Source: Am J Med Genet  |  Posted 7 years ago

By Jerry Ingram

HOUSTON, TX -- October 14, 2004 -- Nontransplant therapies aimed at treating patients with chronic myelogenous leukemia (CML) rarely cure these patients but may help them achieve sustained remission, researchers stated.

"We have no evidence to support the curative potential of Gleevec [imatinib mesylate] in CML. Both laboratory data and experience with anecdotal cases in which treatment was discontinued suggest that the disease may return after treatment stoppage," explained Moshe Talpaz, MD, professor of medicine and internist, The University of Texas MD Anderson Cancer Center, Houston, Texas.

Dr. Talpaz discussed the current state of treatment of CML here on October 8th at Leukemia 2004 - Towards the Cure, the third international meeting of the Global Organization Against Leukemia.

Although treatment with Gleevec induces complete cytogenetic remission in 80% to 90% of patients who were recently diagnosed with CML, most patients still have traces of the disease that are readily seen through polymerase chain reaction.

Some patients may be able to reach complete molecular remission (no detectable PCR-amplified BCR-ABL transcripts) with higher doses of imatinib, but Dr. Talpaz said this raises the issue of whether or not complete molecular remission is an actual cure.

Research indicating that CML progenitor cells (CD34+, CD33-, LIN-) might be refractory to the influence of imatinib suggests that this agent is not a curative treatment.

"Gleevec may create a situation of coexistence of the patient with his disease. This means that the disease may not progress, however, the patient will have to remain on therapy. Of course, only longer follow-up will address this issue," Talpaz added.

Such an outcome lends itself to further research focused on overcoming resistance to imatinib-based therapy and development of strategies to cure CML.

In terms of the future of research for a cure, Talpaz said his hopes are that "we will develop molecular profiles of individual diseases, assess outlook, and define specific treatment based on these profiles which will include pretherapy profiling and therapy-based profiling."

Studies are being designed which will combine imatinib and immunologic modulation to help patients reach sustained remission off-therapy, he said.

In the meantime, current modalities might lead to sustained remission and the prevention of disease progression may result in normal life expectancies for patients living with CML, he concluded.

[Presentation title: Is CML Cured? If Not, Why Not? Session 6]