Discovery of potent Pan-Raf inhibitors with increased solubility to overcome drug resistance

Expanding the landscape of oncogenic drivers and treatment options in acral and mucosal melanomas by targeted genomic profiling

Despite advancements in treating cutaneous melanoma, patients with acral and mucosal (A/M) melanomas still have limited therapeutic options and poor prognoses. We analyzed 156 melanomas (101 cutaneous, 28 acral, and 27 mucosal) using the Foundation One cancer-gene specific clinical testing platform and identified new, potentially targetable genomic alterations (GAs) in specific anatomic sites of A/M melanomas. Using novel pre-clinical models of A/M melanoma, we demonstrate that several GAs and corresponding oncogenic pathways associated with cutaneous melanomas are similarly targetable in A/M melanomas. Other alterations, including MYC and CRKL amplifications, were unique to A/M melanomas and susceptible to indirect targeting using the BRD4 inhibitor JQ1 or Src/ABL inhibitor dasatinib, respectively. We further identified new, actionable A/M-specific alterations, including an inactivating NF2 fusion in a mucosal melanoma responsive to dasatinib in vivo. Our study highlights new molecular differences between cutaneous and A/M melanomas, and across different anatomic sites within A/M, which may change clinical testing and treatment paradigms for these rare melanomas.

The Evolution of BRAF Activation in Non-Small-Cell Lung Cancer

Non-small-cell lung cancer (NSCLC) is the most common subtype of lung cancer, of which approximate 4% had BRAF activation, with an option for targeted therapy. BRAF activation comprises of V600 and non-V600 mutations, fusion, rearrangement, in-frame deletions, insertions, and co-mutations. In addition, BRAF primary activation and secondary activation presents with different biological phenotypes, medical senses and subsequent treatments. BRAF primary activation plays a critical role in proliferation and metastasis as a driver gene of NSCLC, while secondary activation mediates acquired resistance to other targeted therapy, especially for epidermal growth factor tyrosine kinase inhibitor (EGFR-TKI). Treatment options for different activation of BRAF are diverse. Targeted therapy, especially two-drug combination therapy, is an important option. Besides, immune checkpoint inhibitors (ICIs) would be another option since BRAF activation would be a positive biomarker of tumor response of ICIs therapy. To date, no high level evidences support targeted therapy or immunotherapy as prioritized recommendation. After targeted therapy, the evolution of BRAF includes the activation of the upstream, downstream and bypass pathways of BRAF. In this review, therapeutic modalities and post-therapeutic evolutionary pathways of BRAF are discussed, and future research directions are also provided.

Discovery of novel spiro compound as RAF kinase inhibitor with in vitro potency against KRAS mutant cancer

The development of RAF inhibitors targeting cancers with wild type RAF kinase and/or RAS mutation has been challenging due to the paradoxical activation of the RAS-RAF-MEK-ERK cascade following RAF inhibitor treatment. Herein is the discovery and optimization of a series of RAF inhibitors with a novel spiro structure. The most potent spiro molecule 9 showed excellent in vitro potency against b/c RAF enzymes and RAS mutant H358 cancer cells with minimal paradoxical RAF signaling activation. Compound 9 also exhibited good drug-like properties as demonstrated by in vitro cytochrome P450 (CYP), liver microsome stability (LMS) data and moderate oral pharmacokinetics (PK) profiles in rat and mouse.

Systemic review on B-RafV600E mutation as potential therapeutic target for the treatment of cancer

Cancer is one of the major public catastrophes worldwide and as per WHO, cancer is the leading cause of death universally after CVS disorders accounting for 9.6 million deaths in 2018. WHO statistics revealed five dangerous types of cancer viz. lung, breast, colorectal, prostate and skin. In male, lung cancer causes highest death, while in female, breast cancer causes the most. Alteration in MAPK signalling pathway plays a significant role in majority of cancer cases. Raf protein is activated by phosphorylation via downstream regulation of the MAPK pathway. Raf composed of 3 subtypes, viz. A-Raf, B-Raf, and C-Raf. B-Raf kinase plays a significant role in healthy cell growth in the MAPK pathway and the problem associated with B-Raf mutation leads to the development of cancer and other diseases. The progression of mutant B-Raf (B-Raf^V600E) protein is higher in cancer as compare to other diseases. In 2002, B-Raf^V600E mutation was identified for the first time in the development of cancer. The frequency of B-Raf^V600E mutation is higher in melanoma, thyroid, colorectal and ovarian cancer. We have covered small molecule B-Raf^V600E inhibitors reported in various literatures; from 2002 to 2020 and also covered clinical trial data. To widen the scope of readers, we compiled details of small molecules, specifically inhibiting B-Raf^V600E mutant and showing anti-proliferative activity against various cancer cell lines along with in-vivo data. We believe that the information covered here will be important in signifying the potentials of B-Raf^V600E mutation and its inhibitors as potent anticancer agents.

Potential synergistic effects of sorafenib and CP-31398 for treating anaplastic thyroid cancer with p53 mutations

Thyroid cancer is the most commonly diagnosed endocrine cancer. Anaplastic thyroid cancer (ATC) is the most aggressive type of thyroid cancer and has a poor prognosis. Loss of p53 function has been reported to lead to poorly differentiated thyroid tumors; therefore, mutant p53 protein can be considered a crucial therapeutic target in patients with ATC. Sorafenib, a multi-kinase inhibitor, has been approved for the treatment of metastatic and differentiated thyroid cancer. Combined targeted therapy, including sorafenib, may be clinically significant for patients with ATC harboring p53 mutations. In the present study, CP-31398, a p53-restoring agent, was used to improve the therapeutic efficacy of sorafenib in SW579 cells, an ATC cell line harboring p53 mutations. The molecular function of CP-31398 was evaluated using western blot analysis and a luciferase reporter assay. The decreased viability of SW579 cells, following CP-31398 treatment, was augmented by sorafenib, and CP-31398 enhanced the antimitogenic effect of sorafenib; thus, sorafenib and CP-31398 synergistically inhibited the growth of SW579 cells. These results indicate a potential clinical application of CP-31398 for patients with ATC harboring p53 abnormalities, since these individuals generally respond poorly to sorafenib alone.