Jazz Pharmaceuticals to Present Compelling Clinical and Pre-Clinical Data Advancing Oncology Research at AACR 2026

Rhea-AI Summary

Jazz Pharmaceuticals (Nasdaq: JAZZ) announced seven presentations at AACR 2026 (April 17-22) highlighting clinical and preclinical progress across its oncology programs.

Key items include Phase 2 NeoZanHER results showing a 30% pathologic complete response (pCR) rate with zanidatamab at six weeks, mechanistic multi-omics on zanidatamab, preclinical JZP898 tumor-localized interferon activity, and imipridone (dordaviprone) combination studies.

Positive

• NeoZanHER pCR 30% at six weeks
• Statistically significant tumor size and volume decrease at six weeks
• Multiple AACR presentations across zanidatamab, JZP898, and imipridones
• Preclinical tumor-localized interferon signaling shown for JZP898

Negative

• NeoZanHER results from a single-arm Phase 2 study (no randomized control)
• Small sample implied by pCR count (n=6), limiting statistical power
• Key data for JZP898 and imipridones remain preclinical, not clinical efficacy

News Market Reaction – JAZZ

-0.51%

1 alert

-0.51% News Effect

On the day this news was published, JAZZ declined 0.51%, reflecting a mild negative market reaction.

Data tracked by StockTitan Argus on the day of publication.

Key Figures

Pathologic complete response: 30% (n=6) Neoadjuvant treatment duration: 6 weeks AACR 2026 presentations: 7 presentations +1 more

4 metrics

Pathologic complete response 30% (n=6) NeoZanHER Phase 2 early-stage HER2+ breast cancer at six weeks

Neoadjuvant treatment duration 6 weeks Zanidatamab monotherapy in NeoZanHER Phase 2 trial

AACR 2026 presentations 7 presentations One oral and six poster presentations on Jazz oncology programs

AACR 2026 meeting dates April 17–22, 2026 American Association for Cancer Research Annual Meeting in San Diego

Market Reality Check

Price: $180.62 Vol: Volume 814,522 is at 0.71...

normal vol

$180.62 Last Close

Volume Volume 814,522 is at 0.71x the 20-day average (1,149,656), suggesting muted pre-news activity. normal

Technical Shares at $181.37 trade above the 200-day MA of $142.95, sitting 8.4% below the $198 52-week high and up 89.94% from the $95.49 52-week low.

Peers on Argus

JAZZ slipped 0.36% with below-average volume while key biotech peers showed mixe...

JAZZ slipped 0.36% with below-average volume while key biotech peers showed mixed moves: CORT +3.39%, TECH +2.9%, LEGN -2.62%, BPMC +0.09%, VRNA +0.06%. With no peers in the momentum scanner and no same-day peer headlines, the reaction appeared more stock-specific than sector-driven.

Previous Clinical trial Reports

5 past events · Latest: Dec 02 (Positive)

Same Type Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Dec 02	ASCO GI preview	Positive	+0.2%	Pivotal Phase 3 HERIZON-GEA-01 zanidatamab results highlighted ahead of ASCO GI.
Nov 17	Phase 3 top-line	Positive	+20.6%	Positive HERIZON-GEA-01 top-line data with significant PFS and OS improvements.
Sep 22	Phase 4 Xywav data	Positive	+1.5%	Phase 4 DUET trial and real-world evidence supporting Xywav treatment effects.
Sep 16	Phase 2 update	Positive	+0.7%	Updated Phase 2 zanidatamab mGEA data with strong efficacy and durable responses.
Aug 22	Japan Phase 3 miss	Negative	-0.6%	Japan Epidiolex Phase 3 failed primary endpoint in treatment-resistant epilepsies.

Pattern Detected

Clinical trial news for JAZZ has generally been received constructively, with all five past same-tag events showing price reactions aligned with the apparent news tone, including a strong move on positive Phase 3 HER2+ GEA data.

Recent Company History

Over the past two years, Jazz’s clinical news flow has centered on oncology and neuroscience. Positive Phase 3 HERIZON-GEA-01 data for Ziihera® (zanidatamab-hrii) in first-line HER2+ gastroesophageal adenocarcinoma on Nov 17, 2025 drove a 20.57% gain, followed by additional Phase 3 disclosure and ASCO GI presentation plans in Jan 2026. Earlier, updated Phase 2 zanidatamab data at ESMO 2024 and Phase 4 Xywav® real‑world evidence also saw modest positive reactions, while a Japan Epidiolex Phase 3 miss in Aug 2024 produced a small decline. Today’s AACR oncology update extends this pattern of data-rich, pipeline‑focused catalysts.

Historical Comparison

+4.5% avg move · In the past 5 clinical-trial announcements, JAZZ moved on average 4.48%. The AACR 2026 oncology data...

clinical trial

+4.5%

Average Historical Move clinical trial

In the past 5 clinical-trial announcements, JAZZ moved on average 4.48%. The AACR 2026 oncology data fits this pattern of trial readouts acting as consistent, data-driven catalysts.

Recent news shows progression from Phase 2 zanidatamab data in mGEA to positive Phase 3 HERIZON-GEA-01 results and now broader AACR 2026 presentations, extending evidence across HER2+ breast, biliary tract, and other solid tumors while adding preclinical support for JZP898 and imipridones.

Market Pulse Summary

This announcement highlights expanded clinical and preclinical data across Jazz’s oncology portfolio...

Analysis

This announcement highlights expanded clinical and preclinical data across Jazz’s oncology portfolio, including a 30% pathologic complete response rate in early-stage HER2+ breast cancer within the NeoZanHER trial and mechanistic work on zanidatamab, JZP898, and imipridones. In context of prior positive HERIZON‑GEA‑01 results and other HER2+ data, the AACR 2026 presentations reinforce Jazz’s strategic focus on oncology. Investors may watch for subsequent pivotal studies, regulatory filings, and safety updates to gauge future impact.

Key Terms

her2, bispecific antibody, interferon alpha-2b, tumor microenvironment, +4 more

8 terms

her2 medical

"zanidatamab's differentiated HER2 biology, emerging pre-clinical data..."

HER2 is a protein found on the surface of some cancer cells, especially certain breast cancers. When a cancer has too much HER2, it can grow more quickly and be more aggressive. Knowing about HER2 helps doctors choose the best treatments to target these specific cancer cells.

bispecific antibody medical

"Ziihera® (zanidatamab-hrii), a HER2-targeted bispecific antibody; JZP898..."

A bispecific antibody is a specially designed protein that can attach to two different targets at the same time. Think of it as a custom-made connector that brings two things together—such as a disease cell and an immune system component—helping the body fight illnesses more effectively. For investors, understanding bispecific antibodies is important because they represent innovative therapies that could lead to new treatments and potentially lucrative market opportunities.

interferon alpha-2b medical

"JZP898, an investigational, differentiated, conditionally activated interferon alpha-2b (IFN⍺2b) cytokine..."

Interferon alpha-2b is a laboratory-produced version of a natural immune signaling protein used as a medicine to boost the body’s defenses against certain viral infections and some cancers. Think of it as a software update that tells immune cells to act more aggressively; its clinical trial results, regulatory approvals, supply chain and patent position directly affect potential sales, development costs and investment risk in companies that make or sell it.

tumor microenvironment medical

"pro-drug designed for activation within the tumor microenvironment; and imipridone..."

The tumor microenvironment is the immediate area surrounding a cancer cell, made up of nearby cells, blood vessels, and support structures that influence how the cancer grows and spreads. It functions like a bustling neighborhood that can either help or hinder the tumor’s development. For investors, understanding changes in this environment can signal the effectiveness of treatments and potential shifts in a cancer-related market.

dopamine d2 receptor medical

"dordaviprone), a protease activator of the mitochondrial caseinolytic protease P (ClpP) and a dopamine D2 receptor (DRD2) inhibitor."

A dopamine D2 receptor is a protein on nerve cells that receives dopamine, a chemical messenger in the brain; think of it as a lock that dopamine’s key fits into to change cell activity. It matters to investors because many medicines for psychiatric and movement disorders aim at this receptor, so how a drug affects D2 activity can determine clinical benefit, side effects, regulatory approval and the commercial success of a therapy.

pathologic complete response (pCR) medical

"and 30% of patients (n=6) achieved pathologic complete response (pCR)."

Pathologic complete response (pCR) is when no detectable invasive cancer cells are found in tissue samples taken after pre-surgery treatment, meaning the therapy appears to have eliminated visible tumor at the tested sites. For investors, pCR is an important clinical trial milestone because it often predicts better patient outcomes and can speed regulatory decisions or boost a drug’s commercial prospects—like seeing a garden cleared of weeds after a new fertilizer, suggesting the product works.

syngeneic mouse models medical

"interferon alpha, generates efficacy and robust TME engagement in syngeneic mouse models | Karmokar A..."

Syngeneic mouse models are laboratory mice implanted with tumor cells that come from the same genetic strain, so the animal’s immune system recognizes the tumor as ‘self’ rather than foreign. They matter to investors because these models let companies test how cancer therapies interact with an intact immune system—offering early signs of whether an immunotherapy might work in humans and helping to de-risk preclinical development, though results are not perfectly predictive.

poster session technical

"Type: Poster Session: Experimental and Molecular Therapeutics: Next-Generation Targeted Therapies..."

A poster session is a conference event where researchers display concise summaries of studies, data or trial results on large boards and discuss them informally with attendees. For investors it’s a chance to see early scientific evidence, ask questions of the scientists, and gauge how promising a technology or drug is before full publications or regulatory filings—much like reading previews and talking to developers at a trade show to judge which products might succeed.

AI-generated analysis. Not financial advice.

Seven presentations deliver new insights into zanidatamab's differentiated HER2 biology, emerging pre-clinical data on dordaviprone and related imipridones, and advancing research on JZP898, a conditionally activated IFN⍺2b cytokine

For U.S. media and investors only

DUBLIN, March 18, 2026 /PRNewswire/ -- Jazz Pharmaceuticals plc (Nasdaq: JAZZ) today announced that the company and its partners will present one oral and six poster presentations at the 2026 American Association for Cancer Research (AACR) Annual Meeting, taking place April 17-22, 2026, in San Diego.

The research highlights meaningful progress across Jazz's oncology portfolio, including new findings from company-sponsored research evaluating Ziihera^® (zanidatamab-hrii), a HER2-targeted bispecific antibody; JZP898, an investigational, differentiated, conditionally activated interferon alpha-2b (IFN⍺2b) cytokine pro-drug designed for activation within the tumor microenvironment; and imipridone compounds including Modeyso™ (dordaviprone), a protease activator of the mitochondrial caseinolytic protease P (ClpP) and a dopamine D2 receptor (DRD2) inhibitor.

"Jazz is presenting research at AACR that highlights how we are advancing our oncology portfolio with pace and rigor to deliver differentiated science and new insights across multiple development programs," said Rob Iannone, M.D., M.S.C.E., executive vice president, global head of research and development, and chief medical officer of Jazz Pharmaceuticals. "Zanidatamab is already delivering meaningful benefits for adult patients with previously treated, unresectable or metastatic HER2+ (IHC 3+) biliary tract cancer. We are advancing our program in first-line HER2+ locally advanced or metastatic gastroesophageal adenocarcinoma, and generating a robust body of evidence that characterizes its distinct HER2 biology and its potential across additional HER2-expressing tumors, including HER2+ breast cancer. The NeoZanHER trial data being presented at AACR provide supporting evidence for our ongoing research in early-stage breast cancer."

Highlights at the AACR Annual Meeting include:

• An oral presentation with results from the Phase 2 single-arm, open-label NeoZanHER trial (NCT05035836) evaluating zanidatamab for the investigational use as neoadjuvant monotherapy in patients with early-stage HER2+ breast cancer. At six weeks, zanidatamab treatment resulted in a statistically significant decrease in tumor size and volume from baseline, and 30% of patients (n=6) achieved pathologic complete response (pCR). Treatment with zanidatamab was manageable with no new safety signals.
• A poster presentation detailing mechanistic and multi-omics analyses characterizing zanidatamab's differentiated HER2 biology, including dual, domain-specific binding and downstream effects on key cellular signaling pathways, with insights into activity in models following trastuzumab deruxtecan (T-DXd) exposure.
• A poster presentation featuring preclinical data supporting the activity of JZP898 – currently in Phase 1 development – including evidence of tumor-localized interferon signaling and immune engagement in preclinical models.
• A presentation featuring preclinical research evaluating imiprodones, inclusive of dordaviprone (formerly ONC201) and JZP3507 (formerly ONC206), across renal cell carcinoma and small-cell lung cancer models, including combination approaches and comparative analyses to further characterize activity and mechanism.

Additional presentations will further explore zanidatamab's utility across HER2-expressing solid tumors and within innovative biomarker-driven clinical trial designs, including adaptive organ-preservation strategies in gastroesophageal adenocarcinoma (GEA).

The AACR abstracts are available at: https://www.aacr.org/meeting/aacr-annual-meeting-2026/

The full list of Jazz- and partner-supported presentations at the 2026 AACR Annual Meeting are:

Zanidatamab Presentations:

Presentation Title	Authors	Presentation Details
A phase 2 single-arm open-label trial evaluating zanidatamab in patients with early stage HER2 positive breast cancer: The NeoZanHER Study	Valero V, Pohlmann PR, Mouabbi J, Huang X, Qiao W, Alonzo H, Murthy RK, Rauch GM, Adesoye T, Checka C, Symmans FW, Grachev D, Alajajyan F, Nwosu-Iheme A, Hassan A, Patel MM, Giordano SH, Hunt K, Tripathy D, Meric-Bernstam F	Type: Oral Presentation Session: Clinical Trials Minisymposium: Aiming for Cure: Perioperative Clinical Trials Date/Time: April 18, 2026, 12:30-2:30 p.m. PST   Presentation number: CT012
Zanidatamab modulates multiple pathways involved in tumor growth and survival and is efficacious post  T-DXd	Karmokar A, Loro E, Kyakulaga AH, Lau D, Weisser N, Desjardins G, Raghunatha P, Clark E, Humphreys R, and Vaidya K	Type: Poster   Session: Experimental and Molecular Therapeutics: Next-Generation Targeted Therapies Directed Against Tumor Surface Antigens   Date/Time: April 21, 2026, 9:00 a.m.-12:00 p.m. PST Abstract number: 4542
DiscovHER PAN-206: Phase 2 tumor-agnostic study of zanidatamab in patients with previously treated human epidermal growth factor receptor 2-overexpressing solid tumors	Subbiah V, Makker V, Oh DY, Gardener E, Gartner E, Meric-Bernstam F	Type: Poster   Session: Phase II and Phase III Clinical Trials in Progress Date/Time: April 21, 2026, 9:00 a.m.-12:00 p.m. PST Abstract number: CT209
AACR adaptive biomarker-driven organ preservation trial in GE adenocarcinomas (AACR-ADOPT-GEA)	Elimova E, Ajani JA, Klempner SJ, Schalper K, Wainberg ZA, Yuan Y, Baranski JD, Boerner S, Durbin S, Gallagher D, Huh W, McLaughlin R, Strickland M, Rubin EH, Siu LL, Yap TA, LoRusso P	Type: Poster Session: Phase II and Phase III Clinical Trials in Progress Date/Time: April 21, 2026, 9:00 a.m.-12:00 p.m. PST   Abstract number: CT223

Dordaviprone (formerly ONC201) Presentations:

Presentation Title	Authors	Presentation Details
Nuvisertib (TP-3654) and Dordaviprone (ONC201) synergize to reduce renal cell carcinoma cell viability	Meza KS, Holder SL, El-Deiry W	Type: Poster   Session: Experimental and Molecular Therapeutics: Targeting Cell Surface Vulnerabilities to Overcome Therapeutic Resistance   Date/Time: April 20, 2026, 2:00-5:00 p.m. PST   Abstract number: 3174
Imipridones ONC201, ONC206, and ONC212 show potent killing and colony arrest of small-cell lung cancer cell lines	Su AY, Purcell C, Zhang S, Zhou L, Uruchurtu AS, El-Deiry WS	Type: Poster   Session: Experimental and Molecular Therapeutics: Cellular Responses to Anticancer Drugs   Date/Time: April 20, 2026, 2:00-5:00 p.m. PST Abstract number: 2937

JZP898 Presentation:

Presentation Title	Authors	Presentation Details
JZP898, a conditionally activated interferon alpha, generates efficacy and robust TME engagement in syngeneic mouse models	Karmokar A, Loro E, Zhang Z, Mukavilli R, Gupta A, Trouba K, Amber V, Humphreys RC	Type: Poster   Session: Experimental and Molecular Therapeutics: RNA, Gene and Cell Therapies, and Enabling Assay Technologies   Date/Time: April 19, 2026, 2:00-5:00 p.m. PST   Abstract number: 470

About Ziihera^® (zanidatamab-hrii)
Ziihera (zanidatamab-hrii) is a bispecific HER2-directed antibody that binds to two extracellular sites on HER2. Binding of zanidatamab-hrii with HER2 results in internalization leading to a reduction in HER2 expression of the receptor on the tumor cell surface. Zanidatamab-hrii induces complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC), and antibody-dependent cellular phagocytosis (ADCP). These mechanisms result in tumor growth inhibition and cell death in vitro and in vivo.^[1] In the United States, Ziihera is indicated for the treatment of adults with previously treated, unresectable or metastatic HER2-positive (IHC 3+) biliary tract cancer (BTC), as detected by an FDA-approved test.¹ The FDA granted accelerated approval for this indication based on overall response rate and duration of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s).¹ 

Zanidatamab is being developed in multiple clinical trials as a targeted treatment option for patients with solid tumors that express HER2. Zanidatamab is being developed by Jazz and BeOne under license agreements from Zymeworks, which first developed the molecule. 

A supplemental biologics license application for zanidatamab was submitted to the FDA under Real Time Oncology Review in first-line HER2+ locally advanced or metastatic GEA. The FDA granted two Breakthrough Therapy designations for zanidatamab's development: one as a single agent for previously treated HER2 gene-amplified BTC, and one in combination with standard-of-care chemotherapy for first-line HER2+ locally advanced or metastatic GEA. The FDA also granted two Fast Track designations for zanidatamab: one as a single agent for refractory BTC and one in combination with standard-of-care chemotherapy for first-line GEA. Additionally, zanidatamab has received Orphan Drug designations from the FDA for the treatment of BTC, gastric (including gastroesophageal junction) cancer, and esophageal cancer, as well as Orphan Drug designations from the European Medicines Agency for the treatment of BTC, gastric/gastroesophageal junction cancer and oesophageal cancer. 

Important Safety Information for ZIIHERA

WARNING: EMBRYO-FETAL TOXICITY  Exposure to ZIIHERA during pregnancy can cause embryo-fetal harm. Advise patients  of the risk and need for effective contraception.

WARNINGS AND PRECAUTIONS 

Embryo-Fetal Toxicity
ZIIHERA can cause fetal harm when administered to a pregnant woman. In literature reports, use of a HER2-directed antibody during pregnancy resulted in cases of oligohydramnios and oligohydramnios sequence manifesting as pulmonary hypoplasia, skeletal abnormalities, and neonatal death. 

Verify the pregnancy status of females of reproductive potential prior to the initiation of ZIIHERA. Advise pregnant women and females of reproductive potential that exposure to ZIIHERA during pregnancy or within 4 months prior to conception can result in fetal harm. Advise females of reproductive potential to use effective contraception during treatment with ZIIHERA and for 4 months following the last dose of ZIIHERA. 

Left Ventricular Dysfunction
ZIIHERA can cause decreases in left ventricular ejection fraction (LVEF). LVEF declined by >10% and decreased to <50% in 4.3% of 233 patients. Left ventricular dysfunction (LVD) leading to permanent discontinuation of ZIIHERA was reported in 0.9% of patients. The median time to first occurrence of LVD was 5.6 months (range: 1.6 to 18.7). LVD resolved in 70% of patients. 

Assess LVEF prior to initiation of ZIIHERA and at regular intervals during treatment. Withhold dose or permanently discontinue ZIIHERA based on severity of adverse reactions. 

The safety of ZIIHERA has not been established in patients with a baseline ejection fraction that is below 50%. 

Infusion-Related Reactions
ZIIHERA can cause infusion-related reactions (IRRs). An IRR was reported in 31% of 233 patients treated with ZIIHERA as a single agent in clinical studies, including Grade 3 (0.4%), and Grade 2 (25%). IRRs leading to permanent discontinuation of ZIIHERA were reported in 0.4% of patients. IRRs occurred on the first day of dosing in 28% of patients; 97% of IRRs resolved within one day. 

Prior to each dose of ZIIHERA, administer premedications to prevent potential IRRs. Monitor patients for signs and symptoms of IRR during ZIIHERA administration and as clinically indicated after completion of infusion. Have medications and emergency equipment to treat IRRs available for immediate use. 

If an IRR occurs, slow, or stop the infusion, and administer appropriate medical management. Monitor patients until complete resolution of signs and symptoms before resuming. Permanently discontinue ZIIHERA in patients with recurrent severe or life-threatening IRRs. 

Diarrhea
ZIIHERA can cause severe diarrhea. 

Diarrhea was reported in 48% of 233 patients treated in clinical studies, including Grade 3 (6%) and Grade 2 (17%). If diarrhea occurs, administer antidiarrheal treatment as clinically indicated. Perform diagnostic tests as clinically indicated to exclude other causes of diarrhea. Withhold or permanently discontinue ZIIHERA based on severity. 

ADVERSE REACTIONS
Serious adverse reactions occurred in 53% of 80 patients with unresectable or metastatic HER2-positive BTC who received ZIIHERA. Serious adverse reactions in >2% of patients included biliary obstruction (15%), biliary tract infection (8%), sepsis (8%), pneumonia (5%), diarrhea (3.8%), gastric obstruction (3.8%), and fatigue (2.5%). A fatal adverse reaction of hepatic failure occurred in one patient who received ZIIHERA. 

The most common adverse reactions in 80 patients with unresectable or metastatic HER2-positive BTC who received ZIIHERA (≥20%) were diarrhea (50%), infusion-related reaction (35%), abdominal pain (29%), and fatigue (24%). 

USE IN SPECIFIC POPULATIONS 

Pediatric Use
Safety and efficacy of ZIIHERA have not been established in pediatric patients. 

Geriatric Use
Of the 80 patients who received ZIIHERA for unresectable or metastatic HER2-positive BTC, there were 39 (49%) patients 65 years of age and older. Thirty-seven (46%) were aged 65-74 years old and 2 (3%) were aged 75 years or older. 

No overall differences in safety or efficacy were observed between these patients and younger adult patients. 

The full U.S. Prescribing Information for ZIIHERA, including BOXED Warning, is available at: https://pp.jazzpharma.com/pi/ziihera.en.USPI.pdf 

About Modeyso^™ (dordaviprone) 
Modeyso (dordaviprone) is approved by FDA for the treatment of adult and pediatric patients 1 year of age and older with diffuse midline glioma harboring an H3 K27M mutation with progressive disease following prior therapy.^[2] Modeyso is an orally administered small molecule given once weekly. Modeyso is a protease activator of the mitochondrial ClpP and also inhibits DRD2. In vitro, dordaviprone activates the integrated stress response, induces apoptosis, and alters mitochondrial metabolism, leading to restored histone H3 K27 trimethylation in H3 K27M-mutant diffuse glioma.² 

Modeyso received accelerated approval based on a pre-specified integrated efficacy analysis of 50 adult and pediatric patients with recurrent H3 K27M-mutant diffuse midline glioma enrolled across five open-label clinical studies (ONC006, ONC013, ONC014, ONC016, and ONC018). Continued approval may be contingent upon verification and description of clinical benefit in the ongoing Phase 3 ACTION trial (NCT05580562), which is evaluating the safety and clinical benefit of Modeyso in newly diagnosed patients with H3 K27M-mutant diffuse glioma following radiotherapy. The FDA granted dordaviprone Rare Pediatric Disease designation and Fast-Track designation, and dordaviprone received Orphan Drug Designation in the United States, Europe and Australia. Modeyso was developed by Chimerix prior to its acquisition by Jazz Pharmaceuticals in April 2025.

Modeyso (dordaviprone) is not approved anywhere else in the world.

IMPORTANT SAFETY INFORMATION

WARNINGS AND PRECAUTIONS 
Hypersensitivity 
MODEYSO can cause severe hypersensitivity reactions.

In the pooled safety population, Grade 3 hypersensitivity reactions occurred in 0.3% of patients receiving MODEYSO. Signs and symptoms of hypersensitivity may include rash, hives, fever, low blood pressure, wheezing, or swelling of the face or throat.

Inform patients about the signs and symptoms of hypersensitivity reactions and instruct them to seek immediate medical attention if symptoms occur.

If clinically significant hypersensitivity or anaphylaxis occur, immediately interrupt MODEYSO and initiate appropriate medical treatment and supportive care. Based on the severity of the adverse reaction, temporarily interrupt or permanently discontinue MODEYSO.

QTc Interval Prolongation 
MODEYSO causes concentration-dependent QTc interval prolongation, which can increase the risk for ventricular tachyarrhythmias (e.g. torsades de pointes) or sudden death.

In patients who received MODEYSO and underwent at least one post baseline ECG, QTcF increase of >60 msec compared to baseline and QTcF >500 msec occurred in 6% and 1.2% of patients, respectively.

Monitor ECGs and electrolytes prior to initiation and periodically during treatment, as clinically indicated. Increase the frequency of monitoring in patients with congenital long QT syndrome, existing QTc prolongation, a history of ventricular arrhythmias, electrolyte abnormalities, heart failure, or who are taking strong or moderate CYP3A4 inhibitors.

Avoid concomitant use with other agents known to prolong the QT interval. If concomitant use cannot be avoided, increase the frequency of monitoring and separate administration of MODEYSO and QT-prolonging product.

Interrupt or reduce the dose of MODEYSO in patients who develop QT prolongation; permanently discontinue in patients with signs of life-threatening arrhythmias.

Embryo-Fetal Toxicity 
MODEYSO can cause fetal harm when administered to a pregnant woman.

Advise pregnant women and females of reproductive potential of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with MODEYSO and for 1 month after the last dose. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with MODEYSO and for 1 month after the last dose.

ADVERSE REACTIONS 
Serious adverse reactions occurred in 33% of the 376 patients who received MODEYSO. Serious adverse reactions in >2% of patients included hydrocephalus (5%), vomiting (4.3%), headache (3.2%), seizure (2.4%), and muscular weakness (2.1%). Fatal adverse reactions occurred in 1% of patients who received MODEYSO, including cardiac arrest (0.5%), intracranial hemorrhage (0.3%), and encephalopathy (0.3%).

The most common adverse reactions (≥20%) reported in clinical trials with MODEYSO were fatigue (34%), headache (32%), vomiting (24%), nausea (24%), and musculoskeletal pain (20%). The most common (≥2%) Grade 3 or 4 laboratory abnormalities were decreased lymphocytes (7%), decreased calcium (2.7%), and increased alanine aminotransferase (2.4%).

DRUG INTERACTIONS 
Strong and Moderate CYP3A4 Inhibitors 
Avoid concomitant use of MODEYSO with strong and moderate CYP3A4 inhibitors. If concomitant use cannot be avoided, reduce the MODEYSO dose as recommended and monitor for toxicity.

Strong and Moderate CYP3A4 Inducers 
Avoid concomitant use of strong and moderate CYP3A4 inducers with MODEYSO.

USE IN SPECIFIC POPULATIONS 
Lactation 
There are no data on the presence of MODEYSO in human milk because of the potential for serious adverse reactions from MODEYSO in breastfed children, advise women not to breastfeed during treatment with MODEYSO and for 1 week after the last dose.

Pediatric Use
The safety and effectiveness of MODEYSO have not been established in patients less than 1 year of age. Dosing has not been established for patients weighing less than 22 pounds (10 kg).

Please refer to the full Prescribing Information, including both Patient Information and Instructions for Use, for complete safety and administration information.

The full U.S. Prescribing Information for MODEYSO is available at: https://pp.jazzpharma.com/pi/modeyso.en.USPI.pdf

About JZP898
JZP898 is an investigational differentiated, conditionally-activated IFNα INDUKINE™ molecule, and is currently in Phase 1 development for the investigational use in solid tumors as monotherapy and in combination with a PD-1 inhibitor. JZP898 is an engineered IFN⍺2b cytokine pro-drug that is activated specifically within the tumor microenvironment where it can stimulate IFNα receptors on cancer-fighting immune effector cells.

About Jazz Pharmaceuticals
Jazz Pharmaceuticals plc (Nasdaq: JAZZ) is a global biopharma company whose purpose is to innovate to transform the lives of patients and their families. We are dedicated to developing life-changing medicines for people with rare disease — often with limited or no therapeutic options. We have a diverse portfolio of medicines, including leading therapies addressing epilepsies, cancers and sleep disorders. Our patient-focused and science-driven approach powers pioneering research and development advancements across our robust pipeline of innovative therapeutics. Jazz is headquartered in Dublin, Ireland with research and development laboratories, manufacturing facilities and employees in multiple countries committed to serving patients worldwide. Please visit www.jazzpharmaceuticals.com for more information.

Cautionary Note Concerning Forward-Looking Statements 
This press release contains forward-looking statements, including, but not limited to, statements related to the potential therapeutic benefits of zanidatamab in HER2+ first-line GEA and other HER2-expressing cancers, JZP898 and dordaviprone, and other statements that are not historical facts. These forward-looking statements are based on Jazz Pharmaceuticals' current plans, objectives, estimates, expectations and intentions and inherently involve significant risks and uncertainties. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties, which include, without limitation, risks and uncertainties associated with the successful completion of regulatory activities and uncertain regulatory approval, risks related to failure or delays in successfully initiating or completing clinical trials and assessing patients and other risks and uncertainties affecting Jazz Pharmaceuticals and its development programs, including those described from time to time under the caption "Risk Factors" and elsewhere in Jazz Pharmaceuticals' Securities and Exchange Commission filings and reports, including Jazz Pharmaceuticals' Annual Report on Form 10-K for the year ended December 31, 2025, and future filings and reports by Jazz Pharmaceuticals. Other risks and uncertainties of which Jazz Pharmaceuticals is not currently aware may also affect Jazz Pharmaceuticals' forward-looking statements and may cause actual results and the timing of events to differ materially from those anticipated. The forward-looking statements herein are made only as of the date hereof or as of the dates indicated in the forward-looking statements, even if they are subsequently made available by Jazz Pharmaceuticals on its website or otherwise. Jazz Pharmaceuticals undertakes no obligation to update or supplement any forward-looking statements to reflect actual results, new information, future events, changes in its expectations or other circumstances that exist after the date as of which the forward-looking statements were made. 

Contacts:
Media Contact: 
CorporateAffairsMediaInfo@jazzpharma.com
Ireland +353 1 637 2141
U.S. +1 215 867 4948

Investor Contact: 
InvestorInfo@jazzpharma.com
Ireland +353 1 634 3211
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¹ ZIIHERA (zanidatamab-hrii) Prescribing Information. Palo Alto, CA: Jazz Pharmaceuticals, Inc.)
² MODEYSO (dordaviprone) Prescribing Information. Palo Alto, CA: Jazz Pharmaceuticals, Inc.

 

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SOURCE Jazz Pharmaceuticals plc

FAQ

What did Jazz Pharmaceuticals announce about zanidatamab (JAZZ) at AACR 2026?

Jazz reported Phase 2 NeoZanHER data showing a 30% pCR rate at six weeks for zanidatamab. According to the company, the study also showed a statistically significant decrease in tumor size and manageable safety with no new safety signals.

How significant is the 30% pCR in the NeoZanHER study for JAZZ investors?

The 30% pCR indicates promising early activity for neoadjuvant zanidatamab in HER2+ breast cancer. According to the company, this result comes from a Phase 2 single-arm study and should be weighed against study design and sample size limitations.

What preclinical evidence for JZP898 did Jazz present at AACR 2026 (JAZZ)?

Jazz presented preclinical data showing JZP898 generates tumor-localized interferon signaling and immune engagement in models. According to the company, these findings support JZP898's conditional activation and ongoing Phase 1 development plans.

What did Jazz present about dordaviprone (formerly ONC201) and imipridones at AACR 2026 (JAZZ)?

Presentations showed imipridones, including dordaviprone, have activity in renal cell and small-cell lung cancer models and can synergize with other agents. According to the company, the posters detail preclinical combination and comparative analyses across tumor models.

Will zanidatamab data at AACR 2026 change Jazz's clinical development plans (JAZZ)?

The presentations add supporting evidence for zanidatamab's biology and potential utility across HER2 tumors and trial designs. According to the company, data support ongoing programs including first-line GEA studies and early-stage breast cancer research.

Where and when are Jazz's AACR 2026 presentations scheduled for JAZZ investors?

Jazz and partners will present at AACR April 17-22, 2026 in San Diego with sessions April 18-21 listed. According to the company, abstracts and presentation details are available via the AACR 2026 meeting program.