Researchers and clinicians from the Peter MacCallum Cancer Centre, The Royal Melbourne Hospital and the Walter and Eliza Hall Institute for Medical Research are leading an international trial of a new therapy, for people with advanced leukaemia for whom no conventional treatment options are available, which has completely cleared cancer in 23 per cent of patients.
Reporting preliminary results of the ongoing first-in-human clinical trial of the novel compound to treat chronic lymphocytic leukaemia (CLL) at the American Society of Hematology Annual Meeting in New Orleans today, Professor John Seymour: Chair of the Haematology Service at Peter Mac, revealed 84 per cent of patients experienced remission, despite participants’ disease having failed an average of four prior treatment regimes.
Professor Seymour says the results of the trial are unprecedented in the quality of the disease responses.
‘Patients on the trial were typically incurable, with an average life expectancy of up to 18 months, so to see complete clearance of cancer in nearly one quarter of these patients, after taking this single therapy, is incredibly encouraging.’
‘By comparison, the phase I study of ibrutinib, now hailed as a game-changer in CLL, reported cleared disease in only two per cent of a similar group of patients.’
Professor Andrew Roberts: head of clinical translation at the Walter and Eliza Hall Institute and the Metcalf Chair of Leukaemia Research at The University of Melbourne and The Royal Melbourne Hospital, says the therapy works by overcoming the action of a key survival signal within leukaemia cells which allows them to avoid dying.
‘Although CLL cells are slow to proliferate, they accumulate inexorably because they fail to die, creating large tumours that standard treatments have not been able to adequately combat.
‘This novel compound selectively targets the protein-to-protein interaction responsible for keeping the leukaemia cells alive and, in many cases, we’ve seen the number of cancerous lymphocytes simply melt away.’
To date, the phase I study has involved 67 patients, whose cancer was resistant to up to eleven cancer treatment regimens.
Professor Seymour says a further promising aspect of the phase I results is the presence of the same survival instinct in malignant cells of other cancer types.
‘Pre-clinical studies at Peter Mac and the Walter and Eliza Hall Institute have shown this protein interaction can keep cancer cells alive in other haematological malignancies and breast, lung and prostate cancers — and we have already seen extremely exciting effectiveness of this compound in laboratory models, when combined with other anti-cancer treatments.
‘We certainly feel there is potential for therapies similar to this to enter clinical development as complementary therapies for these diseases.’
The final phase of this study in leukaemia is expected to complete accrual around the end of the year.