CellCentric in Cambridge has raised $26 million in private financing to fund clinical testing of its first-in-class oncology drug candidate CCS1477 to treat prostate cancer. The funds are from existing investor, Morningside Venture Investments.

The potential market for a new agent for late stage prostate cancer is highly significant with over 80,000 potential patients each year. 

The new financing will fund development of CCS1477 in this indication up to Phase IIb clinical testing.

CellCentric’s clinical programme in prostate cancer is due to start early summer 2018, initially at the Royal Marsden Hospital in the UK, before expanding nationally and then to the US. It has the potential to be rolled out to treat other cancers, notably bladder and lung.

CellCentric describes CCS1477 as “a potent, selective, orally-bioavailable inhibitor of the conserved bromodomains of twin histone acetyl transferase proteins, p300 and CBP. 

“When p300/CBP are inhibited, expression of the drivers of late-stage prostate cancer the androgen receptor (AR), AR-splice variants (AR-SV) and c-Myc, are significantly reduced. 

“Reducing AR-SV in particular is believed to address inherent or acquired resistance to existing second generation anti-androgen treatments abiraterone (Zytiga), enzalutamide (Xtandi) and apalutamide (Erleada). CCS1477 is clearly differentiated from other approaches currently in development to tackle resistance.”

Data recently presented showed CCS1477 had a profound duration of effect on tumour inhibition after drug dosing cessation, when the compound is no longer present. 

This has been shown in both models of prostate cancer and acute myeloid leukaemia. This reprogramming of cancer cell growth differentiates CCS1477 from other developmental agents, including other bromodomain inhibitors.

As well as pursuing CCS1477’s prostate cancer potential, the new funds will also allow CellCentric to explore tolerability and initial efficacy of CCS1477 in haematological cancers. Tumours with p300 or CBP mutations, notably bladder and small cell lung cancer, will also be explored.

Dr Will West, chairman and CEO of CellCentric, said: “There is a large and growing population of late-stage prostate cancer patients who have inherent or acquired resistance to current second-line anti-androgen therapies.

“CCS1477 has shown promise in addressing this. It is positioned after or in combination with second generation anti-androgen drugs such as abiraterone, enzalutamide and apalutamide.” 

Dr Jason Dinges, CellCentric board director and Morningside representative, added: “Oncology product development is highly competitive. There are few genuine first-in-class new drug opportunities which have a large but specific patient population to treat. 

“Morningside is also encouraged by new data demonstrating that p300/CBP inhibition has significant potential for other areas beyond prostate cancer. We are delighted to support the CellCentric team with their continued momentum.”

• PHOTOGRAPH SHOWS: Will West