Author: RR

FDA Approves TIBSOVO® for IDH1 Mutated Advanced Cholangiocarcinoma

RR

SUMMARY: The FDA on August 25, 2021, approved TIBSOVO® (Ivosidenib) for adult patients with previously treated, locally advanced or metastatic Cholangiocarcinoma, with an Isocitrate DeHydrogenase-1 (IDH1) mutation, as detected by an FDA-approved test. The FDA also approved the Oncomine Dx Target Test (Life Technologies Corporation) as a companion diagnostic device, to aid in selecting patients with Cholangiocarcinoma for treatment with TIBSOVO®.

Bile Duct cancer (Cholangiocarcinoma), comprise about 30% of all primary liver tumors and includes both intrahepatic and extrahepatic bile duct cancers. Klatskin tumor is a type of Cholangiocarcinoma that begins in the hilum, at the junction of the left and right bile ducts. It is the most common type of Cholangiocarcinoma, accounting for more than half of all cases. About 8,000 people in the US are diagnosed with Cholangiocarcinoma each year and approximately 20% of the cases are suitable for surgical resection. The 5-year survival is less than 10%, with limited progress made over the past two decades. There is therefore an unmet need for new effective therapies.

Isocitrate DeHydrogenase (IDH) is a metabolic enzyme that helps generate energy from glucose and other metabolites, by catalyzing the conversion of Isocitrate to Alpha-Ketoglutarate. Alpha-ketoglutarate is required to properly regulate DNA and histone methylation, which in turn is important for gene expression and cellular differentiation. IDH mutations lead to aberrant DNA methylation and altered gene expression thereby preventing cellular differentiation, with resulting immature undifferentiated cells. IDH mutations can thus promote leukemogenesis in Acute Myeloid Leukemia (AML) and tumorigenesis in solid tumors and can result in inferior outcomes. There are three isoforms of IDH. IDH1 is mainly found in the cytoplasm, as well as in peroxisomes, whereas IDH2 and IDH3 are found in the mitochondria, and are a part of the Krebs cycle. Approximately 20% of patients with AML, 70% of patients with Low-grade Glioma and secondary Glioblastoma, 50% of patients with Chondrosarcoma, 20% of patients with Intrahepatic Cholangiocarcinoma, 30% of patients with Angioimmunoblastic T-cell lymphoma and 8% of patients with Myelodysplastic syndromes/Myeloproliferative neoplasms, are associated with IDH mutations.MOA-of-Ivosidenib

TIBSOVO® (Ivosidenib) is an oral, targeted, small-molecule inhibitor of mutant IDH1. A previously published Phase I study demonstrated the safety and activity of TIBSOVO® in patients with IDH1 mutated advanced Cholangiocarcinoma. ClarIDHy is an international, randomized, double-blind, Phase III study, in which 187 previously treated patients with advanced Cholangiocarcinoma with an IDH1 mutation were randomly assigned 2:1 to receive TIBSOVO® 500 mg orally once daily (N=126) or matched placebo (N=61). All patients had advanced unresectable Cholangiocarcinoma. The median age was 62 years, 91% had intrahepatic Cholangiocarcinoma, 93% of patients had metastatic disease and 47% had received two prior therapies. The patient’s disease must have progressed following at least one, but not more than two prior regimens, including at least one Gemcitabine or 5-FU containing regimen. The Primary endpoint was Progression Free Survival (PFS) and Secondary endpoints included Safety, Objective Response Rate (ORR) and Overall Survival (OS). Crossover from placebo to TIBSOVO® was permitted upon radiographic disease progression.

This study met its Primary endpoint and the median PFS was 2.7 months for patients treated with TIBSOVO® compared to 1.4 months with placebo (HR=0.37; P<0.0001). More importantly, the median PFS at 6 and 12 months were 32% and 22% in the TIBSOVO® group, whereas no patients randomized to the placebo group were progression-free for 6 or more months, at the time of data cutoff.
The authors also reported the results of final analysis which showed an improvement in the secondary endpoint of OS, favoring patients randomized to TIBSOVO® compared to those randomized to placebo. However, statistical significance was not reached. The median OS for patients in the TIBSOVO® arm was 10.3 months compared to 7.5 months for patients in the placebo arm (HR=0.79; 1-sided P=0.093). A high proportion of patients in the placebo arm (70.5%) crossed over to TIBSOVO®. After adjusting for crossover from placebo to TIBSOVO®, the median OS for patients in the placebo arm was 5.1 months (HR=0.49; 1-sided P<0.0001).

The 6-month survival rate for patients in the TIBSOVO® arm was 69% compared to 57% of patients in the placebo arm, not adjusted for crossover. The 12-month survival rate for patients in the TIBSOVO® arm was 43% compared to 36% for patients in the placebo arm, not adjusted for crossover. Treatment with TIBSOVO® preserved patients’ physical functioning from baseline, as assessed by the EORTC QLQ-C30 questionnaire, whereas patients in the placebo arm experienced decline from baseline starting cycle 2. The most common Adverse Events of any grade for TIBSOVO® were nausea (38%), diarrhea (33.1%) and fatigue (28.9%). Adverse Events leading to discontinuation were more common with placebo compared with total TIBSOVO® (8.5% versus 6.6%).

It was concluded that treatment with TIBSOVO® in patients with advanced Cholangiocarcinoma with an IDH1 mutation, resulted in significant improvement in Progression Free Survival as well as favorable Overall Survival trend, when compared to Placebo, despite a high rate of crossover. This is the first pivotal study demonstrating the clinical benefit of targeting IDH1 mutation in this patient group. This new oral, non-cytotoxic, targeted treatment option, with a tolerable safety profile, will be a welcome addition to treat this aggressive disease, for which there is an unmet need for new therapies.

Final results from ClarIDHy, a global, phase III, randomized, double-blind study of ivosidenib (IVO) versus placebo (PBO) in patients (pts) with previously treated cholangiocarcinoma (CCA) and an isocitrate dehydrogenase 1 (IDH1) mutation. Zhu A, Macarulla T, Javle MM, et al. J Clin Oncol 39, 2021 (suppl 3; abstr 266)

Myelodysplastic Syndromes: Managing Anemia due to Ineffective Erythropoiesis in Patients with MDS Requiring RBC Transfusions

RR

Dr-M-Yair-Levy

Written by: Dr. M. Yair Levy, Texas Oncology
Promotional Content Sponsored by: Bristol Myers Squibb
Dr. Levy is a paid consultant for BMS and was compensated for his contribution in drafting this article.

 

Myelodysplastic syndromes (MDS) are a heterogeneous group of myeloid malignancies characterized by multilineage cytopenias, including anemia.1 In MDS, stem cells lack the ability for differentiation and maturation, resulting in bone marrow dysfunction and poor blood cell production, in particular red blood cells (RBCs).2 Anemia is present in the majority of patients with MDS and, at diagnosis, anemia is the most common cytopenia present in patients with MDS.1 Anemia in MDS is linked to bone marrow dysfunction characterized by ineffective erythropoiesis.2

Ineffective erythropoiesis in MDS may lead to anemia requiring RBC transfusions and is characterized by increased proliferation of erythroid progenitors, increased death of erythroid precursors, and impaired erythroid maturation.3,4 In fact, 94% (515/546) of patients with MDS received RBC transfusions in the SEER-Sound registry from 2001 to 2007, 13% of whom had ring sideroblasts.5 Ring sideroblasts are erythroblasts with iron-loaded mitochondria associated with anemia that can be identified by iron staining and the results can be found on pathology reports.6

The presence of anemia despite increased proliferation of progenitor cells is indicative of ineffective erythropoiesis in MDS.3,4 There is a need to help address anemia due to ineffective erythropoiesis in patients with MDS requiring RBC transfusions after erythropoiesis stimulating agent (ESA) failure. REBLOZYL® (luspatercept-aamt), the first and only erythroid maturation agent, is approved for the treatment of anemia failing an ESA and requiring 2 or more RBC units over 8 weeks in adult patients with very low- to intermediate-risk myelodysplastic syndromes with ring sideroblasts (MDS-RS) or with myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T).7 REBLOZYL is not indicated for use as a substitute for RBC transfusions in patients who require immediate correction of anemia.7 The approval of REBLOZYL by the FDA marked the first new treatment indicated for patients with MDS in 14 years.8 In my clinical experience, the results that I’ve seen in patients with lower-risk MDS-RS are consistent with those seen in the MEDALIST clinical trial, as discussed below.

As the first and only erythroid maturation agent, REBLOZYL enhances erythroid maturation through differentiation of late-stage erythroid precursors. REBLOZYL works by binding several TGF-β superfamily ligands, thereby diminishing Smad2/3 signaling and increasing the number and quality of mature RBCs in preclinical models.7

REBLOZYL was FDA approved for MDS-associated anemia based on the efficacy and safety outcomes of the pivotal phase 3 MEDALIST trial.7,9 The MEDALIST trial was a multicenter, randomized, double-blind, placebo-controlled, phase 3 trial of 229 adult patients with IPSS-R very low-, low-, or intermediate-risk MDS-RS (<5% bone marrow blasts, presence of ring sideroblasts of ≥15% or ≥5% with an SF3B1 mutation) who required RBC transfusions (≥2 RBC units/8 weeks) were randomized 2:1 to REBLOZYL (n = 153) or placebo (n = 76).7,9 Patients were also required to have had an inadequate response to prior treatment with an ESA (defined as response that is no longer maintained after at least 8 doses of recombinant human erythropoietin or 4 doses of darbepoetin alfa), be intolerant of ESAs, or be ineligible for ESAs (serum EPO >200 U/L).7,9 The MEDALIST trial excluded patients who had del 5q MDS, a white blood cell count >13 Gi/L, neutrophils <0.5 Gi/L, platelets <50 Gi/L, or who had prior use of a disease-modifying agent for treatment of MDS.7

REBLOZYL was administered 1 mg/kg subcutaneously every 3 weeks for at least 24 weeks or until unacceptable toxicity, loss of efficacy, or disease progression. Patients could have their dose increased to 1.33 mg/kg and then to 1.75 mg/kg. Patients received dose increases if they did not achieve transfusion independence after two doses or 6 weeks at 1 mg/kg and 1.33 mg/kg. All patients received best supportive care, which included RBC transfusions as needed.7

In MEDALIST, 36% (83/229) of all patients in the trial were 75 years of age or older, including patients up to 95 years.7,9 95.2% (218/229) of all patients in the trial were ESA-exposed, while only 4.8% (11/229) were ESA-naive, with serum EPO >200 U/L.7,9 All patients in the trial had ring sideroblasts (≥15% ring sideroblasts or ≥5% ring sideroblasts with an SF3B1 mutation), and the majority (206/229) had an SF3B1 mutation.7,9 All patients except 1 were classified as having very low- to intermediate-risk MDS by the IPSS-R criteria.7 57% (130/229) of patients had a baseline RBC transfusion burden <6 RBC units/8 weeks.7

The primary endpoint in MEDALIST was RBC transfusion independence (RBC-TI), defined as the absence of any RBC transfusion during any consecutive 8-week period occurring entirely within the first 24 weeks of treatment.7 Approximately 3 times greater percentage of patients receiving REBLOZYL achieved the primary endpoint of RBC transfusion independence than placebo: 37.9% (58/153) vs 13.2% (10/76; common risk difference [95% CI]: 24.6 [14.5, 34.6]; P < 0.0001), respectively.7 These data support that in patients requiring ≥2 RBC units/8 weeks, REBLOZYL should be started after at least 2 to 3 months of an inadequate response to ESAs.7,9

Key secondary endpoints in MEDALIST were based on RBC transfusion independence (absence of any RBC transfusions) during any consecutive 12-week period occurring entirely within weeks 1 to 24 and 1 to 48. 28.1% (43/153) of patients receiving REBLOZYL achieved transfusion independence ≥12 weeks occurring entirely within weeks 1 to 24 vs 7.9% (6/76) of patients receiving placebo (common risk difference [95% CI]: 20.0 [10.9, 29.1]; P = 0.0002). For weeks 1 to 48,* 33.3% (51/153) of patients receiving REBLOZYL achieved transfusion independence ≥12 weeks vs 11.8% (9/76) of patients receiving placebo (common risk difference [95% CI]: 21.4 [11.2, 31.5]; P = 0.0003).7
*The median (range) duration of treatment was 49 weeks (6–114 weeks) on the REBLOZYL arm and 24 weeks (7-89 weeks) on the placebo arm.

REBLOZYL provided RBC transfusion independence vs placebo in patients with MDS-RS and MDS/MPN-RS-T, based on the WHO 2016 classification. Of patients who were diagnosed with MDS-RS, 34.1% (46/135; 95% CI 26.1, 42.7) of patients receiving REBLOZYL achieved transfusion independence vs 12.3% (8/65; 95% CI 5.5, 22.8) receiving placebo. Of patients who were diagnosed with MDS/MPN-RS-T, 64.3% (9/14; 95% CI 35.1, 87.2) of patients receiving REBLOZYL achieved transfusion independence vs 22.2% (2/9; 95% CI 2.8, 60.0) receiving placebo. Of patients who were diagnosed with other types of MDS (MDS-EB-1, MDS-EB-2, and MDS-U), 75% (3/4; 95% CI 19.4, 99.4) of patients receiving REBLOZYL achieved transfusion independence vs 0% (0/2; 95% CI 0.0, 84.2) receiving placebo.7

RBC transfusion independence was also examined by baseline RBC transfusion burden. Of patients requiring 2 to 3 RBC units/8 weeks at baseline,† 80.4% (37/46; 95% CI 66.1, 90.6) of patients receiving REBLOZYL achieved transfusion independence vs 40% (8/20; 95% CI 19.1, 63.9) receiving placebo. Of patients requiring 4 to 5 RBC units/8 weeks at baseline,‡ 36.6% (15/41; 95% CI 22.1, 53.1) of patients receiving REBLOZYL achieved transfusion independence vs 4.3% (1/23; 95% CI 0.1, 21.9) receiving placebo. Of patients requiring ≥6 RBC units/8 weeks, 9.1% (6/66; 95% CI 3.4, 18.7) of patients receiving REBLOZYL achieved transfusion independence vs 3% (1/33; 95% CI 0.1, 15.8) receiving placebo.7

†Includes patients who received 3.5 units.
‡Includes patients who received 5.5 units.

The safety of REBLOZYL at the recommended dose and schedule was evaluated in 242 patients with MDS-RS (n = 192) or other myeloid neoplasms (n = 50). The median time on treatment with REBLOZYL was 50.4 weeks (range, 3-221 weeks), with 67% of patients exposed for 6 months or longer and 49% exposed for >1 year.7

Among the 242 patients treated with REBLOZYL, 5 (2.1%) had a fatal adverse reaction. 4.5% (11/242) of patients discontinued REBLOZYL due to an adverse reaction and 2.9% (7/242) of patients had their REBLOZYL dose reduced due to adverse reactions. The most common (≥10%) all-grade adverse reactions included fatigue, musculoskeletal pain, dizziness, diarrhea, nausea, hypersensitivity reactions, hypertension, headache, upper respiratory tract infection, bronchitis, and urinary tract infection. The majority of adverse reactions with REBLOZYL were Grade 1 or 2 (mild to moderate). The most common (≥2%) Grade ≥3 adverse reactions included fatigue, hypertension, syncope, and musculoskeletal pain.7

IMPORTANT SAFETY INFORMATION
WARNINGS AND PRECAUTIONS
Thrombosis/Thromboembolism
In adult patients with beta thalassemia, thromboembolic events (TEE) were reported in 8/223 (3.6%) REBLOZYL-treated patients. TEEs included deep vein thrombosis, pulmonary embolus, portal vein thrombosis, and ischemic stroke. Patients with known risk factors for thromboembolism (splenectomy or concomitant use of hormone replacement therapy) may be at further increased risk of thromboembolic conditions. Consider thromboprophylaxis in patients at increased risk of TEE. Monitor patients for signs and symptoms of thromboembolic events and institute treatment promptly.

Hypertension
Hypertension was reported in 10.7% (61/571) of REBLOZYL-treated patients. Across clinical studies, the incidence of Grade 3 to 4 hypertension ranged from 1.8% to 8.6%. In adult patients with MDS with normal baseline blood pressure, 26 (29.9%) patients developed SBP ≥130 mm Hg and 23 (16.4%) patients developed DBP ≥80 mm Hg. Monitor blood pressure prior to each administration. Manage new or exacerbations of preexisting hypertension using anti-hypertensive agents.

Embryo-Fetal Toxicity
REBLOZYL may cause fetal harm when administered to a pregnant woman. REBLOZYL caused increased post-implantation loss, decreased litter size, and an increased incidence of skeletal variations in pregnant rat and rabbit studies. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment and for at least 3 months after the final dose.

ADVERSE REACTIONS
Grade ≥3 (≥2%) adverse reactions included fatigue, hypertension, syncope and musculoskeletal pain. A fatal adverse reaction occurred in 5 (2.1%) patients.

The most common (≥10%) adverse reactions included fatigue, musculoskeletal pain, dizziness, diarrhea, nausea, hypersensitivity reactions, hypertension, headache, upper respiratory tract infection, bronchitis, and urinary tract infection

LACTATION
It is not known whether REBLOZYL is excreted into human milk or absorbed systemically after ingestion by a nursing infant. REBLOZYL was detected in milk of lactating rats. When a drug is present in animal milk, it is likely that the drug will be present in human milk. Because many drugs are excreted in human milk, and because of the unknown effects of REBLOZYL in infants, a decision should be made whether to discontinue nursing or to discontinue treatment. Because of the potential for serious adverse reactions in the breastfed child, breastfeeding is not recommended during treatment and for 3 months after the last dose.

Please see full Prescribing Information for REBLOZYL

References:
1. Greenberg PL, Tuechler H, Schanz J, et al. Revised international prognostic scoring system for myelodysplastic syndromes. Blood. 2012;120(12):2454-2465.
2. Cazzola M, Malcovati L. Myelodysplastic syndromes—coping with ineffective hematopoiesis. N Engl J Med. 2005;352(6):536-538.
3. Santini V. Anemia as the main manifestation of myelodysplastic syndromes. Semin Hematol. 2015;52(4):348-356.
4. Fontenay-Roupie M, Bouscary D, Guesnu M, et al. Ineffective erythropoiesis in myelodysplastic syndromes: correlation with Fas expression but not with lack of erythropoietin receptor signal transduction. Br J Haematol. 1999;106(2):464-473.
5. Ramsey SD, McCune JS, Blough DK, et al. Patterns of blood product use among patients with myelodysplastic syndrome. Vox Sang. 2012;102(4):331-337.
6. Malcovati L, Cazzola M. Recent advances in the understanding of myelodysplastic syndromes with ring sideroblasts. Br J Haematol. 2016;174(6):847-858.
7. REBLOZYL [Prescribing Information]. Summit, NJ: Celgene Corporation; 2020.
8. Steensma, D.P. Myelodysplastic syndromes current treatment algorithm 2018. Blood Cancer J. 2018;8(5):47.
9. Data on file, Celgene Corporation. Summit, New Jersey.

© 2021 Celgene Corporation.
REBLOZYL is a trademark of Celgene Corporation, a Bristol Myers Squibb company.
REBLOZYL is licensed from Acceleron Pharma Inc.
08/21 2007-US-2100270

KEYTRUDA® (Pembrolizumab) in combination with LENVIMA® (Lenvatinib)

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The FDA on July 21, 2021 approved KEYTRUDA® in combination with LENVIMA® for patients with advanced Endometrial carcinoma that is not MicroSatellite Instability-High (MSI-H) or MisMatch Repair deficient (dMMR), who have disease progression following prior systemic therapy in any setting, and are not candidates for curative surgery or radiation. KEYTRUDA® is a product of Merck & Co. and LENVIMA® is a product of Eisai Co., Ltd.

REZUROCK® (Belumosudil)

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The FDA on July 16, 2021 approved REZUROCK®, a kinase inhibitor, for adult and pediatric patients 12 years and older with chronic Graft-Versus-Host Disease (chronic GVHD), after failure of at least two prior lines of systemic therapy. REZUROCK® is a product of Kadmon Pharmaceuticals, LLC.