Response rates to single-agent carfilzomib in patients refractory or intolerant to both bortezomib and immunomodulators in trial PX-171-003-A1
Background: Patients (pts) with relapsed and refractory multiple myeloma (RR MM) who are refractory or intolerant to both bortezomib (BTZ) and immunomodulators (IMiDs; thalidomide [Thal] or lenalidomide [Len]) (ie, “double-refractory/intolerant”), have few therapeutic options and a poor prognosis. Carfilzomib (CFZ), a next generation proteasome inhibitor (PI), has shown durable single-agent activity in clinical studies including 003-A1, an open-label, single-arm phase 2b trial in RR MM. The present analysis describes clinical activity in pts from 003-A1 with double-refractory/intolerant disease and in other groups of clinical interest including pts with disease refractory to all 5 approved classes of anti-MM tx (alkylators, anthracyclines, corticosteroids, IMiDs, and PIs) in clinical use (“refractory to all approved tx”). Methods: Pts from 003-A1 with double-refractory/intolerant disease were analyzed, as were pts with disease refractory to all approved tx. CFZ was given on days 1, 2, 8, 9, 15, 16 of 28-day cycles (C), (20 mg/m2 in C1; 27 mg/m2 in C2–12). Primary endpoint was overall response rate (ORR). Secondary endpoints included duration of response (DOR), overall survival, and safety. Results: The study ORR was 22.9% with median DOR of 7.8 mo (N=266). 228 pts (86%) with double-refractory/intolerant disease had ORRs of 20.6% and a median DOR of 7.4 mo. Conclusions: Single-agent CFZ demonstrated clinically meaningful, durable responses in pts with double-refractory/intolerant MM or disease refractory to all 5 approved classes of tx. The ORRs across groups of clinical interest were generally consistent with results for the entire study population. These results are notable for a next-generation PI and demonstrate the activity of single-agent CFZ in pts with advanced stage MM.
Safety and efficacy of eltrombopag (epag) versus placebo (pbo) for the treatment (tx) of chemotherapy-induced thrombocytopenia (CIT) in patients with solid tumors receiving gemcitabine (gem)-based chemotherapy (ctx): A phase I study.
Eric S. Winer, MD
Background: There are limited tx options for CIT. Epag, an oral, small molecule, thrombopoietin-receptor agonist that increases platelet (plt) production, is being explored for tx of CIT. Methods: This was the Ph I portion of a Ph I/II, blinded, pbo-controlled multicenter study in adults with solid tumors and baseline plts ≤300,000µL, who received up to 6 cycles of gem (1000-1250 mg/m2 IV) as monotherapy on Days 1, 8, and 15 Q28 days or Days 1 and 8 Q21 days in combination with cisplatin (50-80 mg/m2 IV Day 1 or divided 1 and 8) or carboplatin (AUC 4-7 IV Day 1). Patients received ctx alone for Cycle 1 and ctx plus epag or matching pbo (randomized 3:1) daily on Days -5 to -1 and 2 to 6 for subsequent cycles. Epag or pbo was interrupted for plts ≥400,000/µL. Results: 33 patients were randomized; 26 received epag or pbo (Table). Data review with an external, independent physician found no safety concerns, and there were sufficient plt increases with a dose of 100 mg epag vs pbo. No dose-limiting toxicities were reported for epag but 1 for pbo. Most AEs were grade 1 or 2. The most common AE in combined epag- and combined pbo-treated groups was neutropenia. Conclusions: Epag was well-tolerated and improved plt counts. Based on these encouraging Ph I results, Ph II using 100 mg epag in thrombocytopenic patients is planned.
SWOG S0826: A phase II trial of SCH 727965 (NSC 747135) in patients with stage IV melanoma.
Christopher D. Lao, MD, MPH
Background: Cyclin-dependent kinases (cdks) function to regulate cell cycle control and agents that can target cdks in malignant progression remain viable therapeutic strategies. Selective inhibition of cdk2, in particular, may be of therapeutic value in a subset of patients with melanoma. Methods: 60 patients with metastatic melanoma of cutaneous or mucosal origin were planned to be recruited to a multicenter, single-arm phase II trial of the cdk inhibitor, SCH 727965 (NSC747135). Patients were potentially eligible if they had 0-1 previous treatments, PS of 0-1, and adequate organ function. Ocular melanoma patients and patients with a history of brain metastases were excluded. SCH 727965 50 mg IV every 3 weeks was given until progression with disease assessment occurring every 2 cycles. Co-primary endpoints were 1-year overall survival (OS) and 6-month progression free survival (PFS). Results: 72 patients were enrolled from July 1, 2009 to November 1, 2010 at 24 institutions. 68% of patients had M1c disease and 43% had LDH elevation. 19% had prior therapy for metastatic disease. 28 patients (39%) experienced Grade 4 adverse events, including 20 cases of neutropenia, one case each of cardiac ischemia/infarction, cardiac troponin I elevation, dehydration, abdominal pain, leukopenia, muscle weakness, headache, syncope, and anterior ischemic optic neuropathy. 65 patients are currently evaluable for response. The response rate was 0/65 (95% C.I. (0-6%)). Stable disease was observed in 22%. The estimated median PFS was 1.5 months (95% CI: 1.4 – 1.5); 6-month PFS was 11% (5-20%). Median OS was 8 months (95% CI: 5-11 months); 1-year OS was 36% (95% CI: 24-48%). The null hypothesis of 1-year overall survival=25% was rejected (p=0.04) but 6-month PFS=11% was not (p=0.8). Data Analysis will be updated when missing data are received. Correlative studies of Rb phosphorylation and cyclin expression will be pursued. Conclusions: SCH 727965 appears to be reasonably well tolerated although grade 4 events were relatively common, particularly near the time of infusion. There were no responses but few patients had prolonged disease stabilization that may have resulted in improvement in the 1-year OS rate.
ME-143, a novel inhibitor of tumor-specific NADH oxidase (tNOX): Results from a first-in-human phase I study.
Background: ME-143, a second generation isoflavone-derived compound, specifically binds tNOX, shifting the ceramide-S1P equilibrium and resulting in prompt apoptosis via pleotrophic caspase activation. A first generation compound, phenoxodiol (PXD), showed promising phase II activity with cisplatin in ovarian cancer. ME-143 is broadly active against human cancers in both in vitro and in vivo models, with IC50’s 1-2 logs lower than PXD. Toxicology studies up to 140mg/kg (human dose equivalent ~23mg/kg) showed no STD level. The only significant findings were dose dependent hypospermia and testicular atrophy in rats. We report clinical and PK results from the first-in-human phase I study. Methods: A 3+3 dose escalation design was used with 4 dose cohorts: 2.5, 5, 10, and 20mg/kg IV over 30 minutes weekly times 3, followed by a 1 week break, and then continuous weekly dosing in patients with advanced solid tumors. Dense PK sampling was performed at 0, 5, 10, 20, 30, 60, 90, 120, 180, 240, 300, 360 minutes, and 24 hours post-infusion day 1 and 15 of the first treatment cycle. Results: To date, 9 patients have been enrolled, 3 in each of the first 3 cohorts. Median time on treatment is 56 days (range 6 to 62). Five patients have discontinued protocol therapy, all due to PD. No DLT’s have been observed. Related AE’s include grade 1: myalgia (1), anorexia (1), fatigue (2), headache (1), diarrhea (1), vomiting (1) and grade 2: fatigue (1). Preliminary PK analyses in the first 2 cohorts is shown in table below. Conclusions: ME-143 appears to be well tolerated when administered IV. Preliminary PK data suggest that drug levels achieve target concentration extrapolated from pre-clinical studies (AUC0-t ~10mg*hr/mL) and exceed levels obtained with IV PXD in the phase II study (AUC0-t ~2mg*hr/mL) . Updated clinical data from all planned dose cohorts, including the final pharmacokinetic analysis and planned phase II dose, will be presented.
Background: Melphalan-prednisone + thalidomide (MPT) or bortezomib (MPV) are approved in frontline MM patients (pts) >65 years. Both regimens demonstrated significant benefit over MP alone in terms of PFS and OS but this benefit could be hampered by the risk of peripheral neuropathy (PN). Carfilzomib (Cfz) is a novel proteasome inhibitor that has demonstrated promising activity and favorable toxicity profile, with low rates of PN. This phase I/II study was designed to determine the maximum tolerated dose (MTD) of CMP, to assess safety and evaluate efficacy of this combination in newly diagnosed MM >65. Methods: In Phase I, Cfz was the only escalating agent starting at 20 mg/m2 (level 1) with maximal planned dose 36 mg/m2 (level 3), given IV on days 1, 2, 8, 9, 22, 23, 29, 30 for nine 42-day cycles. Oral melphalan 9 mg/m≤ and prednisone 60mg/m≤ were given on days 1 to 4, for all dose levels. Based on toxicity assessment, the study was amended to add dose level 4 (Cfz 45 mg/m2). MTD determination was based on occurrence of Dose limiting toxicities (DLTs) during the first cycle only. DLTs were defined as any grade 4 hematologic toxicity or preventing administration of 2 or more of the 8 Cfz doses of the first treatment cycle except grade 4 thrombocytopenia without bleeding or grade 4 neutropenia lasting "d 7 days; or grade "e 3 febrile neutropenia; or any other grade "e 3 nonhematologic toxicity. Results: As of January 20th 2012, 24 pts have been enrolled in the phase I: 6 pts at level 1 (Cfz 20), 6 at level 2 (Cfz 27), 6 at level 3 (Cfz 36), and 6 at level 4 (Cfz 45). There were 2 DLTs at level 4 (fever and hypotension not related to sepsis) and the MTD was considered to be 36 mg/m≤. Then, 16 additional pts were included in the phase II at level 3. Overall, 40 pts have been enrolled into the phase I/II study and 26 pts are evaluable for response. The ORR was 92% including 42% at least VGPR. These results compare favorably to those achieved with MPV, MPT, MPR or lenalidomide-dex (ORR 71, 76, 80 and 85%, respectively) in the same population. Conclusions: Frontline carfilzomib (36 mg/m2) + MP is a tolerable and very effective combination in elderly MM pts. Treatment is ongoing, with updated toxicity and efficacy data to be presented at the meeting.
A phase I/II trial of cyclophosphamide, carfilzomib, thalidomide, and dexamethasone (CYCLONE) in patients with newly diagnosed multiple myeloma
Background: Carfilzomib is a proteasome inhibitor that irreversibly binds its target with favorable toxicity profile that has shown significant activity in relapsed multiple myeloma (MM). Here we used carfilzomib as the center of a 4 drug induction regimen designed for MM patients pre stem cell transplant (SCT). Methods: We conducted a phase I safety run in 6 patients with no DLT observed before expanding to phase II. The phase II regimen is shown below. Treatment was for 4 cycles with expected SCT post induction. For the phase II portion of this trial, the primary endpoint is the proportion of patients who have ≥ very good partial response to treatment. All patients received herpes zoster prophylaxis and ASA daily. Results: Twenty seven patients were enrolled. Median age was 65 (range 27-74). ORR for evaluable patients (n=17) at phase II dosing is 100%: CR 35%, VGPR 48%, PR 18% after 4 cycles of CYCLONE. Grade 3 toxicity was reported in 52% of patients and 14% experienced a grade 4 toxicity. Grade 3/4 toxicities occurring in >5% of patients included fatigue, neutropenia, lymphopenia, thromboembolism, myopathy. Toxicities of any grade seen in >20% of patients included fatigue, constipation, lethargy, thrombocytopenia, somnolence, creatinine increased, malaise. Four patients (20%) developed grade 1 sensory neuropathy; no higher grade or painful neuropathy was evident. All patients are alive. All patients advancing to SCT successfully collected stem cells. One patient with t(4;14) disease who was not transplanted has progressed. 94% remain progression free. Conclusions: The 4 drug CYCLONE regimen has remarkable efficacy (83% ≥VGPR) and manageable toxicity in newly diagnosed patients with multiple myeloma. Especially notable was the low incidence of neuropathy and depth of response (CR 35%) after only 4 cycles. Given the relative lack of toxicity an extension of this regimen at higher doses of carfilzomib (20/45mg/m2) has been initiated.
Stringent complete response (sCR) in patients (pts) with newly diagnosed multiple myeloma (NDMM) treated with carfilzomib (CFZ), lenalidomide (LEN), and dexamethasone (DEX).
Background: Combination treatment (tx) with CFZ, LEN, and DEX (CRd) is well tolerated and highly active in NDMM. In a phase 1/2 study, CRd provided rapid reduction of disease by 68% after cycle (C) 1 and 94% ≥partial response (PR) at a median of 8C, including 65% ≥very good PR and 53% ≥near CR (nCR), which improved to 79% ≥nCR after C12 (ASH 2011, Abstr 631). Here, we examine the clinical significance of the response rates with longer follow-up. Methods: Pts with NDMM were treated in 28-day (d) C with CFZ 20–36 mg/m2 IV (d1, 2, 8, 9, 15, 16), LEN 25 mg PO (d1–21) and DEX 40/20 mg PO weekly (C1–4/5–8). After C4, autologous stem cell transplant (ASCT) candidates achieving ≥PR could collect stem cells but then continued CRd with the option to proceed to ASCT. After C8, pts received CRd maintenance, using the last tolerated doses, with LEN/DEX at the same schedule but a modified CFZ schedule (d1, 2, 15, 16). Response was assessed by IMWG criteria plus nCR. Results: As of Nov 30, 2011, median follow-up was 14 mo (range 4–25) with 33/53 (62%) pts achieving ≥nCR and 42% sCR. After a median of 13C (range 1–25), 36 pts completed C8 and continued CRd maintenance, 64% achieving sCR. 20/22 pts in CR evaluated for minimal residual disease (MRD) by multiparameter flow cytometry had no MRD. Progression-free survival (PFS) rate was 97% at 12 and 92% at 24 mo. All pts who achieved sCR have maintained response for a median of 9 mo (range 1–20). Extended CRd tx was well tolerated. During CRd maintenance, the most common toxicities (all grades) were lymphopenia (30%), leukopenia (26%), and fatigue (25%), and peripheral neuropathy remained limited (11%, all G1/2). There were no tx discontinuations due to toxicity during maintenance and limited dose modifications (CFZ 19%, LEN 28%, DEX 31%). Conclusions: CRd is highly active in NDMM, providing rapid and deep responses. Extended tx was well tolerated and resulted in improved depth of response with a high sCR rate and a significant proportion of pts without evidence of MRD. Responses were durable with very promising PFS. All pts who achieved sCR remained on CRd with sustained sCR. These results compare favorably to other frontline regimens.