INCA-033989 by Incyte for Myelofibrosis: Likelihood of Approval

January 12, 2024

INCA-033989 is under clinical development by Incyte and currently in Phase I for Myelofibrosis. According to GlobalData, Phase I drugs for Myelofibrosis have an 86% phase transition success rate (PTSR) indication benchmark for progressing into Phase II. GlobalData’s report assesses how INCA-033989’s drug-specific PTSR and Likelihood of Approval (LoA) scores compare to the indication benchmarks.

GlobalData tracks drug-specific phase transition and likelihood of approval scores, in addition to indication benchmarks based off 18 years of historical drug development data. Attributes of the drug, company and its clinical trials play a fundamental role in drug-specific PTSR and likelihood of approval.

INCA-033989 overview

INCA-033989 is under development for the treatment of myelofibrosis (MF), essential thrombocythemia (ET). The drug candidate is a monoclonal antibody which acts by targeting calreticulin (CALR).

It was also under development for post-essential thrombocythemia myelofibrosis (Post-ET MF) and primary myelofibrosis (PMF).

Incyte overview

Incyte is a biopharmaceutical company, which discovers, develops and commercializes proprietary cancer therapeutics. The company’s lead product, Jakafi (ruxolitinib) is marketed in the US for the treatment of patients with high-risk myelofibrosis; and polycythemia vera who are intolerant to hydroxyurea. The company distributes Jakafi through a network of specialty pharmacy providers and wholesalers. In collaboration with Incyte, Novartis International Pharmaceutical Ltd (Novartis) develops and commercializes ruxolitinib outside the US for hematologic and cancer indications under the name Jakavi. The company’s pipeline portfolio encompasses drugs for the treatment of lung cancer, graft versus host disease, b-cell malignancies, solid tumors, non-small cell lung cancer, glioblastoma, liver cancer, and advanced malignancies. Incyte is headquartered in Wilmington, Delaware, the US.

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Tamoxifen Reduces Allele Burden of Patients With Myeloproliferative Neoplasms

In a clinical trial evaluating the use of tamoxifen in patients with stable myeloproliferative neoplasms (MPNs), 3 patients showed a 50% or greater reduction in mutant allele burden at 24 weeks. This and other results from the study appeared to support further investigation of this agent in this population, but with consideration of possible thrombotic risk. Study results were reported in the journal Nature Communications.

The study’s primary endpoint was a ≥50% reduction in the mutant allele burden in peripheral blood at 24 weeks, with trial success involving at least 3 patients having met this outcome. Several secondary and exploratory outcomes were also evaluated.

These results warrant further investigation of tamoxifen as potential therapeutic for MPN in larger studies, after careful consideration of the risk of thrombosis.

There were 38 patients recruited into the study, with 32 patients completing 24 weeks of treatment. In the total population of 38 patients, 36.8% had essential thrombocythemia, 28.9% had polycythemia vera, 15.8% had primary myelofibrosis, 13.2% had post-polycythemia vera myelofibrosis, and 5.3% had post-essential thrombocythemia myelofibrosis. The overall population had a mean age of 66.3 years (range, 50.0-87.0 years).

There were 3 patients who reached the primary outcome of a ≥50% reduction in mutant allele burden at 24 weeks. Therefore, this study was considered a success in terms of its primary outcome. An additional 5 patients met a secondary outcome of achieving a ≥25% reduction in mutant allele burden, of whom 3 patients had JAK2V617F mutations.

The study investigators additionally performed analyses using hematopoietic stem/progenitor cells that revealed distinctive molecular signatures in responders and nonresponders at baseline. In responders, increased expression of genes associated with JAK-STAT signaling and oxidative phosphorylation appeared to become downregulated in the presence of tamoxifen.

References: Fang Z, Corbizi Fattori G, McKerrell T, et al. Tamoxifen for the treatment of myeloproliferative neoplasms: a phase II clinical trial and exploratory analysisNat Commun. 2023;14(1):7725. doi:10.1038/s41467-023-43175-5

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JBI-802 initial Phase I data suggests therapeutic potential in sensitizing immunotherapy resistant tumors and in Myeloproliferative Neoplasms with thrombocytosis

BEDMINSTER, N.J.Jan. 8, 2024 /PRNewswire/ — Jubilant Therapeutics Inc., a clinical-stage biotechnology company pioneering the development of a first-in-class CoREST (Co-repressor of Repressor Element-1 Silencing Transcription) inhibitor JBI-802 with the dual activity on LSD1 and HDAC6, today announced preliminary safety, pharmacokinetic and initial efficacy results of the Phase I trial in advanced cancer patients. Furthermore, the study results provide a human proof of principle for expanding the development of JBI-802 in Essential Thrombocythemia (ET) and related Myeloproliferative Neoplasms (MPN/MDS) with thrombocytosis.

The data from first 11 patients with advanced cancer revealed a dose-proportional increase in exposure across cohorts and a strong correlation between the exposure and the on-target effects of platelet decrease, indicating that pharmacological relevant level of LSD1 inhibition have been achieved. At the same time, platelet decrease is the only adverse event above grade 1 observed in these patients, which differentiates JBI-802 from LSD1-only inhibitors. Specifically, no AEs (Adverse Events) of anemia has been observed, which is potentially due to the positive benefit of inhibition of HDAC6 in erythrocytes. Also, there are no reports of Dysgeusia, an adverse event that has been observed with LSD1-only inhibitors.

Among the 11 patients, two were NSCLC (Non-small Cell Lung Cancer) patients, both had progressed on doublet immunotherapy, nivolumab+ipilimumab as first line treatment and both showed anti-tumor activity. Both the patients were treated at lower dose level (10mg) where no relevant decrease of platelets is seen, suggesting that in patients with sensitive tumors this dose can be pharmacologically active with a desirable safety profile.

Both NSCLC patients had failed first line treatment with doublet immunotherapy, nivoluman/ipilumab prior to enrolling in the JBI-802 study. The first patient had a STK11 mutation, known to decrease the effectiveness of immunotherapy, present in around 10% of NSCLC patients (higher frequency in lung adenocarcinoma). JBI-802 showed a confirmed partial response in this IO-refractory NSCLC patient with a 39% decrease in the target lung tumor mass. The tumor shrinkage outcome was accompanied by a complete resolution of pancoast syndrome (lung lesion affecting the nerves of brachial plexus). The response appears to be durable after nine cycles and the patient remains on JBI-802 therapy.

The second patient had both lung lesion and liver metastasis, which are known to confer resistance to immunotherapy and lead to poor prognosis. Treatment with JBI-802 resulted in over 50% shrinkage of the patient’s liver metastasis and a complete resolution of related portal hypertension, edema and improvement of quality of life.

Dr. Alexander Starodub, The Christ Hospital – Cincinnati, treating physician for the above patients commented, “The anti-tumor activity seen in these two NSCLC patients is remarkable given the poor prognosis based on their genetic and metastatic pattern. The 10 mg dose of JBI-802 was well-tolerated without any clinically significant adverse effects and the initial clinical data suggest a good therapeutic index for JBI-802.”

Preclinical studies showed a synergistic anti-tumor effect by combining immunotherapy and JBI-802 in xenograft models. In addition, the CoREST inhibition was reported to sensitize immunotherapy resistant tumors, especially those with STK11 mutations. Taken together, the preliminary efficacy data from the JBI-802 Phase I study suggest the opportunity that a combination between immunotherapy and JBI-802 could bring a new therapy option to such patient populations with limited treatment options.

In addition, the on-target dose/exposure-proportional decrease in platelet constitute a proof-of-principle that JBI-802 can be an active compound in hematological malignancies like Essential Thrombocythemia (ET) and other MPN/ MDS characterized by thrombocytosis. A follow up Phase I/II study in MPN/ET and MPN/MDS with thrombocytosis is being planned in the first quarter of this year to investigate JBI-802 as potential novel treatment option.

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Merck Announces Phase 3 Trial Initiations for Four Investigational Candidates From its Promising Hematology and Oncology Pipeline

January 5, 2024 6:45 am ET

Global Phase 3 studies started for bomedemstat (LSD1 inhibitor), nemtabrutinib (BTK inhibitor), MK-2870 (anti-TROP2 ADC) and MK-5684 (CYP11A1 inhibitor)

Comprehensive clinical development programs being initiated for each investigational candidate

Demonstrates company’s commitment to research across novel mechanisms of action in hematologic neoplasms/malignancies, as well as lung, endometrial and prostate cancers

Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced the initiation of pivotal Phase 3 trials for four of its investigational candidates from its diverse pipeline in hematologic malignancies and solid tumors. Global Phase 3 studies have been initiated and are actively enrolling for the following investigational candidates:

  • Bomedemstat, an investigational orally available lysine-specific demethylase 1 (LSD1) inhibitor, being evaluated for the treatment of certain patients with essential thrombocythemia (ET);
  • Nemtabrutinib, an investigational oral, reversible, non-covalent Bruton’s tyrosine kinase (BTK) inhibitor, being evaluated for the treatment of certain patients with chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL);
  • MK-2870, an investigational trophoblast cell-surface antigen 2 (TROP2)-directed antibody drug conjugate (ADC) being developed in collaboration with Kelun-Biotech, which is being evaluated for certain patients with non-small cell lung cancer (NSCLC) and certain patients with previously treated endometrial carcinoma;
  • and MK-5684, an investigational CYP11A1 inhibitor being developed in collaboration with Orion, which is being evaluated for the treatment of certain patients with metastatic castration-resistant prostate cancer (mCRPC).

“These Phase 3 trial initiations for four of our investigational candidates represent a critical step forward in our efforts to advance potential treatment options for people with solid tumors and hematologic neoplasms and malignancies,” said Dr. Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories. “We have a proud legacy of turning breakthrough science into medicines that save and improve lives around the world, and we are dedicated to continuing research to expand our broad portfolio of oncology therapeutics to continue to address unmet needs in cancer care.”

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

Pelabresib and ruxolitinib combination significantly reduced spleen size, with an SVR35 response rate nearly double that of placebo plus ruxolitinib

Showed a strong positive trend in reducing symptom burden and a twofold increase in patients achieving both SVR35 and TSS50 versus placebo plus ruxolitinib

Improved measures of anemia, including higher hemoglobin response rates, fewer patients requiring transfusions and fewer anemia adverse events versus placebo plus ruxolitinib

Improved bone marrow fibrosis by at least one grade in more patients versus placebo plus ruxolitinib

Demonstrated safety results consistent with prior clinical trials, with fewer grade ≥3 adverse events compared with placebo plus ruxolitinib

MorphoSys will host an investor event to review findings on Monday, December 11

MorphoSys AG (FSE: MOR; NASDAQ: MOR) today announced 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. These findings were presented in an oral presentation at the 65th American Society of Hematology (ASH) Annual Meeting and Exposition in San Diego, California.

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 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.”

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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(1)

Biomarker Data from Phase 1 Study of Selinexor in Combination with Ruxolitinib in Treatment-Naïve Myelofibrosis (MF) Suggestive of Disease Modification

Data Reinforce the Potential for Selinexor in Combination with Ruxolitinib to Become a Novel, First-Line Treatment for JAKi-Naïve Patients with MF

NEWTON, Mass.Dec. 10, 2023 /PRNewswire/ — Karyopharm Therapeutics Inc. (Nasdaq: KPTI), a commercial-stage pharmaceutical company pioneering novel cancer therapies, today announced 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). The data, featured in an oral presentation at the 65th American Society of Hematology 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.

The data included in the oral presentation for ASH 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 TantravahiUniversity 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 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 KingdomChinaSouth KoreaCanadaIsrael and Taiwan. XPOVIO and NEXPOVIO is marketed by Karyopharm’s partners, Antengene, Menarini, Neopharm and FORUS in ChinaSouth KoreaSingaporeAustraliaHong KongGermanyAustriaIsrael 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.

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Navitoclax Combo Significantly Reduces Spleen Volume in Myelofibrosis

Silas Inman

Combining navitoclax with ruxolitinib produced significant reductions in spleen volume by at least 35% at week 24 (SVR35W24) compared with ruxolitinib plus placebo but did not lead to significant changes in total symptom score (TSS) in those with myelofibrosis, according to data from the phase 3 TRANSFORM-1 study (NCT04472598) presented during the 2023 American Society of Hematology (ASH) Annual Meeting and Exposition.1

After a median follow-up of 14.9 months (range, 0.0-29.5), navitoclax and ruxolitinib elicited a SVR35W24 for 63.2% of patients compared with 31.5% for placebo plus ruxolitinib, marking a significant overall difference of 31.0% (95% CI, 19.5%-42.5%; P <.0001). At week 24, there was a mean -9.7 change in TSS with navitoclax/ruxolitinib from baseline (95% CI, -11.8 to -7.6) compared with a change of -11.1 for placebo plus ruxolitinib (95% CI, -13.2 to -9.1), which was not statistically significant (P = .2852).

“The spleen volume reduction was doubled and highly statistically significant. There’s no question there, but for the secondary end point, the total symptom score, both groups have the reduction, but it was not statistically significant,” said lead investigator Naveen Pemmaraju, MD, Department of Leukemia at The University of Texas MD Anderson Cancer Center in Houston. “There may be multiple reasons for that. Ruxolitinib alone is a nice drug for symptom improvement, but when you add in a second drug, you’re improving the outcomes for the patient but maybe introducing a bit more toxicity. The statistical significance may not have come out because of that.”

Oral navitoclax is a BCL-XL, BCL-2, and BCL-W inhibitor, which may impart unique efficacy for myeloproliferative neoplasms (MPN). “It turns out in MPN and myelofibrosis that the BCL-XL pathway appears to be a bit more important than the BCL-2,” said Pemmaraju. “In myelofibrosis, BCL-XL appears to be upregulated and so in vitro studies showed that either the navitoclax by itself or even better in combination with the ruxolitinib can overcome JAK resistance and add benefit.”

In the combination arm, navitoclax was administered at a starting dose of 200 mg if platelet counts were above 150 x 109 per liter or, if not, at 100 mg, which was later escalated to 200 mg if tolerated and after platelet counts reached greater than 75 x 109 per liter. This methodology was implemented to avoid thrombocytopenia, which was observed in earlier trials with the agent. Ruxolitinib was administered at the standard dose in each arm, although Pemmaraju noted with necessary dose reductions the relative dose intensity was lower. There were 125 patients in the combination arm and 127 in the control group.

In the combination arm, the median age of patients was 70 years (range, 42-87) compared with 69 years (range, 37-85) in the control group. The time from diagnosis to study entry was 8 months (range, 0.3-181.6) in the combination arm and 6 (range, 0.3-198.8) in the control group. Most patients had primary myelofibrosis, at 50% in the investigational arm and 57% in the control group. Other types included transformed version of myelofibrosis, namely those post polycythemia vera and post-essential thrombocythemia. The median spleen volume at entry was 1441 cm3 (range, 419-8020) in the combination group and 1639 cm3 (range, 219-5664) in the control arm.

The median TSS in the combination arm was 21 (range, 0.1-60.6) compared with 24 (range, 6.7-61.6) in the control group. A minority of patients were transfusion dependent at baseline, at 4% in the combination group and 3% in the control arm. The most common risk score was intermediate-2, at 83% in the combination group and 87% in the control. JAK2 V617F was the most common driver mutation, with approximately two-thirds having this mutation in each group. Nearly half of patients had mutations associated with high molecular risk. “These high molecular risk mutations are very important,” said Pemmaraju. “Earlier studies may not have captured this, and we were fortunate to capture this in the majority of patients.”

There was a significantly higher rate of SVR35 with the combination at all time points throughout the study. Across the full-time scale of the study, 76.8% of those in the combination arm experienced a SVR35 compared with 41.7% with ruxolitinib plus placebo, which was a meaningful 34.6% reduction (95% CI, 23.6%-45.6%; P <.0001). The median time to first SVR35 response was similar between groups, at 12.3 (range, 10.1-48.3) vs 12.4 (range, 11.3-72.3) weeks, for the combination and control arms, respectively. Fewer patients lost SVR35 in the combination group (18.8%) compared with the control arm (26.4%). Nearly three-fourths of patients had a 12-month duration of SVR35 in each arm (76.7% vs 76.9%, combination and control, respectively).

The rate of any grade adverse effect (AE) was common between arms, with more patients in the combination arm having a grade 3 or higher AE (85% vs 70%). The most common grade 3 or higher AEs in the combination vs control arms, respectively, were thrombocytopenia (51% vs 15%), anemia (46% vs 39%), and neutropenia (38% vs 4%). For all grade events, diarrhea was more commonly seen with the combination vs control (34% vs 14%). Serious AEs were less common with the combination at 26% compared with 32% for the control arm. AEs that led to dose reduction or dose interruption were twice as common in the combination arm.

“Importantly, dose reductions and interruptions were mostly due to the thrombocytopenia, but importantly none of those were due to clinical bleeding,” said Pemmaraju.

In 2022, AbbVie, the company developing navitoclax noted plans for a submission to the FDA in 2023, pending pivotal study results.2 At this time, the agent is not approved.

References

  1. Pemmaraju N, Mead AJ, Somervaille T, et al. Transform-1: a randomized, double-blind, placebo-controlled, multicenter, international phase 3 study of navitoclax in combination with ruxolitinib versus ruxolitinib plus placebo in patients with untreated myelofibrosis. Blood. 2023;142(suppl 1):620.doi:10.1182/blood-2023-173509
  2. AbbVie presents positive investigational navitoclax combination data in phase 2 REFINE study suggesting anti-fibrosis activity for patients with myelofibrosis. News release. AbbVie. April 12, 2022. Accessed December 10, 2023. https://news.abbvie.com/2022-04-12-AbbVie-Presents-Positive-Investigational-Navitoclax-Combination-Data-in-Phase-2-REFINE-Study-Suggesting-Anti-Fibrosis-Activity-for-Patients-with-Myelofibrosis

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Study yields ‘encouraging’ preliminary data for navitoclax combination in myelofibrosis

December 11, 2023

Key takeaways:

  • Navitoclax plus ruxolitinib led to improvement in spleen volume reduction in patients with untreated myelofibrosis.
  • Adverse events of thrombocytopenia and anemia appeared common but manageable.

SAN DIEGO — Navitoclax added to ruxolitinib led to a significant improvement in spleen volume reduction compared with placebo among patients with untreated myelofibrosis, study results presented at ASH Annual Meeting and Exposition showed.

Findings from the phase 3 TRANSFORM-1 study suggest the combination therapy has a manageable safety profile that appeared consistent with the use of both agents in previous studies, according to researchers.

“The is the first randomized trial in JAKi-naive [myelofibrosis] with a navitoclax and ruxolitinib combination, which led to a in spleen volume reduction 35% at week 24 twice as high as placebo plus ruxolitinib, with similar symptom response despite a lower average dose of ruxolitinib,” Naveen Pemmaraju, MD, associate professor in the department of leukemia at The University of Texas MD Anderson Cancer Center, said during a presentation.

Background and methodology

The double-blind TRANSFORM-1 study assessed the efficacy and safety of navitoclax (AbbVie) — and investigational Bcl-2 inhibitor — plus the JAK2 inhibitor ruxolitinib (Jakafi, Incyte) compared with placebo plus ruxolitinib among adults with JAK2 inhibitor-naive myelofibrosis.

Inclusion criteria included adults with intermediate- or high-risk myelofibrosis with measurable splenomegaly, evidence of myelofibrosis-related symptoms, no prior JAK2 inhibitor treatment, and an ECOG performance score less than or equal to 2.

Researchers randomly assigned patients in a 1:1 ratio to ruxolitinib plus either navitoclax or placebo.

Spleen volume reduction 35% at week 24 served as the study’s primary efficacy endpoint. Secondary endpoints included change in total symptom score at week 24, spleen volume reduction 35% at any time, duration spleen volume reduction 35%, anemia response, reduction in marrow fibrosis, OS, leukemia-free survival, reduction in PROMIS Fatigue scale and improvement in EORTC QLQ-C30 physical functioning scale.

The study included 252 patients (125 received navitoclax and ruxolitinib, 127 received placebo plus ruxolitinib; median age, 69 years; 57% male) with a median follow-up of 14.9 months (0 – 29.5 months).

Results and next steps

Researchers reported that 79 patients (63.2%) in the investigative arm achieved spleen volume reduction 35% at week 24, compared with 40 patients (31.5%) in the control arm, thus meeting the study’s primary efficacy endpoint. Additionally, researchers noted that 96 patients (77%) in the investigative arm achieved spleen volume reduction 35% at any time, whereas 53 patients (42%) did so in the control arm.

Median duration of spleen volume reduction 35% had not been reached in the investigative arm compared with 19.4 months (95% CI, 16.8 months to not yet reached) in the control arm.

Researchers observed grade 3 or higher adverse events among 85% of patients in the navitoclax arm and for 70% of patients in the placebo arm. The most common adverse events among patients receiving navitoclax included thrombocytopenia, anemia, diarrhea, and neutropenia.

Additionally, 26% of patients in the navitoclax arm and 32% of patients in the placebo arm experienced serious adverse events, including anemia, thrombocytopenia and neutropenia.

With navitoclax treatment, adverse events led to a dose reduction of the agent in 101 patients (81%) and treatment interruption in 87 patients (70%).

Among enrolled patients, 83 (33%) discontinued study treatment. The most common reason for discontinuation included adverse events (n=32; 39% of discontinuations) and physician decision (n=14; 17% of discontinuations). Thirteen patient deaths occurred in each study arm.

“Adverse events of thrombocytopenia, anemia and neutropenia were common but manageable with dose modification without any clinically significant sequelae,” Pemmaraju said. “Preliminary data are encouraging and additional evaluations are ongoing to assess additional outcomes of overall survival and responses in subgroups.”

Source: 

Pemmaraju N, et al. Abstract 620. Presented at: ASH Annual Meeting and Exhibition; Dec. 5-9, 2023; San Diego.

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Navitoclax with Ruxolitinib Improves Myelofibrosis with Manageable Safety

By Patrick Daly

December 6, 2023

Ruxolitinib combined with navitoclax induced spleen volume reduction of ≥35% at week 24 (SVR­35W24) at a rate twice as high as with ruxolitinib and placebo in Janus kinase (JAK) inhibitor–naïve patients with primary, post-polycythemia vera, and post-essential thrombocythemia myelofibrosis (MF), according to authors of the ongoing phase III TRANSFORM-1 study.

The study, evaluated the doublet therapy to address “a substantial unmet need for therapies that alter disease trajectory, improve outcomes, and enhance survival” in patients with MF, according to lead author, Naveen Pemmaraju, MD, of the University of Texas MD Anderson Cancer Center in Houston. Findings were presented at the 65th American Society of Hematology Annual Meeting & Exposition in San Diego, California.

The cohort included 252 patients with a median age of 69 (range, 37–87) and intermediate-2 or high-risk MF with splenomegaly, signs of MF-related symptoms, no prior JAK2 inhibitor therapy, and an Eastern Cooperative Oncology Group performance score of 2 or less.

The primary outcome was SVR­35W24, and secondary outcomes included change in Myelofibrosis Symptom Assessment Form total symptom score (TSS) at week 24, SVR­35 at any time, SVR­35 response duration, anemia response, reduction in marrow fibrosis, overall survival, leukemia-free survival, reduction in fatigue, and improvement in physical functioning at the data cutoff of April 13, 2023.

Investigators noted 79 of 125 (63.2%) patients in the navitoclax group achieved SVR­35W24 compared with 40 of 127 (31.5%) in the placebo group (P<0.0001). Furthermore, 96 (77%) patients on navitoclax achieved SVR­35 at any time compared with 53 (42%) patients on placebo.

The median time to SVR response was 12.3 weeks (range, 10.1–48.3) in the navitoclax group versus 12.4 weeks (range, 11.3–72.3) in the placebo group. Patients in the navitoclax group had a mean change from baseline in TSS of –9.7 (95% CI, –11.8 to –7.6) at week 24, whereas patients in the placebo group had a mean change of –11.1 (95%CI, –13.2 to –9.1; P=0.2852).

Adverse events (AEs) of grade 3 or higher occurred in 85% and 70% of navitoclax and placebo patients, respectively. The most common AEs in greater than 30% of patients on navitoclax were thrombocytopenia, anemia, diarrhea, and neutropenia.

Serious AEs occurred in 26% of patients in the navitoclax and 32% of patients in the placebo group, including anemia in two and one patients, respectively, as well as thrombocytopenia and neutropenia in two and one navitoclax patients. Overall, 39% of navitoclax or placebo discontinuations were due to AEs, and 17% were due to a physician’s decision.

Overall, “the responses were durable; AEs of thrombocytopenia and anemia were common but manageable with dose modification without any clinically significant sequalae,” the authors summarized.

Reference

Pemmaraju N, Mead AJ, Somervaille TCP, et al. A randomized, double-blind, placebo-controlled, multicenter, international phase 3 study of navitoclax in combination with ruxolitinib versus ruxolitinib plus placebo in patients with untreated myelofibrosis. Abstract #620. Presented at the 65th American Society of Hematology Annual Meeting & Exposition; December 9-12, 2023; San Diego, California.

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Phase II Data on Pelabresib Combination for Myelofibrosis Leads to Launch of Phase III Double-Blind Trial

By Patrick Daly

December 6, 2023

Pelabresib in combination with ruxolitinib exhibited significant clinical activity and disease-modifying potential without treatment-limiting toxicities among patients with myelofibrosis (MF) in the ongoing phase II MANIFEST study, according to lead author, Raajit Rampal, MD, PhD, of the Memorial Sloan Kettering Cancer Center in New York City.

Pelabresib is an investigational oral small-molecule agent that inhibits BET-driven gene transcription that contributes to MF pathogenesis.

Following the findings of MANIFEST, Dr. Rampal and colleagues initiated the phase III MANIFEST-2 trial to further evaluate pelabresib plus ruxolitinib. Primary findings from MANIFEST-2 were presented at the 65th American Society of Hematology Annual Meeting & Exposition in San Diego, California.

The global, double-blind, active control study screened 591 patients at 138 sites, and ultimately randomized 431 Janus kinase inhibitor (JAKi)-naïve patients with primary MF, post-polycythemia vera MF, or post-essential thrombocythemia MF to either pelabresib plus ruxolitinib or placebo plus ruxolitinib.

Patients were eligible if they had a Dynamic International Prognostic Scoring System score of intermediate-1 or higher, platelet count of ≥100 × 109/L or greater, spleen volume of ≥450 cmor greater, two or more symptoms with an average score of three or greater on the Myeloproliferative Neoplasm Symptom Assessment Form (or a Total Symptom Score [TSS] of ≥10), peripheral blast count less than 5%, and an Eastern Cooperative Oncology Group performance status of two or less.

The primary endpoint was spleen volume reduction of ≥35% (SVR35) at week 24, and secondary endpoints included TSS changes, safety, pharmacokinetics, bone marrow fibrosis changes, progression-free survival, overall survival, and transfusion requirement and rates.

“MANIFEST-2 has completed recruitment and will provide definitive efficacy results of combination therapy in JAKi treatment-naïve pts with MF,” the authors stated, adding that “MANIFEST-2 will also provide important insights in assessing the benefits of starting treatment at an earlier stage of the disease.”

Reference

Rampal RK, Grosicki S, Chraniuk D, et al. Pelabresib in combination with ruxolitinib for Janus kinase inhibitor treatment-naïve patients with myelofibrosis: results of the MANIFEST-2 randomized, double-blind, phase 3 study. Abstract #628. Presented at the 65th ASH Annual Meeting & Exposition; December 9-12, 2023; San Diego, California.

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