Therapeutic Outcomes and Prognostic Impact of Gene Mutations Including TP53 and SF3B1 in Patients with Del(5q) Myelodysplastic Syndromes (MDS).

BACKGROUND: Genetic alterations are increasingly being recognized to play an important role in both diagnosis and prognosis of MDS. In general, MDS patients with SF3B1 mutations (MT) are known to have favorable outcomes whereas those with TP53 mutations have dismal survivals. However, it is unclear if the impact of these mutations applies to all subtypes of MDS including del(5q) which is known for its response to lenalidomide and better prognosis. MATERIALS AND METHODS: We retrospectively reviewed 132 del(5q) MDS patients who were treated at the Moffitt Cancer Center (2001-2019). RESULTS: Among patients who received lenalidomide (n = 98), 50%, 42.9%, and 7.1% achieved hematologic improvement or better, no response, and disease progression/death with a median overall survival (mOS) of 93.2, 72.4, and 25.6 months, respectively (P < .0001). The mOS was 73.3 months but only 25.6 months after patients stopped lenalidomide. TP53 was the most common mutation accounting for 23.8% of the patients. Of the 63 patients with molecular data available, 23.8% harbored TP53 MT and 10% with SF3B1 MT. TP53 status did not impact OS (MT 86.4 vs. wild-type (WT) 73.3 months; P = .72) but those with SF3B1 mutations had a significantly shorter mOS compared to WT (23.9 vs. 83.5 months; P = .001). Multivariate analysis confirmed lenalidomide response and SF3B1 mutations are independently associated with outcomes. CONCLUSION: Our findings indicate many del(5q) MDS patients will benefit from lenalidomide but survival after its failure is limited. Mutations known to have prognostic impact in MDS at large may not have the same implications in the del(5q) subset.

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.

Lenalidomide in patients with red blood cell transfusion-dependent myelodysplastic syndrome and del(5q): a single-centre "real-world" experience.

"Real life" data are needed to complement published trials on the efficacy of lenalidomide in patients with myelodysplastic syndrome (MDS) and del(5q) and on the risk of inducing acute myeloid leukemia (AML) progression. Here, we present results of lenalidomide treatment in a consecutive, population-based series of 21 red blood cell (RBC) transfusion-dependent elderly patients with multiple comorbidities. Of 18 evaluable patients (median follow-up: 22 months), 17 achieved an erythroid hematologic response (HI-E) and 16 an RBC transfusion independence. Cytogenetic response (CyR) rate was 80%, median overall survival was 48 months (range 3-164), and 5-year leukemia-free survival was 84%. Three patients progressed to AML; one, with baseline TP53 mutation, achieved HI-E, partial CyR, and did not progress to AML. Eighteen patients experienced hematological adverse events. Overall, lenalidomide was very effective and well tolerated even in unselected elderly patients with multiple comorbidities and did not appear to increase the risk of AML.