Trends in kinase drug discovery: targets, indications and inhibitor design.

The FDA approval of imatinib in 2001 was a breakthrough in molecularly targeted cancer therapy and heralded the emergence of kinase inhibitors as a key drug class in the oncology area and beyond. Twenty years on, this article analyses the landscape of approved and investigational therapies that target kinases and trends within it, including the most popular targets of kinase inhibitors and their expanding range of indications. There are currently 71 small-molecule kinase inhibitors (SMKIs) approved by the FDA and an additional 16 SMKIs approved by other regulatory agencies. Although oncology is still the predominant area for their application, there have been important approvals for indications such as rheumatoid arthritis, and one-third of the SMKIs in clinical development address disorders beyond oncology. Information on clinical trials of SMKIs reveals that approximately 110 novel kinases are currently being explored as targets, which together with the approximately 45 targets of approved kinase inhibitors represent only about 30% of the human kinome, indicating that there are still substantial unexplored opportunities for this drug class. We also discuss trends in kinase inhibitor design, including the development of allosteric and covalent inhibitors, bifunctional inhibitors and chemical degraders.

A tale of the monoclonal anti-CD20 antibodies, in tribute to prof. Waclaw Szybalski (1921-2020).

Technical advances that lead to the era of targeted therapeutics demanded several milestones that were reached in the second half of the previous century. Professor Waclaw Szybalski was the first one to perform a stable gene transfer in eukaryotic cells. To do so, he used his own designed system consisting of HPRT-deficient cells and HAT selective medium. Moreover, the first-ever hybridoma cells were also constructed by Waclaw Szybalski's team. These spectacular achievements made him not only a forerunner of gene therapy, but also became a foundation for immunotherapy, as hybridoma and their selection by the HPRT-HAT system turned into a crucial technical step during production of monoclonal antibodies (mAbs). Herein, we present a story of anti-CD20 mAbs, one of the most successful lines of anticancer drugs. When looking back into history, the prototypic mAb rituximab was considered the biggest step forward in the therapy of B-cell malignancies. Nowadays, the second and third generations of anti-CD20 mAbs are approved in clinical use and numerous breakthrough studies on immune effector mechanisms were conducted with the aforementioned immunotherapeutics as a model.

State of Melanoma: An Historic Overview of a Field in Transition.

The management of melanoma significantly improved within the last 25 years. Chemotherapy was the first approved systemic therapeutic approach and resulted in a median overall of survival less than 1 year, without survival improvement in phase III trials. High-dose interferon α2b and IL-2 were introduced for resectable high-risk and advanced disease, respectively, resulting in improved survival and response rates. The anti-CTLA4 and anti-programmed death 1 monoclonal antibodies along with BRAF/MEK targeted therapies are the dominant therapeutic classes of agent for melanoma. This article provides an historic overview of the evolution of melanoma management.

DNA-Binding Anticancer Drugs: One Target, Two Actions.

Amsacrine, an anticancer drug first synthesised in 1970 by Professor Cain and colleagues, showed excellent preclinical activity and underwent clinical trial in 1978 under the auspices of the US National Cancer Institute, showing activity against acute lymphoblastic leukaemia. In 1984, the enzyme DNA topoisomerase II was identified as a molecular target for amsacrine, acting to poison this enzyme and to induce DNA double-strand breaks. One of the main challenges in the 1980s was to determine whether amsacrine analogues could be developed with activity against solid tumours. A multidisciplinary team was assembled in Auckland, and Professor Denny played a leading role in this approach. Among a large number of drugs developed in the programme, N-[2-(dimethylamino)-ethyl]-acridine-4-carboxamide (DACA), first synthesised by Professor Denny, showed excellent activity against a mouse lung adenocarcinoma. It underwent clinical trial, but dose escalation was prevented by ion channel toxicity. Subsequent work led to the DACA derivative SN 28049, which had increased potency and reduced ion channel toxicity. Mode of action studies suggested that both amsacrine and DACA target the enzyme DNA topoisomerase II but with a different balance of cellular consequences. As primarily a topoisomerase II poison, amsacrine acts to turn the enzyme into a DNA-damaging agent. As primarily topoisomerase II catalytic inhibitors, DACA and SN 28049 act to inhibit the segregation of daughter chromatids during anaphase. The balance between these two actions, one cell cycle phase specific and the other nonspecific, together with pharmacokinetic, cytokinetic and immunogenic considerations, provides links between the actions of acridine derivatives and anthracyclines such as doxorubicin. They also provide insights into the action of cytotoxic DNA-binding drugs.

Drugging the "Undruggable" MYCN Oncogenic Transcription Factor: Overcoming Previous Obstacles to Impact Childhood Cancers.

Effective treatment of pediatric solid tumors has been hampered by the predominance of currently "undruggable" driver transcription factors. Improving outcomes while decreasing the toxicity of treatment necessitates the development of novel agents that can directly inhibit or degrade these elusive targets. MYCN in pediatric neural-derived tumors, including neuroblastoma and medulloblastoma, is a paradigmatic example of this problem. Attempts to directly and specifically target MYCN have failed due to its similarity to MYC, the unstructured nature of MYC family proteins in their monomeric form, the lack of an understanding of MYCN-interacting proteins and ability to test their relevance in vivo, the inability to obtain structural information on MYCN protein complexes, and the challenges of using traditional small molecules to inhibit protein-protein or protein-DNA interactions. However, there is now promise for directly targeting MYCN based on scientific and technological advances on all of these fronts. Here, we discuss prior challenges and the reasons for renewed optimism in directly targeting this "undruggable" transcription factor, which we hope will lead to improved outcomes for patients with pediatric cancer and create a framework for targeting driver oncoproteins regulating gene transcription.

Mobilizing Toxins for Cancer Treatment: Historical Perspectives and Current Strategies.

The level of complexity in a disease like cancer presents a number of challenges for effective treatment development, which require significant innovation to overcome [...].

How to produce 'marketable and profitable results for the company': from viral interference to Roferon A.

This paper looks at the commodification of interferon, marketed by Hoffmann La Roche (short: Roche) as Roferon A in 1986, as a case study that helps us understand the role of pharmaceutical industry in cancer research, the impact of molecular biology on cancer therapy, and the relationships between biotech start-ups and established pharmaceutical firms. Drawing extensively on materials from the Roche company archives, the paper traces interferon's trajectory from observed phenomenon (viral interference) to product (Roferon A). Roche embraced molecular biology in the late 1960s to prepare for the moment when the patents on some of its bestselling drugs were going to expire. The company funded two basic science institutes to gain direct access to talents and scientific leads. These investments, I argue, were crucial for Roche's success with recombinant interferon, along with more mundane, technical and regulatory know-how held at Roche's Nutley base. The paper analyses in some detail the development process following the initial success of cloning the interferon gene in collaboration with Genentech. It looks at the factors necessary to scale up the production sufficiently for clinical trials. Using Alfred Chandler's concept of 'organizational capabilities', I argue that the process is better described as 'mobilisation' than as 'translation'.

Vismodegib and the Hedgehog Pathway Inhibitors: A Historical Perspective to Current Clinical Application.

Vismodegib (Erivedge, Genentech-Roche) is the first in class of Hedgehog pathway inhibitors approved for treatment of metastatic basal cell carcinoma (BCC), or locally advanced BCC that has recurred after surgery or is not amenable to surgery or radiation. Its path to discovery has been unique and traces its origin to corn lilies, sheep, Drosophila flies, and the Hedgehog signaling pathway. J Drugs Dermatol. 2018;17(5):506-508.

A 25-Year Experience of US Food and Drug Administration Accelerated Approval of Malignant Hematology and Oncology Drugs and Biologics: A Review.

Importance: Accelerated approval (AA) is a US Food and Drug Administration (FDA) expedited program intended to speed the approval of drugs and biologics that may demonstrate a meaningful advantage over available therapies for diseases that are serious or life-threatening. Observations: This review describes all malignant hematology and oncology AAs from inception of the program on December 11, 1992, to May 31, 2017. During this period, the FDA granted AA to 64 malignant hematology and oncology products for 93 new indications. Of these AAs, 53 were for new molecular entities. Overall, the end point of response rate, including hematologic response rates, accounted for most AAs (81 [87%]), followed by time-to-event end points of progression-free survival or time to progression (8 [9%]) and disease-free survival or recurrence-free survival (4 [4%]). Single-arm trial designs provided the data for 67 (72%) of the initial AA indications. Of the 93 AAs, 51 (55%) have fulfilled their postmarketing requirement and verified benefit in a median of 3.4 years after their initial AA. Thirty-seven (40%) indications have not yet completed confirmatory trial(s) or verified benefit, and 5 indications receiving AA (5%) have been withdrawn from the market. Conclusions and Relevance: The use of the AA program during the past 25 years has increased over time, and only a small portion of indications under the AA program fail to verify clinical benefit. For patients with serious or life-threatening oncologic diseases, AA brings products to the market years before confirmatory trials are typically completed.

The Deceptively Similar Ruthenium(III) Drug Candidates KP1019 and NAMI-A Have Different Actions. What Did We Learn in the Past 30 Years?

The general interest in anticancer metal-based drugs and some encouraging pharmacological results obtained at the beginning of the investigations on innovative Ru-based drugs triggered a lot of attention on NAMI-A and KP1019, the two Ru(III) coordination compounds that are the subject of this review. This great attention led to a considerable amount of scientific results and, more importantly, to their eventual admission into clinical trials. Both complexes share a relatively low systemic toxicity that allows reaching rather high dosages, comparable to those of carboplatin. Soon it became evident that NAMI-A and KP1019, in spite of their structural similarity, manifest very distinct chemical and biological properties. The pharmacological performances qualified KP1019 mainly as a cytotoxic drug for the treatment of platinum-resistant colorectal cancers, whereas NAMI-A gained the reputation of a potential anticancer drug with negligible effects on the primary tumor but a pronounced ability to affect metastases. We believe that a strictly comparative exam of NAMI-A and KP1019, based on the substantial body of studies accomplished since their discovery almost 30 years ago, might be an useful exercise, both for assessing the state of the art in terms of biological and clinical profiles, and of the inherent mechanisms, and for envisaging possible future developments in the light of past achievements.

Role of chemotherapy in prostate cancer.

Chemotherapy in prostate cancer (PCa) has undergone dramatic landscape changes. While earlier studies utilized varying chemotherapy regimens which were found to be largely palliative in nature and hardly resulted in durable or meaningful responses, docetaxel resulted in the first chemotherapy agent that showed improvement in overall survival in metastatic castration-resistant prostate cancer (mCRPC). However, combination chemotherapy or any agents added to docetaxel have failed to yield incremental benefits. The improvement in overall survival as well as secondary endpoints of prostate-specific antigen (PSA) and time to recurrence when using docetaxel in the metastatic hormone-sensitive state has changed the standard of care for treatment of newly diagnosed de novo metastatic PCa. There are also promising results in locally advanced PCa and high-risk PCa in both the neoadjuvant and adjuvant settings. This review summarizes the historical as well as the more contemporary use of chemotherapeutic agents in PCa in varying states and phases of disease.