Mechanism of Action and Novel IMiD-Based Compounds and Combinations in Multiple Myeloma

Accessing three-branched high-affinity cereblon ligands for molecular glue and protein degrader design

The Petasis borono-Mannich reaction was employed for an alternative entry towards three-branched cereblon ligands. Such compounds are capabable of making multiple interactions with the protein surface and possess a suitable linker exit vector. The high-affinity ligands were used to assemble prototypic new molecular glues and proteolysis targeting chimeras (PROTACs) targeting BRD4 for degradation. Our results highlight the importance of multicomponent reactions (MCRs) in drug discovery and add new insights into the rapidly growing field of protein degraders.

Design, synthesis and biological evaluation of novel quinazolinone derivatives as CRBN E3 ligase modulators

CRBN E3 ligase modulators, also anteriorly called immunomodulatory drugs (IMiDs), exhibit excellent pharmacological activity by degrading cereblon (CRBN) associated multiple substrates and have become an important field for drug development. These modulators such as Thalidomide, Lenalidomide and CC-122 abduct CRBN to adhere to IKZF1/3 and other neosubstrates, and then induce the degradation of these substrates, thus retarding the further development of related diseases. Herein, we reported a series of CC-122 derivatives that inhibit the proliferation of hematological malignant tumor cell lines. Studies further confirmed that several derivatives which exhibit strong anti-proliferation effect induce the significant degradation of IKZF1/3. In addition, we found that the best compound 14 (SIAIS355035) exhibits better degradation activity and better anti-proliferation activities than CC-122, especially in diffuse large B lymphoma cell lines. Moreover, the PK properties of compound 14 are pretty promising with excellent oral bioavailability. These results clarified the SAR of CC-122 derivatives preliminarily and suggested that compound 14 has great value for further studies as an ideal novel CRBN E3 ligase modulation drug.

What's Old is New: The Past, Present and Future Role of Thalidomide in the Modern-Day Management of Multiple Myeloma

Immunomodulatory drugs (IMiDs) have become an integral part of therapy for both newly diagnosed and relapsed/refractory multiple myeloma (RRMM). IMiDs bind to cereblon, leading to the degradation of proteins involved in B-cell survival and proliferation. Thalidomide, a first-generation IMiD, has little to no myelosuppressive potential, negligible renal clearance, and long-proven anti-myeloma activity. However, thalidomide's adverse effects (e.g., somnolence, constipation, and peripheral neuropathy) and the advent of more potent therapeutic options has led to the drug being less frequently used in many countries, including the US and Canada. Newer-generation IMiDs, such as lenalidomide and pomalidomide, are utilized far more frequently. In numerous previous trials, salvage therapy with thalidomide (50-200 mg/day) plus corticosteroids (with or without selected cytotoxic or targeted agents) has been shown to be effective and well-tolerated in the RRMM setting. Hence, thalidomide-based regimens remain important alternatives for heavily pretreated patients, especially for those who have no access to novel therapies and/or are not eligible for their use (due to renal failure, high-grade myelosuppression, or significant comorbidities). Ongoing and future trials may provide further insights into the current role of thalidomide, especially by comparing thalidomide-containing regimens with protocols based on newer-generation IMiDs and by investigating thalidomide's association with novel therapies (e.g., antibody-drug conjugates, bispecific antibodies, and chimeric antigen receptor T cells).

Pharmacokinetics, bioavailability and metabolism of CC-92480 in rat by liquid chromatography combined with electrospray ionization tandem mass spectrometry

CC-92480 is a cereblon E3 ubiquitin ligase modulating drug with potent antimyeloma activity. In this study, we developed a sensitive UHPLC-MS/MS method for the determination of CC-92480 in rat plasma. The plasma samples were prepared with acetonitrile and the samples were then separated on an Acquity BEH C₁₈ column (2.1 × 50 mm, 1.7 μm) with water containing 0.1% formic acid (A) and acetonitrile (B) as mobile phase. The MS detection was performed using multiple reaction monitoring mode with precursor-to-product ion transitions at m/z 568.3 > 363.1 for CC-92480 and m/z 441.2 > 138.1 for ibrutinib (internal standard). The assay showed excellent linearity over the concentration range of 1-1,000 ng/ml, with correlation coefficient >0.995. The method was further validated for selectivity, precision, accuracy, recovery and stability according to the US Food and Drug Administration's guideline. The validated method was successfully applied to the pharmacokinetic and bioavailability studies of CC-92480 in rat plasma. Based on the pharmacokinetic results, the oral bioavailability of CC-92480 was >63%. In addition, the circulating metabolites of CC-92480 were detected by UHPLC-HRMS and the structures were proposed according to their accurate masses and fragment ions. The proposed metabolic pathways of CC-92480 were oxidative dealkylation and amide hydrolysis.

Future Options of Molecular-Targeted Therapy in Small Cell Lung Cancer

Lung cancer is the leading cause of cancer-related deaths worldwide. With a focus on histology, there are two major subtypes: Non-small cell lung cancer (NSCLC) (the more frequent subtype), and small cell lung cancer (SCLC) (the more aggressive one). Even though SCLC, in general, is a chemosensitive malignancy, relapses following induction therapy are frequent. The standard of care treatment of SCLC consists of platinum-based chemotherapy in combination with etoposide that is subsequently enhanced by PD-L1-inhibiting atezolizumab in the extensive-stage disease, as the addition of immune-checkpoint inhibition yielded improved overall survival. Although there are promising molecular pathways with potential therapeutic impacts, targeted therapies are still not an integral part of routine treatment. Against this background, we evaluated current literature for potential new molecular candidates such as surface markers (e.g., DLL3, TROP-2 or CD56), apoptotic factors (e.g., BCL-2, BET), genetic alterations (e.g., CREBBP, NOTCH or PTEN) or vascular markers (e.g., VEGF, FGFR1 or CD13). Apart from these factors, the application of so-called 'poly-(ADP)-ribose polymerases' (PARP) inhibitors can influence tumor repair mechanisms and thus offer new perspectives for future treatment. Another promising therapeutic concept is the inhibition of 'enhancer of zeste homolog 2' (EZH2) in the loss of function of tumor suppressors or amplification of (proto-) oncogenes. Considering the poor prognosis of SCLC patients, new molecular pathways require further investigation to augment our therapeutic armamentarium in the future.