Clinical Activity of Crizotinib In Advanced, Chemoresistant ALK+ Lymphoma Patients

Abstract 2877

The Anaplastic Lymphoma Kinase (ALK) gene is fused to several partner genes (mainly NPM) in the majority of Anaplastic Large Cell lymphoma (ALCL) patients (pts). Deregulated ALK tyrosine kinase activity represents the driver alteration in this disease, through the phosphorylation of proteins belonging to signal transduction pathways involved in cellular proliferation, apoptosis and differentiation. Although ALK+ ALCL pts are responsive to cytotoxic drugs, relapses occur frequently and bear a dismal prognosis.

Crizotinib is a competitive small-molecule inhibitor of the ALK and c-Met/HGFR receptor tyrosine kinases with cellular IC50 values in NPM-ALK expressing cells comprised between 24 and 60 nM. A dose of 250 mg BID orally was previously established as the recommended dose in a phase I study.

We report here on the safety and activity profile of crizotinib in two ALK+ ALCL pts resistant to cytotoxic therapy who received crizotinib 250 mg BID as part of a compassionate use named patient protocol. No steroids or drugs with antineoplastic activity were allowed; potent CYP3A4 inhibitors/inducers were also excluded.

Pt # 1 is a 26 year old female who received 7 cycles of CHOP-15 with a partial response that lasted only 1 month. Subsequently she was treated with the DHAP and ICE regimens in an attempt to collect stem cells for an autologous BMT. However, even with these two salvage regimens, the pts relapsed within 2–3 weeks after each one. Pretreatment evaluation included fever (>38 C), cervical and inguinal adenopathies, positive PET and CT scans of para-aortic and iliac adenopathies; a bone marrow (BM) aspirate showed 3% of cells with positivity using an ALK break-apart probe by FISH. Fever disappeared within 48 hours after starting crizotinib; by day 7 all superficial adenopathies were no longer present. PET, CT and BM aspirate performed at day 28 days showed regression of previous lesions persisting so far for 2 months. Side effects included transient ocular flashes and grade I LFT elevation.

Pt # 2 is a 21 year old male diagnosed with ALK+ ALCL in August 2009. The pt was treated with 6 cycles of CHOP obtaining a CR that was lost in February 2010. The pt underwent re-induction/mobilization chemotherapy with MAD and received an Autologous Bone Marrow Transplantation in May 2010 after conditioning with the BEAM regimen; he obtained a PR which was lost again after 1 month. Pretreatment evaluation included fever (>39 C, requiring 60 mg prednisone and 3 g paracetamol daily), axillary and inguinal adenopathies, positive PET and CT scans of all internal nodal stations; BM showed 8% of positive cells using an ALK break-apart probe. Within 8 days of treatment constitutional symptoms subsided, all superficial adenopathies disappeared and PET scan shows complete regression of all lesions. Adverse events reported so far include grade I dizziness.

Longer follow-up data along with results from a third ALCL patient will be presented at the meeting.