Olaratumab and doxorubicin versus doxorubicin alone for treatment of soft-tissue sarcoma: an open-label phase 1b and randomised phase 2 trial.

BACKGROUND: Treatment with doxorubicin is a present standard of care for patients with metastatic soft-tissue sarcoma and median overall survival for those treated is 12-16 months, but few, if any, novel treatments or chemotherapy combinations have been able to improve these poor outcomes. Olaratumab is a human antiplatelet-derived growth factor receptor α monoclonal antibody that has antitumour activity in human sarcoma xenografts. We aimed to assess the efficacy of olaratumab plus doxorubicin in patients with advanced or metastatic soft-tissue sarcoma. METHODS: We did an open-label phase 1b and randomised phase 2 study of doxorubicin plus olaratumab treatment in patients with unresectable or metastatic soft-tissue sarcoma at 16 clinical sites in the USA. For both the phase 1b and phase 2 parts of the study, eligible patients were aged 18 years or older and had a histologically confirmed diagnosis of locally advanced or metastatic soft-tissue sarcoma not previously treated with an anthracycline, an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, and available tumour tissue to determine PDGFRα expression by immunohistochemistry. In the phase 2 part of the study, patients were randomly assigned in a 1:1 ratio to receive either olaratumab (15 mg/kg) intravenously on day 1 and day 8 plus doxorubicin (75 mg/m(2)) or doxorubicin alone (75 mg/m(2)) on day 1 of each 21-day cycle for up to eight cycles. Randomisation was dynamic and used the minimisation randomisation technique. The phase 1b primary endpoint was safety and the phase 2 primary endpoint was progression-free survival using a two-sided α level of 0.2 and statistical power of 0.8. This study was registered with ClinicalTrials.gov, number NCT01185964. FINDINGS: 15 patients were enrolled and treated with olaratumab plus doxorubicin in the phase 1b study, and 133 patients were randomised (66 to olaratumab plus doxorubicin; 67 to doxorubicin alone) in the phase 2 trial, 129 (97%) of whom received at least one dose of study treatment (64 received olaratumab plus doxorubicin, 65 received doxorubicin). Median progression-free survival in phase 2 was 6.6 months (95% CI 4.1-8.3) with olaratumab plus doxorubicin and 4.1 months (2.8-5.4) with doxorubicin (stratified hazard ratio [HR] 0.67; 0.44-1.02, p=0.0615). Median overall survival was 26.5 months (20.9-31.7) with olaratumab plus doxorubicin and 14.7 months (9.2-17.1) with doxorubicin (stratified HR 0.46, 0.30-0.71, p=0.0003). The objective response rate was 18.2% (9.8-29.6) with olaratumab plus doxorubicin and 11.9% (5.3-22.2) with doxorubicin (p=0.3421). Steady state olaratumab serum concentrations were reached during cycle 3 with mean maximum and trough concentrations ranging from 419 µg/mL (geometric coefficient of variation in percentage [CV%] 26.2) to 487 µg/mL (CV% 33.0) and from 123 µg/mL (CV% 31.2) to 156 µg/mL (CV% 38.0), respectively. Adverse events that were more frequent with olaratumab plus doxorubicin versus doxorubicin alone included neutropenia (37 [58%] vs 23 [35%]), mucositis (34 [53%] vs 23 [35%]), nausea (47 [73%] vs 34 [52%]), vomiting (29 [45%] vs 12 [18%]), and diarrhoea (22 [34%] vs 15 [23%]). Febrile neutropenia of grade 3 or higher was similar in both groups (olaratumab plus doxorubicin: eight [13%] of 64 patients vs doxorubicin: nine [14%] of 65 patients). INTERPRETATION: This study of olaratumab with doxorubicin in patients with advanced soft-tissue sarcoma met its predefined primary endpoint for progression-free survival and achieved a highly significant improvement of 11.8 months in median overall survival, suggesting a potential shift in the treatment of soft-tissue sarcoma. FUNDING: Eli Lilly and Company.

Rationale for the development of IMC-3G3, a fully human immunoglobulin G subclass 1 monoclonal antibody targeting the platelet-derived growth factor receptor alpha.

A large body of evidence suggests that the platelet-derived growth factor (PDGF) family and associated receptors are potential targets in oncology therapeutic development because of their critical roles in the proliferation and survival of various cancers and in the regulation and growth of the tumor stroma and blood vessels. Several small molecules that nonspecifically target the PDGF signaling axis are in current use or development as anticancer therapies. However, for the majority of these agents, PDGF and its receptors are neither the primary targets nor the principal mediators of anticancer activity. IMC-3G3, a fully human monoclonal antibody of the immunoglobulin G subclass 1, specifically binds to the human PDGF receptor alpha (PDGFRalpha) with high affinity and blocks PDGF ligand binding and PDGFRalpha activation. The results of preclinical studies and the frequent expression of PDGFRalpha in many types of cancer and in cancer-associated stroma support a rationale for the clinical development of IMC-3G3. Currently, IMC-3G3 is being evaluated in early clinical development for patients with several types of solid malignancies.

Combined immunochemotherapy with reduced whole-brain radiotherapy for newly diagnosed primary CNS lymphoma.

PURPOSE: Our goals were to evaluate the safety of adding rituximab to methotrexate (MTX)-based chemotherapy for primary CNS lymphoma, determine whether additional cycles of induction chemotherapy improve the complete response (CR) rate, and examine effectiveness and toxicity of reduced-dose whole-brain radiotherapy (WBRT) after CR. PATIENTS AND METHODS: Thirty patients (17 women; median age, 57 years; median Karnofsky performance score, 70) were treated with five to seven cycles of induction chemotherapy (rituximab, MTX, procarbazine, and vincristine [R-MPV]) as follows: day 1, rituximab 500 mg/m2; day 2, MTX 3.5 gm/m2 and vincristine 1.4 mg/m2. Procarbazine 100 mg/m2/d was administered for 7 days with odd-numbered cycles. Patients achieving CR received dose-reduced WBRT (23.4 Gy), and all others received standard WBRT (45 Gy). Two cycles of high-dose cytarabine were administered after WBRT. CSF levels of rituximab were assessed in selected patients, and prospective neurocognitive evaluations were performed. RESULTS: With a median follow-up of 37 months, 2-year overall and progression-free survival was 67% and 57%, respectively. Forty-four percent of patients achieved a CR after five or fewer cycles, and 78% after seven cycles. The overall response rate was 93%. Nineteen of 21 CR patients received the planned 23.4 Gy WBRT. The most commonly observed grade 3 to 4 toxicities included neutropenia (43%), thrombocytopenia (36%), and leukopenia (23%). No treatment-related neurotoxicity has been observed. CONCLUSION: The addition of rituximab to MPV increased the risk of significant neutropenia requiring routine growth factor support. Additional cycles of R-MPV nearly doubled the CR rate. Reduced-dose WBRT was not associated with neurocognitive decline, and disease control to date is excellent.

Adjuvant therapy of melanoma.

PURPOSE: The purpose of this article was to review the current state of knowledge regarding the efficacy of adjuvant therapy for melanoma. PATIENTS AND METHODS: We reviewed the published literature, focusing on randomized clinical trials. RESULTS: There have been no meaningful trials addressing adjuvant chemotherapy in melanoma because all trials have been underpowered. Adjuvant interferon-alpha has been tested both at high dose and at lower doses. None of the trials have shown a reproducible benefit in survival, although the high-dose trials and some of the low-dose trials have shown improvement in time to relapse. These experiences raise the question of whether chronic administration is more important than dose. An adjuvant pegylated interferon-alpha trial using a 5-year treatment period is currently under investigation. At least 7 randomized adjuvant vaccine trials have been published, but none have shown a beneficial effect on relapse-free or overall survival except in subset analyses. CONCLUSIONS: To date, no adjuvant therapy has resulted in improved overall survival. To be attractive as an adjuvant therapy, experience from other tumor types indicates that a chemotherapy regimen should have a response rate of at least 20% in metastatic melanoma. Currently, biochemotherapy is being tested as an adjuvant treatment but other, less toxic, regimens should be sought. Once such a regimen with acceptable toxicity is identified, it would be reasonable to test it as an adjuvant therapy in a properly powered randomized trial. High-dose interferon-alpha for 1 year remains the only U.S. Food and Drug Administration-approved adjuvant therapy for melanoma, but long-term chronic dosing of interferon-alpha may prove more effective than short-term dose schedules. Development of melanoma vaccines remains an appealing and important goal. New technologies and understanding of the immune response against melanoma are leading to novel vaccine strategies designed to break immunologic tolerance against melanoma.

Myelosuppression in patients benefiting from imatinib with hydroxyurea for recurrent malignant gliomas.

Reports suggest reasonable efficacy and minimal myelosuppression from combination imatinib and hydroxyurea for recurrent malignant glioma. We retrospectively reviewed 16 patients treated with this regimen who were evaluable for toxicity; 14 were also evaluable for response. The incidence of grade 3-4 hematologic toxicity was 25%. The best radiographic response, by Macdonald criteria, was partial response (PR) in three patients (21%), stable disease (SD) in four (29%), and progressive disease (PD) in seven (50%). One patient with a PR developed therapy-limiting hematologic toxicity on day 19 of treatment, progressing to grade 4 on day 64, and persisting until death on day 127 despite discontinuing both drugs. Another patient with PR and two of four patients with SD also developed grade 3 hematologic toxicity. All patients with grade 3-4 hematologic toxicity had disease control (PR or SD) as best radiographic response, whereas none with PD suffered grade 3-4 hematologic toxicity. Combining imatinib with hydroxyurea is effective in some patients with malignant glioma. However, myelosuppression can persist for months after discontinuing the regimen, precluding further chemotherapy. Disease control may also correlate with hematologic toxicity (p = 0.08), suggesting that glioma and marrow stem cells may share a common sensitivity to this chemotherapy regimen.

Comparison of linear and volumetric criteria in assessing tumor response in adult high-grade gliomas.

The Response Evaluation Criteria in Solid Tumors, or RECIST criteria (one-dimensional [1D] measurement), are widely used to measure response in tumors, but there are few studies evaluating these criteria in brain tumors. We compared linear and volumetric measurements in adult high-grade supratentorial enhancing gliomas to determine the agreement between measurements, in defining responses and in their subsequent relation to survival. We hypothesized that the 1D RECIST criteria maybe suitable for response assessment in adult high-grade gliomas. Tumor size on MRI scans in 104 patients with high-grade enhancing gliomas treated on clinical trial protocols was measured by using 1D (greatest length), 2D (two-dimensional: product of the two longest perpendicular diameters), 3D (three dimensional: product of the longest perpendicular diameters in one plane and the longest orthogonal diameter to that plane), enhancing volume (EV), and total volume (TV). A total of 388 T1 postgadolinium MRI scans (104 baseline and 284 follow-up scans) were evaluated. Volumetric analysis (EV and TV) was performed with commercially available software. Intraobserver and interobserver correlations (rho) were high for all modalities (rho > 0.92 and rho > 0.71, respectively). Correlation was excellent (rho > 0.9) among all modalities except for 3D (rho < 0.6). Patient response rates ranged from 12% to 26%. Median progression-free survival (mPFS) and six-month progression-free survival (6mPFS) were not significantly different among the methods (range, 5.3 months to 5.9 months and 42% to 48%, respectively). Landmark analyses of response at two months using linear methods predicted overall survival with hazard ratios of 0.19 to 0.29 (P < 0.005). These results suggest high concordance among 1D, 2D, TV, and EV, but not 3D, methods in assessing enhancing tumor progression and in estimating mPFS and 6mPFS in adult brain tumor patients. The tumor response at two months assessed by linear methods correlated better with overall survival. Thus, linear methods are comparable to volumetric methods, but simpler to implement for routine clinical use and for designing clinical trials of brain tumors.

Systemic high-dose intravenous methotrexate for central nervous system metastases.

BACKGROUND: Treatment options for patients with recurrent central nervous system (CNS) metastases are limited. Rapid infusion of high-dose intravenous methotrexate (HD IV MTX) penetrates the blood-brain barrier (BBB) and has reported activity in leptomeningeal metastases. METHODS: Medical records were reviewed for all patients treated with HD IV MTX (3.5 g/m2) for CNS parenchymal or leptomeningeal metastases. Radiographic response rate, survival, and toxicity were determined. RESULTS: Thirty-one women and one man with a median age of 52 years (range 33-76) were treated with a total of 141 cycles (median 4, range 1-13). Twenty-nine patients had breast cancer, and one each had cancer of unknown primary (CUP), squamous cell carcinoma of the head and neck, and non-small cell lung cancer (NSCLC). An objective radiographic response and stable disease were each observed in nine patients (28%), and 13 (44%) patients progressed. Prior treatment with low-dose MTX for systemic disease did not affect response (P = 0.8). The median overall survival (n = 32) was 19.9 weeks (range 2.9-135.4+) with one patient alive at 135.4 weeks. Myelosuppression and elevated serum hepatic transaminases were the most common acute toxicities (21% and 9% of HD IV MTX cycles, respectively). CONCLUSIONS: HD IV MTX is effective in the treatment of CNS metastases with disease control (response or stable) as a best response in 56% of assessable patients. Further study is warranted.

Treatment of primary central nervous system lymphoma.

Primary central nervous system lymphoma (PCNSL) describes a malignant non-Hodgkin's lymphoma (NHL) whose sole site of involvement is the central nervous system (CNS). The diagnosis of PCNSL must be differentiated from systemic NHL with metastasis to the CNS, which usually occurs late in the course of systemic disease. PCNSL accounts for approximately 4% to 7% of primary brain tumors, and its incidence has been increasing since the mid-1970s. Compared with other more common malignant primary brain tumors, PCNSL tends to be more amenable to radiotherapeutic and chemotherapeutic intervention. In this article, the authors review the standard treatment for upfront and recurrent PCNSL.

Functional role of auditory cortex in frequency processing and pitch perception.

Microelectrode studies in nonhuman primates and other mammals have demonstrated that many neurons in auditory cortex are excited by pure tone stimulation only when the tone's frequency lies within a narrow range of the audible spectrum. However, the effects of auditory cortex lesions in animals and humans have been interpreted as evidence against the notion that neuronal frequency selectivity is functionally relevant to frequency discrimination. Here we report psychophysical and anatomical evidence in favor of the hypothesis that fine-grained frequency resolution at the perceptual level relies on neuronal frequency selectivity in auditory cortex. An adaptive procedure was used to measure difference thresholds for pure tone frequency discrimination in five humans with focal brain lesions and eight normal controls. Only the patient with bilateral lesions of primary auditory cortex and surrounding areas showed markedly elevated frequency difference thresholds: Weber fractions for frequency direction discrimination ("higher"-"lower" pitch judgments) were about eightfold higher than Weber fractions measured in patients with unilateral lesions of auditory cortex, auditory midbrain, or dorsolateral frontal cortex; Weber fractions for frequency change discrimination ("same"-"different" pitch judgments) were about seven times higher. In contrast, pure-tone detection thresholds, difference thresholds for pure tone duration discrimination centered at 500 ms, difference thresholds for vibrotactile intensity discrimination, and judgments of visual line orientation were within normal limits or only mildly impaired following bilateral auditory cortex lesions. In light of current knowledge about the physiology and anatomy of primate auditory cortex and a review of previous lesion studies, we interpret the present results as evidence that fine-grained frequency processing at the perceptual level relies on the integrity of finely tuned neurons in auditory cortex.