MorphoSys’ Pelabresib Improves All Four Hallmarks of Myelofibrosis in Phase 3 MANIFEST-2 Study

On December 10, 2023 MorphoSys AG (FSE: MOR; NASDAQ: MOR) reported comprehensive results from the Phase 3 MANIFEST-2 study investigating pelabresib, an investigational BET inhibitor, in combination with the JAK inhibitor ruxolitinib in JAK inhibitor-naïve patients with myelofibrosis (Press release, MorphoSys, DEC 10, 2023, View Source [SID1234638379]). These findings were presented in an oral presentation at the 65th American Society of Hematology (ASH) (Free ASH Whitepaper) Annual Meeting and Exposition in San Diego, California.

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Myelofibrosis is characterized by four hallmarks: an enlarged spleen, anemia, bone marrow fibrosis and disease-associated symptoms. In MANIFEST-2, all hallmarks were improved with the pelabresib and ruxolitinib combination versus placebo plus ruxolitinib, which is the standard of care in myelofibrosis. Ruxolitinib dosing was similar in both arms of the study and was determined based on its approved myelofibrosis indication.

"The MANIFEST-2 results demonstrated clear benefits across the four hallmarks of myelofibrosis, including a significant reduction in spleen size – a key finding given the known association between spleen volume reduction and patient survival," said Raajit K. Rampal, M.D., Ph.D., Director, Center for Hematologic Malignancies, and Director, Myeloproliferative Neoplasms Program, Memorial Sloan Kettering Cancer Center. "The comprehensive results presented at ASH (Free ASH Whitepaper) also show that the pelabresib combination improves anemia, disease-associated symptoms and bone marrow fibrosis, and that it is well-tolerated. These findings point to pelabresib and ruxolitinib as a potential paradigm-shifting first-line treatment of this debilitating disease."

MANIFEST-2 Comprehensive Findings

MANIFEST-2 is a global, multicenter, double-blind, Phase 3 study of 430 JAK inhibitor-naïve adults with myelofibrosis, randomized 1:1 to receive the pelabresib and ruxolitinib combination or placebo plus ruxolitinib. MANIFEST-2 is one of the largest studies in this disease to date.

Strong Reductions in Spleen Size and Symptoms

In the MANIFEST-2 study, pelabresib and ruxolitinib demonstrated a near doubling in the proportion of patients achieving a ≥35% reduction in spleen volume (SVR35) at 24 weeks, the primary endpoint, versus placebo plus ruxolitinib (p<0.001).

For the first key secondary endpoint assessing symptom reduction, absolute change in total symptom score (TSS) at 24 weeks, there was a strong numerical improvement for patients receiving pelabresib and ruxolitinib versus placebo plus ruxolitinib. The response rate for the second key secondary endpoint, proportion of patients achieving ≥50% reduction in symptom score (TSS50) at 24 weeks, was also numerically greater for patients receiving pelabresib and ruxolitinib. Significant improvements in both key secondary endpoints were observed with the pelabresib combination for patients classified as intermediate-risk (Dynamic International Prognostic Scoring System [DIPSS] Int-1 and Int-2), who account for over 90% of the MANIFEST-2 population.

The proportion of patients achieving both SVR35 and TSS50 at 24 weeks was doubled with pelabresib and ruxolitinib versus placebo plus ruxolitinib (40.2% vs. 18.5%, respectively).

Details are included in the table below.

Endpoint Pelabresib + Ruxolitinib
(N=214) Placebo +
Ruxolitinib
(N=216) Difference
SVR35 65.9% 35.2% 30.4%*
P-value: p<0.001
Absolute Change in TSS -15.99
(Mean Baseline: 28.26)
-14.05
(Mean Baseline: 27.36) -1.94**
P-value: 0.0545
TSS50 52.3% 46.3% 6.0%*
P-value: 0.216
*Difference calculated using Cochran–Mantel–Haenszel (CMH) common risk difference

**Least square mean estimate

Improvement in Anemia

Patients receiving pelabresib in combination with ruxolitinib reported fewer anemia adverse events (43.9%, grade ≥3: 23.1%) compared with placebo plus ruxolitinib (55.6%, grade ≥3: 36.4%). Additionally, by week 24, fewer patients in the pelabresib and ruxolitinib arm required red blood cell transfusions compared with the placebo arm (30.8% vs. 41.2%, respectively).

A greater proportion of patients achieved a hemoglobin response — defined as a ≥1.5 g/dL mean increase in hemoglobin levels over baseline in the absence of transfusions during the previous 12 weeks — with pelabresib and ruxolitinib versus placebo plus ruxolitinib (9.3% vs. 5.6%, respectively). Average hemoglobin levels were greater in patients receiving pelabresib and ruxolitinib than in those receiving placebo plus ruxolitinib, starting at week 9 and continuing to week 24. Anemia benefits were observed across all studied patient risk groups.

"Anemia can reduce patients’ quality of life by causing severe fatigue and necessitating blood transfusions," said Professor Claire Harrison, Guy’s and St. Thomas’ NHS Foundation Trust, London, United Kingdom. "In MANIFEST-2, patients receiving the combination therapy showed clear benefits on anemia, including greater hemoglobin levels, fewer red blood cell transfusions and fewer anemia and fatigue adverse events. Given its strong efficacy, safety profile and signs of disease modification, the pelabresib and ruxolitinib combination has the potential to become the new standard of care in the first-line treatment of myelofibrosis."

Improvement in Bone Marrow Fibrosis

Bone marrow fibrosis, or the replacement of bone marrow with fibrous scar tissue, is a central pathological feature of myelofibrosis. In MANIFEST-2, fibrosis was improved by at least one grade in a greater proportion of patients receiving pelabresib and ruxolitinib (38.5% vs. 24.2% with placebo plus ruxolitinib) and worsened by at least one grade in a smaller proportion of patients receiving pelabresib and ruxolitinib (16.3% vs. 28.3% with placebo plus ruxolitinib) at 24 weeks. Bone marrow fibrosis is graded on a scale from 0 (normal) to 3 (most severe) based on fiber density; studies suggest a correlation between the grade of bone marrow fibrosis and patient prognosis.

Biomarker Analysis Suggests Disease Modification

In a biomarker analysis, average plasma levels of inflammatory cytokines (IL-8, IL-6, TNF-α and NF-κB-regulated cytokines) were reduced in patients receiving pelabresib and ruxolitinib compared with placebo plus ruxolitinib at 24 weeks. Increased cytokine levels are associated with all four disease hallmarks; increased IL-8 levels are also associated with worse survival outcomes. These biomolecular improvements suggest early evidence of a disease-modifying effect.

Well-Tolerated Safety Profile

Overall, grade ≥3 treatment-emergent adverse events (TEAEs) were reported less frequently with pelabresib and ruxolitinib than with placebo plus ruxolitinib (49.1% vs. 57.5%, respectively).

In the pelabresib and ruxolitinib arm, the most common (≥10%) hematologic TEAEs were anemia (43.9%; grade ≥3: 23.1%), thrombocytopenia (32.1%; grade ≥3: 9.0%) and platelet count decrease (20.8%; grade ≥3: 4.2%). In the placebo plus ruxolitinib arm, the most common hematologic TEAEs were anemia (55.6%; grade ≥3: 36.4%), thrombocytopenia (23.4%; grade ≥3: 5.6%) and platelet count decrease (15.9%; grade ≥3: 0.9%).

The most common (≥10%) nonhematologic TEAEs in the pelabresib and ruxolitinib arm were diarrhea (23.1%; grade ≥3: 0.5%), dysgeusia (18.4%; grade ≥3: 0.5%), constipation (18.4%; grade ≥3: 0%), nausea (14.2%; grade ≥3: 0.5%), cough (12.7% grade ≥3: 0), asthenia (11.8% grade ≥3: 0.5%), fatigue (11.8%; grade ≥3: 0.5%), dizziness (11.3%; grade ≥3: 0%), headache (11.3% grade ≥3: 0.5%) and COVID-19 (11.3%; grade ≥3: 0%). The most common nonhematologic TEAEs in the placebo plus ruxolitinib arm were constipation (24.3%; grade ≥3: 0%), diarrhea (18.7%; grade ≥3: 1.4%), fatigue (16.8%; grade ≥3: 0.9%), COVID-19 (15.9%; grade ≥3: 1.9%), nausea (15.0%; grade ≥3: 0%), asthenia (13.6%; grade ≥3: 0%), dyspnea (13.1%; grade ≥3: 0.9%), cough (11.2%; grade ≥3: 0%) and headache (10.7%; grade ≥3: 0%). Discontinuation rates due to adverse events were 10.7% with pelabresib and ruxolitinib and 6.5% with placebo plus ruxolitinib.

The safety profile of the pelabresib and ruxolitinib combination therapy was consistent with previous clinical studies. No new safety signals were observed.

"The four hallmarks of myelofibrosis – enlarged spleen, anemia, bone marrow fibrosis and disease-associated symptoms – have a strong impact on a patient’s life. In MANIFEST-2, the combination of JAK and BET inhibition addressed all four of these hallmarks with the potential to modify the course of the disease," said Tim Demuth, M.D., Ph.D., MorphoSys Chief Research and Development Officer. "We are confident that the comprehensive data package will provide impactful insights into the promising and well-tolerated combination of pelabresib and ruxolitinib. Our goal now is to bring this first-line therapy to patients with intermediate- and high-risk myelofibrosis as quickly as possible. We look forward to meeting with regulatory agencies regarding these data and are diligently preparing regulatory filings with the intention of submitting applications to the U.S. Food and Drug Administration and the European Medicines Agency in the middle of 2024."

Investor Event at ASH (Free ASH Whitepaper) 2023

MorphoSys will host an in-person investor event to review these detailed findings and address questions with the company’s management team and medical experts, including Professor Claire Harrison, Guy’s and St. Thomas’ NHS Foundation Trust, London, United Kingdom, and Ruben Mesa, M.D., FACP, President and Executive Director, Atrium Health Levine Cancer Center and Atrium Health Wake Forest Baptist Comprehensive Cancer Center.

The event, taking place on Monday, December 11 at the Hilton San Diego Bayfront Hotel, will start with a networking breakfast at 6:30 a.m. PST and continue with a formal presentation at 7:00 a.m. PST (4:00 p.m. CET / 3:00 p.m. GMT / 10:00 a.m. EST). A webcast will also be available for those not attending ASH (Free ASH Whitepaper) 2023 in person.

Webcast participants may pre-register and will receive dial-in details to access the call easily and quickly: View Source;linkSecurityString=c1a71840b. Please dial in 10 minutes before the beginning of the conference.

The live webcast (audio and presentation) can be directly accessed via View Source or via the Investors section under "Events & Conferences" on the MorphoSys website, www.morphosys.com; after the call, a slide-synchronized audio replay of the conference call will be available at the same location.

Schrödinger Presents Data Supporting Advancement of SGR-1505 and SGR-2921 at American Society of Hematology 2023 Annual Meeting

On December 10, 2023 Schrödinger (Nasdaq: SDGR), whose physics-based computational platform is transforming the way therapeutics and materials are discovered, reported new preclinical data on SGR-1505, its investigational MALT1 inhibitor, and SGR-2921, its investigational CDC7 inhibitor, in a poster session at the American Society of Hematology (ASH) (Free ASH Whitepaper) 65th Annual Meeting taking place virtually and in San Diego, California (Press release, Schrodinger, DEC 10, 2023, View Source [SID1234638395]). The preclinical data reported show that both SGR-1505 and SGR-2921 have multiple favorable attributes and the potential for combination activity with standard-of-care agents.

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Schrödinger also reported preliminary pharmacodynamic data from the Phase 1 study of SGR-1505 in healthy subjects, which showed that SGR-1505 inhibited cytokine release in human whole blood and demonstrated evidence of MALT1 inhibition in humans. The company will report additional data from the healthy subject study at its Pipeline Day on December 14, 2023.

"The pharmacological data for SGR-1505 and SGR-2921 demonstrate that our development candidates have favorable, differentiated profiles with best-in-class potential," stated Karen Akinsanya, Ph.D., president of R&D therapeutics at Schrödinger. "Our progress within these programs further validates our computational approach to designing therapies with the potential to address the limitations of current treatments. SGR-1505 and SGR-2921 are now being evaluated in Phase 1 clinical studies, and we look forward to seeing these programs advance."

A Phase 1 dose-escalation study of SGR-1505 in relapsed or refractory B-cell malignancy patients is ongoing in the U.S. and Europe. Additionally, a Phase 1 clinical study of SGR-2921 was recently initiated in patients with acute myeloid leukemia or myelodysplastic syndrome. Both studies are designed to evaluate the safety, pharmacokinetics, pharmacodynamics, and determine the recommended dose for further development.

SGR-1505 Data at ASH (Free ASH Whitepaper)

The presentation (Abstract # 2997), "SGR-1505 is a Potent MALT1 Protease Inhibitor with a Potential Best-in-Class Profile," includes preclinical data demonstrating the potency of SGR-1505 and the potential for combination activity with standard of care agents. Preclinical data showed that SGR-1505 is more potent than JNJ-6633, which has previously provided clinical validation for MALT1 inhibition as a potential therapeutic strategy for treating both chronic lymphocytic leukemia (CLL) and non-Hodgkin’s lymphomas (NHL). In a preclinical model of diffuse large B-cell lymphoma, SGR-1505, in combination with venetoclax, demonstrated a stronger combination impact on cell viability compared to JNJ-633 plus venetoclax. Gene expression analysis showed that SGR-1505 provides greater modulation of NF-ΚΒ and related pathway genes compared to JNJ-6633. Signaling of the NF-ΚΒ pathway is known to play a critical role in the initiation and progression of many types of cancers, particularly B cell malignancies.

Preliminary clinical biomarker data from the Phase 1 study in healthy subjects showed that SGR-1505 inhibited cytokine release in ex vivo stimulation of human whole blood. The inhibition of certain cytokines in whole blood from human subjects dosed with SGR-1505 provides pharmacodynamic evidence of MALT1 inhibition. These data are consistent with prior preclinical observations in an in vitro whole blood assay from healthy human subjects, where approximately a 50-fold lower concentration of SGR-1505 was needed to achieve 90 percent inhibition of cytokine release compared to JNJ-6633. The data support continued evaluation of SGR-1505 in the ongoing Phase 1 study in patients with advanced B-cell malignancies.

SGR-2921 Data at ASH (Free ASH Whitepaper)

The presentation (Abstract #2801), "SGR-2921, a Potent CDC7 Inhibitor, Demonstrates Significant Anti-Leukemic Responses in Patient-Derived AML Models Representing Difficult-to-Treat Disease," includes preclinical data for SGR-2921 which demonstrate the potency, breadth of activity and synergistic effects of SGR-2921 in combination with standard-of-care therapies. In vitro, SGR-2921 exhibited greater potency compared to other clinical-stage CDC7 inhibitors and showed anti-proliferative activity in AML patient-derived samples regardless of driver mutations. In vivo, SGR-2921 showed dose-dependent reduction of AML blasts in multiple AML models representing difficult-to-treat disease. SGR-2921 also showed synergistic activity in combination with decitabine in p53-mutated AML models in vivo. Together, these data support the ongoing evaluation of SGR-2921 as a potential treatment for AML, with particular utility in patients with high-risk mutations and relapsed and refractory AML.

Schrödinger Pipeline Day Webcast Information

Schrödinger will review the company’s proprietary research and development programs, including updates on SGR-1505 and SGR-2921, at its Pipeline Day taking place in-person and virtually on December 14, 2023. Pipeline Day will be a hybrid event, with a webcast and limited in-person attendance available to members of the investment community. The presentation can be accessed in the "Investors" section of Schrödinger’s website and will be archived for approximately 90 days. To participate in the live webcast, please register for the event here. It is recommended that participants register at least 15 minutes in advance of the event.

New Data Reinforce the Benefit of Early Preventative Treatment with Chugai’s Hemlibra for Babies with Severe Hemophilia A

On December 10, 2023 Chugai Pharmaceutical Co., Ltd. (TOKYO: 4519) reported that the primary analysis of the Phase III HAVEN 7 study reinforced the efficacy and safety of Hemlibra (generic name: emicizumab) in previously untreated or minimally treated infants with severe hemophilia A without factor VIII inhibitors (Press release, Chugai, DEC 10, 2023, View Source;category= [SID1234638380]). Results showed that Hemlibra achieved meaningful bleed control in babies up to 12 months of age, and was well tolerated.1 The new data were presented at the 65th American Society of Hematology (ASH) (Free ASH Whitepaper) Annual Meeting and Exposition taking place 9-12 December 2023, in San Diego, California, and included in the press program.

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"Hemlibra, which can be administered subcutaneously, is an option to reduce the treatment burden for infants who have difficulty with intravenous administration in the treatment of severe hemophilia A to prevent bleeding. In this study, Hemlibra demonstrated effective bleeding control in infants for the first time. This complements data across a wide range of ages shown in previous clinical trials and supports earlier initiation of Hemlibra treatment aimed at preventing bleeding in infants. We remain committed to building evidence including long-term data to support the safe use of this drug for those who need it," said Dr. Osamu Okuda, Chugai’s President and CEO.

The burden of severe hemophilia A in babies and on their parents and caregivers is significant. The World Federation of Hemophilia treatment guidelines consider the standard of care in hemophilia to be regular prophylaxis initiated at a young age, as studies have shown this improves long-term outcomes, while reducing the risk of intracranial hemorrhage.2-4 However, for many babies with hemophilia A, prophylaxis is not started until after the first year of life.5-8 Hemlibra, which is already approved and being used to treat babies with hemophilia A, provides a flexible treatment option that can be administered subcutaneously from birth at different dosing frequencies for maintenance dosing.9

The HAVEN 7 study is a Phase III, descriptive, single-arm study, set up in collaboration with the hemophilia A community to evaluate the efficacy, safety, pharmacokinetics and pharmacodynamics of subcutaneous Hemlibra in infants with severe hemophilia A without factor VIII inhibitors. These results, which included data from 55 participants, showed that at 101.9 weeks median follow-up, 54.5% of participants (n=30) did not have any bleeds that required treatment, while 16.4% (n=9) did not have any treated or untreated bleeds at all. There were no spontaneous bleeds requiring treatment in any participant, and all treated bleeds were as a result of trauma. A total of 207 bleeds occurred in 46 participants (83.6%); 87.9% of these were as a result of trauma. Model-based annualized bleeding rate (95% CI) was 0.4 (0.30-0.63) for treated bleeds. No new safety signals were observed and there were no treatment-related serious adverse events, intracranial hemorrhages or deaths reported. 3.6% of participants (n=2) tested positive for factor VIII inhibitors which may be a consequence of reduced factor VIII usage in participants treated with Hemlibra, and no participant tested positive for anti-drug antibodies.1 Results were consistent with positive results from the interim analysis and from previous Phase III HAVEN studies.10-14

The results of additional research on biomarkers in the HAVEN 7 study were also presented at ASH (Free ASH Whitepaper), and were supportive of the study’s primary efficacy analysis. This additional research showed that the pharmacodynamic profiles of Hemlibra in babies were consistent with those previously observed in older children and adults with hemophilia A. The data showed that Hemlibra exhibits the expected pharmacodynamic response, despite the reduced presence of the clotting factors that Hemlibra binds to in this age group.15

The HAVEN 7 study results complement data from the broader, pivotal HAVEN clinical program, providing insights into the evolution of hemophilia A in babies, and the impact of initiating preventative treatment from birth. The primary analysis is being followed by a seven year extension period.1

About Hemlibra
Hemlibra is a bispecific monoclonal antibody created with Chugai’s proprietary antibody engineering technologies. The drug is designed to bind factor IXa and factor X. In doing so, Hemlibra provides the cofactor function of factor VIII in people with hemophilia A, who either lack or have impaired coagulation function of factor VIII.16,17 The product was approved by the U.S. Food and Drug Administration (FDA) in November 2017, for the first time in the world, for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients with hemophilia A (congenital factor VIII deficiency) with factor VIII inhibitors. Hemlibra has been approved in more than 115 countries for congenital hemophilia A with and without factor VIII inhibitors. In Japan, it was first approved in March 2018 for congenital hemophilia A with factor VIII inhibitors, and its indication was later expanded to include congenital hemophilia A without factor VIII inhibitors, and acquired hemophilia A.

ImmunoGen Presents Findings from Newly Diagnosed Acute Myeloid Leukemia Cohorts in Phase 1b/2 Study of Pivekimab Sunirine in Combination with Azacitidine and Venetoclax at ASH

On December 10, 2023 ImmunoGen Inc. (Nasdaq: IMGN), a leader in the expanding field of antibody-drug conjugates (ADCs) for the treatment of cancer, reported new safety and efficacy findings from the newly diagnosed (ND) cohorts of the Phase 1b/2 study of pivekimab sunirine (pivekimab) in combination with azacitidine (Vidaza) and venetoclax (Venclexta), (pivekimab triplet) in patients with ND acute myeloid leukemia (AML) (Press release, ImmunoGen, DEC 10, 2023, View Source [SID1234638396]). These findings will be presented in a poster session at the 65th American Society of Hematology (ASH) (Free ASH Whitepaper) Annual Meeting in San Diego, California.

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"Building upon our initial findings in frontline AML presented last year, these data show broad and consistent response rates in a larger study population and across major molecular subsets of interest, including those patients with biological mutations making them high-risk"

Post this
"We are pleased to share these new findings at ASH (Free ASH Whitepaper), which demonstrate encouraging anti-leukemia activity of the pivekimab triplet in newly diagnosed AML, a disease in which long-term survival unfortunately remains limited," said Naval Daver, MD, Associate Professor in the Department of Leukemia at The University of Texas MD Anderson Cancer Center. "The MRD negativity rates, which are indicative of a deep remission, are particularly promising in the treated patient population. This encouraging activity, along with a manageable safety profile, support the continued evaluation of this novel triplet in this setting."

PIVEKIMAB SUNIRINE, A CD123-TARGETING ANTIBODY-DRUG CONJUGATE, IN COMBINATION WITH AZACITIDINE AND VENETOCLAX IN PATIENTS WITH NEWLY DIAGNOSED ACUTE MYELOID LEUKEMIA
Lead Author: Navel Daver, MD
Poster Session: 616 (Acute Myeloid Leukemias: Investigational Therapies, Excluding Transplantation and Cellular Immunotherapies: Poster II)
Date and Time: Sunday, December 10, 2023, 6:00-8:00 p.m. PT / 9:00-11:00 p.m. ET
Publication Number: 2906

In the open-label, multicenter, Phase 1b/2 study of pivekimab in combination with azacitidine and venetoclax in patients with ND CD123-positive AML, patients received the recommended Phase 2 dose of pivekimab at 0.045 mg/kg on day 7, azacitidine at 75 mg/m2 daily on days 1-7, and venetoclax at up to 400 mg for at least 14 days or up to 28 days, based on cohort assignment, in a 28-day cycle. The primary endpoints are complete remission (CR) rate, composite CR rate (CCR [CR+CRh+CRp+CRi]), minimal residual disease (MRD) negativity rate, and duration of remission. Key secondary endpoints are safety, pharmacokinetics, and immunogenicity.

Key findings for 50 ND patients (n=25 per cohort) as of September 29, 2023 (data cut-off) include:

Anti-Leukemia Activity

In the overall population, CCR rate was 68% (34/50), CR rate was 54% (27/50), and MRD negativity rate among evaluable patients achieving CCR was 76% (22/29). MRD was assessed centrally by flow cytometry with <0.1% considered negative. Response rates and MRD negativity were numerically comparable between cohorts 1 and 2, despite differences in the venetoclax schedule.
In a post hoc subset analysis of patients unfit for intensive chemotherapy (i.e. patients >75 years of age, and/or with pre-specified comorbidities) (n=23), CCR rate was 78% (18/23), CR rate was 61% (14/23), and MRD negativity rate was 79% (11/14).
In patients known to be TP53wt (n=25), CCR rate was 88% (22/25), CR rate was 84% (21/25), and MRD negativity rate was 80% (16/20). CCR and MRD negativity rates, respectively, were high across other major molecular subsets, including:
FLT3 (ITD or TKD): 100% (6/6) and 100% (6/6)
IDH1 mutant: 100% (4/4) and 67% (2/3)
IDH2 mutant: 100% (6/6) and 83% (5/6)
NPM1 mutant: 100% (8/8) and 86% (6/7)
K/NRAS mutant: 50% (3/6) and 67% (2/3)
TP53 mutant: 50% (7/14) and 50% (3/6)
Among all MRD negative patients, the median time to MRD negativity was 1.87 months (range: 0.79-5.16 months).
Although follow-up duration was short (median 5.2 months), landmark overall survival estimate at 6 months is 86%.
The study is continuing to enroll newly diagnosed unfit AML patients.
Safety

The triplet displayed a manageable safety profile; no new safety signals were observed compared to previously reported data.
The most common non-hematologic treatment-emergent adverse events (TEAEs) (all grades [grade 3+]) seen in ≥20% of all patients were constipation (48% [2%]), peripheral edema (44% [4%]), diarrhea (40% [2%]), hypophosphatemia (34% [2%]), nausea (32% [4%]), hypokalemia (28% [4%]), fatigue (24% [6%]), hypotension (24% [2%]), and pyrexia (24% [0%]). In the overall population:
Rates of cytopenias were similar to those observed with azacitidine and venetoclax, with a median neutrophil recovery to ≥500/µL and platelet recovery to ≥50,000/µL by day 34 and day 22, respectively.
No veno-occlusive disease, capillary leak syndrome, or sinusoidal obstruction syndrome were observed.
Infusion-related reactions (IRRs) occurred in 16% of patients (0 grade 3+ IRRs).
Discontinuations due to an adverse event (AE) were 4% (2 patients).
30-day mortality was 0%.
60-day mortality was 4% (2 patients; due to pneumonia and early disease progression).
"Building upon our initial findings in frontline AML presented last year, these data show broad and consistent response rates in a larger study population and across major molecular subsets of interest, including those patients with biological mutations making them high-risk," said Michael Vasconcelles, MD, ImmunoGen’s Executive Vice President, Research, Development, and Medical Affairs. "We are pleased with the low early mortality and manageable safety profile observed, in particular the lack of prolonged cytopenias. We look forward to continuing to expand our cohort of newly diagnosed unfit patients to inform the development path for pivekimab in AML."

PRECLINICAL POSTERS
ImmunoGen is also presenting two preclinical posters at ASH (Free ASH Whitepaper).

Title: Venetoclax Synergizes with IMGN632, a Novel CD123-Targeting Antibody Conjugated to a DNA Alkylating Payload, By Suppressing DNA Damage Response and Potentiating Apoptosis in Acute Myeloid Leukemia in Vitro Models
Presenter: Anna Skwarska
Session: 604 (Molecular Pharmacology and Drug Resistance: Myeloid Neoplasms: Poster III)
Date and Time: Monday, December 11, 2023, 6:00-8:00 p.m. PT / 9:00-11:00 p.m. ET
Publication Number: 4155

Title: Spatial Response to Pivekimab Sunirine In Vivo in a BPDCN Model
Presenter: Margaux Poussard
Session: 604 (Molecular Pharmacology and Drug Resistance: Myeloid Neoplasms: Poster II)
Date and Time: Sunday, December 10, 2023, 6:00-8:00 p.m. PT / 9:00-11:00 p.m. ET
Publication Number: 2791

Additional information can be found at View Source, including abstracts.

ABOUT PIVEKIMAB SUNIRINE
Pivekimab sunirine is a CD123-targeting ADC in clinical development for hematological malignancies, including blastic plasmacytoid dendritic cell neoplasm (BPDCN), acute myeloid leukemia (AML), and other CD123+ hematologic malignancies. Pivekimab is currently being evaluated as monotherapy for patients with BPDCN and in combination with azacitidine (Vidaza) and venetoclax (Venclexta) for patients with untreated and relapsed/refractory AML. Pivekimab uses one of ImmunoGen’s novel indolinobenzodiazepine (IGN) payloads, which alkylate DNA and cause single-strand breaks without crosslinking. IGNs are designed to have high potency against tumor cells, while demonstrating less toxicity to normal marrow progenitors than other DNA-targeting payloads. The European Medicines Agency (EMA) granted orphan drug designation to pivekimab for the treatment of BPDCN in June 2020. Pivekimab also holds this designation in the US. In October 2020, the FDA granted pivekimab Breakthrough Therapy designation in relapsed/refractory BPDCN.

ABOUT ACUTE MYELOID LEUKEMIA (AML)
AML is a cancer of the bone marrow cells that produce white blood cells. It causes the marrow to increasingly generate abnormal, immature white blood cells (blasts) that do not mature into effective infection-fighting cells. The blasts quickly fill the bone marrow, impacting the production of normal platelets and red blood cells. The resulting deficiencies in normal blood cells leave the patient vulnerable to infections, bleeding problems, and anemia. It is estimated that, in the US alone, more than 20,000 people will be diagnosed with AML and more than 11,000 will die from the disease this year.

ABOUT CD123
CD123, the interleukin-3 alpha chain, is expressed on multiple myeloid and lymphoid cancers including AML, BPDCN, ALL, chronic myeloid leukemia, and myeloproliferative neoplasms. With limited expression on normal hematopoietic cells, rapid internalization, and expression on AML leukemia stem cells, CD123 is a clinically validated therapeutic target.

Karyopharm Shares Data at ASH 2023 Showing Strong SVR and TSS Durability Observed from Phase 1 Study of Selinexor 60mg and Ruxolitinib in JAK Inhibitor (JAKi)-Naïve Myelofibrosis Patients, with no SVR or TSS Progressions Observed As of the Data Cutoff

On December 10, 2023 Karyopharm Therapeutics Inc. (Nasdaq: KPTI), a commercial-stage pharmaceutical company pioneering novel cancer therapies, reported long-term follow up of treatment-naïve patients with myelofibrosis (MF) who participated in the Phase 1 portion of its study evaluating once-weekly selinexor in combination with ruxolitinib (NCT04562389) (Press release, Karyopharm, DEC 10, 2023, View Source,-with-no-SVR-or-TSS-Progressions-Observed-As-of-the-Data-C [SID1234638381]). The data, featured in an oral presentation at the 65th American Society of Hematology (ASH) (Free ASH Whitepaper) Annual Meeting and Exposition (ASH 2023), show patients treated with 60mg selinexor, and who achieved ≥35% reduction in spleen volume (SVR35) at week 24, continued to remain in radiographic response. In addition, all patients who achieved TSS50 at Week 24 remained in response as of the data cut-off.

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The data included in the oral presentation for ASH (Free ASH Whitepaper) 2023 were based on the Phase 1 portion of the Phase 1/3 study evaluating the safety and efficacy of once-weekly selinexor in combination with ruxolitinib in patients with treatment-naïve MF (NCT04562389). As of August 1, 2023, 24 patients had been assigned to either selinexor 40mg (N= 10) or 60mg (N=14), in combination with ruxolitinib. The maximum duration of follow-up was 78 weeks with a median duration of 32 weeks for SVR35 durability, and a maximum duration of follow-up was 64 weeks with a median duration of 51 weeks for TSS50 durability.

An exploratory biomarker analysis showed a reduction of variant allele frequency (VAF) at week 24 for all three MF driver genes (CALR, MPL, and JAK2) and rapid and sustained reduction of pro-inflammatory cytokine production. Early cytokine reduction at Week 4 was associated with spleen volume reduction (SVR) at Week 24 and was sustained until the end of treatment. The clinical efficacy associated with biomarkers impacting MF biological hallmarks may suggest disease modification.

"The growing body of data from this study suggests that selinexor in combination with ruxolitinib may provide spleen reduction, symptom improvement, long-term durability and disease modification, expanding the benefit this combination may provide to patients with treatment-naïve myelofibrosis, " said Reshma Rangwala, MD, PhD, Chief Medical Officer of Karyopharm. "We’re excited about the potential to change treatment paradigms for these patients – and expand the number of patients who benefit from first-line therapy."

The safety profile was consistent with previous data cuts with no new safety signals observed as of Aug 1st.

"The current standard of care is not associated with consistent molecular or pathologic responses," said Dr. Sri Tantravahi, University of Utah. "The long-term findings are very exciting as they underscore the potential for durable, clinically relevant responses and modification of disease course. The wait for new options has been long and difficult for the myelofibrosis community, and we welcome this important research to help advance the understanding of XPO1 and JAK inhibitor combinations as a meaningful treatment option for patients."

"We are encouraged by the attention MPNs (Myeloproliferative Neoplasms) are getting in recent years from companies like Karyopharm," said Kapila Viges, Chief Executive Officer of MPN Research Foundation. "With patients waiting for more answers to these chronic yet serious blood cancers, we look forward to the data readouts at ASH (Free ASH Whitepaper) this year. Efforts to develop better therapies and now combinations of therapies bring hope to the myelofibrosis community and open the potential for more options in the treatment paradigm. For patients, options matter."

About XPOVIO (selinexor)

XPOVIO is a first-in-class, oral exportin 1 (XPO1) inhibitor and the first of Karyopharm’s Selective Inhibitor of Nuclear Export (SINE) compounds to be approved for the treatment of cancer. XPOVIO functions by selectively binding to and inhibiting the nuclear export protein XPO1. XPOVIO is approved in the U.S. and marketed by Karyopharm in multiple oncology indications, including: (i) in combination with Velcade (bortezomib) and dexamethasone (XVd) in patients with multiple myeloma after at least one prior therapy; (ii) in combination with dexamethasone in patients with heavily pre-treated multiple myeloma; and (iii) in patients with diffuse large B-cell lymphoma (DLBCL), including DLBCL arising from follicular lymphoma, after at least two lines of systemic therapy. XPOVIO (also known as NEXPOVIO in certain countries) has received regulatory approvals in various indications in a growing number of ex-U.S. territories and countries, including but not limited to the European Union, the United Kingdom, China, South Korea, Canada, Israel and Taiwan. XPOVIO and NEXPOVIO is marketed by Karyopharm’s partners, Antengene, Menarini, Neopharm and FORUS in China, South Korea, Singapore, Australia, Hong Kong, Germany, Austria, Israel and Canada.

Please refer to the local Prescribing Information for full details.

Selinexor is also being investigated in several other mid- and late-stage clinical trials across multiple high unmet need cancer indications, including in endometrial cancer and myelofibrosis.

For more information about Karyopharm’s products or clinical trials, please contact the Medical Information department at:

Tel: +1 (888) 209-9326
Email: [email protected]

SELECT IMPORTANT SAFETY INFORMATION

Warnings and Precautions

Thrombocytopenia: Monitor platelet counts throughout treatment. Manage with dose interruption and/or reduction and supportive care.
Neutropenia: Monitor neutrophil counts throughout treatment. Manage with dose interruption and/or reduction and granulocyte colony‐stimulating factors.
Gastrointestinal Toxicity: Nausea, vomiting, diarrhea, anorexia, and weight loss may occur. Provide antiemetic prophylaxis. Manage with dose interruption and/or reduction, antiemetics, and supportive care.
Hyponatremia: Monitor serum sodium levels throughout treatment. Correct for concurrent hyperglycemia and high serum paraprotein levels. Manage with dose interruption, reduction, or discontinuation, and supportive care.
Serious Infection: Monitor for infection and treat promptly.
Neurological Toxicity: Advise patients to refrain from driving and engaging in hazardous occupations or activities until neurological toxicity resolves. Optimize hydration status and concomitant medications to avoid dizziness or mental status changes.
Embryo‐Fetal Toxicity: Can cause fetal harm. Advise females of reproductive potential and males with a female partner of reproductive potential, of the potential risk to a fetus and use of effective contraception.
Cataract: Cataracts may develop or progress. Treatment of cataracts usually requires surgical removal of the cataract.
Adverse Reactions

The most common adverse reactions (≥20%) in patients with multiple myeloma who receive XVd are fatigue, nausea, decreased appetite, diarrhea, peripheral neuropathy, upper respiratory tract infection, decreased weight, cataract and vomiting. Grade 3‐4 laboratory abnormalities (≥10%) are thrombocytopenia, lymphopenia, hypophosphatemia, anemia, hyponatremia and neutropenia. In the BOSTON trial, fatal adverse reactions occurred in 6% of patients within 30 days of last treatment. Serious adverse reactions occurred in 52% of patients. Treatment discontinuation rate due to adverse reactions was 19%.
The most common adverse reactions (≥20%) in patients with multiple myeloma who receive Xd are thrombocytopenia, fatigue, nausea, anemia, decreased appetite, decreased weight, diarrhea, vomiting, hyponatremia, neutropenia, leukopenia, constipation, dyspnea and upper respiratory tract infection. In the STORM trial, fatal adverse reactions occurred in 9% of patients. Serious adverse reactions occurred in 58% of patients. Treatment discontinuation rate due to adverse reactions was 27%.
The most common adverse reactions (incidence ≥20%) in patients with DLBCL, excluding laboratory abnormalities, are fatigue, nausea, diarrhea, appetite decrease, weight decrease, constipation, vomiting, and pyrexia. Grade 3‐4 laboratory abnormalities (≥15%) are thrombocytopenia, lymphopenia, neutropenia, anemia, and hyponatremia. In the SADAL trial, fatal adverse reactions occurred in 3.7% of patients within 30 days, and 5% of patients within 60 days of last treatment; the most frequent fatal adverse reactions was infection (4.5% of patients). Serious adverse reactions occurred in 46% of patients; the most frequent serious adverse reaction was infection (21% of patients). Discontinuation due to adverse reactions occurred in 17% of patients.
Use In Specific Populations

Lactation: Advise not to breastfeed.

For additional product information, including full prescribing information, please visit www.XPOVIO.com.

To report SUSPECTED ADVERSE REACTIONS, contact Karyopharm Therapeutics Inc. at 1‐888‐209‐9326 or FDA at 1‐800‐FDA‐1088 or www.fda.gov/medwatch.