Camille L. Bedrosian

Phase I Trial of the Novel Mammalian Target of Rapamycin Inhibitor Deforolimus (AP23573; MK-8669) Administered Intravenously Daily for 5 Days Every 2 Weeks to Patients With Advanced Malignancies

PURPOSEnThis phase I trial was conducted to determine the safety, tolerability, pharmacokinetics, and pharmacodynamics of deforolimus (previously known as AP23573; MK-8669), a nonprodrug rapamycin analog, in patients with advanced solid malignancies.nnnPATIENTS AND METHODSnPatients were treated using an accelerated titration design with sequential escalating flat doses of deforolimus administered as a 30-minute intravenous infusion once daily for 5 consecutive days every 2 weeks (QDx5) in a 28-day cycle. Safety, pharmacokinetic, pharmacodynamic, and tumor response assessments were performed.nnnRESULTSnThirty-two patients received at least one dose of deforolimus (3 to 28 mg/d). Three dose-limiting toxicity events of grade 3 mouth sores were reported. The maximum-tolerated dose (MTD) was 18.75 mg/d. Common treatment-related adverse events included reversible mouth sores and rash. Whole-blood clearance increased with dose. Pharmacodynamic analyses demonstrated mammalian target of rapamycin inhibition at all dose levels. Four patients (one each with non-small-cell lung cancer, mixed müllerian tumor [carcinosarcoma], renal cell carcinoma, and Ewing sarcoma) experienced confirmed partial responses, and three additional patients had minor tumor regressions.nnnCONCLUSIONnThe MTD of this phase I trial using an accelerated titration design was determined to be 18.75 mg/d. Deforolimus was well tolerated and showed encouraging antitumor activity across a broad range of malignancies when administered intravenously on the QDx5 schedule. On the basis of these overall results, a dose of 12.5 mg/d is being evaluated in phase II trials.

Analysis of Factors That Correlate With Mucositis in Recipients of Autologous and Allogeneic Stem-Cell Transplants

PURPOSEnTo identify predictors of oral mucositis and gastrointestinal toxicity after high-dose therapy.nnnPATIENTS AND METHODSnMucositis and gastrointestinal toxicity were prospectively evaluated in 202 recipients of high-dose therapy and autologous or allogeneic stem-cell rescue. Of 10 outcome variables, three were selected as end points: the peak value for the University of Nebraska Oral Assessment Score (MUCPEAK), the duration of parenteral nutritional support, and the peak daily output of diarrhea. Potential covariates included patient age, sex, diagnosis, treatment protocol, transplantation type, stem-cell source, and rate of neutrophil recovery. The three selected end points were also examined for correlation with blood infections and transplant-related mortality.nnnRESULTSnA diagnosis of leukemia, use of total body irradiation, allogeneic transplantation, and delayed neutrophil recovery were associated with increased oral mucositis and longer parenteral nutritional support. No factors were associated with diarrhea. Also, moderate to severe oral mucositis (MUCPEAK > or = 18 on a scale of 8 to 24) was correlated with blood infections and transplant-related mortality: 60% of patients with MUCPEAK > or = 18 had positive blood cultures versus 30% of patients with MUCPEAK less than 18 (P =.001); 24% of patients with MUCPEAK > or = 8 died during the transplantation procedure versus 4% of patients with MUCPEAK less than 18 (P =.001).nnnCONCLUSIONnGastrointestinal toxicity is a major cause of transplant-related morbidity and mortality, emphasizing the need for corrective strategies. The peak oral mucositis score and the duration of parenteral nutritional support are useful indices of gastrointestinal toxicity because these end points are correlated with clinically significant events, including blood infections and treatment-related mortality.

Phase I, pharmacokinetic (PK), and pharmacodynamic (PD) study of AP23573, an mTOR Inhibitor, administered IV daily X 5 every other week in patients (pts) with refractory or advanced malignancies

3076 Background: AP23573, a non-prodrug rapamycin analog, potently inhibits mTOR, a downstream effector of the PI3K/Akt and nutrient signaling pathways. AP23573 demonstrated potent inhibition of proliferation in vitroin several human tumor cell lines and elicited antitumor activity in vivo in multiple xenograft animal models.nnnMETHODSnThis dose escalation trial utilizes an accelerated titration scheme to determine safety, tolerability and maximum tolerated dose of AP23573 administered without premedication as 30-minute IV infusion daily x 5 days every 2 weeks for 4-week cycles. It also is designed to characterize the PK profile, evaluate potential PD markers using western blot analysis of peripheral blood mononuclear cells (PBMCs) and immunohistochemical analysis of skin biopsies, and ascertain preliminary data on antitumor activity.nnnRESULTSnAs of 01 Dec 03: 11 pts (6M/5F), median age 57 yrs (range 23-65 yrs), were treated with AP23573 doses ranging from 3 to 28 mg in 5 dose level cohorts (total cycles, 32; median cycles, 2/pt). No dose-limiting toxicity or AP23573-related serious adverse events have been observed. Side effects for first cycle included grade (gr) 2 anemia (2 pts); gr 3 transient transaminase elevation (1 pt with hepatocellular cancer); gr 2 mucositis (2 pts); gr 1 skin rash (2 pts). PK analyses (doses 3 to 12.5 mg) suggest a mean AP23573 half-life of 44-54 hours. PD analyses (doses 3 and 6.25 mg) indicate rapid (within 1 hr) and prolonged (up to 10 days between doses) inhibition of mTOR activity as demonstrated by >80% decrease in phosphorylated 4EBP1 levels in PBMCs. Of 8 evaluable pts, one partial response has been observed in a pt with metastatic renal cell cancer; (6.25 mg) and 1 pt with metastatic sarcoma (3 mg) has had stable disease > 6 months.nnnCONCLUSIONSnAP23573 can be administered safely using this schedule, and has exhibited antitumor activity as well as evidence of a substantial PD effect. Patient dosing and enrollment are ongoing. Further dose escalation as well as exploration of the relationship between PD (PBMC and skin) and PK are planned. [Table: see text].