Alpelisib

Data spans seven presentations across both solid tumors and hematologic malignancies , providing updates on the potential benefit these therapies may bring to patients. Data from the elacestrant plus capivasertib regimen of the ELEVATE study will be presented underscoring its potential in combination settings in mBC, along with updates from the robust elacestrant clinical development program, including its potential role as a monotherapy option in adjuvant breast cancer. Stemline’s partner, Karyopharm Therapeutics, will present a late-breaking oral presentation from the phase 3 SENTRY trial of selinexor in myelofibrosis FLORENCE, Italy and NEW YORK, May 14, 2026 (GLOBE NEWSWIRE) -- The Menarini Group (“Menarini”), a leading international pharmaceutical and diagnostics company, and Stemline Therapeutics, Inc. (“Stemline”), a wholly-owned subsidiary of the Menarini Group, focused on bringing transformational oncology treatments to cancer patients, announced that new data related to ORSERDU ® (elacestrant) and ELZONRIS ® (tagraxofusp-erzs) will be presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting. New data exploring the safety and preliminary efficacy of elacestrant in combination with capivasertib in patients with ER+/HER2- PI3K/AKT/PTEN- pathway altered metastatic breast cancer (mBC) from the phase 1 ELEVATE study will be presented. Additional details on ongoing studies of elacestrant in combination, in the advanced setting, will be shared: ADELA (pivotal phase 3 combination with everolimus); ELECTRA (phase 1b/2 combination with abemaciclib in patients with brain metastases); and CAPELA (phase 2 combination with capecitabine). Lastly, an update from the ELEGANT study, exploring elacestrant as adjuvant treatment in node-positive early breast cancer with high risk of recurrence, will be presented at the congress. Also accepted for presentation is new phase 2 tagraxofusp combination data in patients with blastic plasmacytoid dendritic cell neoplasm (BPDCN), which will be presented by Naveen Pemmaraju, MD, Professor, Department of Leukemia, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center. Additionally, Stemline’s partner, Karyopharm Therapeutics, will present a late-breaking oral presentation from the phase 3 SENTRY trial of selinexor in JAKi naïve patients with myelofibrosis (MF). Selinexor is marketed as XPOVIO ® in the U.S. by Karyopharm Therapeutics, and as NEXPOVIO ® in the EU by Stemline. “The extensive oncology data that will be presented, encompassing both solid tumors and hematologic malignancies, highlights our dedication to tackling the most difficult-to-treat cancers with high unmet needs,” said Elcin Barker Ergun, CEO of the Menarini Group. “Our focus remains on accelerating innovation to provide transformational, targeted therapies that offer meaningful advances to patients and the healthcare communities dedicated to their care.” See below for full details of upcoming presentations: 2026 American Society of Clinical Oncology (ASCO) Annual Meeting Lead Author​ Abstract Title and ID​ Presentation Details​ Elacestrant Wassim McHayleh ​ Elacestrant in combination with capivasertib in patients with ER+/HER2- advanced breast cancer: Update from ELEVATE, a phase 1b/2 open-label, umbrella study Abstract: 1098 June 1, 2026; 1:30 – 4:30 PM CT Poster Board 212 Aditya Bardia ELEGANT: Elacestrant versus standard endocrine therapy in women and men with node-positive, estrogen receptor-positive (ER+), HER2-negative (HER2-), early breast cancer with high risk of recurrence in a global, multicenter, randomized, open-label phase 3 study Abstract: TPS1153 June 1, 2026; 1:30 – 4:30 PM CT Poster Board 262a Antonio Llombart-Cussac ADELA: A double-blind, placebo-controlled, randomized phase 3 trial of elacestrant + everolimus versus elacestrant + placebo in ER+/HER2- advanced breast cancer patients with ESR1-mutated tumors progressing on endocrine therapy + CDK4/6i* # Abstract: TPS1154 June 1, 2026; 1:30 – 4:30 PM CT Poster Board 262b Nuhad Ibrahim ELECTRA: An open-label multicenter, phase 1b/2 study of elacestrant in combination with abemaciclib in patients with brain metastasis from ER+/HER2- breast cancer Abstract: TPS1155 June 1, 2026; 1:30 – 4:30 PM CT Poster Board 263a Kristina Fanucci CAPELA: A phase II multicenter open-label randomized study of capecitabine in combination with elacestrant versus capecitabine alone in advanced estrogen receptor (ER)–positive breast cancer (TBCRC 070)* Abstract: TPS1156 June 1, 2026; 1:30 – 4:30 PM CT Poster Board 263b Tagraxofusp Naveen Pemmaraju A Phase II Trial of Tagraxofusp, Hyper-CVAD, and Venetoclax for Patients with Newly Diagnosed or Relapsed/Refractory BPDCN* Abstract: 6502 Oral Presentation June 2, 2026; 10:09 – 10:21 am CT Selinexor John Mascarenhas Selinexor plus ruxolitinib in JAK inhibitor–naïve myelofibrosis: Phase 3 SENTRY trial* Abstract: LBA6500 Oral Presentation June 2, 2026; 9:45 am – 12:45 pm CT *Denotes investigator sponsored research or collaborative research #The ADELA study is a pivotal study co-sponsored with MEDSIR About The Elacestrant Clinical Development Program Elacestrant is also being investigated in several company-sponsored clinical trials in breast cancer disease, alone or in combination with other therapies. ELEGANT ( NCT06492616 ) is a phase 3 trial evaluating the effectiveness of elacestrant versus standard endocrine therapy in women and men with node-positive, ER+, HER2- early breast cancer with high risk of recurrence. ADELA ( NCT06382948 ) is a phase 3 randomized, double-blinded trial evaluating elacestrant in combination with everolimus in patients with ER+, HER2- mBC with ESR1-mut tumors. ELEVATE ( NCT05563220 ) is a phase 1b/2 clinical trial evaluating the safety and efficacy of elacestrant combined with alpelisib, everolimus, capivasertib, palbociclib, ribociclib or abemaciclib. ELECTRA ( NCT05386108 ) is an open-label phase 1b/2, multicenter study evaluating elacestrant in combination with abemaciclib in patients with ER+, HER2- breast cancer. The phase 2 portion evaluates this treatment regimen in patients with brain metastases. ELCIN ( NCT05596409 ) is a phase 2 trial evaluating the efficacy of elacestrant in patients with ER+, HER2- advanced/metastatic breast cancer who received one or two prior hormonal therapies and no prior CDK4/6 inhibitors in the metastatic setting. Elacestrant is also being evaluated in additional investigator-led trials, in trials conducted in collaboration with other companies, in metastatic breast cancer as well as in early disease. About ORSERDU ® (elacestrant) U.S. Indication: ORSERDU (elacestrant), 345 mg tablets, is approved by the U.S. Food & Drug Administration (FDA) for the treatment of postmenopausal women or adult men with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, ESR1-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy. Full prescribing information for the U.S. can be found at Important Safety Information, ORSERDU ® Warning and Precautions Dyslipidemia : Hypercholesterolemia and hypertriglyceridemia occurred in patients taking ORSERDU at an incidence of 30% and 27%, respectively. The incidence of Grade 3 and 4 hypercholesterolemia and hypertriglyceridemia were 0.9% and 2.2%, respectively. Monitor lipid pro to starting and periodically while taking ORSERDU. Embryo-Fetal Toxicity : Based on findings in animals and its mechanism of action, ORSERDU 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 ORSERDU and for 1 week after the last dose. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with ORSERDU and for 1 week after the final dose. Adverse Reactions Serious adverse reactions occurred in 12% of patients who received ORSERDU. Serious adverse reactions in >1% of patients who received ORSERDU were musculoskeletal pain (1.7%) and nausea (1.3%). Fatal adverse reactions occurred in 1.7% of patients who received ORSERDU, including cardiac arrest, septic shock, diverticulitis, and unknown cause (one patient each). The most common adverse reactions ( > 10%) , including laboratory abnormalities, of ORSERDU were musculoskeletal pain (41%), nausea (35%), increased cholesterol (30%), increased AST (29%), increased triglycerides (27%), fatigue (26%), decreased hemoglobin (26%), vomiting (19%), increased ALT (17%), decreased sodium (16%), increased creatinine (16%), decreased appetite (15%), diarrhea (13%), headache (12%), constipation (12%), abdominal pain (11%), hot flush (11%), and dyspepsia (10%). Drug interactions Concomitant use with CYP3A4 Inducers and/or inhibitors : Avoid concomitant use of strong or moderate CYP3A4 inhibitors with ORSERDU. Avoid concomitant use of strong or moderate CYP3A4 inducers with ORSERDU. Use in specific populations Lactation : Advise lactating women to not breastfeed during treatment with ORSERDU and for 1 week after the last dose. Hepatic Impairment : Avoid use of ORSERDU in patients with severe hepatic impairment (Child-Pugh C). Reduce the dose of ORSERDU in patients with moderate hepatic impairment (Child-Pugh B). The safety and effectiveness of ORSERDU in pediatric patients have not been established. To report SUSPECTED ADVERSE REACTIONS, contact Stemline Therapeutics, Inc. at 1-877-332-7961 or FDA at 1-800-FDA-1088 or . Elacestrant is also being investigated in several clinical trials in metastatic breast cancer disease, alone or in combination with other therapies: ELEVATE ( NCT05563220 ); ELECTRA ( NCT05386108 ); and ELCIN ( NCT05596409 ). Elacestrant is also being evaluated in early breast cancer disease. About ELZONRIS ® (tagraxofusp-erzs) U.S. Indication: ELZONRIS (tagraxofusp-erzs) is a prescription medicine used to treat blastic plasmacytoid dendritic cell neoplasm (BPDCN) in adults and pediatric patients 2 years and older. Full prescribing information for the U.S. can be found at IMPORTANT SAFETY INFORMATION, ELZONRIS ® Boxed WARNING: CAPILLARY LEAK SYNDROME Capillary Leak Syndrome (CLS) which may be life-threatening or fatal, can occur in patients receiving ELZONRIS. Monitor for signs and symptoms of CLS and take actions as recommended. Warnings and Precautions Capillary Leak Syndrome Capillary leak syndrome (CLS), including life-threatening and fatal cases, has been reported among patients treated with ELZONRIS. In patients receiving ELZONRIS in clinical trials, the overall incidence of CLS was 53% (65/122), including Grade 1 or 2 in 43% (52/122) of patients, Grade 3 in 7% (8/122) of patients, Grade 4 in 1% (1/122) of patients, and four fatalities (3%). The median time to onset was 4 days (range - 1 to 46 days), and all but 5 patients experienced an event in Cycle 1. Before initiating therapy with ELZONRIS, ensure that the patient has adequate cardiac function and serum albumin is greater than or equal to 3.2 g/dL. During treatment with ELZONRIS, monitor serum albumin levels prior to the initiation of each dose of ELZONRIS and as indicated clinically thereafter, and assess patients for other signs or symptoms of CLS, including weight gain, new onset or worsening edema, including pulmonary edema, hypotension or hemodynamic instability. Hypersensitivity Reactions ELZONRIS can cause severe hypersensitivity reactions. In patients receiving ELZONRIS in clinical trials, hypersensitivity reactions were reported in 43% (53/122) of patients treated with ELZONRIS and were Grade ≥ 3 in 7% (9/122). Manifestations of hypersensitivity reported in ≥ 5% of patients include rash, pruritus, and stomatitis. Monitor patients for hypersensitivity reactions during treatment with ELZONRIS. Interrupt ELZONRIS infusion and provide supportive care as needed if a hypersensitivity reaction should occur. Hepatotoxicity Treatment with ELZONRIS was associated with elevations in liver enzymes. In patients receiving ELZONRIS in clinical trials, elevations in ALT occurred in 79% (96/122) and elevations in AST occurred in 76% (93/122). Grade 3 ALT elevations were reported in 26% (32/122) of patients. Grade 3 AST elevations were reported in 30% (36/122) and Grade 4 AST elevations were reported in 3% (4/122) of patients. Elevated liver enzymes occurred in the majority of patients in Cycle 1 and were reversible following dose interruption. Monitor alanine aminotransferase (ALT) and aspartate aminotransferase (AST) prior to each infusion with ELZONRIS. Withhold ELZONRIS temporarily if the transaminases rise to greater than 5 times the upper limit of normal and resume treatment upon normalization or when resolved. Adverse Reactions Most common adverse reactions (incidence ≥ 30%) are capillary leak syndrome, nausea, fatigue, pyrexia, peripheral edema, and weight increase. Most common laboratory abnormalities (incidence ≥ 50%) are decreases in albumin, platelets, hemoglobin, calcium, and sodium, and increases in glucose, ALT and AST. Please see full Prescribing Information , including Boxed WARNING. To report SUSPECTED ADVERSE REACTIONS, contact Stemline Therapeutics, Inc. at 1-877-332-7961 or contact the FDA at 1-800-FDA-1088 or . About NEXPOVIO ® (selinexor) NEXPOVIO ® has been approved in the following oncology indications by the European Commission: (i) in combination with dexamethasone for the treatment of multiple myeloma in adult patients who have received at least four prior therapies and whose disease is refractory to at least two proteasome inhibitors, two immunomodulatory agents and an anti-CD38 monoclonal antibody, and who have demonstrated disease progression on the last therapy; and (ii) in combination with bortezomib and dexamethasone for the treatment of adults with multiple myeloma who have received at least one prior therapy. The marketing authorization of NEXPOVIO is valid in the EU Member States as well as Iceland, Liechtenstein, Norway, and Northern Ireland. NEXPOVIO has been commercially available in Germany and Austria since Q4 2022. NEXPOVIO is a first-in-class, oral exportin 1 (XPO1) inhibitor. NEXPOVIO functions by selectively binding to and inhibiting the nuclear export protein exportin 1 (XPO1, also called CRM1). NEXPOVIO blocks the nuclear export of tumor suppressor, growth regulatory and anti-inflammatory proteins, leading to accumulation of these proteins in the nucleus and enhancing their anti-cancer activity in the cell. The forced nuclear retention of these proteins can counteract a multitude of the oncogenic pathways that, unchecked, allow cancer cells with severe DNA damage to continue to grow and divide in an unrestrained fashion. Please see NEXPOVIO® Summary of Product Characteristics (SmPC) and European Public Assessment Report at Please refer to local prescribing information where NEXPOVIO is approved for full information. In the U.S., Karyopharm Therapeutics markets selinexor as XPOVIO and the full prescribing information is available here . IMPORTANT SAFETY INFORMATION for NEXPOVIO Contraindications: Hypersensitivity to selinexor or to any of the excipients listed in the SmPC. Special warnings and precautions for use: Recommended concomitant treatments Patients should be advised to maintain adequate fluid and caloric intake throughout treatment. Intravenous hydration should be considered for patients at risk of dehydration. Prophylactic concomitant treatment with a 5-HT3 antagonist and/or other anti-nausea agents should be provided prior to and during treatment with NEXPOVIO ® . Haematology: Patients should have their complete blood counts (CBC) assessed at baseline, during treatment, and as clinically indicated. Monitor more frequently during the first two months of treatment. Thrombocytopenia: Thrombocytopenic events (thrombocytopenia and platelet count decreased) were frequently reported in adult patients receiving selinexor, which can be severe (Grade 3/4). Grade 3/4 thrombocytopenia can sometimes lead to clinically significant bleeding and in rare cases may lead to potentially fatal haemorrhage. Thrombocytopenia can be managed with dose interruptions, modifications, platelet transfusions, and/or other treatments as clinically indicated. Patients should be monitored for signs and symptoms of bleeding and evaluated promptly. Neutropenia: Severe neutropenia (Grade 3/4) has been reported with selinexor. In a few cases concurrent infections occurred in patients with Grade 3/4 neutropenia. Patients with neutropenia should be monitored for signs of infection and evaluated promptly. Gastrointestinal toxicity: Nausea, vomiting, diarrhoea, which sometimes can be severe and may require the use of anti-emetic and anti-diarrhoeal medicinal products. Prophylaxis with 5HT3 antagonists and/or other anti-nausea agents should be provided prior to and during treatment with selinexor. Fluids with electrolytes should be administered to prevent dehydration in patients at risk. Nausea/vomiting can be managed by dose interruptions, modifications, and/or initiation of other antiemetics medicinal products as clinically indicated. Diarrhoea can be managed with dose interruptions, modifications and/or administration of anti-diarrhoea medicinal products. Weight loss and anorexia: Patients should have their body weight, nutritional status and volume checked at baseline, during treatment, and as clinically indicated. Monitoring should be more frequent during the first two months of treatment. Patients experiencing new or worsening decreased appetite and weight may require dose modification, appetite stimulants, and nutritional consultations. Confusional state and dizziness: Patients should be instructed to avoid situations where dizziness or confusional state may be a problem and to not take other medicinal products that may cause dizziness or confusional state without adequate medical advice. Patients should be advised not to drive or operate heavy machinery until symptoms resolve. Hyponatraemia: Patients should have their sodium levels checked at baseline, during treatment, and as clinically indicated. Monitoring should be more frequent during the first two months of treatment. Hyponatraemia should be treated as per medical guidelines (intravenous sodium chloride solution and/or salt tablets), including dietary review. Cataract: Selinexor can cause new onset or exacerbation of cataract. Ophthalmologic evaluation may be performed as clinically indicated. Cataract should be treated as per medical guidelines, including surgery if warranted. Tumour lysis syndrome (TLS): TLS has been reported in patients receiving therapy with selinexor. Patients at a high risk for TLS should be monitored closely. Treat TLS promptly in accordance with institutional guidelines. Fertility, pregnancy and lactation : Women of childbearing potential should be advised to avoid becoming pregnant or abstain from sexual intercourse while being treated with selinexor and for at least 1 week following the last dose of selinexor. Women of childbearing potential/contraception in males and females: Women of childbearing potential and male adult patients of reproductive potential should be advised to use effective contraceptive measures or abstain from sexual intercourse while being treated with selinexor and for at least 1 week following the last dose of selinexor. Pregnancy: There are no data from the use of selinexor in pregnant women. Selinexor is not recommended during pregnancy and in women of childbearing potential not using contraception. If the patient becomes pregnant while taking selinexor, selinexor should be immediately discontinued, and the patient should be apprised of the potential hazard to the foetus. Breast-feeding: It is unknown whether selinexor or its metabolites are excreted in human milk. A risk to breast-fed children cannot be excluded. Breast-feeding should be discontinued during treatment with selinexor and for 1 week after the last dose. Undesirable effects Summary of the safety profile : The most frequent adverse reactions (≥30%) of selinexor in combination with bortezomib and dexamethasone were nausea, thrombocytopenia, fatigue, anaemia, decreased weight, diarrhea, and peripheral neuropathy. The most commonly reported serious adverse reactions (≥3%) were pneumonia, cataract, sepsis, diarrhoea, vomiting and anaemia. The most frequent adverse reactions (≥30%) of selinexor in combination with dexamethasone were nausea, thrombocytopenia, fatigue, anaemia, decreased appetite, decreased weight, diarrhoea, vomiting, hyponatraemia, neutropenia and leukopenia. The most commonly reported serious adverse reactions were pneumonia, sepsis thrombocytopenia, acute kidney injury, and anaemia. Description of selected adverse reactions: Infections: Infection was the most common non-haematological toxicity. In patients who received selinexor in combination with bortezomib and dexamethasone, upper respiratory tract infection and pneumonia were the most commonly reported infections in 21% and 15% of patients, respectively. In patients who received selinexor in combination with dexamethasone, upper respiratory tract infection and pneumonia were the most commonly reported infections (in 15% and 13% of patients, respectively) with 25% of reported infections being serious and fatal infections occurring in 3% of treated patients. Elderly population: Patients 75 years and older had a higher incidence of discontinuation due to an adverse reaction, higher incidence of serious adverse reactions, and higher incidence of fatal adverse reactions. Reporting of suspected adverse reactions : Reporting of suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national reporting system listed in Appendix V. About The Menarini Group The Menarini Group is a leading international pharmaceutical and diagnostics company, with a turnover of $5.5 billion and over 17,000 employees. Menarini is focused on therapeutic areas with high unmet needs with products for cardiology, oncology, pneumology, gastroenterology, infectious diseases, diabetology, inflammation, and analgesia. With 18 production sites and 9 Research and Development centers, Menarini’s products are available in 140 countries worldwide. For further information, please visit . About Stemline Therapeutics Inc. Stemline Therapeutics, Inc. (“Stemline”), a wholly-owned subsidiary of the Menarini Group, is a commercial-stage biopharmaceutical company focused on bringing transformational oncology treatments to patients. Stemline commercializes elacestrant, an oral endocrine therapy indicated for the treatment of postmenopausal women or adult men with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, ESR1 -mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy, in the U.S., Europe, and other global regions. Stemline also commercializes tagraxofusp-erzs, a novel targeted therapy directed to CD123, for patients with blastic plasmacytoid dendritic cell neoplasm (BPDCN), an aggressive hematologic cancer, in the United States, Europe, and other global regions. In addition, Stemline commercializes selinexor, an XPO1 inhibitor for multiple myeloma, in Europe. The company is also conducting multiple label-expansion studies with elacestrant and tagraxofusp in breast and hematologic cancer indications, respectively, and has an extensive clinical pipeline of additional drug candidates in various stages of development for a host of solid and hematologic cancers. Media Contacts The Menarini Group Valeria Speroni Cardi Email: pressoffice@menarini.com Stemline Therapeutics, Inc. Cheya Pope Email: media@menarinistemline.com

Phase 3 VIKTORIA-1 trial achieved primary endpoint with clinically meaningful improvement in progression-free survival in PIK3CA mutant cohort; detailed data for gedatolisib regimens will be presented at the 2026 ASCO Annual Meeting Phase 3 VIKTORIA-2 trial expanded to include a second study evaluating gedatolisib as first-line treatment in patients with endocrine-sensitive HR+/HER2- advanced breast cancer Development of a gedatolisib formulation for subcutaneous injection underway; first patent application submitted to the U.S. Patent and Trademark Office Management to host webcast and conference call today, May 14, 2026, at 4:30 p.m. EDT MINNEAPOLIS, May 14, 2026 (GLOBE NEWSWIRE) -- Celcuity Inc. (Nasdaq: CELC), a clinical-stage biotechnology company focused on the development of targeted therapies for the treatment of multiple solid tumor indications, today announced financial results for the first quarter ended March 31, 2026 and other recent business developments. “With positive results in both cohorts of the pivotal VIKTORIA-1 study, we believe gedatolisib regimens have the potential to advance the standard of care in the second-line setting for a significant number of patients with HR+/HER2- advanced breast cancer, regardless of PIK3CA status,” said Brian Sullivan, CEO and co-founder of Celcuity. “We are on track to launch gedatolisib commercially in anticipation of its potential FDA approval in the third quarter of 2026, and we look forward to bringing this important therapy to physicians treating patients with advanced breast cancer.” Mr. Sullivan added, “Our positive Phase 3 results, combined with our promising Phase 1b clinical trial results in treatment-naive late-stage patients, provide a strong scientific rationale to evaluate gedatolisib combinations as first-line therapy. By expanding our VIKTORIA-2 study to enable evaluation of treatment-naive patients who have endocrine-sensitive breast cancer, we are positioning gedatolisib regimens to potentially be available for nearly all patients in the first-line setting, irrespective of their endocrine sensitivity or PIK3CA status.” First Quarter 2026 Business Highlights and Other Recent Developments Celcuity reported positive topline results from the PIK3CA mutant-type (“MT”) cohort of the Phase 3 VIKTORIA-1 clinical trial evaluating gedatolisib in combination with fulvestrant with or without palbociclib in patients with hormone receptor positive (“HR+”), human epidermal growth factor receptor 2 negative (“HER2-”) (“HR+/HER2-”), PIK3CA MT locally advanced or metastatic breast cancer (“ABC”). The primary efficacy analysis of gedatolisib combined with fulvestrant and palbociclib (the “gedatolisib triplet”) demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (“PFS”) compared with alpelisib, a PI3Kα inhibitor, and fulvestrant. The secondary endpoint comparing gedatolisib in combination with fulvestrant (the “gedatolisib doublet”) versus alpelisib plus fulvestrant, which was not part of the primary efficacy analysis in the hierarchical order, also demonstrated a statistically significant and clinically meaningful improvement in PFS. Both gedatolisib regimens were generally well tolerated, with manageable safety pro and no new safety signals. Detailed data for the gedatolisib triplet and doublet regimens will be presented in a late-breaking abstract (“LBA”) oral session on June 2, 2026, at the American Society of Clinical Oncology (“ASCO”) Annual Meeting in Chicago, Illinois. Celcuity intends to submit these data to the FDA in the third quarter as a supplemental New Drug Application (“sNDA”) and to submit VIKTORIA-1 data to other regulatory authorities outside the U.S. following the sNDA submission. The Phase 3 VIKTORIA-2 clinical trial now includes two studies, Study 1 and Study 2, each with independent statistical analysis plans that include primary endpoints for their respective intent-to-treat populations. Study 1, which is ongoing, is evaluating the efficacy and safety of gedatolisib in combination with palbociclib and fulvestrant in approximately 440 patients with endocrine-resistant HR+/HER2- ABC. Study 2, which was added in conjunction with a VIKTORIA-2 protocol amendment, is evaluating the efficacy and safety of gedatolisib in combination with palbociclib and letrozole in approximately 740 patients with treatment-naive endocrine-sensitive HR+/HER2- ABC. Eligible patients include those whose cancer relapsed or progressed 12 months or more after completion of adjuvant endocrine therapy, or those with de novo metastatic disease without prior endocrine therapy exposure. Approximately 60,000 adults are newly diagnosed each year in the United States with endocrine-sensitive HR+/HER2- ABC . 1 To support its long-term lifecycle development plan, Celcuity submitted its first patent application to the United States Patent and Trademark Office (“USPTO”) for a subcutaneous formulation of gedatolisib that would enable a patient to receive gedatolisib as an injection as an alternative to an infusion. Development of the subcutaneous gedatolisib formulation is ongoing with the goal of demonstrating clinical equivalence to the current intravenous formulation of gedatolisib. The subcutaneous formulation is aimed to support potential future indications for gedatolisib regimens that may result in duration of treatment periods greater than several years. In January 2026, the FDA accepted the submission of Celcuity’s New Drug Application (“NDA”) for gedatolisib in HR+/HER2- PIK3CA wild-type (“WT”) ABC. The FDA granted Priority Review and assigned a Prescription Drug User Fee Act (“PDUFA”) goal date of July 17, 2026. First Quarter 2026 Financial Results Unless otherwise stated, all comparisons are for the first quarter ended March 31, 2026, compared to the first quarter ended March 31, 2025. Net loss for the first quarter of 2026 was $52.8 million, or $0.97 per share, compared to a net loss of $37.0 million, or $0.86 per share, for the first quarter of 2025. Non-GAAP adjusted net loss for the first quarter of 2026 was $46.8 million, or $0.86 per share, compared to non-GAAP adjusted net loss of $34.7 million, or $0.81 per share, for the first quarter of 2025. Non-GAAP adjusted net loss excludes stock-based compensation expense, non-cash interest expense, and non-cash interest income. Because these items have no impact on Celcuity’s cash position, management believes non-GAAP adjusted net loss better enables Celcuity to focus on cash used in operations. For a reconciliation of financial measures calculated in accordance with generally accepted accounting principles in the United States (“GAAP”) to non-GAAP financial measures, please see the financial tables at the end of this press release. Total operating expenses were $50.5 million for the first quarter of 2026, compared to $36.1 million for the first quarter of 2025. Research and development (“R&D”) expenses were $33.1 million for the first quarter of 2026, compared to $29.8 million for the prior year period. The $3.3 million increase in R&D expenses was primarily due to a $3.0 million increase in employee-related and consulting expenses. The remaining increase was primarily due to a $5.4 million increase in manufacturing and other costs, partially offset by a $5.1 million decrease in clinical trial costs, which was primarily driven by decreased costs for the VIKTORIA-1 Phase 3 clinical trial. Selling, general and administrative (“SG&A”) expenses were $17.4 million for the first quarter of 2026, compared to $6.3 million for the prior year period. The $11.1 million increase in SG&A expenses was primarily due to an $8.7 million increase in employee-related and consulting expenses, of which $6.6 million was due to commercial headcount additions and other launch-related activities, and a $2.4 million increase primarily due to software costs, professional fees and other costs. Net cash used in operating activities for the first quarter of 2026 was $55.1 million, compared to $35.9 million for the prior year period. Cash, cash equivalents and short-term investments were $387.1 million at the end of the first quarter of 2026. We expect cash, cash equivalents, investments and drawdowns on our debt facility to finance our operations through 2027. Webcast and Conference Call Information To participate in the teleconference, domestic callers should dial 1-800-717-1738 and international callers should dial 1-646-307-1865. A live webcast presentation can also be accessed using this weblink: . A replay of the webcast will be available on the Celcuity website following the live event. About Celcuity Celcuity is a clinical-stage biotechnology company focused on the development of targeted therapies for the treatment of multiple solid tumor indications. Our lead therapeutic candidate is gedatolisib, a kinase inhibitor of the PI3K/AKT/mTOR (“PAM”) pathway that binds to all class I PI3K isoforms and the mTOR complexes, mTORC1 and mTORC2. By targeting all class I PI3K isoforms and mTORC1/2, gedatolisib induces comprehensive inhibition of the PAM pathway. Its mechanism of action and pharmacokinetic properties are differentiated from other currently approved and investigational therapies that target PI3Kα, AKT, or mTORC1 alone or together. Our Phase 3 clinical trial, VIKTORIA-1, evaluating gedatolisib in combination with fulvestrant with or without palbociclib in patients with HR+/HER2- ABC, has reported detailed results for Study 1, which evaluated patients with PIK3CA WT tumors, and announced topline results for Study 2, which evaluated patients with PIK3CA MT tumors. Our Phase 3 clinical trial, VIKTORIA-2, is ongoing and incorporates two independent studies, Study 1 and Study 2, evaluating two separate cohorts of patients with ABC who are treatment-naive in the advanced setting. Study 1 is evaluating gedatolisib combined with palbociclib and fulvestrant as first-line treatment for patients with endocrine-resistant HR+/HER2- ABC. Study 2 is evaluating gedatolisib combined with palbociclib and letrozole as first-line treatment for patients with endocrine-sensitive HR+/HER2- ABC. A Phase 1b/2 clinical trial, CELC-G-201, evaluating gedatolisib in combination with darolutamide in patients with metastatic castration resistant prostate cancer, is ongoing. More detailed information about Celcuity’s active clinical trials can be found at ClinicalTrials.gov . Celcuity is headquartered in Minneapolis. Further information about Celcuity can be found at . Follow us on LinkedIn and X . Forward Looking Statements This press release contains statements that constitute "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995 including statements relating to the potential therapeutic benefits of gedatolisib; the size, design and timing of our clinical trials; our interpretation of clinical trial data; the status and timing of the FDA’s review of our NDA for gedatolisib, including the PDUFA goal date assigned by the FDA; the ability of our data to support the filing of an sNDA with the FDA and comparable filings with other regulatory authorities outside the U.S.; our intent to present data at the 2026 ASCO Annual Meeting; the market opportunity for gedatolisib; our expectations regarding the timing of and our ability to obtain FDA approval to commercialize gedatolisib; our strategy, marketing and commercialization plans, including the benefits of strategic decisions regarding studies and trials; other expectations with respect to gedatolisib, including subcutaneous formulations to support potential future indications for gedatolisib regimens; our anticipated use of cash; and the strength of our balance sheet. Words such as, but not limited to, “look forward to,” “believe,” “expect,” “anticipate,” “estimate,” “intend,” "confidence," "encouraged," “potential,” “plan,” “targets,” “likely,” “may,” “will,” “would,” “should” and “could,” and similar expressions or words identify forward-looking statements. The forward-looking statements included in this press release are based on management's current expectations and beliefs which are subject to a number of risks, uncertainties and factors, including that our topline clinical results are based on an ongoing analysis of key efficacy and safety data, and such data may change following a more comprehensive review of the data related to the clinical trial; unforeseen delays in our clinical trials or the FDA’s review of our NDA for gedatolisib; our ability to obtain and maintain regulatory approvals to commercialize gedatolisib, and the market acceptance of gedatolisib; the development of therapies and tools competitive with gedatolisib; and our ability to access capital upon favorable terms. In addition, all forward-looking statements are subject to other risks detailed in our Annual Report on Form 10-K for the year ended December 31, 2025, filed with the Securities and Exchange Commission on March 26, 2026, as such risks may be updated in our subsequent filings with the Securities and Exchange Commission. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. All forward-looking statements are qualified in their entirety by these cautionary statements, and we undertake no obligation to revise or update this press release to reflect events or circumstances after the date hereof. References: 1. Internal estimates using data from National Cancer Institute, SEER, 2024; Pan, H, NEJM, 2017;377:1836-46; Dowsett, M 2009; Salvo, E. M. et al. 2021 Contacts: Celcuity Inc. Brian Sullivan, bsullivan@celcuity.com Vicky Hahne, vhahne@celcuity.com (763) 392-0123 Jodi Sievers, jsievers@celcuity.com (415) 494-9924 Celcuity Inc. Condensed Balance Sheets (in thousands) March 31, 2026 December 31, 2025 (unaudited) Assets Current assets: Cash and cash equivalents $ 145,191 $ 165,703 Investments 241,873 275,794 Other current assets 21,865 24,162 Total current assets 408,929 465,659 Property and equipment, net 619 499 Operating lease right-of-use assets 13 51 Other non-current assets 603 349 Total assets $ 410,164 $ 466,558 Liabilities and stockholders' equity Current liabilities: Accounts payable $ 10,454 $ 6,407 Accrued expenses 22,744 37,691 Operating lease liabilities, current 13 54 Total current liabilities 33,211 44,152 Convertible notes 195,566 195,324 Note payable 127,862 126,527 Total liabilities 356,639 366,003 Total stockholders' equity 53,525 100,555 Total liabilities and stockholders' equity $ 410,164 $ 466,558 Celcuity Inc. Condensed Statements of Operations (unaudited) (in thousands, except share and per share amounts) Three Months Ended March 31, 2026 2025 Operating expenses: Research and development (1) $ 33,063 $ 29,759 Selling, general and administrative (1) 17,444 6,374 Total operating expenses 50,507 36,133 Loss from operations (50,507 ) (36,133 ) Other (expense) income: Interest expense (6,085 ) (3,183 ) Interest income 3,751 2,319 Other (expense) income, net (2,334 ) (864 ) Net loss before income taxes (52,841 ) (36,997 ) Income taxes — — Net loss $ (52,841 ) $ (36,997 ) Net loss per share, basic and diluted $ (0.97 ) $ (0.86 ) Weighted average common shares outstanding, basic and diluted 54,462,826 43,052,757 (1) Certain prior period amounts have been reclassified from research and development expenses to selling, general and administrative expenses to conform to the current period presentation. Cautionary Statement Regarding Non-GAAP Financial Measures This press release contains references to non-GAAP adjusted net loss and non-GAAP adjusted net loss per share. Management believes these non-GAAP financial measures are useful supplemental measures for planning, monitoring, and evaluating operational performance as they exclude stock-based compensation expense, non-cash interest expense, and non-cash interest income from net loss and net loss per share. Management excludes these items because they do not impact Celcuity’s cash position, which management believes better enables Celcuity to focus on cash used in operations. However, non-GAAP adjusted net loss and non-GAAP adjusted net loss per share are not recognized measures under GAAP and do not have a standardized meaning prescribed by GAAP. As a result, management’s method of calculating non-GAAP adjusted net loss and non-GAAP adjusted net loss per share may differ materially from the method used by other companies. Therefore, non-GAAP adjusted net loss and non-GAAP adjusted net loss per share may not be comparable to similarly titled measures presented by other companies. Investors are cautioned that non-GAAP adjusted net loss and non-GAAP adjusted net loss per share should not be construed as alternatives to net loss, net loss per share or other statements of operations data (which are determined in accordance with GAAP) as an indicator of Celcuity’s performance or as a measure of liquidity and cash flows. Celcuity Inc. Reconciliation of GAAP Net Loss to Non-GAAP Adjusted Net Loss and GAAP Net Loss Per Share to Non-GAAP Adjusted Net Loss Per Share (unaudited) (in thousands, except share and per share amounts) Three Months Ended March 31, 2026 2025 GAAP net loss $ (52,841 ) $ (36,997 ) Adjustments to net loss: Stock-based compensation Research and development (1) , (2) 2,112 1,164 Selling, general and administrative ( 1 ) , (3) 3,213 1,280 Non-cash interest expense ( 4 ) 1,577 800 Non-cash interest income ( 5 ) (883 ) (946 ) Non-GAAP adjusted net loss $ (46,822 ) $ (34,699 ) GAAP net loss per share - basic and diluted $ (0.97 ) $ (0.86 ) Adjustments to net loss: Stock-based compensation Research and development 0.04 0.02 Selling, general and administrative 0.06 0.03 Non-cash interest expense 0.03 0.02 Non-cash interest income (0.02 ) (0.02 ) Non-GAAP adjusted net loss per share - basic and diluted $ (0.86 ) $ (0.81 ) Weighted average common shares outstanding, basic and diluted 54,462,826 43,052,757 (1) Certain prior period amounts have been reclassified from research and development expenses to selling, general and administrative expenses to conform to the current period presentation. (2) To reflect a non-cash adjustment to operating expenses for research and development stock-based compensation. (3) To reflect a non-cash adjustment to operating expenses for selling, general and administrative stock-based compensation. (4) To reflect a non-cash adjustment to other expense for amortization of debt issuance costs and discount and payment-in-kind interest related to the issuance of the convertible notes and note payable. (5) To reflect a non-cash adjustment to other income for accretion on investments and change in accrued interest income.