Treatment of CD30-Expressing Germ Cell Tumors and Sex Cord Stromal Tumors with Brentuximab Vedotin: Identification and Report of Seven Cases

BACKGROUND

Cytotoxic therapy for relapsed and refractory germ cell tumors or metastatic sex cord stromal tumors is rarely effective and is often accompanied by high adverse event rates. Expression of CD30 has been observed in testicular cancers, and patients with CD30-expressing embryonal carcinomas have worse progression-free survival and overall survival than those with CD30-negative tumors. The objective of this study (NCT01461538) was to characterize the antitumor activity of brentuximab vedotin in patients with CD30-expressing nonlymphomatous malignancies. Enrolled patients included seven patients with relapsed or refractory germ cell tumors or metastatic sex cord stromal tumors described in this case series.

MATERIALS AND METHODS

Forty patients with relapsed or refractory germ cell tumors, metastatic sex cord stromal tumors, or testicular tumors were screened for CD30 expression; 14 patients had tumors that expressed CD30. Seven patients with CD30-expressing testicular cancer were enrolled in the treatment study: five patients with germ cell tumors, one patient with a Leydig cell tumor, and one patient with a Sertoli cell tumor. Patients were treated with brentuximab vedotin at initial doses of 1.8 or 2.4 mg/kg every 3 weeks. Response assessments were performed at cycles 2 and 4 and every 4 cycles thereafter while the patient was receiving treatment.

RESULTS

Two of seven patients achieved an objective response, including one durable complete response and one partial response at a single time point. Both responding patients had germ cell tumors. Treatment with brentuximab vedotin was generally well tolerated.

CONCLUSION

Treatment of relapsed or refractory germ cell tumors with brentuximab vedotin can induce durable responses with a manageable toxicity profile.

IMPLICATIONS FOR PRACTICE

This case series of seven patients with relapsed or refractory CD30-expressing germ cell tumors (GCTs) or sex cord stromal tumors demonstrates that brentuximab vedotin has activity against GCTs and is well tolerated in heavily pretreated patients with these aggressive tumor types. One patient achieved a complete response that has been durable for almost 4 years since the discontinuation of treatment with brentuximab vedotin. Therefore, brentuximab vedotin may be a valuable option for physicians who care for this difficult-to-treat patient population.

A Phase I Study of the Safety, Pharmacokinetics, and Pharmacodynamics of Combination Therapy with Refametinib plus Sorafenib in Patients with Advanced Cancer

PURPOSE

To assess the safety and tolerability of the small-molecule allosteric MEK inhibitor refametinib combined with sorafenib, in patients with advanced solid malignancies.

EXPERIMENTAL DESIGN

This phase I dose-escalation study included an expansion phase at the maximum tolerated dose (MTD). Patients received refametinib/sorafenib twice daily for 28 days, from a dose of refametinib 5 mg plus sorafenib 200 mg to a dose of refametinib 50 mg plus sorafenib 400 mg. Plasma levels of refametinib, refametinib metabolite M17, and sorafenib were measured for pharmacokinetic assessments. Tumors were biopsied at the MTD for analysis of MEK pathway mutations and ERK phosphorylation.

RESULTS

Thirty-two patients were enrolled in the dose-escalation cohort. The MTD was refametinib 50 mg twice daily plus sorafenib 400 mg twice daily. The most common treatment-related toxicities were diarrhea and fatigue. Refametinib was readily absorbed following oral administration (plasma half-life of ∼16 hours at the MTD), and pharmacokinetic parameters displayed near-dose proportionality, with less than 2-fold accumulation after multiple dosing. Another 30 patients were enrolled in the MTD cohort; 19 had hepatocellular carcinoma. The combination was associated with significantly reduced ERK phosphorylation in 5 out of 6 patients biopsied, with the greatest reductions in those with KRAS or BRAF mutations. Disease was stabilized in approximately half of patients, and 1 patient with colorectal cancer achieved a partial response at the MTD lasting approximately 1 year.

CONCLUSIONS

In this phase I study, refametinib plus sorafenib was well tolerated, with good oral absorption, near-dose proportionality, and target inhibition in a range of tumor types. Clin Cancer Res; 22(10); 2368-76. ©2015 AACR.

Phase II study of amrubicin as second-line therapy in patients with platinum-refractory small-cell lung cancer

PURPOSE

Amrubicin is a synthetic anthracycline with potent topoisomerase II inhibition. This phase II study was conducted to confirm safety and activity of amrubicin in the treatment of refractory small-cell lung cancer (SCLC).

PATIENTS AND METHODS

Patients with refractory SCLC (either with progressive disease as best response or progression within 90 days of first-line therapy) received amrubicin (40 mg/m(2)/d for 3 every 21 days). The primary end point was overall response rate (ORR); secondary end points included progression-free survival (PFS), overall survival (OS), and change in left ventricular ejection fraction (LVEF).

RESULTS

Seventy-five patients with a median progression-free interval after first-line therapy of 38 days were enrolled; 69 patients received a median of four amrubicin cycles (range, one to 12 cycles). The ORR was 21.3% (95% CI, 12.7% to 32.3%), with one complete response (1.3%) and 15 partial responses (20%). Median PFS and OS were 3.2 months (95% CI, 2.4 to 4.0 months) and 6.0 months (95% CI, 4.8 to 7.1 months), respectively. The ORR in 43 patients who never responded to first-line therapy was 16.3% (95% CI, 6.8% to 30.7%). Most commonly reported grade 3 or 4 adverse events included neutropenia (67%), thrombocytopenia (41%), and anemia (30%), with febrile neutropenia in 12%. There was no decrease in mean LVEF with cumulative amrubicin doses exceeding 750 mg/m(2).

CONCLUSION

Single-agent amrubicin showed promising activity with a 21.3% ORR and an acceptable safety profile when used as second-line therapy patients with platinum-refractory SCLC. Amrubicin did not induce early cardiotoxicity, but its long-term effects are unknown.

A phase I study of the safety and pharmacokinetics (PK) of XMT-1001 given as an intravenous (IV) infusion once every three weeks to patients with advanced solid tumors

2574

Background: XMT-1001 is a water soluble macromolecular conjugate of camptothecin (CPT). In this novel CPT pro- drug, CPT is conjugated with a 70 kDa biodegradable hydrophilic polyacetal, poly (1-hydroxymethylethylene hydroxymethylformal). XMT-1001 demonstrated an improved therapeutic window as compared with CPT and irinotecan in human tumor xenograft models, providing a compelling rationale for its clinical development. Methods: This is an open label, dose escalation study of XMT- 1001 administered as an IV infusion once every 3 weeks. The objectives of this phase I study are to determine the maximum tolerated dose and to assess safety and PK of XMT-1001. Initially 3 patients (pts) are entered at each dose level. The cohort is expanded to 6 pts if a patient experiences a dose limiting toxicity. Analyses of plasma and urine were performed for XMT-1001 (conjugated CPT), 2 major drug release products, and for unconjugated (free) CPT. Results: Thirty two pts with refractory solid tumors have received 82 cycles of XMT-1001 at 8 dose levels ranging from 1.0 to 20.5 mg CPT equivalents/m2. Two pts had Gr 3 infusion reactions consistent with hypersensitivity to study drug. Symptoms reversed upon discontinuation of study drug. After the introduction of new clinical trial material with an improved formulation, to date, no infusion reactions suggestive of hypersensitivity have occurred (11 patients, 22 cycles). No hemorrhagic cystitis or ≥ Gr 3 diarrhea was noted. Myelosuppression was observed in 3 pts treated at 15.4 mg CPT equiv/m2 dose level. Stable disease was observed in 7 pts with the following tumor types and dose levels expressed in mg CPT equivalents/m2: NSCLC (1.0 mg/m2, 6 wks), ovarian (4.9 mg/m2, 12 wks), pancreas (4.9 mg/m2, 36 wks), appendiceal (7.3 mg/m2, 12 wks), bile duct (9.1 mg/m2, 18 wks), basal cell (11.6 mg/m2, 6 wks), and colon (15.4 mg/m2, 6 wks). PK demonstrates dose proportional increases in plasma levels of XMT-1001 (conjugated CPT) and confirms the formation of its expected release products. To date, levels of free CPT in urine are low. Conclusions: 1. XMT-1001 can be given safely to patients; 2. XMT-1001 has a favorable PK profile; 3. Prolonged stable disease was observed in patients with refractory tumors.

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Results of a phase II trial of single-agent amrubicin (AMR) in patients with extensive disease small cell lung cancer (ED-SCLC) refractory to first-line platinum-based chemotherapy: An update

8103

Background: Amrubicin (AMR), a third-generation synthetic anthracycline and potent topoisomerase II inhibitor, is approved in Japan for the treatment of lung cancer. Patients (pts) with SCLC, who are refractory to first-line chemotherapy or progress within 3 months (mos) of treatment completion, are less likely to respond to additional chemotherapy and have an expected median survival of 3–5 mos. Here, we investigate the efficacy and safety of single-agent AMR in the treatment of Western pts with refractory ED-SCLC. Methods: In this phase II trial, pts with ED-SCLC refractory to prior 1st-line platinum-based chemotherapy (defined as progression (PD) while on therapy or relapse within 90 days of treatment completion) and ECOG performance status (PS) ≤2 were eligible. Patients were treated with intravenous AMR 40 mg/m2/day x 3 days every 21 days until PD or intolerable toxicity. The primary endpoint was response rate (ORR, by RECIST), with a goal to demonstrate an ORR ≥18% (point estimate). Secondary endpoints included progression-free survival (PFS) and overall survival (OS). Results: In all, 75 pts were enrolled with a median age of 63 years (range 43–88), 52% female, 17% PS 2. Response to 1st-line therapy was 5% complete remission (CR), 36% partial remission (PR) and 28% PD. Median time from completion of 1st-line therapy to PD was 1.3 mos. Sixty-nine pts received AMR for a median of 4 cycles (range 1–12). Six pts died or discontinued before receiving treatment. The primary endpoint was met with an ORR of 21% (16/75, 95% confidence interval [CI] 13.6% - 31.9%), including CR in 1 pt (1%) and PR in 15 pts (20%). Stable disease was achieved in 40% of pts. Two pts with PD as best response to 1st line chemotherapy achieved a PR. Median OS was 6.0 mos (95% CI 4.8–7.1 mos). Median PFS was 3.2 mos (95% CI 2.4–4.0 mos). The most common grade 3 or 4 adverse events were neutropenia (65%), thrombocytopenia (39%), and leukopenia (35%). Seven (10%) patients experienced febrile neutropenia. Dose reductions were required in 26 patients (38%). Conclusions: AMR shows promising activity, with an ORR of 21%, and an acceptable safety profile in patients with refractory ED-SCLC, and warrants further study in these pts.

[Table: see text]

An open-label, multicenter, phase II study of AT-101 in combination with rituximab (R) in patients with untreated, grade 1-2, follicular non-Hodgkin's lymphoma (FL)

8582

Background: Bcl-2 family proteins are overexpressed in the majority of patients with FL and contribute to resistance to therapy. AT-101 is a pan-Bcl-2 inhibitor (Bcl-2, Bcl-XL, Bcl-W, and Mcl-1) and potent inducer of proapoptotic proteins. It is active as a single agent and in combination with R in NHL tumor models. Methods: Patients with untreated FL who did not require immediate chemotherapy were eligible. Treatment consisted of an induction cycle of AT-101 (30mg po daily × 21) and R (375 mg/m2 weekly × 4) followed by up to 4 maintenance cycles of AT-101 (30mg po daily × 21) and R (375 mg/m2) every 8 weeks in nonprogressors. Endpoints evaluated the response rate (RR) at week 8 (primary), overall response rate (ORR), molecular response rate (BCL-2JH rearrangement in blood and bone marrow), and safety of the combination. A mini-Max, 2-stage design (52 pts planned) was used to detect >70% RR with power of 90% and alpha of 0.10. Results: 23 pts enrolled: median age 64 yrs; FLIPI 0–5: 0%/17%/65%/13%/4%; Grade 1/2: 61%/39%; bulky disease (>5cm3): 35%; stage: 1–4 4%/4%/30%/61%; bone marrow + 48%. All pts received induction and 18 pts received 1 or more maintenance cycles. RR following induction was 26% (95%CI=10.2–48.4), 4% CR and the best ORR was 70% (95%CI=47.1–86.8), 35% CR. Molecular response analysis is ongoing. Grade 3/4 AEs that occurred in ≥2 pts: nausea 4(17%), vomiting 2(9%), abdominal pain 2(9%), fatigue 2(9%), and small bowel obstruction 2(9%). AT-101 was reduced to 20mg daily x 21 which improved GI tolerability. Conclusions: The combination of AT-101 and R was well tolerated. The week 8 RR did not meet statistical criteria to enroll stage II. The best ORR is at the upper limit of reported ORR for R alone; therefore a randomized trial is required to definitively determine activity of the combination.

[Table: see text]

Phase III study of standard triweekly versus dose-dense biweekly capecitabine (C) + oxaliplatin (O) + bevacizumab (B) as first-line treatment for metastatic colorectal cancer (mCRC): XELOX-A-DVS (dense versus standard): Interim analysis

4078

Background: Every 3 week (Q3W) COB has been shown to be highly active and non-inferior to FOLFOX+B in first-line mCRC. Phase II data suggest that dose-dense every 2 week (Q2W) COB may be significantly more active and better tolerated than Q3W COB. Methods: XELOXA-DVS was a phase III, open-label study of 435 patients with chemonaive mCRC who met standard eligibility criteria. Patients were randomized to Q3W: C 850 mg/m2 BID d1–14 + O 130 mg/m2 d1 + B 7.5 mg/kg d1 or Q2W: C 1500 mg/m2 BID d1–7 + O 85 mg/m2 d1 + B 5 mg/kg d1 for up to 72 weeks. Complete surgical resection was allowed using pre-defined criteria. The primary endpoint, progression-free survival (PFS), was estimated using the Kaplan- Meier method, while the hazard ratio and 95% CI were estimated using Cox regression analysis, based on the intent-to-treat population. No formal statistical testing was conducted. Results: The median PFS was 8.4 months (Q2W) and 9.7 months (Q3W) (hazard ratio [HR]=0.84; 95% CI=0.62–1.13). The median PFS (on-treatment) was 9.1 months and 10.2 months, respectively (HR=0.81). Of the 72 and 73 patients with disease progression (DP), the median time to DP was 9.4 and 10.8 months, respectively (HR=0.86). The objective response rates were 21.7% vs 29.4%, respectively (HR=1.05). Patients in the Q2W vs Q3W group experienced higher rates of grade 3/4 diarrhea (29% vs 24%), hand-foot syndrome (12% vs 8%), and treatment discontinuation rates (40% vs 20%), respectively. Other grade 3/4 toxicities (>5%, Q2W vs Q3W) included fatigue (13% vs 13%), dehydration (12% vs 10%), nausea (8% vs 9%), peripheral neuropathy (5% vs 9%), anorexia (5% vs 7%), and abdominal pain (5% vs 7%). Conclusions: At the dose and schedule used, dose-dense Q2W COB was not superior to standard Q3W COB. These data further confirm the activity and tolerability of Q3W COB. The activity and tolerability of a lower C dose Q2W, with more aggressive dose reduction, combined with B and O or irinotecan is currently being evaluated (X-BIO).

[Table: see text]

A phase Ib study to evaluate the safety and efficacy of AMG 655 in combination with gemcitabine (G) in patients (pts) with metastatic pancreatic cancer (PC)

4501

Background: AMG 655 is an investigational, fully human agonist monoclonal antibody (IgG1) that binds human death receptor 5 (DR5), activates caspases, and induces apoptosis in sensitive tumor cells. In preclinical PC models, cooperative activity is observed when G is added to AMG 655. We performed a multi-center phase I trial to evaluate AMG 655 + G in metastatic PC pts. The primary endpoint was dose-limiting toxicity (DLT). Secondary endpoints included toxicity, pharmacokinetics, antibody formation, objective response rate, progression-free survival (PFS), 6-month and overall survival. Methods: Eligible pts had previously untreated metastatic PC and ECOG PS 0 or 1. Pts enrolled into sequential cohorts and received AMG 655 3 or 10 mg/kg IV days (D) 1 and 15 and G 1000 mg/m2 IV D 1, 8, and 15 every 28 D. CT scans were obtained Q8 weeks. Results: 13 pts (3 mg/kg cohort = 6; 10 mg/kg cohort = 7) enrolled from 7/07–11/07. Pt characteristics: females 61%; ECOG PS 1 69%; median age 65 (range 35–81); liver metastases 77%. Median number of cycles: 6 (range 2–12). There were no DLT. Nine (69%) pts had grade 3–4 toxicity, the most common were: thrombocytopenia (4 pts), neutropenia (2 pts), and abdominal pain (2 pts). No anti-AMG 655 antibodies were detected. After one 3 or 10 mg/kg dose of AMG 655 after G, the Cmax and AUC of AMG 655 were similar to those in the first- in-human single-agent study (LoRusso JCO 2007; 25: abstract 3534). Preliminary data indicate no effect of AMG 655 on PK of G. Partial response 31% (4 pts, 2 unconfirmed); stable disease 38%. Median PFS: 5.3 months (95% CI, 3.5, 6.2); 6-month survival rate: 76.2% (95% CI: 42.7%-91.7%). Conclusions: AMG 655 + G is well-tolerated and may have activity in metastatic pancreatic cancer. A randomized phase II trial of G ± AMG 655 at 10-mg/kg is currently enrolling.

[Table: see text]

Thalidomide and rituximab in Waldenstrom macroglobulinemia

Thalidomide enhances rituximab-mediated, antibody-dependent, cell-mediated cytotoxicity. We therefore conducted a phase 2 study using thalidomide and rituximab in symptomatic Waldenstrom macroglobulinemia (WM) patients naive to either agent. Intended therapy consisted of daily thalidomide (200 mg for 2 weeks, then 400 mg for 50 weeks) and rituximab (375 mg/m(2) per week) dosed on weeks 2 to 5 and 13 to 16. Twenty-five patients were enrolled, 20 of whom were untreated. Responses were complete response (n = 1), partial response (n = 15), and major response (n = 2), for overall and major response rate of 72% and 64%, respectively, on an intent-to-treat basis. Median serum IgM decreased from 3670 to 1590 mg/dL (P < .001), whereas median hematocrit rose from 33.0% to 37.6% (P = .004) at best response. Median time to progression for responders was 38 months. Peripheral neuropathy to thalidomide was the most common adverse event. Among 11 patients experiencing grade 2 or greater neuropathy, 10 resolved to grade 1 or less at a median of 6.7 months. Thalidomide in combination with rituximab is active and produces long-term responses in WM. Lower doses of thalidomide (ie, Collapse

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MESH Headings

• Adult
• Aged
• Aged, 80 and over
• Antibodies, Monoclonal/administration & dosage
• Antibodies, Monoclonal/adverse effects
• Antibodies, Monoclonal, Murine-Derived
• Antineoplastic Combined Chemotherapy Protocols/adverse effects
• Antineoplastic Combined Chemotherapy Protocols/therapeutic use
• Disease-Free Survival
• Dose-Response Relationship, Drug
• Drug Administration Schedule
• Female
• Follow-Up Studies
• Humans
• Immunoglobulin M/blood
• Male
• Middle Aged
• Neoadjuvant Therapy
• Receptors, IgG/genetics
• Rituximab
• Thalidomide/administration & dosage
• Thalidomide/adverse effects
• Treatment Outcome
• Waldenstrom Macroglobulinemia/blood
• Waldenstrom Macroglobulinemia/drug therapy
• Waldenstrom Macroglobulinemia/genetics

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Grants

• K23 CA087977 NCI NIH HHS
• K23CA087977-03 NCI NIH HHS

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