Early-phase clinical drug development of novel agents: a changing paradigm

In vitro antiproliferative activity of alkaloids isolated from Tabernaemontana catharinensis A.DC (Apocynaceae)

In this work, four alkaloids from the stem bark of T. catharinensis were isolated, namely: voacangine (1); ethyl apovincaminate (2); affinisine (3) and voachalotine (4). The alkaloids were tested in vitro for antiproliferative capacity in eight tumor cell lines: U251 (glioma), MCF-7 (breast), NCI-ADR/RES (drug resistant ovary), 786-0 (kidney), NCI-H460 (lung), HT-29 (colon), K562 (leukemia) and PC-3 (prostate) and a non-tumor keratinocyte cell line (HaCat). Antiproliferative activity was observed after 48 hours and results expressed as the concentration needed to induce 50% growth inhibition (GI50) in µM. The chemotherapy drug Doxorubicin was used as a standard. The alkaloid affinisine (3) was the most promising, showing moderate inhibition rates in addition to the cytotoxic and cytocidal effect against all strains tested. It also proved to be a very promising compound, showing high selectivity rates when compared to the non-tumor keratinocyte cell line (HaCat).

New horizons in early drugs development in solid cancers

PURPOSE OF REVIEW

Drug development is the process of bringing new anticancer agents into clinical practice. From the basic research to clinical research each step is essential and intimately linked. The aim of this review is to describe emerging preclinical models and to provide an overview of selected drugs recently developed in oncology.

RECENT FINDINGS

Preclinical models reproducing human immune-tumor interactions, 3D cell cultures and microfluidic platforms are of great interest for the development of immunotherapies and combination therapies and offer the opportunity to better understand the interplay between cancer and stromal cells.Following a better biological understanding of cancer and advances in precision oncology, new exciting drugs (e.g. antibodies-drugs conjugates [ADCs], immunotherapeutic strategies, molecular-targeted therapies) have entered the field of clinical research and even clinical practice.

SUMMARY

Recent improvements in preclinical models will allow an accurate selection of drug candidates for clinical research. Innovative drugs are currently being developed from early to later phases of development. An important remaining challenge in drug development is to set up a new model of patient-centered clinical research to facilitate quick access to innovation and target-oriented trials.

Mentha aquatica L. aerial parts: in vitro anti-proliferative evaluation on human tumour and non-tumour cell lines

Bearing in mind the several medicinal properties of Mentha genus, this work aimed to evaluate the anti-proliferative potential of the ethanolic extract (EE) and fractions from M. aquatica L aerial parts. Using the anti-proliferative protocol developed by the NCI/USA, four fractions (F2 - F4 and F6) obtained from EE showed promising anti-proliferative profile against a panel of human tumor and non-tumor cell lines. After 24-h exposure, F2 (0.25 µg/mL) showed potent and irreversible anti-proliferative effect without inducing cell cycle arrest in both NCI-H460 and MCF-7 cells, without (anti) estrogenic activity. These effects were lost after storage of F2 diluted in dimethyl sulfoxide at -80 °C during 2 weeks. Analysis by gas chromatography coupled to mass detection evidenced some chemical changes induced by F2 storage in solution. The present study demonstrated the anti-proliferative effect of M. aquatica. Further studies are necessary to determine better storage conditions to enhance F2 stability.

Clinical Challenges of Immune Checkpoint Inhibitors

Even though the immuno-oncology (IO) era has achieved many successes, some signs of research development deceleration are arising. Recently, the number of FDA immunotherapy approvals has decreased concurrently with a decline in the relative number of patients recruited to these trials. Identifying the unique features of IO treatments and taking them into consideration on clinical research will lead to a better evaluation of these agents and patient outcomes. In this review, we discuss current challenges and new potential approaches to implement rationally designed clinical trials of IO drugs, particularly those targeting immune checkpoints.

New designs in early clinical drug development

The availability of an unprecedented massive amount of data has provided a magnificent window of opportunity for the development of new drugs. There are currently more drugs in development targeting cancer than any other disease. While this has brought us new waves of drugs, the counterpart is that with these new molecules we have different mechanisms of action, drug kinetics and dynamics, response types and toxicity profiles, which impair classical early clinical trial designs from being effective and efficient. What we once treated as a 'one-size-fits-all' homogeneous disease, has now been uncovered to be a rather heterogeneous condition with multiple targetable mutations. As this generates endless scenarios, it will be impossible to design single 'me-too' trials for every different disease, target, biomarker and agent. To overcome this, we must focus on improving early phase studies, undoubtedly the most critical step from bench to bedside. Goals include decreasing clinical development times, lowering research and development costs and optimizing decisions in advancing through the several phases with a higher degree of certainty in exchange for less failed attempts. We need more informative and, really, transformative early phase designs that seek to obtain the typical late phase objectives in a time continuum and to allow for more robust and efficient go/no-go decisions. With this in mind, different classes of drugs seem to fit with different designs, which present solutions to the different challenges that they pose after finding the maximum tolerated dose/optimum biological dose. This article reviews these concepts and designs and how they can adapt to this new reality in early phase investigation.