L. Gardner

Perifosine Plus Bortezomib and Dexamethasone in Patients With Relapsed/Refractory Multiple Myeloma Previously Treated With Bortezomib: Results of a Multicenter Phase I/II Trial

PURPOSE Novel agents have improved patient outcome in relapsed or relapsed/refractory multiple myeloma (MM). Preclinical data show that the novel signal transduction modulator, perifosine, enhances the cytotoxicity of dexamethasone and bortezomib. Clinical data suggest that perifosine in combination with dexamethasone has activity in relapsed or relapsed/refractory MM. PATIENTS AND METHODS In a phase I/II study, perifosine in combination with bortezomib with or without dexamethasone was prospectively evaluated in 84 patients with relapsed or relapsed/refractory MM. All were heavily pretreated and bortezomib exposed; 73% were refractory to bortezomib, and 51% were refractory to bortezomib and dexamethasone. The dose selected for the phase II study was perifosine 50 mg/d plus bortezomib 1.3 mg/m(2), with the addition of low-dose dexamethasone at 20 mg if progression occurred on perifosine plus bortezomib alone. RESULTS An overall response rate (ORR; defined as minimal response or better) of 41% was demonstrated with this combination in 73 evaluable patients, including an ORR of 65% in bortezomib-relapsed patients and 32% in bortezomib-refractory patients. Therapy was generally well tolerated; toxicities, including gastrointestinal adverse effects and fatigue, proved manageable. No treatment-related mortality was seen. Median progression-free survival was 6.4 months, with a median overall survival of 25 months (22.5 months in bortezomib-refractory patients). CONCLUSION Perifosine-bortezomib ± dexamethasone demonstrated encouraging activity in heavily pretreated bortezomib-exposed patients with advanced MM. A phase III trial is underway comparing perifosine-bortezomib plus dexamethasone with bortezomib-dexamethasone in patients with relapsed/refractory MM previously treated with bortezomib.

Randomized Placebo-Controlled Phase II Trial of Perifosine Plus Capecitabine As Second- or Third-Line Therapy in Patients With Metastatic Colorectal Cancer

PURPOSE In a multicenter, double-blind phase II trial, we compared the efficacy and safety of perifosine plus capecitabine (P-CAP) with placebo plus capecitabine (CAP) in patients with metastatic colorectal cancer (mCRC) who had progressed after as many as two prior therapies. PATIENTS AND METHODS Patients (n = 38) not previously treated with capecitabine received P-CAP (perifosine 50 mg orally once daily, days 1 to 21 and CAP 825 mg/m(2) orally twice daily, days 1 to 14) or CAP (825 mg/m(2) orally twice daily, days 1 to 14) in 21-day cycles until disease progression. The primary end point was time to progression (TTP). Secondary end points included overall survival (OS), overall response rate (ORR), safety, and tolerability. RESULTS Twenty patients were randomly assigned to P-CAP and 18 to CAP. Median TTP (27.5 v 10.1 weeks; P < .001) and median OS (17.7 v 7.6 months; P = .0052) were improved in patients receiving P-CAP versus CAP. ORR was 20% v 7% in the P-CAP and CAP groups, respectively, and one patient in the P-CAP group had a complete response. A subset analysis of fluorouracil-refractory patients showed a median TTP of 17.6 v 9.0 weeks (P < .001) and median OS of 15.1 v 6.5 months (P = .0061). Toxicities, including diarrhea, nausea, fatigue, and hand-foot syndrome, were manageable. CONCLUSION P-CAP showed promising clinical activity compared with CAP in previously treated patients with mCRC. A phase III trial is underway comparing P-CAP with CAP in patients with refractory mCRC.

Perifosine plus lenalidomide and dexamethasone in relapsed and relapsed/refractory multiple myeloma: a Phase I Multiple Myeloma Research Consortium study

The combination of lenalidomide–dexamethasone is active in multiple myeloma (MM). Preclinical data showed that the Akt inhibitor, perifosine, sensitized MM cells to lenalidomide and dexamethasone, providing the rationale for this Phase I, multicentre, single‐arm study to assess the safety and determine the maximum‐tolerated dose (MTD) of perifosine–lenalidomide–dexamethasone in relapsed and relapsed/refractory MM. Patients received escalating doses of perifosine 50–100 mg daily and lenalidomide 15–25 mg once daily on days 1–21 of each 28‐d cycle, plus dexamethasone 20–40 mg weekly thereafter, as indicated. Thirty‐two patients were enrolled across four dose cohorts. MTD was not reached, with 31 patients evaluable for safety/tolerability. The most common all‐causality grade 1‐2 adverse events were fatigue (48%) and diarrhoea (45%), and grade 3–4 neutropenia (26%), hypophosphataemia (23%), thrombocytopenia (16%), and leucopenia (13%). Among 30 evaluable patients, 73% (95% confidence interval, 57·5–89·2%) achieved a minimal response or better, including 50% with a partial response or better. Median progression‐free survival was 10·8 months and median overall survival 30·6 months. Response was associated with phospho‐Akt in pharmacodynamic studies. Perifosine–lenalidomide–dexamethasone was well tolerated and demonstrated encouraging clinical activity in relapsed and relapsed/refractory MM.

Results of the X-PECT study: A phase III randomized double-blind, placebo-controlled study of perifosine plus capecitabine (P-CAP) versus placebo plus capecitabine (CAP) in patients (pts) with refractory metastatic colorectal cancer (mCRC).

LBA3501 Background: Perifosine (P) is an oral, synthetic alkylphospholipid that inhibits or modifies signal transduction pathways including AKT, NFkB and JNK. A randomized phase II study examined P-CAP vs. CAP in pts with 2nd or 3rd line mCRC. This study showed improvement in mTTP (HR 0.254 [0.117, 0.555]) and mOS (HR 0.370 [0.180,0.763]). Based on these results, a randomized phase III study of P-CAP vs. CAP with a primary endpoint of overall survival (OS) in pts with refractory mCRC was initiated. METHODS The study was a prospective, randomized, double-blind, placebo-controlled randomized phase III trial. Eligible pts had mCRC which was refractory to all standard therapies. Pts randomized 1:1 to Arm A = P-CAP (P 50 mg PO QD + CAP 1000 mg/m2PO BID d1-14) or Arm B = CAP (placebo + CAP 1000 mg/m2 PO BID d 1-14). Cycles were 21 days. Baseline tumor block collection and a biomarker cohort of pts with pre- and on-treatment tumor and blood samples were performed. RESULTS Between 3/31/10 and 8/12/11, 468 pts were randomized, 234 pts were in each arm. Baseline demographics were balanced between the arms: age < 65y (A: 65%, B: 58.5%), male (A: 57.7%, B: 53.0%), ECOG PS 0 (A: 39.7%, B: 39.7%), K-ras mutant (A: 50.4%, B: 51.3%), and median number of prior therapies (A: 4, B: 4). As of 3/19/12, median follow up was 6.6 months. Median overall survival: Arm A = 6.4 mo, Arm B = 6.8 mo, HR 1.111 [0.905,1.365], p = 0.315. Median overall survival for K-ras WT pts: Arm A = 6.6 mo, Arm B = 6.8 mo, HR 1.020 [0.763,1.365], p = 0.894; K-ras mutant pts: Arm A = 5.4 mo, Arm B = 6.9 mo HR 1.192 [0.890,1.596], p = 0.238. CONCLUSIONS Despite promising randomized phase II data, this phase III study shows no benefit in overall survival adding perifosine to capecitabine in the refractory colorectal cancer setting. Response rate, progression free survival, and safety data will be presented. Biomarker analysis is pending to see if subgroups of patients may have potential benefit.