Cutting chemo for leukemia sufferers

New medicines from Gilead Sciences, Roche Holding, Pharmacyclics and others are poised to reshape treatment of the most common form of leukemia among adults, potentially eliminating chemotherapy from regimens and extending patients' lives.

The therapies target specific biological pathways known to drive chronic lymphocytic leukemia, a typically slow-moving cancer of the blood and bone marrow that usually strikes older people, some of whom can't tolerate the toxic chemotherapies that are part of current treatment regimens.

Data presented on several of the medicines at the American Society of Hematology meeting in New Orleans at the weekend suggest combination regimens may arise that remove the need for chemotherapy and its related toxic side effects while driving better results, said Richard Furman, director of the CLL Research Center at Weill Cornell Medical College in New York.

The new drugs "herald a dawn of a new age for CLL patients," Furman said.

"This really is, I think, a great opportunity for us to do what I consider to be the most important thing for our patients: Eliminate chemotherapy from our treatment paradigm."

The progress being made in CLL is indicative of the way cancer may increasingly be treated, with combination regimens of targeted therapies aimed at different biological pathways.

Potential new drugs for CLL include ibrutinib, from Pharmacyclics and Johnson & Johnson; Gilead's idelalisib; Infinity Pharmaceuticals Inc.'s IPI-145; AbbVie Inc.'s ABT-199; and Roche's Gazyva, approved in the US last month.

Chemotherapy's short-term side effects can include suppression of bone marrow and immune response, fatigue, hair loss, nausea and vomiting, according to the US National Cancer Institute.

It also has the potential to cause longer-term problems, like additional cancers, said Furman, a lead investigator in Gilead's late-stage trial of idelalisib.

"The bar has been set much higher now in terms of where we should be thinking and what the goals of therapy are," Furman said in an interview.

"No longer just getting your patient into remission, but getting your patient into remission safely. That's a very nice place to be."

Idelalisib, from California-based Gilead, performed so much better when given in combination with a Roche drug, Rituxan, than Rituxan alone that the late-stage trial was stopped early.

The research was presented at the New Orleans meeting. Analysts expect the drug to draw US$1.2 billion (NZ$1.6b) in 2018 revenue.

Switzerland-based Roche's Gazyva, in a study also presented in New Orleans, helped patients live almost a year longer without their disease progressing than Rituxan when both medicines were given along with the chemotherapy chlorambucil.

Analysts expect the drug will draw 1.4 billion Swiss francs (NZ$1.9b) in annual revenue in 2018, according to estimates compiled by Bloomberg.

IPI-145, an earlier-stage drug from Infinity, showed promise in CLL patients who had already tried other drugs, according to updated study results reported at the weekend.

Almost half of the 27 patients in an early-stage study responded to the drug, and six of eight patients who had been on the medicine for at least 12 months still hadn't had their cancer progress.

The highest expectation among new CLL drugs is for ibrutinib, from Pharmacyclics and J&J, said Michael Yee, an analyst with RBC Capital Markets. The medicine was expected to draw US$4.7b (NZ$6b) in 2019 revenue for California-based Pharmacyclics.

Ibrutinib was approved by the US Food and Drug Administration last month for mantle cell lymphoma, with a decision expected for CLL by the end of February.

A study presented at last year's hematology meeting and published in June in the New England Journal of Medicine showed that 71 per cent of patients responded to the drug. Further data are being presented at this year's meeting.

"These agents are both game changers," Furman said of ibrutinib and idelalisib.

"People who should have died five years ago are alive and well and in complete remission. It's a huge paradigm shift."

Researchers in New Orleans this year also presented data on a technology that reprograms human immune cells in the laboratory to attack leukemia, showing 15 of 32 patients with CLL experienced a reduction of their cancers and seven achieved remission.

In patients with acute lymphoblastic leukemia, 19 of 22 children experienced complete remission, as did all five adults tested.

The technology, led by Carl June at the University of Pennsylvania, has been licensed to Swiss drugmaker Novartis to open international trials.

"This is the year of CLL," Sandra Horning, head of oncology at Roche's Genentech unit, said in an interview Sunday.

"There's never been a better time for CLL patients."

- Washington Post