PROTACs in the Management of Prostate Cancer.

Cancer treatments with targeted therapy have gained immense interest due to their low levels of toxicity and high selectivity. Proteolysis-Targeting Chimeras (PROTACs) have drawn special attention in the development of cancer therapeutics owing to their unique mechanism of action, their ability to target undruggable proteins, and their focused target engagement. PROTACs selectively degrade the target protein through the ubiquitin-proteasome system, which describes a different mode of action compared to conventional small-molecule inhibitors or even antibodies. Among different cancer types, prostate cancer (PC) is the most prevalent non-cutaneous cancer in men. Genetic alterations and the overexpression of several genes, such as FOXA1, AR, PTEN, RB1, TP53, etc., suppress the immune response, resulting in drug resistance to conventional drugs in prostate cancer. Since the progression of ARV-110 (PROTAC for PC) into clinical phases, the focus of research has quickly shifted to protein degraders targeting prostate cancer. The present review highlights an overview of PROTACs in prostate cancer and their superiority over conventional inhibitors. We also delve into the underlying pathophysiology of the disease and explain the structural design and linkerology strategies for PROTAC molecules. Additionally, we touch on the various targets for PROTAC in prostate cancer, including the androgen receptor (AR) and other critical oncoproteins, and discuss the future prospects and challenges in this field.

Efficacy and Safety of Nanosomal Docetaxel Lipid Suspension (NDLS) versus Conventional Docetaxel as Neoadjuvant and Adjuvant Therapy for Primary Operable Breast Cancer.

Objective: Nanosomal docetaxel lipid suspension (NDLS) is a novel formulation developed to overcome toxicity issues caused by excipients (polysorbate 80 and ethanol) present in commercially available docetaxel formulation. We conducted a prospective, observational study to compare the outcomes of nanosomal docetaxel lipid suspension (NDLS)-based versus conventional docetaxel-based chemotherapy in primary operable breast cancer. Methods: Sixty adult women with newly diagnosed stage IIb-III breast cancer were included. Patients received NDLS-based (n=30) or docetaxel-based (n=30) chemotherapy. Patients received (1) four cycles of preoperative doxorubicin and cyclophosphamide (AC) followed by four cycles of NDLS or docetaxel (T) and surgery (neoadjuvant AC→NDLS [n=9], or neoadjuvant AC→T [n=10]), or (2) four cycles of preoperative AC followed by surgery and postoperative NDLS or T (neoadjuvant AC→adjuvant NDLS [n=14], or neoadjuvant AC→adjuvant T [n=15]), or (3) surgery followed by postoperative AC→NDLS or T (adjuvant AC→NDLS [n=7], or adjuvant AC→T [n=5]) regimens. The study outcomes were pathological complete response (pCR) rates, clinical overall response rates (ORR), disease-free survival (DFS), overall survival (OS), and adverse event (AE) profile. Results: For neoadjuvant AC→T (n=10) vs neoadjuvant AC→NDLS (n=9), the pCR rates were 100% each, and the ORR were 100% vs 88.9% (p=1.0). All patients were alive at 6 months, and the median OS was not reached. Three patients had progressive disease (T: n=2, NDLS: n=1) with a DFS of 12 weeks in all three patients. Grade 3 infusion-related reactions were seen in five patients (16.7%) in T vs none in NDLS arms. Conclusion: NDLS-based neo/adjuvant chemotherapy was efficacious in the treatment of primary operable breast cancer and showed comparable pCR, ORR, DFS and OS rates versus conventional docetaxel. NDLS was better tolerated than conventional docetaxel.