Starpharma announced that the US Patent and Trademark Office has granted a new patent in relation to DEP® cabazitaxel. The composition of matter patent builds on Starpharma's suite of existing international DEP® patents for the product. It specifically covers a DEP® dendrimer conjugated to multiple cabazitaxel drug molecules via a particular releasable linker, with a patent term to 2039 and the potential for a further 5 year extension. The DEP® cabazitaxel nanoparticle is currently in late phase 2 clinical development, recruiting patients with solid tissue tumours, including prostate, ovarian and gastro-oesophageal cancers. DEP® cabazitaxel is a proprietary nanoparticle version of leading prostate cancer drug cabazitaxel (Jevtana®), which had global sales of USD 536 million in 2020. DEP® cabazitaxel is an aqueous nanoparticle formulation which has a number of advantages compared to the original formulation of cabazitaxel. DEP® cabazitaxel is a water soluble, polysorbate-80 (detergent)-free formulation, with no requirement for pre-treatment with steroids nor G-CSF to reduce the risk of severe bone marrow toxicity. In both preclinical and clinical studies, DEP® cabazitaxel has shown an improved side effect profile, notably markedly reduced bone marrow toxicity demonstrated by lower rates of severe neutropenia, thrombocytopenia and severe anaemia, which are all experienced by a significant proportion of patients treated with Jevtana®. The company has completed a phase 1 trial of DEP® cabazitaxel in patients with solid tissue tumours where efficacy signals were observed including in patients with prostate, gastro-oesophageal, breast, ovarian, cholangiocarcinoma and pancreatic cancer. Patients in the phase 1 trial were treated with up to 15 cycles of DEP® cabazitaxel with no steroid, antihistamine or anti-emetic pre-treatment. Patients experienced significantly lower levels of side effects commonly associated with Jevtana® such as bone marrow toxicity (neutropenia, anaemia, thrombocytopenia) anorexia and vomiting. There were no cases of hypersensitivity; no cases of hair-loss; no need for anti-nausea medications. Starpharma's phase 2 trial of DEP® cabazitaxel is well advanced with more than 40 patients treated with multiple cycles of DEP® cabazitaxel in which the markedly reduced rates of severe /life-threatening bone marrow toxicity and a lack of severe hypersensitivity continues to be demonstrated. In the trial, encouraging efficacy signals have been observed in multiple tumour types, including in prostate cancer where radiological responses, significant reductions in prostate-specific antigen (PSA) and no new bone metastases were observed. These encouraging efficacy signals were observed despite patients having been heavily pre-treated - with an average of 30 prior cycles of treatment, and in some cases with more than 100 cycles and up to 10 different treatment regimens. In addition to the responses described above in prostate cancer, patients treated with DEP® cabazitaxel have also exhibited encouraging efficacy signals in gastro-oesophageal, ovarian, cholangiocarcinoma, lung, and head and neck cancers.