Starpharma (ASX: SPL, OTCQX: SPHRY) today announced AstraZeneca’s first patent application on DEPBcl2/xL conjugates has been published by the World Intellectual Property Organisation.
These DEP Bcl2/xL conjugates combine Starpharma’s innovative DEP delivery technology with AstraZeneca’s novel Bcl2/xL inhibitor for treating various cancers, including leukemias.
The published patent application shows compelling efficacy data on DEP Bcl2/xL conjugates, both alone and in combination with other leading current anti-cancer treatments, in various preclinical human tumour models.
As announced on 28 September 2017, AstraZeneca describes its DEP Bcl2/xL conjugate, AZD0466, as ‘best-in-class’ with a broad combination opportunity in both solid and haematological tumours (blood cancers)[1]. Bcl2 is a clinically validated oncology target with the leukemia drug venetoclax (Venclexta – AbbVie/Genentech) approved by the US FDA in 2016. Peak global sales of venetoclax are projected to be greater than US$7 billion[2]. However, venetoclax has only anti-Bcl2 activity and its efficacy may be limited because cancer cells are potentially able to exploit a parallel survival mechanism[3]. Therefore, targeting both Bcl2 and Bcl/xL (as AstraZeneca’s novel DEP Bcl2/xL conjugate AZD0466 does), and using it in combination with other therapies, are attractive strategies that may overcome problematic drug resistance which occurs in many human cancers and thereby provide better efficacy.
Starpharma CEO, Dr Jackie Fairley commented: ‘AstraZeneca’s impressive data published today demonstrates that the DEP Bcl2/xL conjugates are highly effective across a range of cancer types both alone and in combination with other anti-cancer agents. Especially exciting for Starpharma is the combination with blockbuster products such as Rituximab, where the DEP Bcl2/xL conjugates, including AZD0466 showed a strong synergistic effect. Given the synergy appears to also occur with other leading anti-cancer drugs this could represent an important additional benefit for the DEP platform’.
The publication of this patent application results from the highly successful collaborative research effort between Starpharma and AstraZeneca and names inventors from both companies.
Under the AstraZeneca multiproduct DEP licence, Starpharma is eligible to receive potential development, launch and sales milestones of US$124 million for the first DEP product, and US$93.3 million for each subsequent qualifying product. Starpharma will also receive tiered royalties on net sales, and AstraZeneca funds development costs of DEP AstraZeneca products, including these DEP Bcl2/xL conjugates.
Summary of the Published Data
In one study utilising an Acute Lymphoblastic Leukemia model, AstraZeneca compared its Bcl2/xL inhibitor alone to two DEPBcl2/xL conjugates.
Combination therapy is extremely common in cancer treatment to improve efficacy outcomes. The recently published patent also explored the performance of the novel DEP Bcl2/xL conjugates in combination with leading anti-cancer drugs including Rituximab and AstraZeneca’s acalabrutinib (Calquence) in lymphoma models. The efficacy of the DEP Bcl2/xL conjugates in combination with these widely used cancer drugs was extremely impressive, showing significant synergistic effects compared to the drugs alone. This finding is significant, particularly given the fact that this strongly synergistic effect is seen reproducibly.
In a study utilising a B cell Lymphoma model (SuDHL-4), DEP Bcl2/xL conjugates in combination with Rituximab performed much better than Rituximab alone. The combination significantly inhibited tumor growth and resulted in complete tumor regression in most animals, whereas none was seen with single drug treatment.
Rituximab is a leading leukemia therapy sold under the brand names Rituxan and Mabthera. In 2017 Rituximab had sales of approximately US$7.5 billion and is primarily used to treat non-Hodgkin’s lymphoma and chronic lymphocytic leukemia[4].
