BioOncology Watch

Timely Information for Practicing Physicians

 

FEBRUARY 2004

ACUTE MYELOID LEUKEMIA (AML)

Gemtuzumab ozogamicin (GO) combined with intensive chemotherapy.  William Kell and colleagues evaluated the effect of adding GO, an anti-CD33 monoclonal antibody chemically linked to calicheamicin, to induction and consolidation therapy in patients <60 years of age as first-line treatment.  Patients (n = 64) received induction chemotherapy with DA (daunorubicin, ara-C), DAT (DA plus thioguanine), and FLAG-Ida (fludarabine, ara-C, G-CSF, idarubicin) with GO administered on Day 1.  The GO doses were planned to be escalated from 3 to 6 to 9 mg/m2.  However, GO 3 mg/m2 given in consecutive courses and GO 6 mg/m2 given in course 1 were not feasible due to hepatotoxicity and delayed hematopoietic recovery. Grade 4 liver toxicity and sinusoidal obstruction syndrome were more common in thioguanine-containing schedules (p = 0.007).  GO plus DA or FLAG-Ida in induction achieved CR in 91% of patients and 78% of these patients remained in CR at 8 months.  GO 3 mg/m2 was tolerated well with consolidation MACE (amsacrine, ara-C, etoposide) or HidAC (high-dose ara-C) chemotherapy.  Furthermore, none of the 9 patients who subsequently underwent stem cell transplantation developed liver toxicity after the transplantation.  The preliminary efficacy data from this study are encouraging and the results provide a framework for the design of future phase III trials.  (Kell WJ, et al. Blood 2003;102:4277-4283)

 

TRANSPLANTATION

BEAM-alemtuzumab reduced intensity allogeneic stem cell transplantation.  Rowena Faulkner et al. report the results of BEAM (carmustine, etoposide, cytosine arabinoside, melphalan)-alemtuzumab conditioning therapy in 65 consecutive patients with lymphoproliferative disease undergoing transplantation in 6 UK centers.  Following transplantation, 73% of patients achieved CR and among 56 evaluable patients, 35 (63%) patients demonstrated full donor chimerism.  No cases of > grade II acute GVHD were observed and only 11 (17%) of 64 patients developed grade I-II acute GVHD.  The estimated 1-year transplantation-related mortality rate was 8% for patients undergoing first transplantation.  In the six patients that relapsed, histology (mantle-cell lymphoma and high-grade lymphoma) and age (>46 years) were associated with higher relapse risk and shorter event-free survival.  Thus, BEAM-alemtuzumab conditioning therapy is associated with a high CR rate and low toxicity.  (Faulkner RD, et al. Blood 2004;103:428-434)

 

SOLID TUMORS

Three new targeted therapies.  Jeremy Rich and others evaluated the efficacy and safety of oral gefitinib, a novel epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, in 57 patients with first recurrence of glioblastoma following surgical resection, radiation, and chemotherapy in most patients.  No objective tumor responses were seen among 11 patients with measurable disease.  The median event-free and overall survival times were 8.1 weeks and 39.4 weeks, respectively.  Development of diarrhea, but not EGFR expression, predicted for favorable survival.  A second oral EGFR tyrosine kinase inhibitor, erlotinib, was evaluated by Denis Soulieres et al. in 115 patients with locally recurrent or metastatic head and neck squamous cell cancer.  A partial response (PR) was achieved in 5 patients (4.3%) and disease stabilization was maintained in 44 patients (38.3%) for a median duration of 16.1 weeks.  The median overall survival was 6 months and patients who had a least grade 2 skin rashes were observed to have a survival advantage.  No survival difference was detected based on HER1/EGFR expression.  In addition, Udo Vanhoefer and coworkers evaluated a humanized monoclonal antibody, EMD72000, directed against EGFR in 22 patients with EGFR-positive advanced solid tumors.  EMD72000 was administered as a 1-hour i.v. infusion once weekly and the maximum-tolerated dose was 1,600 mg/week.  Pharmacodynamic studies revealed an abrogation of EGFR-mediated cell signaling and objective responses were achieved in 23% of patients.  Patients received EMD72000 for up to 18 months without cumulative toxicity.  These 3 novel targeted therapies warrant further investigation.  (Rich JN, et al. J Clin Oncol 2004;22:133-142; Soulieres D, et al. J Clin Oncol 2004;22:77-85; Vanhoefer U, et al. J Clin Oncol 2004;22:175-184)

 

GASTROINTESTINAL STOMAL TUMORS (GISTS)

Kinase mutations predict response to imatinib.  GISTs are mesenchymal neoplasms of the gut wall that constitutively express activated mutant forms of KIT (CD117) or tyrosine kinase platelet-derived growth factor receptor alpha (PDGFRA).  Michael Heinrich and coworkers analyzed pretreatment pathology specimens for mutations of KIT or PDGFRA from patients with metastatic GIST enrolled onto a phase II study of imatinib (Gleevec; Novartis Pharmaceuticals).  Activating mutations of KIT and PDGFRA were found in 112 (88.2%) and 6 (4.7%) patients, respectively.  The partial response (PR) rate to imatinib was 83.5% for patients with GISTs that had an exon 11 KIT mutation (n = 85) compared to PR rates of 47.8% for GISTs with an exon 9 KIT mutation (n = 23) (p = 0.0006) and 0% for GISTs with no detectable KIT or PDGFRA mutation (p <0.0001).  These data show that the mutational status of KIT and PDGFRA is predictive of clinical response to imatinib. (Heinrich MC, et al. J Clin Oncol 2003;21:4342-4349)

 

HYPEREOSINOPHILIC SYNDROME (HES)

Anti-interleukin-5 antibody therapy.  Sabine-Gisela Plotz et al. report treatment results in 3 patients with HES and dermatologic manifestations with mepolizumab, a neutralizing anti-interleukin-5 antibody.  Eosinophil counts fell to the normal range within 24 hours of starting mepolizumab therapy and serum levels of eosinophil cationic protein normalized within 2 days.  The dermatitis was controlled in all 3 patients, leukopenia was not observed, and no adverse events were reported.  These early findings show that further study of mepolizumab treatment of HES is warranted. (Plotz S-G, et al. N Eng J Med 2003;349:2334-2339)  

 

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