed as of August 17 using 100 million cells in the second dose cohort
• DSG3-CAART persistence observed in all three patients in the second dose cohort during the 28 days followinginfusion
• Dosing initiated in third cohort at 500 million cells, with biologicactivity data from the first two dosing cohorts and third cohort safety data anticipated in 4Q21
PHILADELPHIA, Aug 18, 2021 — Cabaletta Bio, Inc. (Nasdaq: CABA), a clinical-stage biotechnology company focused on the discovery and development of engineered T cell therapies for patients with B cell-mediated autoimmune diseases, today announced 28-day data from the second dose cohort, at the 100 million cell dose level, in the DesCAARTes^™^ Phase 1 clinical trial of DSG3-CAART for the treatment of patients with mucosal-dominant pemphigus vulgaris (mPV).
“We continue to be encouraged by the safety profile of DSG3-CAART in all patients dosed to date. In the second cohort, with patients receiving 100 million DSG3-CAART cells – a five-fold higher dose than the initial cohort – there were no clinically relevant adverse events or DLTs observed either acutely or in the 28-day DLT monitoring period following infusion,” said David J. Chang, M.D., Chief Medical Officer of Cabaletta. “Similar to the first cohort, this safety profile was observed in the presence of circulating anti-DSG3 antibodies. In the absence of preconditioning, DSG3-CAART persistence was observed via quantitative polymerase chain reaction in peripheral blood samples of all three patients in the second dose cohort during the 28 days following infusion.”
In addition to assessing the safety and tolerability of DSG3-CAART, the trial is designed to evaluate early signs of efficacy through clinical outcomes, such as persistent decline in disease activity, reduction or discontinuation of immunosuppressive therapies and systemic corticosteroids, and absence of systemic rescue medication, as well as other biologic activity measures, including a persistent decline in anti-DSG3 antibody titers, indicating target engagement. “The persistence of DSG3-CAART post-infusion is also being evaluated as it may be an important indicator. We look forward to generating data on potential biologic activity, with the goal of providing a targeted and highly effective, and perhaps curative, therapy without generalized immunosuppression,” continued Dr. Chang.
The DesCAARTes^™^ trial has initiated dosing of patients in the third cohort at a treatment dose of 500 million DSG3-CAART cells. Cabaletta expects to announce top-line data on biologic activity from the first two cohorts as well as safety data from the 500 million dose cohort in the fourth quarter of 2021. Absent DLTs in the third cohort, a fourth dose cohort using 2.5 billion cells is also anticipated to initiate dosing this year. Cabaletta will continue to provide additional data on a cohort-by-cohort basis for the DesCAARTes^™^ trial as they become available.
About the DesCAARTes^™^ Clinical Trial
Cabaletta’s DesCAARTes^™^ Phase 1 trial is an open-label, multi-center study of DSG3-CAART in adults with mucosal-dominant pemphigus vulgaris (mPV). The trial is designed to evaluate the safety and tolerability of DSG3-CAART as well as to identify evidence of target engagement and early signs of efficacy. The study consists of three parts: 1) dose escalation, 2) dose consolidation, and 3) expansion at the final selected dose and schedule. The trial is expected to enroll approximately 30 patients across multiple clinical sites throughout the United States. Visit our website (DesCAARTes^™^ Phase 1 Trial) for more information.
About PemphigusVulgaris
mPV is a rare autoimmune blistering disease that is characterized by the loss of adhesion between cells of the skin or mucous membranes. mPV is caused by the production of autoantibodies that disrupt structural proteins within the skin and/or mucosa that connect with other proteins to enable the skin and/or mucosal cells to connect with each other. The autoantibodies can target DSG3 and/or desmoglein 1 (DSG1), which are primarily expressed in the mucosal membranes and skin, respectively. mPV is characterized by autoantibodies against DSG3 only whereas mucocutaneous PV (mcPV) is characterized by autoantibodies against DSG3 and DSG1.
About CAAR T Cell Therapy
Chimeric AutoAntibody Receptor (CAAR) T cells are designed to selectively bind and eliminate only disease-causing B cells, while sparing the normal B cells that are essential for human health. CAAR T cells are based on the chimeric antigen receptor (CAR) T cell technology. While CAR T cells typically contain a CD19-targeting molecule, CAAR T cells express an autoantibody-targeted antigen on their surface. The co-stimulatory domain and the signaling domain of both a CAR T cell and a CAAR T cell carry out the same activation and cytotoxic functions. Thus, Cabaletta’s CAARs are designed to direct the patient’s T cells to kill only the pathogenic cells that express disease-causing autoantibodies on their surface, potentially leading to complete and durable remission of disease while sparing all other B cell populations that provide beneficial immunity from infection.
About Cabaletta Bio
Cabaletta Bio is a clinical-stage biotechnology company focused on the discovery and development of engineered T cell therapies, and exploring their potential to provide a deep and durable, perhaps curative, treatment, for patients with B cell-mediated autoimmune diseases. The Cabaletta Approach to selective B cell Ablation (CABA^™^) platform, in combination with Cabaletta’s proprietary technology, utilizes CAAR T cells that are designed to selectively bind and eliminate only specific autoantibody-producing B cells while sparing normal antibody-producing B cells, which are essential for human health. The Company’s lead product candidate, DSG3-CAART, is being evaluated in the DesCAARTes^™^ phase 1 clinical trial as a potential treatment for patients with mucosal pemphigus vulgaris, a prototypical B cell-mediated autoimmune disease. The FDA granted Fast Track Designation for DSG3-CAART in May 2020. For more information about the DesCAARTes^™^ Phase 1 clinical trial, please visit our website (DesCAARTes^™^ Phase 1 Trial). The Company’s lead preclinical product candidate, MuSK-CAART, is in IND-enabling studies and is designed as a potential treatment for patients with MuSK-associated myasthenia gravis. For more information, visit www.cabalettabio.com.
Forward-Looking Statements
This press release contains “forward-looking statements” of Cabaletta Bio within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including without limitation, express or implied statements regarding expectations regarding the progress and results of its DesCAARTes^™^ Phase 1 trial, including Cabaletta Bio’s ability to enroll the requisite number of patients and dose each dosing cohort in the intended manner; the expectation that Cabaletta Bio may improve outcomes for patients suffering from mPV; the effectiveness and timing of product candidates that Cabaletta may develop, including in collaboration with academic partners; the safety, efficacy and tolerability of DSG3-CAART for the treatment of mPV; the impact of COVID-19 on the timing, progress, interpretability of data, and results of ongoing or planned clinical trials; the significance of data Cabaletta may announce regarding certain efficacy outcomes assessed in the DesCAARTes^™^ trial; the impact of preclinical data on the future development of CAAR T therapies in our pipeline portfolio expectations of the potential impact of COVID-19 on strategy, future operations, and the timing of its clinical trials, including the potential impacts on conduct of its DesCAARTes^™^ Phase 1 trial; and statements regarding regulatory filings regarding its development programs.
Any forward-looking statements in this press release are based on management’s current expectations and beliefs of future events, and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to: the risk that signs of biologic activity may not inform long-term results; Cabaletta Bio’s ability to demonstrate sufficient evidence of safety, efficacy and tolerability in its preclinical and clinical trials of DSG3-CAART; risks related to clinical trial site activation or enrollment rates that are lower than expected; risks related to unexpected safety or efficacy data observed during clinical studies; risks related to the impact of public health epidemics affecting countries or regions in which we have operations or do business, such as COVID-19; Cabaletta’s ability to retain and recognize the intended incentives conferred by Orphan Drug Designation and Fast Track Designation for DSG3-CAART for the treatment of PV; risks related to Cabaletta’s ability to protect and maintain its intellectual property position; uncertainties related to the initiation and conduct of studies and other development requirements for its product candidates; and the risk that the initial or interim results of preclinical studies or clinical studies will not be predictive of future results in connection with future studies. For a discussion of these and other risks and uncertainties, and other important factors, any of which could cause Cabaletta’s actual results to differ from those contained in the forward-looking statements, see the section entitled “Risk Factors” in Cabaletta’s most recent annual report on Form 10-K as well as discussions of potential risks, uncertainties, and other important factors in Cabaletta’s other filings with the Securities and Exchange Commission. All information in this press release is as of the date of the release, and Cabaletta undertakes no duty to update this information unless required by law.
Contacts:
Anup Marda
Chief Financial Officer
investors@cabalettabio.com
Sarah McCabe
Stern Investor Relations, Inc.
sarah.mccabe@sternir.com