Patients with the incurable blood cancers chronic lymphocytic leukaemia (CLL) and follicular lymphoma (FL) have gained access to a new treatment option in Europe with the approval of Gilead’s Zydelig (idelalisib). 

For CLL, the drug can now be used alongside Rituxan (rituximab) in patients who have received at least one prior therapy, and it has also been green lighted for first-line use in those carrying a 17p deletion or TP53 mutation who are unsuitable for chemo-immunotherapy. 

For FL, officials have cleared Zydelig as a monotherapy in patients who are refractory to two prior lines of treatment. 

CLL is the most common leukaemia in adults in the West, with an estimated 19,400 new cases expected this year in Europe, while FL is the most common subtype of Indolent Non-Hodgkin Lymphoma (iNHL), accounting for one-third of all cases.

Zydelig, a first-in-class drug, works by inhibiting PI3K delta, a protein over-expressed in many B-cell malignancies known to play a role in the viability, proliferation and migration of these cancer cells. According to Peter Hillmen, Professor of Experimental Haematology and honorary consultant haematologist at Leeds Teaching Hospitals NHS Trust, the drug is a “welcomed treatment option” offering a new approach in managing CLL and FL. 

Unmet need

Although chemo-immunotherapy is initially used to treat both CLL and FL, relapse is common and many patients run out of treatment options as the disease progresses, he said, and noted that, being unsuitable for chemo-immunotherapy, CLL patients with the 17p deletion or TP53 mutation also require alternative first-line treatment options.

As yet there is no information on the drug’s pricing in Europe, but, over in the US, at $7,200 per month Zydelig has reportedly been priced lower than its closest rival, Johnson & Johnson’s Imbruvica, which costs $8,200. However, adding Rituxan into the equation and the price of CLL treatment with the Zydelig combo could rocket to $12,000, analysts note, according to FiercePharma.