Korro Bio

Thank you to everyone who joined our virtual Analyst Day and contributed to a thoughtful discussion. We appreciated the engagement and the opportunity to share insights on KRRO-121 for #hyperammonemia, alongside a powerful caregiver perspective. If you weren’t able to join live or would like to revisit the discussion, the full replay is now available here: event.webcasts.com/viewer/event.j… $KRRO

ICYMI: Join us tomorrow for Korro Bio’s virtual Analyst Day, taking place at 8:00 AM ET. The program will include an overview of ammonia-driven diseases such as urea cycle disorders (UCD) and hepatic encephalopathy, a caregiver perspective on living with UCD, and updates on KRRO-121 for hyperammonemia. Live Q&A begins at 9:15 AM ET. Register and tune in: event.webcasts.com/starthere.jsp?… $KRRO

Korro Bio will host a virtual Analyst Day on Tuesday, January 27, 2026, at 8:00 AM ET. The program will feature an overview of ammonia-driven diseases – urea cycle disorders (UCD) and hepatic encephalopathy, a caregiver’s perspective on living with UCD, and insights into KRRO-121, our development candidate for the potential treatment of patients with hyperammonemia. The Q&A session will take place at 9:15 AM. To learn more and join via webcast, visit: ir.korrobio.com/news-releases/… $KRRO

We were grateful for the opportunity to share Korro’s progress at #JPM2026 this week. Our CEO, @RamAiyar’s, presentation reflected the strength of our science, our disciplined decision-making, and the momentum across our pipeline. A few highlights we were excited to share: - KRRO-121, a GalNAc-conjugated ASO targeting hyperammonemia, has anticipated regulatory filing in H2’26, and an analyst teach-in planned for Jan 27. - GalNAc-conjugated ASO intended for AATD achieved >90% in vivo RNA editing — the highest reported to date; DC expected in H1’26. - GalNAc-conjugated ASO targeting AMPKγ1 for longevity showed improved liver health in early preclinical studies in mice. - ASO modulating TDP-43 intended for ALS reduced aggregation and mis-localization and restored normal splicing in preclinical studies. - KRRO-110, an LNP-encapsulated ASO for AATD, terminated Ph 1/2 clinical trial following a clear, data-driven decision. Watch a recording of the presentation here: ir.korrobio.com/events/event-d… $KRRO

Korro Bio will be attending the 44th Annual @JPMorgan Healthcare Conference in San Francisco. Our CEO, @ramaiyar will be presenting on Thursday, January 15, at 10:30 AM PT / 1:30 PM ET. Our COO Todd Chappell and CSO Loïc Vincent will also be participating at the conference. Learn more: ir.korrobio.com/news-releases/… $KRRO #JPM20256 #JPMHealthcare

Happy holidays from Korro Bio! We look forward to continuing to advance innovative RNA therapies and exploring new possibilities to address complex diseases in the year ahead. Thank you to our team and community for your continued support.

Korro Bio is presenting at the International Symposium on #ALS/#MND. Leah Liu, Ph.D., our Associate Director, Target Biology, will share new data in a poster presentation on our RNA editing-based therapeutic strategy targeting TDP-43 dysfunction in ALS: symposium.mndassociation.org

Korro Bio will be presenting at @OTSociety in Budapest, Hungary, during the poster session on Tuesday, October 21, from 5-8 pm CEST. Learn more: 2025oligomeeting.com #OTS25 $KRRO

Korro Bio will present new, non-clinical data from our Alpha-1 Antitrypsin Deficiency (#AATD) program in a poster at the European Respiratory Society Congress on Sunday, Sept. 28, from 8:00-9:30 CEST in Amsterdam. Learn more: ersnet.org/congress-and-e… $KRRO #ERSCongress #RNAEditing

Todd Chappell, our Chief Operating Officer, will deliver a presentation titled, “Developing Novel RNA Editing Therapies to Address Unmet Needs for Rare and Highly Prevalent Diseases” at #RNALeaders USA Congress on Thursday, September 11, at 11:45 AM ET. To learn more about the Congress, visit: informaconnect.com/rna-leaders-us… $KRRO #RNAediting

Korro management will be taking part in the following investor conferences this September: @WellsFargo Securities Healthcare Conference: Loic Vincent, Ph.D., CSO, and Todd Chappell, COO will join 1x1 investor meetings on September 5. @HCWCO 27th Annual Global Investment Conference: Vineet Agarwal, CFO, and Mr. Chappell will participate in 1x1 meetings on September 8. @MorganStanley 23rd Annual Global Healthcare Conference: Mr. Agarwal and Mr. Chappell will participate in 1x1 meetings on September 8. Learn more: ir.korrobio.com/news-releases/… $KRRO

Korro management will be participating in several upcoming September investor conferences: @Citi's 2025 Biopharma Back to School Conference: @ramaiyar, Korro CEO & President, and Loic Vincent, Ph.D., CSO, will take part in 1x1 investor meetings on September 3. @Official_Cantor Global Healthcare Conference: Dr. Aiyar will participate in a fireside chat on September 4 at 3:55 PM ET. Vineet Agarwal, CFO will also participate in 1x1 investor meetings. Learn more: ir.korrobio.com/news-releases/… $KRRO

Today, we reported our 2Q’25 financial results and provided a business update. We completed dosing in over 80% of the planned healthy volunteers in the Phase 1/2a REWRITE clinical trial. An interim readout is on track for 2H’25. Additionally, a development candidate for our rare metabolic disorder program will be announced by end of 2025. Read the full release: ir.korrobio.com/news-releases/… $KRRO

Korro CEO and President, @ramaiyar, will speak at the 6th Annual RNA Editing Summit on Thursday, July 31, at 10:00 AM ET. He will join a distinguished panel of CEOs at the fireside chat: Lessons from RNA Editing’s CEOs on Driving Clinical & Commercial Development to Accelerate RNA Editors to Patients For more information about the event, visit rnaediting-summit.com #RNAEditing #RNAEditingSummit

Venkat Krishnamurthy, Ph.D., SVP, Head of Platform, will discuss advances in Korro’s OPERA® platform at the 6th Annual RNA Editing Summit on Wednesday, July 30, at 9:00 AM ET in Boston. For more information about the event, visit rnaediting-summit.com. #RNAEditing #RNAEditingSummit

The European Medicines Agency granted orphan drug designation to KRRO-110, our investigational medicine for the treatment of Alpha-1 Antitrypsin Deficiency (#AATD). This important regulatory milestone highlights the urgent need to bring innovative solutions to people with AATD and takes us one step closer to making that a reality with KRRO-110. Learn more at: ir.korrobio.com/news-releases/… $KRRO #OrphanDrugDesignation

A great panel of experts came together to discuss what makes biotech and pharma R&D partnerships truly work at #BIO2025: Korro President & CEO, @ramaiyar, Uli Stilz, Head of @NovoNordisk’s Bio Innovation Hub, and @afzelius_lovisa, General Partner at @FlagshipPioneer. A key takeaway: achieving successful outcomes requires an innovative mindset, a commitment to a shared vision, and the ability to harness the strengths of both nimble biotechs and resource-rich pharma companies to bring much-needed therapies to patients faster. #BIOInternational

At #BIO2025, our CMO, Kemi Olugemo, MD, and her fellow panelists Nasha Fitter and Sunitha Malepati discussed what a true partnership between patients and rare drug development companies looks like. It must include continuity of engagement, transparency, accessibility, and respect throughout the entire R&D process. The more we embed patient voice across that continuum, the more likely we are to create solutions that truly meet the needs of those they’re intended to serve. #RareDisease #DrugDevelopment

Korro CMO, Kemi Olugemo, MD, will discuss advancements in rare disease drug development at a #BIO2025 panel, together with Nicole Verdun, MD, of the FDA, Nasha Fitter from Citizen Health / FOXG1 Research Foundation, and Sunitha Malepati from Buffalo Initiative / CACNA1A Foundation. - Innovative Patient-Focused Models for Accelerating Rare Drug Development Tuesday, June 17 | 4:15 PM – 5:15 PM ET | 254B #RareDisease #DrugDevelopment convention.bio.org/program-1/inno…