Decitabine plus thalidomide yields more sustained survival rates than decitabine monotherapy for risk-tailored elderly patients with myelodysplastic syndrome

Lenalidomide Plus Decitabine Treatment in a Myelodysplastic Syndrome Patient With Deletion 5q and Excess Blasts

This is the first case of decitabine plus lenalidomide treatment for a myelodysplastic syndrome (MDS) patient with 5q deletion (del(5q)) and elevated number of blasts. Upon bone marrow aspiration and biopsy with conventional cytogenetical studies she was diagnosed with MDS with del(5q) and refractory anemia with excess blasts (RAEB-1). Decitabine was started at a daily dose of 20 mg/m² 1 - 5 days and lenalidomide was started at daily doses of 10 mg 6 - 20 days a month. After two cycles, her hemoglobin level increased and transfusion dependency ceased. After four cycles, bone marrow aspiration showed blast ratio of < 5%. Decitabine and lenalidomide were applied for three more cycles. Decitabine was terminated after seven cycles and lenalidomide has been continued for 12 months. Latest blood values (February 2020) were as follows: white blood cells (WBCs) of 8,670/mm³, neutrophil count of 3,470/mm³, hemoglobin (Hb) level of 11.7 g/dL and platelet count of 203,000/mm³, and the patient continues to follow-up without treatment. In conclusion, combination of lenalidomide and decitabine seems to be an effective treatment modality without notable side effects in MDS patients with del(5q) and excess blasts. The efficacy of this combination should be validated with studies including large patient groups and with longer follow-up periods.

Treatment of Lymphoid and Myeloid Malignancies by Immunomodulatory Drugs

Thalidomide and its derivatives (lenalidomide, pomalidomide, avadomide, iberdomide hydrochoride, CC-885 and CC-90009) form the family of immunomodulatory drugs (IMiDs). Lenalidomide (CC5013, Revlimid®) was approved by the US FDA and the EMA for the treatment of multiple myeloma (MM) patients, low or intermediate-1 risk transfusion-dependent myelodysplastic syndrome (MDS) with chromosome 5q deletion [del(5q)] and relapsed and/or refractory mantle cell lymphoma following bortezomib. Lenalidomide has also been studied in clinical trials and has shown promising activity in chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL). Lenalidomide has anti-inflammatory effects and inhibits angiogenesis. Pomalidomide (CC4047, Imnovid® [EU], Pomalyst® [USA]) was approved for advanced MM insensitive to bortezomib and lenalidomide. Other IMiDs are in phases 1 and 2 of clinical trials. Cereblon (CRBN) seems to have an important role in IMiDs action in both lymphoid and myeloid hematological malignancies. Cereblon acts as the substrate receptor of a cullin-4 really interesting new gene (RING) E3 ubiquitin ligase CRL4CRBN. This E3 ubiquitin ligase in the absence of lenalidomide ubiquitinates CRBN itself and the other components of CRL4CRBN complex. Presence of lenalidomide changes specificity of CRL4CRBN which ubiquitinates two transcription factors, IKZF1 (Ikaros) and IKZF3 (Aiolos), and casein kinase 1α (CK1α) and marks them for degradation in proteasomes. Both these transcription factors (IKZF1 and IKZF3) stimulate proliferation of MM cells and inhibit T cells. Low CRBN level was connected with insensitivity of MM cells to lenalidomide. Lenalidomide decreases expression of protein argonaute-2, which binds to cereblon. Argonaute-2 seems to be an important drug target against IMiDs resistance in MM cells. Lenalidomide decreases also basigin and monocarboxylate transporter 1 in MM cells. MM cells with low expression of Ikaros, Aiolos and basigin are more sensitive to lenalidomide treatment. The CK1α gene (CSNK1A1) is located on 5q32 in commonly deleted region (CDR) in del(5q) MDS. Inhibition of CK1α sensitizes del(5q) MDS cells to lenalidomide. CK1α mediates also survival of malignant plasma cells in MM. Though, inhibition of CK1α is a potential novel therapy not only in del(5q) MDS but also in MM. High level of full length CRBN mRNA in mononuclear cells of bone marrow and of peripheral blood seems to be necessary for successful therapy of del(5q) MDS with lenalidomide. While transfusion independence (TI) after lenalidomide treatment is more than 60% in MDS patients with del(5q), only 25% TI and substantially shorter duration of response with occurrence of neutropenia and thrombocytopenia were achieved in lower risk MDS patients with normal karyotype treated with lenalidomide. Shortage of the biomarkers for lenalidomide response in these MDS patients is the main problem up to now.

A comparison of therapeutic dosages of decitabine in treating myelodysplastic syndrome: a meta-analysis

Decitabine is used to treat myelodysplastic syndrome (MDS). This meta-analysis evaluated the efficacy and safety of different dosing regimens of decitabine in treating intermediate and/or high-risk MDS. Medline, Cochrane, EMBASE, and Google Scholar databases were searched up to October 23, 2015. Randomized controlled trials, prospective, cohort, and case series studies were included. Fifteen studies were included with a total of 1378 patients. The decitabine 100 mg/m²/course dosing regimen had a greater overall response rate than the 60-75 mg/m²/course (51 vs. 25%; P = 0.003). It also had higher complete response rate compared with the 135 mg/m²/course regimen (24.2 vs.13.7%; P = 0.016). The three dosing regimens were similar with respect to bone marrow complete response and partial response and hematologic improvement (P values > 0.05). Decitabine 135 mg/m²/course regimen had similar hematologic improvement as best supportive care (P = 0.066). The incidence of neutropenia, thrombocytopenia, infections, and anemia was similar across treatment groups (range, 31 to 38%; P values ≥ 0.899). The 100 mg/m²/course decitabine regimen showed benefit with respect to overall response rate compared with the 60-75 mg/m²/course regimen, as well as greater improvement in complete response rate compared with the 135 mg/m²/course regimen. All three dosing regimens had similar frequency of adverse events.

Treatment of Low-Blast Count AML using Hypomethylating Agents

In 2002, the WHO classification reduced the proportion of blasts in the bone marrow (BM) necessary for the diagnosis of acute myeloid leukemia (AML) from 30% to 20%, eliminating the RAEB-t subtype of myelodysplastic syndromes (MDS). However, this AML subtype, defined as low-blast count AML (LBC-AML, with 20-30% BM-blasts) is characterized by peculiar features, as increased frequency in elderly individuals and after cytotoxic treatment for a different primary disease (therapy-related), poor-risk cytogenetics, lower white blood cell counts, and less frequent mutations of NPM1 and FLT3 genes. The clinical course of this entity is often similar to MDS with 10-19% BM-blasts. The hypomethylating agents azacitidine and decitabine have been shown to induce responses and prolong survival both in MDS and LBC-AML. The role of these agents has also been demonstrated in AML with >30% BM-blasts, particularly in patients with poor-risk cytogenetics and in AML with myelodysplasia-related changes. Most recent studies are evaluating strategies to improve outcome, including combinations of hypomethylating agents with immune-response checkpoint inhibitors, which have a role in cancer immune surveillance. Efforts are also ongoing to identify mutations which may predict response and survival in these patients.

Decitabine priming prior to low-dose chemotherapy improves patient outcomes in myelodysplastic syndromes-RAEB: a retrospective analysis vs. chemotherapy alone

Purpose

The aim of this study was to examine whether decitabine priming prior to low-dose chemotherapeutic regimens could improve outcomes in patients with myelodysplastic syndromes—refractory anemia with excess of blasts (MDS-RAEB).

Methods

The current retrospective analysis included all MDS-RAEB patients receiving idarubicin/cytarabine (IA) or aclacinomycin/cytarabine (AA), with or without decitabine priming during a period from February 2010 to May 2015. Treatment response and toxicity were compared between patients receiving decitabine priming and those who did not. A panel of 6 MDS-related genes was examined using bone marrow specimens.

Results

A total of 81 patients were included in the analysis: 40 received decitabine priming prior to chemotherapy (decitabine priming group). The median follow-up was 10.9 months (IQR: 6.2–21.9). The rate of overall response (OR) and complete remission (CR) was significantly higher in the decitabine priming group than in the chemotherapy group (OR: 75.0 vs. 51.2%, p = 0.027; CR: 55.0 vs. 29.3%, p = 0.019). Overall survival (OS) did not differ significantly between the two groups (19.5 vs. 14.7 months, p = 0.082). In a subgroup analysis that included only patients at < 60 years of age, the CR rate in the decitabine priming group was significantly higher than in the chemotherapy group (65.5 vs. 31.0%, p = 0.009). Survival benefit of decitabine priming was apparent in patients at < 60 years of age (22.4 months with 95% CI of 6.7–38.1 vs. 14.7 months with 95% CI of 11.4–18.0 months in the chemotherapy group, p = 0.028), patients with intermediate and unfavorable karyotypes (22.4 months with 95% CI of 15.1–29.7 vs. 11.9 months with 95% CI of 4.0–19.8 months in the chemotherapy group, p = 0.042), and patients with mutated splicing factor genes (35.3 months with 95% CI of 21.4–49.2 vs. 17.8 months with 95% CI of 13.8–21.8 months in the chemotherapy group, p = 0.039). Grade 3–4 hematological and non-hematological toxicities were not significantly different between the two groups.

Conclusions

Decitabine priming prior to low-dose chemotherapy could improve treatment responses in patients with MDS-RAEB.

Epigenetic therapy of myelodysplastic syndromes and acute myeloid leukemia

PURPOSE OF REVIEW

This review will discuss issues arising along with the expanding use of hypomethylating treatment (HMT) in the management of acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS).

RECENT FINDINGS

HMT has been shown to induce responses in MDS and AML, and azacitidine (Vidaza, Celgene) has been shown to prolong survival in higher-risk MDS. Recent studies have supported the idea that disease stability may also be a treatment goal, whereas treatment interruption in responding patients is associated with rapid disease relapse and death. In AML, a modest but significant survival advantage has been shown for HMT by censoring patients at the time of subsequent AML therapy, but the major limitation remains the short duration of responses. Unfortunately, some of the strategies to overcome these limitations have failed, including the combination of HMT to histone-deacetylase inhibitors, which has not definitively shown to significantly prolong survival. Molecules interfering with other pathways impacting the survival and proliferation of blasts, used alone or in combination, including guadecitabine, selinexor, or inhibitors of IDH2 mutations, are more promising approaches.

SUMMARY

Hypomethylating drugs are the first successful treatment for elderly patients with higher-risk MDS and are effective for some AML subtypes. Translational studies will hopefully identify patients with a favorable profile of response to these drugs, and help to identify newer targets for combination treatments.