The role of fedratinib for the treatment of patients with primary or secondary myelofibrosis

JAK2 inhibitors for the treatment of Philadelphia-negative myeloproliferative neoplasms: current status and future directions

The overactivation of Janus kinases 2 (JAK2) by gain-of-function mutations in the JAK2, Myeloproliferative leukemia virus oncogene, or Calreticulin genes are the most important factor in the development of Philadelphia-negative myeloproliferative neoplasms (MPNs). The discovery of the JAK2V617F mutation is a significant breakthrough in understanding the pathogenesis of MPNs, and inhibition of JAK2 abnormal activation has become one of the most effective strategies against MPNs. Currently, three JAK2 inhibitors for treating MPNs have been approved, and several are being evaluated in clinical trials. However, persistent challenges in terms of drug resistance and off-target effects remain unresolved. In this review, we introduce and classify the available JAK2 inhibitors in terms of their mechanisms and clinical considerations. Additionally, through an analysis of target points, binding modes, and structure-activity inhibitor relationships, we propose strategies such as combination therapy and allosteric inhibitors to overcome specific challenges. This review offers valuable insights into current trends and future directions for optimal management of MPNs using JAK2 inhibitors.

Nitrogen Containing Heterocycles as Anticancer Agents: A Medicinal Chemistry Perspective

Cancer is one of the major healthcare challenges across the globe. Several anticancer drugs are available on the market but they either lack specificity or have poor safety, severe side effects, and suffer from resistance. So, there is a dire need to develop safer and target-specific anticancer drugs. More than 85% of all physiologically active pharmaceuticals are heterocycles or contain at least one heteroatom. Nitrogen heterocycles constituting the most common heterocyclic framework. In this study, we have compiled the FDA approved heterocyclic drugs with nitrogen atoms and their pharmacological properties. Moreover, we have reported nitrogen containing heterocycles, including pyrimidine, quinolone, carbazole, pyridine, imidazole, benzimidazole, triazole, β-lactam, indole, pyrazole, quinazoline, quinoxaline, isatin, pyrrolo-benzodiazepines, and pyrido[2,3-d]pyrimidines, which are used in the treatment of different types of cancer, concurrently covering the biochemical mechanisms of action and cellular targets.

Germline-somatic JAK2 interactions are associated with clonal expansion in myelofibrosis

Myelofibrosis is a rare myeloproliferative neoplasm (MPN) with high risk for progression to acute myeloid leukemia. Our integrated genomic analysis of up to 933 myelofibrosis cases identifies 6 germline susceptibility loci, 4 of which overlap with previously identified MPN loci. Virtual karyotyping identifies high frequencies of mosaic chromosomal alterations (mCAs), with enrichment at myelofibrosis GWAS susceptibility loci and recurrently somatically mutated MPN genes (e.g., JAK2). We replicate prior MPN associations showing germline variation at the 9p24.1 risk haplotype confers elevated risk of acquiring JAK2V617F mutations, demonstrating with long-read sequencing that this relationship occurs in cis. We also describe recurrent 9p24.1 large mCAs that selectively retained JAK2V617F mutations. Germline variation associated with longer telomeres is associated with increased myelofibrosis risk. Myelofibrosis cases with high-frequency JAK2 mCAs have marked reductions in measured telomere length - suggesting a relationship between telomere biology and myelofibrosis clonal expansion. Our results advance understanding of the germline-somatic interaction at JAK2 and implicate mCAs involving JAK2 as strong promoters of clonal expansion of those mutated clones.

Ruxolitinib Re-Treatment in Patients with Myelofibrosis: Real-World Evidence on Patient Characteristics and Outcomes

Ruxolitinib is an FDA-approved treatment of intermediate- and high-risk myelofibrosis. In the phase 3 COMFORT studies, ruxolitinib reduced spleen volume in patients with myelofibrosis, with a median time to response of 3 months. However, nearly 20% of patients discontinued by month 4 with few treatment options available following discontinuation of ruxolitinib treatment. In this study, 2 independent patient care data sources were queried (Cardinal Health Oncology Provider Extended Network [OPEN] and HealthCore Integrated Research Environment [HIRE®]), and a retrospective review of medical charts was conducted. Patients aged ≥18 years with a diagnosis of myelofibrosis (primary or secondary), use of ruxolitinib for myelofibrosis, and documented physician-directed ruxolitinib interruption were included. Among 26 included patients, pre-interruption median (interquartile range [IQR]) ruxolitinib treatment duration was 123 (57-391, OPEN) and 110 (37-148, HIRE) days. Half the patients interrupted treatment within 3 months, commonly for adverse events (42% and 71%, respectively). After restarting ruxolitinib, median (IQR) re-treatment duration was 196 (54-553) and 166 (108-262) days, respectively. Consistent with previous reports, symptoms and spleen size improved in (OPEN/HIRE) 45%/43% and 40%/33% of evaluable patients, respectively. Further studies investigating the management of dose modifications and interruptions are needed to optimize benefit from ruxolitinib therapy.