This multicenter phase 1 study sought to determine the MTD of oral Lisavanbulin in combination with standard RT (60 Gy/30 fractions) but without temozolomide in patients with newly diagnosed MGMT promoter unmethylated GBM (uGBM). Avanbulin exposures increased in a relatively dose-proportional manner with increasing oral dose of Lisavanbulin from 4 to 15 mg. Lisavanbulin in combination with RT was considered safe up to the highest predefined oral dose level of 15 mg daily.

P1, N=40, Recruiting, Columbia University | Trial primary completion date: Sep 2023 --> Sep 2024

P1/2, N=78, Recruiting, AB Science | Trial completion date: Jun 2023 --> Dec 2024 | Trial primary completion date: Jun 2023 --> Dec 2024

Due to its unique binding to the colchicine site of tubulin, differently from other MTAs, avanbulin has previously shown activity in solid tumor cell lines. Half of the cell lines tested showed an induction of apoptosis already in the first 24 h of treatment, the other half in the first 48 h. EB1 showed expression in DLBCL clinical specimens, opening the possibility for a cohort of patients that could potentially benefit from treatment with lisavanbulin. These data show the basis for further preclinical and clinical evaluation of lisavanbulin in the lymphoma field.

It has promising antitumoral activity in orthotopic glioblastoma (GBM) models in combination with radiation (RT) ± temozolomide (TMZ), including in MGMT promoter unmethylated (uMGMT) tumors. The maximum studied safe dose for Lisavanbulin in combination with RT in newly diagnosed uMGMT GBM was determined at 15 mg daily during radiation. Overall, the safety of this combination was acceptable. Next steps in developing Lisavanbulin in newly diagnosed GBM include safety studies in combination with TMZ and of TMZ+RT in MGMT promoter methylated GBM prior to formally studying efficacy in a prospective randomized trial.

Finally, the results from in silico studies revealed that the predicted absorption, distribution, metabolism, excretion, and the toxicity (ADMET) profile of the most potent MACs might have several advantages in addition to potential disadvantages, and compound 7h could bind into (ΔG -10.08 kcal·mol) and access wider space at the colchicine-binding site (CBS) than that of colchicine or nocodazole via molecular docking studies. In conclusion, our study serves as a basis for the design of promising synthetic compounds as anticancer agents in the future.

P1, N=26, Terminated, Basilea Pharmaceutica | Active, not recruiting --> Terminated; Due to the National Cancer Institute's (NCI)-mandated termination of the Adult Brain Tumor Consortium which was conducting the study

While examining the functional consequence in cell response to hypoxia, we discovered that PARP3 acts to maintain the cytoskeletal microtubule stability. As a result, the absence of PARP3 markedly increases the sensitivity of glioblastoma cells to microtubule-destabilizing agents providing a new therapeutic avenue for PARP3 inhibition in brain cancer therapy.

P1, N=26, Active, not recruiting, Basilea Pharmaceutica | Recruiting --> Active, not recruiting

MTAs are active agents for lymphoma patients, as exemplified by the inclusion of vincristine in the R-CHOP regimen, standard treatment for diffuse large B cell lymphoma (DLBCL). Our data demonstrate the high cytotoxic anti-lymphoma activity of avanbulin, suggesting a potential activity of its prodrug lisavanbulin in lymphoma patients.

P1, N=30, Recruiting, Basilea Pharmaceutica | Trial primary completion date: Jun 2021 --> Apr 2022

Although MTAs characteristically induce death in mitosis, microtubule destabilizing agents such as vincristine also induce death directly in G1 phase in primary acute lymphoblastic leukemia (ALL) cells...Signals specifically associated with cell death were identified by pre-treatment with the CDK4/6 inhibitor palbociclib, which caused G1 arrest and precluded death induction. These results provide insights into signaling mechanisms regulating cellular responses to microtubule inhibition and provide a foundation for a better understanding of the clinical mechanisms of MTAs and for the design of novel drug combinations. The mass spectrometry proteomics data have been deposited to the PRIDE Archive (http://www.ebi.ac.uk/pride/archive/) via the PRIDE partner repository with the data set identifier PXD027190 and 10.6019/PXD027190.

Additionally, Ferulin C displayed an acceptable antiproliferatory activity in an MCF-7 xenograft model without inducing obvious weight loss in the Ferulin C treated mice. Summarily, our findings substantiated that Ferulin C was a potent, colchicine site binding microtubule-destabilizing agent with anti-proliferation and anti-metastasis activity via PAK1 and p21-mediated signaling in breast cancer cells.

Funding: Basilea Pharmaceutica International Ltd. Clinical trial identification: NCT02490800.

Furthermore, viral spread in cultured HER2 human ovarian cancer patient-derived ascites samples was enhanced by the combination of VSVΔ51 and T-DM1. Our data using the clinically approved Kadcyla® in combination with VSVΔ51 demonstrates proof of concept that targeted delivery of a viral-sensitizing molecule using an antibody-drug conjugate can enhance oncolytic virus activity and provides rationale for translation of this approach.

Global transcriptome analysis using RNA-sequencing suggested that dolastatin 15 could affect other major cancer pathways that may not directly involve tubulin or HIF. The identification of the true producer of a clinically relevant agent is important for sustainable supply, understanding the biosynthesis and future genetic manipulation of the biosynthetic gene cluster for analogue production.

In addition, CA4 showed a similar effect as DHPAC against angiogenesis and VM formation. These new findings support the use of microtubule destabilizing agents as a promising strategy for cancer therapy.

In addition, it was also demonstrated that the glycogen synthase kinase‑3β pathway may be involved in AREG‑induced VCR resistance. These findings may provide rationale to combine VCR with blockade of AREG‑related pathways for the effective treatment of OSCC.

Combination GBM therapies that include immunomodulation will likely require selection of patients according to immunological characteristics. Most clinical exploration of immunomodulators focusses on enhancing T-cell mediated anti-tumour immunity but our data suggest that synergistic combination of a tumour checkpoint controller and immunostimulation can be appropriate for poorly immunogenic GBM that is refractory to T-cell control.Legal entity responsible for the study: The authors. Funding: Basilea Pharmaceutica Ltd.

ABT-414 is a novel antibody-drug conjugate (ADC) of monomethyl auristatin F (MMAF), a microtubule destabilizing agent, and an anti-EGFR antibody (ABT-806). In summary, the majority of EGFR amplified lines tested are sensitive to ABT-414 in vitro and as flank tumors, but efficacy in treatment of orthotopic tumors is more limited. We hypothesize this effect may be related to heterogeneity of drug delivery.