A thalidomide derivative has had “striking” results in the treatment of an incurable form of leukaemia, according to Phase III trials reported at the European Haematology Association meeting in Amsterdam on Saturday.

Celgene announced two studies showing big increases in life expectancy among late-stage multiple myeloma patients who received its drug Revlimid (lenalidomide). Multiple myeloma strikes one in person in 20,000 in Western countries. The median survival time after diagnosis is three to four years.

The results presented in Amsterdam by Dr Meletios Dimopoulos, professor of therapeutics at the University of Athens School of Medicine suggested, however, that adding the thalidomide analogue to the standard dexamethasone chemotherapy, can dramatically extend the survival of late-stage patients.

In one of the studies more half than of the patients were still alive and stable or in remission 18 months after the trial started, compared to less than a quarter on dexamethasone alone.

“This is quite unprecented in the treatment of this disease,” said Dr Aristotle Giagounidis, a haematologist at St Johannes Hospital in Duisburg, Germany. “The most striking thing is that more than 50% of patients are still alive even though the research has been going on for nearly two years now.

“In fact after nearly two years more than 50% are stable, or even in remission, which is quite amazing. I’m fairly confident that this treatment will be licensed in the US and Europe.”

The $4,500-a-month cost could mitigate against its use in some countries, however.

In the principal international MM-010 study, the median time-to-disease progression with lenalidomide plus dexamethasone was 11 months, compared with 5 months for dexamethasone plus placebo. The overall response rate with lenalidomide plus dexamethasone was 59% compared with 24% for dexamethasone plus placebo. And the remission rate among lenalidomide-treated patients was 15%, compared with just 3.4% for those on standard treatment.

Patients receiving lenalidomide in the north American MM-009 study also survived longer than those on standard treatment. In total, 705 patients in 97 centres around the world took part in the both studies. All patients had been heavily treated prior to enrollment, many having failed three or more rounds of therapy with other agents. More than 50% of patients in the study had undergone stem cell transplantation.

The researchers did note an increase in some serious side-effects including anaemia, blood clots and pulmonary embolism, among patients who received lenalidomide in addition to dexamethasone.

Lenalidomide is chemically very similar to the notorious human teratogen, thalidomide. It is believed to fight multiple myeloma by directly killing tumour cells, as well as interfering with other biochemical processes that help them grow and proliferate.

Progress in the treatment of non-Hodgkin’s lymphoma with lenalidomide was also reported at the Amsterdam meeting. Dr Peter Wiernik, the director of clinical oncology at Our Lady of Mercy Medical Center, Bronx, New York, reported results of a Phase II study that showed 31% of patients with aggressive late-stage disease responded to lenalidomide treatment.