{"success":true,"data":{"pressRelease":{"id":"53027","rtpr_id":"nGNX571Qg7","ticker":"ZBIO","exchange":"NASDAQ","all_tickers":["ZBIO"],"title":"Zenas BioPharma Announces Data from the Registrational Phase 3 INDIGO Trial of Obexelimab in Immunoglobulin G4-Related Disease (IgG4-RD), Simultaneously Presented at the EULAR 2026 Congress and Published in the New England Journal of Medicine","author":"Globe Newswire","published_at":"2026-06-02T23:05:00.144Z","article_body":"- The INDIGO study met its primary and all key secondary endpoints with\nstatistically significant results -\n\n- Obexelimab significantly lowered the total amount of glucocorticoid use and\nreduced glucocorticoid-related toxicities -\n\n- A Biologics License Application (BLA) for obexelimab in IgG4-RD was\nsubmitted to the FDA in May -\n\nWALTHAM, Mass., June 02, 2026 (GLOBE NEWSWIRE) -- Zenas BioPharma, Inc.\n(“Zenas,” “Zenas BioPharma” or the “Company”) (Nasdaq: ZBIO), a\nclinical-stage global biopharmaceutical company committed to being a leader in\nthe development and commercialization of transformative therapies for patients\nliving with autoimmune diseases, today announced the presentation of\nadditional positive data from the Phase 3 INDIGO trial evaluating obexelimab\nin Immunoglobulin G4-Related Disease (IgG4-RD) at the European Alliance of\nAssociations for Rheumatology (EULAR) 2026 Congress\n(https://www.globenewswire.com/Tracker?data=5MwcvQfjZc9ZfKy4M3warnhfuGuUBlPLzlEyKUps1vfia9Id9gCjTS_8Jk5BR4v_SVUjzSGoNUZpKWQh752ySp_XUaqjwwSVxgtPENd3mW-0tiylIZIRbvjzaKP0lzI56Z6Oriv2o55uBEc76TT8eN2e9ehoj1W-XinySD7qWSn2m3wWaz4-6H4pfYhj7T2btUwJrclQlAjuUlyV0DDD_CDQTvbYeYGKPWmonmvuj3PN0_WFw5Hs7cK0qZ1NHNsxc9ucNTQsbuDZAuUOUACl3xPB4_oXfj8j9JJbBrGazoQ=),\nheld from June 3-6, 2026, in London, England and published online by the New\nEngland Journal of Medicine\n(https://www.globenewswire.com/Tracker?data=js71Cfouh21UMlnmDk_s_TMtfVytubw7O9PJ4aUtz6TSk2MbjUnvzXFy7RH-ziURYGz3AU9Keg0-Poytuzf3w6lMfp7Do6kdXBP9D-_3bZ_Diiz_mNLrHCxm0YgSSR5kI0gggHSd2nlAjrBPAT9j9G7PY717LK6YxVqpEEnxf7aF63s37EXdOaoil7_6ic6mV4BhUSUcvgIM8-0FjxThDv31d9IzmBHPB_whgwHlCc0=).\n\nCollectively, the results consistently demonstrated reductions in disease\nactivity including flare burden as well as glucocorticoid use and toxicity\nacross multiple endpoints. The safety profile of obexelimab was comparable to\nplacebo.\n\n“The findings from the Phase 3 INDIGO trial for obexelimab in IgG4-RD mark a\nsignificant milestone for both the rheumatology community and patients living\nwith this devastating disease,” said Lonnie Moulder, Founder and Chief\nExecutive Officer of Zenas. “These results further validate the significant\nclinical activity of obexelimab and its favorable safety and tolerability\nprofile. Combined with its unique inhibitory mechanism of action, potential\nfor steroid sparing and convenient at-home subcutaneous self-administration,\nwe believe obexelimab has the opportunity to become an important first-line\ntherapy for the long-term management of IgG4-RD. We are excited about the\npossibility of making this important therapy available to patients.”\n\n“Physicians currently have very few treatment options for patients living\nwith this chronic, progressive and debilitating disease,” said Emanuel Della\nTorre, M.D., Ph.D., Associate Professor of Medicine at Vita-Salute San\nRaffaele University in Milan, Italy. “The Phase 3 INDIGO data indicate\nobexelimab could offer a novel, highly active, self-administered therapy for\npeople living with IgG4-RD, one that has the potential to avoid the safety\nconcerns associated with chronic steroid use and long-term B cell\ndepletion.”\n\n“INDIGO is the largest clinical trial ever conducted in IgG4-RD and\nrepresents the most extensive dataset to support the clinical activity of any\nadvanced therapy for this disease,” said Lisa von Moltke, M.D., Head of\nResearch and Development and Chief Medical Officer at Zenas. “INDIGO adds to\na substantial body of evidence demonstrating the broad potential of targeting\nCD19 and FcγRIIb in rheumatic and autoimmune diseases. We look forward to\nproviding further updates on the development of obexelimab, including, topline\nresults from our Phase 2 SunStone SLE trial later this year, and advancing\nZB014, our half-life-extended CD19 and FcγRIIb antibody, toward clinical\ndevelopment.”\n\nAbout the Phase 3 INDIGO Trial\nIn INDIGO, 194 IgG4-RD patients with newly diagnosed or recurrent disease were\nrandomized 1:1 to receive 250 mg of obexelimab or placebo subcutaneously\nweekly for 52 weeks. Patient demographics and clinical characteristics were\ngenerally balanced across arms at baseline.\n\nINDIGO Met its Primary Endpoint of Reducing the Risk of IgG4-RD Flares\n* Obexelimab demonstrated a highly statistically significant and clinically\nmeaningful 56% reduction in the risk of IgG4-RD flare compared to placebo (HR\n0.44; 95% CI 0.277–0.711; p=0.0005) during the 52-week randomized controlled\nperiod.\n* A majority of patients treated with obexelimab (73.2%) remained flare-free\nthrough Week 52, compared to fewer than half (45.4%) of placebo-treated\npatients.\n* These findings indicate a sustained reduction in flare risk over time\nfollowing glucocorticoid withdrawal.\nObexelimab Demonstrated Highly Statistically Significant Activity on All Four\nKey Secondary Endpoints\n* Time to first investigator-determined flare requiring rescue therapy was\nsignificantly longer with obexelimab and risk of investigator-determined\ndisease flare requiring rescue therapy was reduced by 59% with obexelimab\ncompared to placebo (HR 0.41; 95% CI 0.26-0.66; p=0.0001).\n* The annualized adjudicated flare rate was 52% lower for obexelimab compared\nto placebo (HR 0.48; 95% CI 0.32-0.74; p=0.0008); 36 flares were observed in\nthe obexelimab group compared with 72 in the placebo group.\n* At Week 52, 37.1% of patients receiving obexelimab achieved complete\nremission compared to 19.6% of patients who received placebo, representing a\n17.7% improvement (p=0.0049). Complete remission was defined as no\nAC-determined flare, no treatment for flare and an IgG4-RD Responder Index\n(RI) of 0 or investigator determination of no active disease.\n* At Week 52, mean cumulative glucocorticoid rescue therapy use was 329.5 mg\nacross all obexelimab-treated patients and 929.8 mg for placebo-treated\npatients, representing an approximate 600 mg difference (p=0.0042; 65%\nreduction with obexelimab). Importantly, unlike IV administered B cell\ndepleting agents used for the treatment of IgG4-RD, obexelimab was not\nadministered with routine GC prophylaxis for hypersensitivity prior to dosing.\nObexelimab Lowered Glucocorticoid Toxicity\n* Glucocorticoid toxicity was assessed using the Glucocorticoid Toxicity Index\n(GTI) and included 8 domains: body mass index, glucose tolerance, blood\npressure, lipid metabolism, infection, GC myopathy, skin toxicity, and\nneuropsychiatric effects.\n* At Week 52, the proportion of patients exceeding predefined glucocorticoid\ntoxicity worsening thresholds was significantly lower in the obexelimab group\ncompared to placebo, with 42.2% vs. 61.2% of patients reaching a ≥20-point\nGTI-CWS increase (p=0.0135) and 28.9% vs. 49.4% reaching a ≥30-point\nincrease (p=0.0090).\nObexelimab Demonstrated Favorable Safety and Tolerability\n* After an initial decrease that remained above the lower limit of normal\n(LLN), mean B-cell levels in obexelimab-treated patients stabilized and\nconsistently remained above the LLN.\n* Treatment-emergent adverse events (TEAEs) occurred in 97.9% of\nobexelimab-treated patients compared to 95.9% of placebo-treated patients.\n* The incidence of Grade ≥3 TEAEs was lower with obexelimab (11.3%) compared\nto placebo (23.7%), and the incidence of serious adverse events was also lower\nfor obexelimab (10.3%) compared with placebo (18.6%).\n* Infections occurred in 53.6% of obexelimab-treated patients compared to\n62.9% of placebo-treated patients.\n* 3.5% of obexelimab doses resulted in injection-site reactions compared to\n2.3% of placebo doses.\n* Grade 2 or higher hypersensitivity occurred in 16.5% of obexelimab-treated\npatients compared to 11.3% of placebo-treated patients. All were Grade 2\nexcept one Grade 3 reaction in an obexelimab-treated patient.\n* There were no deaths in the obexelimab group and one death (1.0%) in the\nplacebo group.\nAbout Obexelimab\nObexelimab is a bifunctional monoclonal antibody designed to bind both CD19\nand FcγRIIb, which are broadly present across B cell lineage, to inhibit the\nactivity of cells that are implicated in many autoimmune diseases without\ndepleting them. This unique inhibitory mechanism of action and\nself-administered, subcutaneous injection regimen may broadly and effectively\naddress the pathogenic role of the B cell lineage in chronic autoimmune\ndisease.\n\nObexelimab has been evaluated in eight clinical trials in a total of 383\nsubjects, including INDIGO. Obexelimab was well tolerated and demonstrated\nclinical activity across these clinical trials.\n\nThe registrational Phase 3 INDIGO trial for Immunoglobulin G4-Related Disease\nmet its primary endpoint and all four key secondary endpoints with high\nstatistical significance. The trial continues to evaluate patients in the\n3-year open label extension period which will further build upon the largest\nbody of clinical data reported for IgG4-RD patients to date.\n\nEnrollment in a randomized Phase 2 trial for Systemic Lupus Erythematosus is\ncompleted. Zenas expects to report topline results, including biomarker data\nfrom this trial in the fourth quarter of 2026.\n\nAbout Zenas BioPharma\nZenas is a clinical-stage global biopharmaceutical company committed to\nbecoming a leader in the development and commercialization of transformative\ntherapies for patients living with autoimmune diseases. Zenas’ core business\nstrategy combines our experienced leadership team with a disciplined product\ncandidate acquisition approach to identify, acquire and develop product\ncandidates globally that we believe can provide superior clinical benefits to\npatients living with autoimmune diseases. Zenas is advancing two late-stage,\npotential franchise molecules, obexelimab and orelabrutinib. Obexelimab,\nZenas’ lead product candidate, is a bifunctional monoclonal antibody\ndesigned to bind both CD19 and FcγRIIb, which are broadly present across B\ncell lineage, to inhibit the activity of cells that are implicated in many\nautoimmune diseases without depleting them. Zenas believes that the unique\nmechanism of action of obexelimab and its self-administered, subcutaneous\ninjection regimen may broadly and effectively address the pathogenic role of B\ncell lineage in chronic autoimmune disease. Orelabrutinib is a potentially\nbest-in-class, highly selective CNS-penetrant, oral, small molecule BTK\ninhibitor. Orelabrutinib’s mechanism of action targets pathogenic B cells\nnot only in the periphery but also within the CNS. Additionally, it directly\nmodulates macrophages and microglial cells in the CNS, with the potential to\naddress compartmentalized inflammation and disease progression in MS. Zenas’\nearlier stage programs include ZB021, a novel, potentially best-in-class, oral\nsmall molecule IL-17AA/AF inhibitor, ZB022, a preclinical, potentially\nbest-in-class, oral, brain-penetrant, TYK2 inhibitor, and ZB014, a\npreclinical, half-life extended anti-CD19 and FcγRIIb monoclonal antibody.\nFor more information about Zenas BioPharma, please visit\nhttps://zenasbio.com/ and follow us on LinkedIn\n(https://www.globenewswire.com/Tracker?data=KmEiW_vAKiDKVRVQAvN9ORuB9VhcMvLwBm75R4tM2DgzMkNwrSaHOo1NcAhIiXiBKT6WxL3xZXfUlWuJKhonb3h5va5sz23c0fQiax9wd1nIzneD0OMmGa3y1BvJO3hyAoRvk9vLISOANQUcYk6okLVEt528FN0Swr930ISfqRFbRJsnyYESN5zS9Ne6kISn43rZKgdSLTV2fYnCWj1NIe5MiSwOuTQtmQdv3NQyCDScGwBab1XUjqi7wLinHD8rGjAdJXnd1Xs1ViufOG76pRggxmXthzi2YWM02Ll7TzrNJOjPPf5NFghF7-mnRqSy).\n\nZenas BioPharma Forward-Looking Statements\nThis press release contains “forward-looking statements” which involve\nrisks, uncertainties and contingencies, many of which are beyond the control\nof the Company, which may cause actual results, performance, or achievements\nto differ materially from anticipated results, performance, or achievements.\nAll statements other than statements of historical facts contained in this\npress release are forward-looking statements. In some cases, forward-looking\nstatements can be identified by terms such as “may,” “will,”\n“should,” “expect,” “plan,” “anticipate,” “could,”\n“intend,” “target,” “project,” “contemplate,” “believe,”\n“estimate,” “predict,” “potential” or “continue” or the\nnegative of these terms or other similar expressions, although not all\nforward-looking statements contain these words. Forward looking statements\ninclude, but are not limited to, statements regarding the Company’s product\ncandidates, including the timing, progress and results of preclinical studies\nand clinical trials; the Company’s ability to obtain and maintain regulatory\napprovals for obexelimab; the Company’s belief that obexelimab may have an\nimportant role as a first time therapy in the long-term management of IgG4-RD;\nand the Company’s plans for development of its pipeline and potential\ncommercialization of obexelimab. The forward-looking statements in this press\nrelease speak only as of the date of this press release and are subject to a\nnumber of known and unknown risks, uncertainties and assumptions that could\ncause the Company’s actual results to differ materially from those\nanticipated in the forward-looking statements, including, but not limited to:\nthe Company’s limited operating history, incurrence of substantial losses\nsince the Company’s inception and anticipation of incurring substantial and\nincreasing losses for the foreseeable future; the Company’s need for\nsubstantial additional financing to achieve the Company’s goals; the\nuncertainty of clinical development, which is lengthy and expensive, and\ncharacterized by uncertain outcomes, and risks related to additional costs or\ndelays in completing, or failing to complete, the development and\ncommercialization of the Company’s current product candidates or any future\nproduct candidates; delays or difficulties in the enrollment and dosing of\npatients in clinical trials; the impact of any significant adverse events or\nundesirable side effects caused by the Company’s product candidates;\npotential competition, including from large and specialty pharmaceutical and\nbiotechnology companies, many of which already have approved therapies in the\nCompany’s current indications; the Company’s ability to realize the\nbenefits of the Company’s current or future collaborations or licensing\narrangements and ability to successfully consummate future partnerships; the\nCompany’s ability to obtain regulatory approval to commercialize any product\ncandidate in the United States or any other jurisdiction; the risk that the\ndata from our clinical trials is not sufficient to the satisfaction of the FDA\nor comparable foreign regulatory authorities to support the submission of a\nbiologics license application or other comparable submission or to obtain\nregulatory approval for our product candidates for which we seek approval in\nthe U.S. or elsewhere, and the risk that any such approval may be for a more\nnarrow indication than the Company seeks; the Company’s dependence on the\nservices of the Company’s senior management and other clinical and\nscientific personnel, and the Company’s ability to retain these individuals\nor recruit additional management or clinical and scientific personnel; the\nCompany’s ability to grow the Company’s organization, and manage the\nCompany’s growth and expansion of the Company’s operations; risks related\nto the manufacturing of the Company’s product candidates, which is complex,\nand the risk that the Company’s third-party manufacturers may encounter\ndifficulties in production; the Company’s ability to obtain and maintain\nsufficient intellectual property protection for the Company’s product\ncandidates or any future product candidates the Company may develop; the\nCompany’s reliance on third parties to conduct the Company’s preclinical\nstudies and clinical trials; the Company’s compliance with the Company’s\nobligations under the licenses granted to the Company by others, for the\nrights to develop and commercialize the Company’s product candidates;\nsignificant political, trade, and regulatory developments, including changes\nin relations between the U.S. and China; risks related to the operations of\nthe Company’s suppliers, many of which are located outside of the United\nStates, including the Company’s current sole contract manufacturing\norganization for obexelimab drug substance and drug product, WuXi Biologics\n(Hong Kong) Limited, and our partner, InnoCare, both of which are located in\nChina; the risk that the Company’s indebtedness resulting from the\nCompany’s loan agreement with Pharmakon Advisors LP, and the guarantors\nparty to such agreement, or future indebtedness could adversely affect the\nCompany’s financial condition or restrict the Company’s future operations;\nand other risks and uncertainties described in the section “Risk Factors”\nin the Company’s Annual Report on Form 10-K for the year ended December 31,\n2025, and Quarterly Report on Form 10-Q for the quarter ended March 31, 2026,\nas well as other information we file with the Securities and Exchange\nCommission. The forward-looking statements in this press release are\ninherently uncertain, speak only as of the date of this press release and may\nprove incorrect. These statements are based upon information available to the\nCompany as of the date of this press release and while the Company believes\nsuch information forms a reasonable basis for such statements, such\ninformation may be limited or incomplete, and our statements should not be\nread to indicate that the Company has conducted an exhaustive inquiry into, or\nreview of, all potentially available relevant information. Because\nforward-looking statements are inherently subject to risks and uncertainties,\nsome of which cannot be predicted or quantified and some of which are beyond\nthe Company’s control, these forward-looking statements should not be relied\nupon as guarantees of future events. The events and circumstances reflected in\nthe forward-looking statements may not be achieved or occur and actual future\nresults, levels of activity, performance and events and circumstances could\ndiffer materially from those projected in the forward-looking statements.\nMoreover, the Company operates in an evolving environment. New risks and\nuncertainties may emerge from time to time, and management cannot predict all\nrisks and uncertainties. Except as required by applicable law, the Company\ndoes not undertake to publicly update or revise any forward-looking statements\ncontained herein, whether as a result of any new information, future events,\nchanged circumstances or otherwise.\n\nThe Zenas BioPharma word mark, logo mark, and the “lightning bolt” design\nare trademarks of Zenas BioPharma, Inc. or its affiliated companies.\n\nInvestor and Media Contact:\nArgot Partners\nZenas@argotpartners.com\n\n(https://www.globenewswire.com/NewsRoom/AttachmentNg/11a7c081-eaf9-4e1d-b413-227c20d8d41a)\n\n\n\nGlobeNewswire, Inc. 2026","article_body_html":"","raw_payload":{"data":{"id":"nGNX571Qg7","title":"Zenas BioPharma Announces Data from the Registrational Phase 3 INDIGO Trial of Obexelimab in Immunoglobulin G4-Related Disease (IgG4-RD), Simultaneously Presented at the EULAR 2026 Congress and Published in the New England Journal of Medicine","author":"Globe Newswire","ticker":"ZBIO","created":"2026-06-02T23:05:00.144Z","tickers":["ZBIO"],"exchange":"NASDAQ","article_body":"- The INDIGO study met its primary and all key secondary endpoints with\nstatistically significant results -\n\n- Obexelimab significantly lowered the total amount of glucocorticoid use and\nreduced glucocorticoid-related toxicities -\n\n- A Biologics License Application (BLA) for obexelimab in IgG4-RD was\nsubmitted to the FDA in May -\n\nWALTHAM, Mass., June 02, 2026 (GLOBE NEWSWIRE) -- Zenas BioPharma, Inc.\n(“Zenas,” “Zenas BioPharma” or the “Company”) (Nasdaq: ZBIO), a\nclinical-stage global biopharmaceutical company committed to being a leader in\nthe development and commercialization of transformative therapies for patients\nliving with autoimmune diseases, today announced the presentation of\nadditional positive data from the Phase 3 INDIGO trial evaluating obexelimab\nin Immunoglobulin G4-Related Disease (IgG4-RD) at the European Alliance of\nAssociations for Rheumatology (EULAR) 2026 Congress\n(https://www.globenewswire.com/Tracker?data=5MwcvQfjZc9ZfKy4M3warnhfuGuUBlPLzlEyKUps1vfia9Id9gCjTS_8Jk5BR4v_SVUjzSGoNUZpKWQh752ySp_XUaqjwwSVxgtPENd3mW-0tiylIZIRbvjzaKP0lzI56Z6Oriv2o55uBEc76TT8eN2e9ehoj1W-XinySD7qWSn2m3wWaz4-6H4pfYhj7T2btUwJrclQlAjuUlyV0DDD_CDQTvbYeYGKPWmonmvuj3PN0_WFw5Hs7cK0qZ1NHNsxc9ucNTQsbuDZAuUOUACl3xPB4_oXfj8j9JJbBrGazoQ=),\nheld from June 3-6, 2026, in London, England and published online by the New\nEngland Journal of Medicine\n(https://www.globenewswire.com/Tracker?data=js71Cfouh21UMlnmDk_s_TMtfVytubw7O9PJ4aUtz6TSk2MbjUnvzXFy7RH-ziURYGz3AU9Keg0-Poytuzf3w6lMfp7Do6kdXBP9D-_3bZ_Diiz_mNLrHCxm0YgSSR5kI0gggHSd2nlAjrBPAT9j9G7PY717LK6YxVqpEEnxf7aF63s37EXdOaoil7_6ic6mV4BhUSUcvgIM8-0FjxThDv31d9IzmBHPB_whgwHlCc0=).\n\nCollectively, the results consistently demonstrated reductions in disease\nactivity including flare burden as well as glucocorticoid use and toxicity\nacross multiple endpoints. The safety profile of obexelimab was comparable to\nplacebo.\n\n“The findings from the Phase 3 INDIGO trial for obexelimab in IgG4-RD mark a\nsignificant milestone for both the rheumatology community and patients living\nwith this devastating disease,” said Lonnie Moulder, Founder and Chief\nExecutive Officer of Zenas. “These results further validate the significant\nclinical activity of obexelimab and its favorable safety and tolerability\nprofile. Combined with its unique inhibitory mechanism of action, potential\nfor steroid sparing and convenient at-home subcutaneous self-administration,\nwe believe obexelimab has the opportunity to become an important first-line\ntherapy for the long-term management of IgG4-RD. We are excited about the\npossibility of making this important therapy available to patients.”\n\n“Physicians currently have very few treatment options for patients living\nwith this chronic, progressive and debilitating disease,” said Emanuel Della\nTorre, M.D., Ph.D., Associate Professor of Medicine at Vita-Salute San\nRaffaele University in Milan, Italy. “The Phase 3 INDIGO data indicate\nobexelimab could offer a novel, highly active, self-administered therapy for\npeople living with IgG4-RD, one that has the potential to avoid the safety\nconcerns associated with chronic steroid use and long-term B cell\ndepletion.”\n\n“INDIGO is the largest clinical trial ever conducted in IgG4-RD and\nrepresents the most extensive dataset to support the clinical activity of any\nadvanced therapy for this disease,” said Lisa von Moltke, M.D., Head of\nResearch and Development and Chief Medical Officer at Zenas. “INDIGO adds to\na substantial body of evidence demonstrating the broad potential of targeting\nCD19 and FcγRIIb in rheumatic and autoimmune diseases. We look forward to\nproviding further updates on the development of obexelimab, including, topline\nresults from our Phase 2 SunStone SLE trial later this year, and advancing\nZB014, our half-life-extended CD19 and FcγRIIb antibody, toward clinical\ndevelopment.”\n\nAbout the Phase 3 INDIGO Trial\nIn INDIGO, 194 IgG4-RD patients with newly diagnosed or recurrent disease were\nrandomized 1:1 to receive 250 mg of obexelimab or placebo subcutaneously\nweekly for 52 weeks. Patient demographics and clinical characteristics were\ngenerally balanced across arms at baseline.\n\nINDIGO Met its Primary Endpoint of Reducing the Risk of IgG4-RD Flares\n* Obexelimab demonstrated a highly statistically significant and clinically\nmeaningful 56% reduction in the risk of IgG4-RD flare compared to placebo (HR\n0.44; 95% CI 0.277–0.711; p=0.0005) during the 52-week randomized controlled\nperiod.\n* A majority of patients treated with obexelimab (73.2%) remained flare-free\nthrough Week 52, compared to fewer than half (45.4%) of placebo-treated\npatients.\n* These findings indicate a sustained reduction in flare risk over time\nfollowing glucocorticoid withdrawal.\nObexelimab Demonstrated Highly Statistically Significant Activity on All Four\nKey Secondary Endpoints\n* Time to first investigator-determined flare requiring rescue therapy was\nsignificantly longer with obexelimab and risk of investigator-determined\ndisease flare requiring rescue therapy was reduced by 59% with obexelimab\ncompared to placebo (HR 0.41; 95% CI 0.26-0.66; p=0.0001).\n* The annualized adjudicated flare rate was 52% lower for obexelimab compared\nto placebo (HR 0.48; 95% CI 0.32-0.74; p=0.0008); 36 flares were observed in\nthe obexelimab group compared with 72 in the placebo group.\n* At Week 52, 37.1% of patients receiving obexelimab achieved complete\nremission compared to 19.6% of patients who received placebo, representing a\n17.7% improvement (p=0.0049). Complete remission was defined as no\nAC-determined flare, no treatment for flare and an IgG4-RD Responder Index\n(RI) of 0 or investigator determination of no active disease.\n* At Week 52, mean cumulative glucocorticoid rescue therapy use was 329.5 mg\nacross all obexelimab-treated patients and 929.8 mg for placebo-treated\npatients, representing an approximate 600 mg difference (p=0.0042; 65%\nreduction with obexelimab). Importantly, unlike IV administered B cell\ndepleting agents used for the treatment of IgG4-RD, obexelimab was not\nadministered with routine GC prophylaxis for hypersensitivity prior to dosing.\nObexelimab Lowered Glucocorticoid Toxicity\n* Glucocorticoid toxicity was assessed using the Glucocorticoid Toxicity Index\n(GTI) and included 8 domains: body mass index, glucose tolerance, blood\npressure, lipid metabolism, infection, GC myopathy, skin toxicity, and\nneuropsychiatric effects.\n* At Week 52, the proportion of patients exceeding predefined glucocorticoid\ntoxicity worsening thresholds was significantly lower in the obexelimab group\ncompared to placebo, with 42.2% vs. 61.2% of patients reaching a ≥20-point\nGTI-CWS increase (p=0.0135) and 28.9% vs. 49.4% reaching a ≥30-point\nincrease (p=0.0090).\nObexelimab Demonstrated Favorable Safety and Tolerability\n* After an initial decrease that remained above the lower limit of normal\n(LLN), mean B-cell levels in obexelimab-treated patients stabilized and\nconsistently remained above the LLN.\n* Treatment-emergent adverse events (TEAEs) occurred in 97.9% of\nobexelimab-treated patients compared to 95.9% of placebo-treated patients.\n* The incidence of Grade ≥3 TEAEs was lower with obexelimab (11.3%) compared\nto placebo (23.7%), and the incidence of serious adverse events was also lower\nfor obexelimab (10.3%) compared with placebo (18.6%).\n* Infections occurred in 53.6% of obexelimab-treated patients compared to\n62.9% of placebo-treated patients.\n* 3.5% of obexelimab doses resulted in injection-site reactions compared to\n2.3% of placebo doses.\n* Grade 2 or higher hypersensitivity occurred in 16.5% of obexelimab-treated\npatients compared to 11.3% of placebo-treated patients. All were Grade 2\nexcept one Grade 3 reaction in an obexelimab-treated patient.\n* There were no deaths in the obexelimab group and one death (1.0%) in the\nplacebo group.\nAbout Obexelimab\nObexelimab is a bifunctional monoclonal antibody designed to bind both CD19\nand FcγRIIb, which are broadly present across B cell lineage, to inhibit the\nactivity of cells that are implicated in many autoimmune diseases without\ndepleting them. This unique inhibitory mechanism of action and\nself-administered, subcutaneous injection regimen may broadly and effectively\naddress the pathogenic role of the B cell lineage in chronic autoimmune\ndisease.\n\nObexelimab has been evaluated in eight clinical trials in a total of 383\nsubjects, including INDIGO. Obexelimab was well tolerated and demonstrated\nclinical activity across these clinical trials.\n\nThe registrational Phase 3 INDIGO trial for Immunoglobulin G4-Related Disease\nmet its primary endpoint and all four key secondary endpoints with high\nstatistical significance. The trial continues to evaluate patients in the\n3-year open label extension period which will further build upon the largest\nbody of clinical data reported for IgG4-RD patients to date.\n\nEnrollment in a randomized Phase 2 trial for Systemic Lupus Erythematosus is\ncompleted. Zenas expects to report topline results, including biomarker data\nfrom this trial in the fourth quarter of 2026.\n\nAbout Zenas BioPharma\nZenas is a clinical-stage global biopharmaceutical company committed to\nbecoming a leader in the development and commercialization of transformative\ntherapies for patients living with autoimmune diseases. Zenas’ core business\nstrategy combines our experienced leadership team with a disciplined product\ncandidate acquisition approach to identify, acquire and develop product\ncandidates globally that we believe can provide superior clinical benefits to\npatients living with autoimmune diseases. Zenas is advancing two late-stage,\npotential franchise molecules, obexelimab and orelabrutinib. Obexelimab,\nZenas’ lead product candidate, is a bifunctional monoclonal antibody\ndesigned to bind both CD19 and FcγRIIb, which are broadly present across B\ncell lineage, to inhibit the activity of cells that are implicated in many\nautoimmune diseases without depleting them. Zenas believes that the unique\nmechanism of action of obexelimab and its self-administered, subcutaneous\ninjection regimen may broadly and effectively address the pathogenic role of B\ncell lineage in chronic autoimmune disease. Orelabrutinib is a potentially\nbest-in-class, highly selective CNS-penetrant, oral, small molecule BTK\ninhibitor. Orelabrutinib’s mechanism of action targets pathogenic B cells\nnot only in the periphery but also within the CNS. Additionally, it directly\nmodulates macrophages and microglial cells in the CNS, with the potential to\naddress compartmentalized inflammation and disease progression in MS. Zenas’\nearlier stage programs include ZB021, a novel, potentially best-in-class, oral\nsmall molecule IL-17AA/AF inhibitor, ZB022, a preclinical, potentially\nbest-in-class, oral, brain-penetrant, TYK2 inhibitor, and ZB014, a\npreclinical, half-life extended anti-CD19 and FcγRIIb monoclonal antibody.\nFor more information about Zenas BioPharma, please visit\nhttps://zenasbio.com/ and follow us on LinkedIn\n(https://www.globenewswire.com/Tracker?data=KmEiW_vAKiDKVRVQAvN9ORuB9VhcMvLwBm75R4tM2DgzMkNwrSaHOo1NcAhIiXiBKT6WxL3xZXfUlWuJKhonb3h5va5sz23c0fQiax9wd1nIzneD0OMmGa3y1BvJO3hyAoRvk9vLISOANQUcYk6okLVEt528FN0Swr930ISfqRFbRJsnyYESN5zS9Ne6kISn43rZKgdSLTV2fYnCWj1NIe5MiSwOuTQtmQdv3NQyCDScGwBab1XUjqi7wLinHD8rGjAdJXnd1Xs1ViufOG76pRggxmXthzi2YWM02Ll7TzrNJOjPPf5NFghF7-mnRqSy).\n\nZenas BioPharma Forward-Looking Statements\nThis press release contains “forward-looking statements” which involve\nrisks, uncertainties and contingencies, many of which are beyond the control\nof the Company, which may cause actual results, performance, or achievements\nto differ materially from anticipated results, performance, or achievements.\nAll statements other than statements of historical facts contained in this\npress release are forward-looking statements. In some cases, forward-looking\nstatements can be identified by terms such as “may,” “will,”\n“should,” “expect,” “plan,” “anticipate,” “could,”\n“intend,” “target,” “project,” “contemplate,” “believe,”\n“estimate,” “predict,” “potential” or “continue” or the\nnegative of these terms or other similar expressions, although not all\nforward-looking statements contain these words. Forward looking statements\ninclude, but are not limited to, statements regarding the Company’s product\ncandidates, including the timing, progress and results of preclinical studies\nand clinical trials; the Company’s ability to obtain and maintain regulatory\napprovals for obexelimab; the Company’s belief that obexelimab may have an\nimportant role as a first time therapy in the long-term management of IgG4-RD;\nand the Company’s plans for development of its pipeline and potential\ncommercialization of obexelimab. The forward-looking statements in this press\nrelease speak only as of the date of this press release and are subject to a\nnumber of known and unknown risks, uncertainties and assumptions that could\ncause the Company’s actual results to differ materially from those\nanticipated in the forward-looking statements, including, but not limited to:\nthe Company’s limited operating history, incurrence of substantial losses\nsince the Company’s inception and anticipation of incurring substantial and\nincreasing losses for the foreseeable future; the Company’s need for\nsubstantial additional financing to achieve the Company’s goals; the\nuncertainty of clinical development, which is lengthy and expensive, and\ncharacterized by uncertain outcomes, and risks related to additional costs or\ndelays in completing, or failing to complete, the development and\ncommercialization of the Company’s current product candidates or any future\nproduct candidates; delays or difficulties in the enrollment and dosing of\npatients in clinical trials; the impact of any significant adverse events or\nundesirable side effects caused by the Company’s product candidates;\npotential competition, including from large and specialty pharmaceutical and\nbiotechnology companies, many of which already have approved therapies in the\nCompany’s current indications; the Company’s ability to realize the\nbenefits of the Company’s current or future collaborations or licensing\narrangements and ability to successfully consummate future partnerships; the\nCompany’s ability to obtain regulatory approval to commercialize any product\ncandidate in the United States or any other jurisdiction; the risk that the\ndata from our clinical trials is not sufficient to the satisfaction of the FDA\nor comparable foreign regulatory authorities to support the submission of a\nbiologics license application or other comparable submission or to obtain\nregulatory approval for our product candidates for which we seek approval in\nthe U.S. or elsewhere, and the risk that any such approval may be for a more\nnarrow indication than the Company seeks; the Company’s dependence on the\nservices of the Company’s senior management and other clinical and\nscientific personnel, and the Company’s ability to retain these individuals\nor recruit additional management or clinical and scientific personnel; the\nCompany’s ability to grow the Company’s organization, and manage the\nCompany’s growth and expansion of the Company’s operations; risks related\nto the manufacturing of the Company’s product candidates, which is complex,\nand the risk that the Company’s third-party manufacturers may encounter\ndifficulties in production; the Company’s ability to obtain and maintain\nsufficient intellectual property protection for the Company’s product\ncandidates or any future product candidates the Company may develop; the\nCompany’s reliance on third parties to conduct the Company’s preclinical\nstudies and clinical trials; the Company’s compliance with the Company’s\nobligations under the licenses granted to the Company by others, for the\nrights to develop and commercialize the Company’s product candidates;\nsignificant political, trade, and regulatory developments, including changes\nin relations between the U.S. and China; risks related to the operations of\nthe Company’s suppliers, many of which are located outside of the United\nStates, including the Company’s current sole contract manufacturing\norganization for obexelimab drug substance and drug product, WuXi Biologics\n(Hong Kong) Limited, and our partner, InnoCare, both of which are located in\nChina; the risk that the Company’s indebtedness resulting from the\nCompany’s loan agreement with Pharmakon Advisors LP, and the guarantors\nparty to such agreement, or future indebtedness could adversely affect the\nCompany’s financial condition or restrict the Company’s future operations;\nand other risks and uncertainties described in the section “Risk Factors”\nin the Company’s Annual Report on Form 10-K for the year ended December 31,\n2025, and Quarterly Report on Form 10-Q for the quarter ended March 31, 2026,\nas well as other information we file with the Securities and Exchange\nCommission. The forward-looking statements in this press release are\ninherently uncertain, speak only as of the date of this press release and may\nprove incorrect. These statements are based upon information available to the\nCompany as of the date of this press release and while the Company believes\nsuch information forms a reasonable basis for such statements, such\ninformation may be limited or incomplete, and our statements should not be\nread to indicate that the Company has conducted an exhaustive inquiry into, or\nreview of, all potentially available relevant information. Because\nforward-looking statements are inherently subject to risks and uncertainties,\nsome of which cannot be predicted or quantified and some of which are beyond\nthe Company’s control, these forward-looking statements should not be relied\nupon as guarantees of future events. The events and circumstances reflected in\nthe forward-looking statements may not be achieved or occur and actual future\nresults, levels of activity, performance and events and circumstances could\ndiffer materially from those projected in the forward-looking statements.\nMoreover, the Company operates in an evolving environment. New risks and\nuncertainties may emerge from time to time, and management cannot predict all\nrisks and uncertainties. Except as required by applicable law, the Company\ndoes not undertake to publicly update or revise any forward-looking statements\ncontained herein, whether as a result of any new information, future events,\nchanged circumstances or otherwise.\n\nThe Zenas BioPharma word mark, logo mark, and the “lightning bolt” design\nare trademarks of Zenas BioPharma, Inc. or its affiliated companies.\n\nInvestor and Media Contact:\nArgot Partners\nZenas@argotpartners.com\n\n(https://www.globenewswire.com/NewsRoom/AttachmentNg/11a7c081-eaf9-4e1d-b413-227c20d8d41a)\n\n\n\nGlobeNewswire, Inc. 2026"},"type":"article","timestamp":"2026-06-02T23:05:00.190642247Z","server_sent_at_ms":1780441500190},"received_at":"2026-06-02T23:05:00.363Z","source_url":null},"analysis":{"id":"42458","press_release_id":"53027","analysis_json":{"industry":{"label":"Biotechnology","sector":"Health Care"},"redFlags":["Reliance on contract manufacturer WuXi Biologics located in China","Significant indebtedness from loan agreement with Pharmakon Advisors LP","Hypersensitivity reactions occurred in 16.5% of treatment group vs 11.3% placebo"],"eventType":"clinical_trial","narrative":"Zenas BioPharma announced positive Phase 3 INDIGO trial data for obexelimab in IgG4-RD, published in the New England Journal of Medicine and presented at EULAR 2026.\n\nThe study met its primary endpoint, showing a 56% reduction in flare risk (HR 0.44, p=0.0005) and all four key secondary endpoints, including a 65% reduction in glucocorticoid use and improved safety profile compared to placebo.\n\nA Biologics License Application (BLA) for obexelimab in IgG4-RD was submitted to the FDA in May, positioning the company for a potential regulatory decision on its lead asset.","sentiment":"bullish","agentHooks":{"shouldPost":true,"suggestedAngle":"Zenas posts robust Phase 3 data for obexelimab in IgG4-RD, supporting recent BLA submission and potential first approval."},"keyFigures":{"drugName":"obexelimab","phaseOfTrial":"Phase 3","customDimensions":{"deaths_placebo":1,"dosing_regimen":"250 mg subcutaneously weekly for 52 weeks","total_patients":194,"sae_placebo_pct":"18.6%","deaths_treatment":0,"teae_placebo_pct":"95.9%","sae_treatment_pct":"10.3%","teae_treatment_pct":"97.9%","primary_endpoint_hr":0.44,"flare_risk_reduction":"56%","flare_free_rate_placebo":"45.4%","grade3_teae_placebo_pct":"23.7%","primary_endpoint_p_value":0.0005,"flare_free_rate_treatment":"73.2%","grade3_teae_treatment_pct":"11.3%","gti_worsening_placebo_pct":"61.2%","complete_remission_placebo":"19.6%","infection_rate_placebo_pct":"62.9%","gti_worsening_treatment_pct":"42.2%","complete_remission_treatment":"37.1%","glucocorticoid_reduction_pct":"65%","infection_rate_treatment_pct":"53.6%","glucocorticoid_use_placebo_mg":929.8,"rescue_therapy_risk_reduction":"59%","glucocorticoid_use_treatment_mg":329.5,"adjudicated_flare_rate_reduction":"52%","injection_site_reaction_placebo_pct":"2.3%","injection_site_reaction_treatment_pct":"3.5%","hypersensitivity_grade2plus_placebo_pct":"11.3%","hypersensitivity_grade2plus_treatment_pct":"16.5%"}},"quotedText":"The findings from the Phase 3 INDIGO trial for obexelimab in IgG4-RD mark a significant milestone for both the rheumatology community and patients living with this devastating disease","namedEntities":{"people":[{"name":"Lonnie Moulder","role":"Founder and Chief Executive Officer"},{"name":"Emanuel Della Torre","role":"Associate Professor of Medicine at Vita-Salute San Raffaele University"},{"name":"Lisa von Moltke","role":"Head of Research and Development and Chief Medical Officer"}],"products":["obexelimab","orelabrutinib","ZB021","ZB022","ZB014"],"companies":[{"name":"Zenas BioPharma, Inc.","ticker":"ZBIO","relationship":"filer"},{"name":"New England Journal of Medicine","relationship":"publisher"},{"name":"European Alliance of Associations for Rheumatology","relationship":"conference organizer"},{"name":"Argot Partners","relationship":"investor relations"},{"name":"WuXi Biologics (Hong Kong) Limited","relationship":"contract manufacturer"},{"name":"InnoCare","relationship":"partner"},{"name":"Pharmakon Advisors LP","relationship":"lender"}],"dollarAmounts":[]},"materialImpact":{"score":5,"reasoning":"Positive Phase 3 registrational data for the lead asset (obexelimab) in IgG4-RD, meeting primary and all key secondary endpoints with high statistical significance. This data supports the BLA submitted to the FDA in May, representing a binary catalyst for potential approval and first commercial revenue for the company."},"tickerRelevance":{"others":[],"primary":"ZBIO"},"globalImportance":65,"audienceRelevance":45,"eventTypeSecondary":["regulatory"],"importanceComponents":{"tickerTier":"small-cap","eventGravity":"phase3_positive_data","sectorWeight":"high","binaryCatalyst":"true","householdBrandBoost":"low","marketCapAdjustment":"neutral","retailFavoriteBoost":"low"}},"event_type":"clinical_trial","event_type_secondary":["regulatory"],"sentiment":"bullish","material_impact_score":5,"narrative":"Zenas BioPharma announced positive Phase 3 INDIGO trial data for obexelimab in IgG4-RD, published in the New England Journal of Medicine and presented at EULAR 2026.\n\nThe study met its primary endpoint, showing a 56% reduction in flare risk (HR 0.44, p=0.0005) and all four key secondary endpoints, including a 65% reduction in glucocorticoid use and improved safety profile compared to placebo.\n\nA Biologics License Application (BLA) for obexelimab in IgG4-RD was submitted to the FDA in May, positioning the company for a potential regulatory decision on its lead asset.","key_figures":{"drugName":"obexelimab","phaseOfTrial":"Phase 3","customDimensions":{"deaths_placebo":1,"dosing_regimen":"250 mg subcutaneously weekly for 52 weeks","total_patients":194,"sae_placebo_pct":"18.6%","deaths_treatment":0,"teae_placebo_pct":"95.9%","sae_treatment_pct":"10.3%","teae_treatment_pct":"97.9%","primary_endpoint_hr":0.44,"flare_risk_reduction":"56%","flare_free_rate_placebo":"45.4%","grade3_teae_placebo_pct":"23.7%","primary_endpoint_p_value":0.0005,"flare_free_rate_treatment":"73.2%","grade3_teae_treatment_pct":"11.3%","gti_worsening_placebo_pct":"61.2%","complete_remission_placebo":"19.6%","infection_rate_placebo_pct":"62.9%","gti_worsening_treatment_pct":"42.2%","complete_remission_treatment":"37.1%","glucocorticoid_reduction_pct":"65%","infection_rate_treatment_pct":"53.6%","glucocorticoid_use_placebo_mg":929.8,"rescue_therapy_risk_reduction":"59%","glucocorticoid_use_treatment_mg":329.5,"adjudicated_flare_rate_reduction":"52%","injection_site_reaction_placebo_pct":"2.3%","injection_site_reaction_treatment_pct":"3.5%","hypersensitivity_grade2plus_placebo_pct":"11.3%","hypersensitivity_grade2plus_treatment_pct":"16.5%"}},"named_entities":{"people":[{"name":"Lonnie Moulder","role":"Founder and Chief Executive Officer"},{"name":"Emanuel Della Torre","role":"Associate Professor of Medicine at Vita-Salute San Raffaele University"},{"name":"Lisa von Moltke","role":"Head of Research and Development and Chief Medical Officer"}],"products":["obexelimab","orelabrutinib","ZB021","ZB022","ZB014"],"companies":[{"name":"Zenas BioPharma, Inc.","ticker":"ZBIO","relationship":"filer"},{"name":"New England Journal of Medicine","relationship":"publisher"},{"name":"European Alliance of Associations for Rheumatology","relationship":"conference organizer"},{"name":"Argot Partners","relationship":"investor relations"},{"name":"WuXi Biologics (Hong Kong) Limited","relationship":"contract manufacturer"},{"name":"InnoCare","relationship":"partner"},{"name":"Pharmakon Advisors LP","relationship":"lender"}],"dollarAmounts":[]},"model_name":"qwen3_6_27b_awq","prompt_hash":"sha256:727b4b9429a443af","schema_hash":"sha256:05005c02d9cffac9","created_at":"2026-06-02T23:06:28.672Z","global_importance":65,"audience_relevance":45,"importance_components":{"tickerTier":"small-cap","eventGravity":"phase3_positive_data","sectorWeight":"high","binaryCatalyst":"true","householdBrandBoost":"low","marketCapAdjustment":"neutral","retailFavoriteBoost":"low"}},"durationMs":88294,"modelName":"george-droid-qwen-72b"}}