Pralsetinib for patients with advanced or metastatic RET-altered thyroid cancer (ARROW): a multi-cohort, open-label, registrational, phase 1/2 study

BACKGROUND

Oncogenic alterations in RET represent important therapeutic targets in thyroid cancer. We aimed to assess the safety and antitumour activity of pralsetinib, a highly potent, selective RET inhibitor, in patients with RET-altered thyroid cancers.

METHODS

ARROW, a phase 1/2, open-label study done in 13 countries across 71 sites in community and hospital settings, enrolled patients 18 years or older with RET-altered locally advanced or metastatic solid tumours, including RET-mutant medullary thyroid and RET fusion-positive thyroid cancers, and an Eastern Co-operative Oncology Group performance status of 0-2 (later limited to 0-1 in a protocol amendment). Phase 2 primary endpoints assessed for patients who received 400 mg once-daily oral pralsetinib until disease progression, intolerance, withdrawal of consent, or investigator decision, were overall response rate (Response Evaluation Criteria in Solid Tumours version 1.1; masked independent central review) and safety. Tumour response was assessed for patients with RET-mutant medullary thyroid cancer who had received previous cabozantinib or vandetanib, or both, or were ineligible for standard therapy and patients with previously treated RET fusion-positive thyroid cancer; safety was assessed for all patients with RET-altered thyroid cancer. This ongoing study is registered with clinicaltrials.gov, NCT03037385, and enrolment of patients with RET fusion-positive thyroid cancer was ongoing at the time of this interim analysis.

FINDINGS

Between Mar 17, 2017, and May 22, 2020, 122 patients with RET-mutant medullary and 20 with RET fusion-positive thyroid cancers were enrolled. Among patients with baseline measurable disease who received pralsetinib by July 11, 2019 (enrolment cutoff for efficacy analysis), overall response rates were 15 (71%) of 21 (95% CI 48-89) in patients with treatment-naive RET-mutant medullary thyroid cancer and 33 (60%) of 55 (95% CI 46-73) in patients who had previously received cabozantinib or vandetanib, or both, and eight (89%) of nine (95% CI 52-100) in patients with RET fusion-positive thyroid cancer (all responses confirmed for each group). Common (≥10%) grade 3 and above treatment-related adverse events among patients with RET-altered thyroid cancer enrolled by May 22, 2020, were hypertension (24 patients [17%] of 142), neutropenia (19 [13%]), lymphopenia (17 [12%]), and anaemia (14 [10%]). Serious treatment-related adverse events were reported in 21 patients (15%), the most frequent (≥2%) of which was pneumonitis (five patients [4%]). Five patients [4%] discontinued owing to treatment-related events. One (1%) patient died owing to a treatment-related adverse event.

INTERPRETATION

Pralsetinib is a new, well-tolerated, potent once-daily oral treatment option for patients with RET-altered thyroid cancer.

FUNDING

Blueprint Medicines.

Pralsetinib for RET fusion-positive non-small-cell lung cancer (ARROW): a multi-cohort, open-label, phase 1/2 study

BACKGROUND

Oncogenic alterations in RET have been identified in multiple tumour types, including 1-2% of non-small-cell lung cancers (NSCLCs). We aimed to assess the safety, tolerability, and antitumour activity of pralsetinib, a highly potent, oral, selective RET inhibitor, in patients with RET fusion-positive NSCLC.

METHODS

ARROW is a multi-cohort, open-label, phase 1/2 study done at 71 sites (community and academic cancer centres) in 13 countries (Belgium, China, France, Germany, Hong Kong, Italy, Netherlands, Singapore, South Korea, Spain, Taiwan, the UK, and the USA). Patients aged 18 years or older with locally advanced or metastatic solid tumours, including RET fusion-positive NSCLC, and an Eastern Cooperative Oncology Group performance status of 0-2 (later limited to 0-1 in a protocol amendment) were enrolled. In phase 2, patients received 400 mg once-daily oral pralsetinib, and could continue treatment until disease progression, intolerance, withdrawal of consent, or investigator decision. Phase 2 primary endpoints were overall response rate (according to Response Evaluation Criteria in Solid Tumours version 1·1 and assessed by blinded independent central review) and safety. Tumour response was assessed in patients with RET fusion-positive NSCLC and centrally adjudicated baseline measurable disease who had received platinum-based chemotherapy or were treatment-naive because they were ineligible for standard therapy. This ongoing study is registered with ClinicalTrials.gov, NCT03037385, and enrolment of patients with treatment-naive RET fusion-positive NSCLC was ongoing at the time of this interim analysis.

FINDINGS

Of 233 patients with RET fusion-positive NSCLC enrolled between March 17, 2017, and May 22, 2020 (data cutoff), 92 with previous platinum-based chemotherapy and 29 who were treatment-naive received pralsetinib before July 11, 2019 (efficacy enrolment cutoff); 87 previously treated patients and 27 treatment-naive patients had centrally adjudicated baseline measurable disease. Overall responses were recorded in 53 (61%; 95% CI 50-71) of 87 patients with previous platinum-based chemotherapy, including five (6%) patients with a complete response; and 19 (70%; 50-86) of 27 treatment-naive patients, including three (11%) with a complete response. In 233 patients with RET fusion-positive NSCLC, common grade 3 or worse treatment-related adverse events were neutropenia (43 patients [18%]), hypertension (26 [11%]), and anaemia (24 [10%]); there were no treatment-related deaths in this population.

INTERPRETATION

Pralsetinib is a new, well-tolerated, promising, once-daily oral treatment option for patients with RET fusion-positive NSCLC.

FUNDING

Blueprint Medicines.

Glembatumumab vedotin for patients with metastatic, gpNMB overexpressing, triple-negative breast cancer ("METRIC"): a randomized multicenter study

The METRIC study (NCT#0199733) explored a novel antibody–drug conjugate, glembatumumab vedotin (GV), targeting gpNMB that is overexpressed in ~40% of patients with triple-negative breast cancer (TNBC) and associated with poor prognosis. The study was a randomized, open-label, phase 2b study that evaluated progression-free survival (PFS) of GV compared with capecitabine in gpNMB-overexpressing TNBC. Patients who had previously received anthracycline and taxane-based therapy were randomized 2:1 to receive, GV (1.88 mg/kg IV q21 days) or capecitabine (2500 mg/m² PO daily d1–14 q21 days). The primary endpoint was RECIST 1.1 PFS per independent, blinded central review. In all, 327 patients were randomized to GV (213 treated) or capecitabine (92 treated). Median PFS was 2.9 months for GV vs. 2.8 months for capecitabine. The most common grade ≥3 toxicities for GV were neutropenia, rash, and leukopenia, and for capecitabine were fatigue, diarrhea, and palmar-plantar erythrodysesthesia. The study did not meet the primary endpoint of improved PFS over capecitabine or demonstrate a relative risk/benefit improvement over capecitabine.

Clinical activity of the RET inhibitor pralsetinib (BLU-667) in patients with RET fusion–positive solid tumors

467

Background: Recent tumor-agnostic drug approvals have resulted in a paradigm shift in cancer treatment away from organ/histology specific indications to biomarker-guided tumor-agnostic approaches. Pralsetinib is a potent and selective RET inhibitor, which has recently been approved by the U.S. Food and Drug Administration (FDA) for the treatment of adults with metastatic RET fusion–positive non-small cell lung cancer (NSCLC) and is under New Drug Application review for RET mutant thyroid cancers by the FDA. RET fusions occur in up to approximately 7‒8% of patients with gastrointestinal malignancies, including pancreatic, liver, and colorectal cancers. There are currently no approved selective RET inhibitors for patients with RET fusion–positive solid tumors other than NSCLC and thyroid cancer. Here, we present data on the clinical activity of pralsetinib in patients with RET fusion–positive solid tumor types other than NSCLC enrolled in the Phase I/II ARROW study (NCT03037385). Methods: ARROW consists of a phase I dose escalation (30–600 mg once [QD] or twice daily) followed by a phase II expansion (400 mg QD) in patients with advanced RET-altered solid tumors. Primary objectives are overall response rate (ORR), per RECICT v1.1 and safety. Results: A total of 13 patients with RET fusion–positive thyroid cancer (12 papillary, 1 poorly differentiated; enrollment cutoff July 11, 2019) and 14 patients with RET fusion–positive solid tumors other than NSCLC and thyroid (3 pancreatic, 3 colon, 2 cholangiocarcinoma, 6 other; enrollment cutoff November 19, 2019) were enrolled in ARROW and received pralsetinib. At the February 13, 2020, data cutoff, the ORR (blinded central review) in response-evaluable patients with RET fusion–positive thyroid cancer was 91% (10/11; 95% CI: 59‒100) and disease control rate was 100% (95% CI: 72‒100). Treatment was ongoing in 7 of 11 patients. In RET fusion–positive solid tumors other than NSCLC and thyroid, ORR (investigator’s assessment) was 50% (6/12; 95% CI: 21‒79) and responses were observed in all patients with pancreatic cancer (3/3) and cholangiocarcinoma (2/2). Treatment was ongoing in 6 of 12 patients, including 2 of 3 patients with pancreatic cancer and 1 of 2 patients with cholangiocarcinoma. Responses were observed across multiple fusion genotypes. In the 27 patients with RET fusion–positive tumors other than NSCLC, most frequent treatment-related adverse events (TRAEs) were grade 1–2, and included anemia (33%), increased aspartate aminotransferase (33%), decreased white blood cell count (33%), hypertension (30%), increased alanine aminotransferase (26%), hyperphosphatemia (19%), and neutropenia (19%). No patients discontinued due to TRAEs. Conclusions: Pralsetinib demonstrated broad and durable antitumor activity across multiple advanced solid tumor types, regardless of RET fusion genotype, and was well tolerated. The study is ongoing. Clinical trial information: NCT03037385.

AcceleRET Lung: A phase III study of first-line pralsetinib in patients (pts) with RET-fusion+ advanced/metastatic non-small cell lung cancer (NSCLC)

TPS9633

Background: RET gene fusions have been identified as oncogenic drivers in multiple tumor types, including 1-2% of NSCLC, but no selective RET inhibitors are approved for use. The investigational RET inhibitor, pralsetinib, potently and selectively targets oncogenic RET alterations, including those that confer resistance to multikinase inhibitors. In the registration-enabling phase 1/2 study (ARROW; NCT03037385), pts with RET-fusion+ NSCLC treated with 400 mg once daily (QD) of pralsetinib (N = 80) after platinum-based chemotherapy achieved an overall response rate (ORR) of 61% (95% CI 50, 72; 2 responses pending confirmation) per independent central review. In addition, a promising ORR of 73% (all centrally confirmed responses) was attained in the treatment naïve cohort (N = 26). Most treatment-related adverse events were grade 1-2 across the entire safety population treated at 400 mg QD (N = 354). AcceleRET Lung, an international, open-label, randomized, phase 3 study, will evaluate the efficacy and safety of pralsetinib versus standard of care (SOC) for first-line treatment of advanced/metastatic RET fusion+ NSCLC (NCT04222972). Methods: Approximately 250 pts with metastatic RET-fusion+ NSCLC will be randomized 1:1 to oral pralsetinib (400 mg QD) or SOC (non-squamous histology: platinum/pemetrexed ± pembrolizumab followed by maintenance pemetrexed ± pembrolizumab; squamous histology: platinum/gemcitabine). Stratification factors include intended use of pembrolizumab, history of brain metastases, and ECOG PS. Key eligibility criteria include no prior systemic treatment for metastatic disease; RET-fusion+ tumor by local or central assessment; no additional actionable oncogenic drivers; no prior selective RET inhibitor; measurable disease per RECIST v1.1. Pts randomized to SOC will be permitted to cross-over to receive pralsetinib upon disease progression. The primary endpoint is progression-free survival (blinded independent central review; RECIST v1.1). Secondary endpoints include ORR, overall survival, duration of response, disease control rate, clinical benefit rate, time to intracranial progression, intracranial ORR, safety/tolerability and quality of life evaluations. Recruitment has begun with sites (active or planned) in North America, Europe and Asia. Clinical trial information: NCT04222972 .

Registrational dataset from the phase I/II ARROW trial of pralsetinib (BLU-667) in patients (pts) with advanced RET fusion+ non-small cell lung cancer (NSCLC)

9515

Background: Pralsetinib is an investigational, highly potent, selective RET kinase inhibitor targeting oncogenic RET alterations. We provide the registrational dataset for pts with RET fusion+ NSCLC with and without prior treatment from the global ARROW study. Methods: ARROW (75 sites in 11 countries; NCT03037385) consists of a phase I dose escalation to establish recommended phase II dose (400 mg once daily [QD] orally) and phase II expansion cohorts defined by tumor type and/or RET alteration. Primary objectives were overall response rate (ORR; blinded independent central review per RECIST v1.1) and safety. Efficacy analyses are shown for response-evaluable pts (REP) with RET fusion+ NSCLC who initiated 400 mg QD pralsetinib by July 11 2019 and safety for all pts (regardless of diagnosis) treated with 400 mg QD. Results: As of November 18 2019, 354 pts with advanced solid tumors had received pralsetinib at starting dose of 400 mg QD with median follow-up 8.8 months. ORR, disease control rate (DCR), and % of pts with tumor size reduction are shown in the table for pts with metastatic RET fusion+ NSCLC (n=116; 72% KIF5B; 16% CCDC6; 12% other/fusion present but type unknown) and with prior platinum treatment (n=80) or without prior systemic treatment (n=26). ORR was similar regardless of RET fusion partner, prior therapies, or central nervous system involvement. Overall there were 7 (6%) complete responses, 4 (5%) in prior platinum pts and 3 (12%) in treatment naïve pts; median time to response overall was 1.8 months and median duration of response (DOR) was not reached (95% CI, 11.3–NR). In the safety population (n=354), most treatment-related adverse events (TRAEs) were grade 1-2, and included increased aspartate aminotransferase (31%), anemia (22%), increased alanine aminotransferase (21%), constipation (21%) and hypertension (20%). 4% of pts in the safety population (all tumor types) discontinued due to TRAEs. Conclusions: Updated, registrational, centrally reviewed data demonstrate that pralsetinib has rapid, potent, and durable clinical activity in pts with advanced RET fusion+ NSCLC regardless of RET fusion genotype or prior therapies, and QD oral dosing is well-tolerated. Clinical trial information: NCT03037385 . [Table: see text]

Clinical activity of the RET inhibitor pralsetinib (BLU-667) in patients with RET fusion+ solid tumors

109

Background: RET gene fusions are targetable oncogenic drivers in multiple tumor types, including up to 20% of papillary thyroid cancers (PTC). Pralsetinib is an investigational, highly potent, selective inhibitor of oncogenic RET alterations. In the registration-enabling Phase 1/2 ARROW study (NCT03037385), pralsetinib demonstrated an overall response rate (ORR; response-evaluable patients [REP], central review) of 73% (19/26) in treatment-naïve patients and 61% (49/80; 2 pending confirmation) in platinum-exposed patients with RET fusion+ non-small cell lung cancer (NSCLC) and was well tolerated (data cut-off November 18, 2019). We provide an update on the clinical activity of pralsetinib in other RET fusion+ solid tumor types. Methods: ARROW consists of a phase 1 dose escalation (30–600 mg once [QD] or twice daily) followed by a phase 2 expansion (400 mg QD) in patients with advanced RET-altered solid tumors. Primary objectives were ORR and safety. Results: As of November 18, 2019, 29 patients with metastatic solid tumor types other than NSCLC (16 PTC, 1 undifferentiated thyroid, 3 pancreatic, 3 colon, 6 other) bearing a RET fusion have received pralsetinib. Efficacy data are presented for REP enrolled by July 11, 2019. In patients with thyroid cancer that is RET fusion+, ORR (investigator assessment) was 75% (9/12; all confirmed). Median (range) duration of response (DOR) was 14.5 (3.7+, 16.8) months (mo), with 67% of responding patients continuing treatment. Two patients with stable disease were continuing treatment at 11.5+ and 19.3+ mo. In other RET fusion+ cancers, ORR was 60% (3/5; all confirmed) with partial responses in 2/2 patients with pancreatic cancer (DOR 5.5, 7.4+ mo) and 1 patient with intrahepatic bile duct carcinoma (DOR 7.5 mo). Two patients with colon cancer had stable disease for 7.3 and 9.3 mo. Responses were observed across multiple fusion genotypes. In the entire safety population (all patients treated with 400 mg QD pralsetinib, regardless of diagnosis; n = 354), most treatment-related adverse events (TRAEs) were grade 1-2, and included increased aspartate aminotransferase (31%), anemia (22%), increased alanine aminotransferase (21%), constipation (21%) and hypertension (20%). Only 4% of patients in the safety population discontinued due to TRAEs. Conclusions: Pralsetinib demonstrated broad and durable antitumor activity across multiple advanced solid tumor types, regardless of RET fusion genotype, and was well tolerated. The study is ongoing and still enrolling patients in this cohort. Clinical trial information: NCT03037385.

Activity and tolerability of BLU-667, a highly potent and selective RET inhibitor, in patients with advanced RET-altered thyroid cancers

6018

Background: RET alterations are targetable oncogenic drivers in ~90% of advanced medullary thyroid cancer (MTC) and 20% of papillary thyroid cancer (PTC), yet no selective RET inhibitors are approved. BLU-667 is an investigational highly potent and selective RET inhibitor targeting oncogenic RET alterations including those that confer resistance to multikinase inhibitors (MKIs). We provide an update on the expanded experience of BLU-667 in RET-altered thyroid cancer from the registration-enabling ARROW study (NCT03037385). Methods: ARROW is a global DE (30-600 mg daily [QD or BID]) and dose expansion (DX; 400 mg QD) study in pts with advanced solid tumors. Primary objectives are response rate (ORR; RECIST 1.1) and safety. Results: As of 19Dec2018, 60 pts with RET-mutated MTC (M918T [37], C634R/S/W [8], V804M [4], other/pending [11]) and 5 pts with RET-fusion+ PTC (NCOA4 [3], CCDC6 [2]) received BLU-667 (37 DE, 28 DX). 58% had prior MKI therapy. Among 49 response-evaluable MTC pts, ORR is 47% (95% CI: 33, 62; 2 complete and 21 partial responses (PR); 4 PR pending confirmation; 25 stable disease; 1 progressive disease). 96% (22/23) of responding pts continue treatment; 15 with response duration ≥ 6 months. 2/4 evaluable PTC pts had PR; all 5 enrolled PTC pts continue treatment at 8-11 months. Responses in MTC occur regardless of MKI resistance (prior cabozantinib/vandetanib: ORR 46% (12/26)) or RET genotype (PR in 2/3 evaluable pts with V804M). Disease control rate in MTC pts is 98%. Rapid plasma clearance of RET variants and marked reduction in CEA and calcitonin is observed. Treatment-related toxicity in MTC/PTC pts, generally low-grade and reversible (28% had grade 3 events, no grade 4/5 events, no events requiring discontinuation), includes decreased WBC (23%), increased AST (17%), increased ALT, blood creatinine, and phosphate, hypertension, and decreased neutrophils (all 15%). Conclusions: BLU-667 demonstrates potent, durable and broad antitumor activity and is well tolerated in MTC/PTC pts regardless of MKI resistance and may significantly improve outcomes for pts with RET-altered thyroid cancers. Enrollment of the expansion is ongoing with registrational intent. Clinical trial information: NCT03037385.

Clinical activity and tolerability of BLU-667, a highly potent and selective RET inhibitor, in patients (pts) with advanced RET-fusion+ non-small cell lung cancer (NSCLC)

9008

Background: RET fusions are targetable oncogenic drivers in up to 2% of NSCLC, yet no selective RET inhibitors are approved. BLU-667 is an investigational highly potent and selective RET inhibitor targeting oncogenic RET alterations, including those that confer resistance to multikinase inhibitors (MKIs). We provide an update on the registration-enabling ARROW study (NCT03037385) of BLU-667 in pts with RET-fusion+ NSCLC. Methods: The global ARROW study includes DE (30-600 mg daily [QD or BID]) and dose expansion (DX) at the recommended phase 2 dose (RP2D; 400 mg QD) in pts with advanced solid tumors. Primary objectives are overall response rate (ORR; RECIST 1.1) and safety. Results: As of 19Dec2018, 79 pts (21 DE, 58 DX) with advanced RET fusion+ NSCLC (44 KIF5B, 16 CCDC6, 19 other/pending) received BLU-667. Median number of prior therapies was 2 (range 0-8) and includes chemotherapy (76%), immunotherapy (41%), and MKI (27%). 39% had baseline brain metastases. ORR among 57 response-evaluable pts with measurable disease and at least one follow-up disease assessment was 56% (95% CI: 42, 69; 32 partial responses (PR), 9 PR pending confirmation, 20 stable disease, 5 progressive disease). 91% (29/32) of responding pts remain on treatment; 6 have achieved response duration ≥ 6 months. Disease control rate (DCR) was 91% (52/57). Among 30 pts at the RP2D previously treated with platinum chemotherapy, ORR was 60% (18 PRs; 7 pending confirmation). Responses occur regardless of prior treatment or RET fusion genotypes. Intracranial activity has been observed with shrinkage of brain metastases. 80% of NSCLC pts treated at RP2D remain on treatment and only 3% discontinued due to related adverse event. In NSCLC patients, treatment-related toxicity (TRT), generally low-grade and reversible (28% had ≥ grade 3 events), included increased AST (22%), hypertension (18%), increased ALT (17%), constipation (17%), fatigue (15%) and decreased neutrophils (15%). Conclusions: BLU-667 demonstrated potent, durable and broad antitumor activity and was well tolerated in pts with advanced RET-fusion+ NSCLC. Enrollment of the expansion is ongoing with registrational intent. Clinical trial information: NCT03037385.

A phase 2 study of glembatumumab vedotin, an antibody-drug conjugate targeting glycoprotein NMB, in patients with advanced melanoma

BACKGROUND

Glembatumumab vedotin is an antibody-drug conjugate that produced preliminary clinical activity against advanced melanoma in a phase 1 dose-escalation trial. The objective of the current study was to investigate further the antitumor activity of glembatumumab vedotin at the recommended phase 2 dose in heavily pretreated patients with melanoma.

METHODS

This single-arm, phase 2 study enrolled patients with stage IV melanoma who were refractory to checkpoint inhibition and to B-raf proto-oncogene, serine/threonine kinase (BRAF)/mitogen-activated protein kinase kinase (MEK) inhibition (in the presence of a BRAF valine mutation at codon 600). Patients received 1.9 mg/kg glembatumumab vedotin intravenously every 3 weeks until they developed disease progression or intolerance. The primary endpoint was objective response rate (ORR), which was determined according to Response Evaluation Criteria in Solid Tumors, version 1.1. Secondary endpoints included progression-free survival (PFS), duration of response, overall survival (OS), safety, and clinical efficacy versus tumor glycoprotein NMB (gpNMB) expression. Tumor expression of gpNMB was assessed using immunohistochemistry.

RESULTS

In total, 62 patients received treatment. The ORR was 11% and the median response duration was 6.0 months (95% confidence interval [CI], 4.1 months to not reached). The median PFS was 4.4 months (95% CI, 2.6-5.5 months), and the median OS was 9.0 months (95% CI, 6.1-11.7 months). For patients who developed rash during the first cycle versus those who did not, the ORR was 21% versus 7%, respectively, and there was an overall improvement in PFS (hazard ratio, 0.43; P = .013) and OS (hazard ratio, 0.43; P = .017). The most frequent adverse events were alopecia, neuropathy, rash, fatigue, and neutropenia. With one exception, all evaluable tumors were positive for gpNMB, and 46 of 59 tumors (76%) had 100% gpNMB-positive epithelial cells.

CONCLUSIONS

Glembatumumab vedotin had modest activity and an acceptable safety profile in patients with advanced melanoma who were refractory to checkpoint inhibitors and MEK/BRAF inhibition. Treatment-related rash may be associated with response.

Prevalence and clinical implications of T-cell immunoglobulin mucin type-1 (TIM-1) in multiple tumor types

34

Background: TIM-1 (KIM-1, HAVcr-1) is a type 1 transmembrane glycoprotein. Expression is limited in healthy tissues but upregulated after kidney injury, in ovarian cancer and renal cell carcinoma (RCC). TIM-1 is associated with a more malignant RCC phenotype and immune response regulation. CDX-014, an antibody drug conjugate, contains a fully human IgG1 monoclonal antibody (mAb) conjugated to the potent cytotoxin MMAE. CDX-014 is in a Ph 1/2 trial for RCC (NCT02837991). The prevalence of TIM-1 in other cancers was investigated to explore the broader potential for CDX-014. Methods: Tumors and normal adjacent tissues (NAT) were provided (Mosaic Labs) via IRB-reviewed protocol MOS001 for in vitro analysis of remnant, anonymized human samples. The study included 188 tumors: 30 renal, 45 ovarian, 34 endometrial, 2 cervical, 2 vaginal, 15 bile duct, 15 CRC, 30 NSCLC and 15 thymoma plus 75 NAT. Mosaic performed a validated immunohistochemistry assay on FFPE tissues. A FITC-conjugated, anti-TIM-1 mAb was applied after slide deparaffinization and antigen retrieval. Anti-FITC (Novus Bio), Envision+ HRP and DAB (Dako) were used for visualization. A pathologist scored hematoxylin-counterstained slides for % positive cells and staining intensity. A cut-off of > 2% of cells staining at any intensity was deemed positive. Results: TIM-1 was universally prevalent in renal papillary (14/14) and clear cell carcinoma (CCC [13/13]) plus vaginal CCC (2/2). TIM-1 was also seen in ovarian CCC (12/15; 80%), endometrial CCC (9/21; 43%), adeno NSCLC (2/15; 13%), serous ovarian (1/10; 10%), adeno endometrial (1/13; 8%) and CRC (1/15; 7%). There was no staining in chromophobe RCC (3/3), cervical CCC, endometrioid or mucinous ovarian (10 each), bile duct carcinoma, squamous NSCLC or thymoma. There was minimal to no TIM-1 in NAT except for 7/10 kidney samples (possibly from unappreciated kidney injury). Conclusions: The data suggest that in addition to renal and ovarian cancer, TIM-1 targeted therapy such as CDX-014 warrants exploration in patients with endometrial CCC, vaginal CCC and adeno NCSLC. These results support the ongoing first in human Ph 1/2 study in RCC and potential broader clinical development of CDX-014 in other indications.

Evaluation of the effect of multiple doses of lansoprazole on the pharmacokinetics and safety of ponatinib in healthy subjects

BACKGROUND

In vitro studies have demonstrated that the aqueous solubility of the tyrosine kinase inhibitor ponatinib decreases as pH increases.

OBJECTIVES

The primary aim of this study was to assess the effects of the gastric proton pump inhibitor lansoprazole on the pharmacokinetics of ponatinib. The single-dose safety profile of ponatinib with and without coadministration of lansoprazole was also characterized.

METHODS

This was a phase I, open-label, non-randomized, two-period crossover study in 20 healthy subjects aged 18-55 years. Subjects received a single oral dose of ponatinib 45 mg alone on day 1, an oral dose of lansoprazole 60 mg on day 14, and ponatinib 45 mg plus lansoprazole 60 mg on day 15.

RESULTS

Lansoprazole coadministration resulted in a 1-h increase in the time to maximum plasma concentration (t max) of ponatinib (6 vs. 5 h post-dose; P < 0.001). A corresponding 25 % decrease in the geometric mean maximum plasma concentration (C max) of ponatinib was observed for ponatinib + lansoprazole versus ponatinib alone (40.67 vs. 53.96 ng/mL). Importantly, lansoprazole did not decrease the overall ponatinib systemic exposure as assessed by the ponatinib area under the plasma concentration-time curve from time zero to infinity (AUC∞ 1,153 ng·h/mL for lansoprazole + ponatinib vs. 1,222 ng·h/mL for ponatinib alone). The safety profile was considered acceptable when ponatinib was administered alone or with lansoprazole.

CONCLUSIONS

Although coadministration of lansoprazole led to a modest, albeit statistically significant, reduction in ponatinib C max, overall systemic exposure to ponatinib did not change. The findings suggest that no dose adjustment is necessary when ponatinib is administered with drugs that increase gastric pH.

Evaluation of the effect of multiple doses of rifampin on the pharmacokinetics and safety of ponatinib in healthy subjects

Ponatinib, an oral tyrosine kinase inhibitor with significant activity in heavily pretreated patients with chronic myeloid leukemia, is a CYP3A4 substrate. This open-label, nonrandomized, fixed-order crossover study evaluated the effect of multiple oral doses of rifampin, a strong CYP3A4 inducer, on the pharmacokinetics of ponatinib (45 mg, single dose). Twenty healthy adults received ponatinib on day 1, rifampin 600 mg alone on days 8-13, 15, and 16, and rifampin 600 mg with ponatinib on day 14. Rifampin decreased maximum plasma concentration (Cmax ) and area under the plasma concentration-time curve (AUC) from time zero to time of last measurable concentration (AUC0-t ) and from time zero to infinity (AUC0-∞ ) of ponatinib by 42%, 59%, and 63%, respectively, with no effect on time to Cmax . The limits of the 90% confidence intervals of the estimated geometric mean ratios of ponatinib Cmax , AUC0-t , and AUC0-∞ did not fall within the 80-125% margins for equivalence, suggesting a statistically significant interaction. Coadministration of ponatinib with strong CYP3A4 inducers should be avoided unless the benefit outweighs the possible risk of ponatinib underexposure, because the safety of ponatinib dose increases has not been studied in this context.

A phase II trial of a multi-agent oral antiangiogenic (metronomic) regimen in children with recurrent or progressive cancer

BACKGROUND

Preclinical models show that an antiangiogenic regimen at low-dose daily (metronomic) dosing may be effective against chemotherapy-resistant tumors. We undertook a prospective, open-label, single-arm, multi-institutional phase II study to evaluate the efficacy of a "5-drug" oral regimen in children with recurrent or progressive cancer.

PROCEDURE

Patients ≤21 years old with recurrent or progressive tumors were eligible. Treatment consisted of continuous oral celecoxib, thalidomide, and fenofibrate, with alternating 21-day cycles of low-dose cyclophosphamide and etoposide. Primary endpoint was to assess, within eight disease strata, activity of the 5-drug regimen over 27 weeks. Blood and urine angiogenesis markers were assessed.

RESULTS

One hundred one patients were enrolled; 97 began treatment. Median age was 10 years (range: 191 days-21 years); 47 (49%) were female. Disease strata included high-grade glioma (HGG, 21 patients), ependymoma (19), low-grade glioma (LGG, 12), bone tumors (12), medulloblastoma/primitive neuroectodermal tumor (PNET, 8), leukemia (4), neuroblastoma (3), and miscellaneous tumors (18). Treatment was generally well tolerated; most common toxicities were hematologic. Twenty-four (25%) patients completed 27 weeks therapy without progression, including HGG: 1 (5%), ependymoma: 7 (37%), LGG: 7 (58%), medulloblastoma/PNET: 1, neuroblastoma: 1, and miscellaneous tumors: 7 (39%). Best response was complete response (one patient with medulloblastoma), partial response (12), stable disease (36), progressive disease (47), and inevaluable (1). Baseline serum thrombospondin levels were significantly higher in patients successfully completing therapy than in those who progressed (P = 0.009).

CONCLUSION

The 5-drug regimen was well tolerated. Clinical activity was demonstrated in some but not all tumor strata.

A phase 2 trial of ponatinib in Philadelphia chromosome-positive leukemias

BACKGROUND

Ponatinib is a potent oral tyrosine kinase inhibitor of unmutated and mutated BCR-ABL, including BCR-ABL with the tyrosine kinase inhibitor-refractory threonine-to-isoleucine mutation at position 315 (T315I). We conducted a phase 2 trial of ponatinib in patients with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL).

METHODS

We enrolled 449 heavily pretreated patients who had CML or Ph-positive ALL with resistance to or unacceptable side effects from dasatinib or nilotinib or who had the BCR-ABL T315I mutation. Ponatinib was administered at an initial dose of 45 mg once daily. The median follow-up was 15 months.

RESULTS

Among 267 patients with chronic-phase CML, 56% had a major cytogenetic response (51% of patients with resistance to or unacceptable side effects from dasatinib or nilotinib and 70% of patients with the T315I mutation), 46% had a complete cytogenetic response (40% and 66% in the two subgroups, respectively), and 34% had a major molecular response (27% and 56% in the two subgroups, respectively). Responses were observed regardless of the baseline BCR-ABL kinase domain mutation status and were durable; the estimated rate of a sustained major cytogenetic response of at least 12 months was 91%. No single BCR-ABL mutation conferring resistance to ponatinib was detected. Among 83 patients with accelerated-phase CML, 55% had a major hematologic response and 39% had a major cytogenetic response. Among 62 patients with blast-phase CML, 31% had a major hematologic response and 23% had a major cytogenetic response. Among 32 patients with Ph-positive ALL, 41% had a major hematologic response and 47% had a major cytogenetic response. Common adverse events were thrombocytopenia (in 37% of patients), rash (in 34%), dry skin (in 32%), and abdominal pain (in 22%). Serious arterial thrombotic events were observed in 9% of patients; these events were considered to be treatment-related in 3%. A total of 12% of patients discontinued treatment because of an adverse event.

CONCLUSIONS

Ponatinib had significant antileukemic activity across categories of disease stage and mutation status. (Funded by Ariad Pharmaceuticals and others; PACE ClinicalTrials.gov number, NCT01207440 .).

EPIC: A phase III randomized, open-label study of ponatinib versus imatinib in adult patients with newly diagnosed chronic myeloid leukemia in chronic phase

TPS7129

Background: The hallmark genetic abnormality of chronic myeloid leukemia (CML), known as the Philadelphia chromosome, generates the BCR-ABL fusion gene; expression of BCR-ABL in hematopoietic stem cells gives rise to CML. Ponatinib is a potent oral pan–BCR-ABL tyrosine kinase inhibitor (TKI) that is active against native and mutated forms of BCR-ABL, including the T315I gatekeeper mutant. Results from the phase 1 and phase 2 studies of ponatinib demonstrated that ponatinib is generally well tolerated and has substantial anti-leukemic activity in patients with CML who are resistant or intolerant to prior TKI therapy, regardless of baseline mutation status. In addition, multivariate analyses suggest that ponatinib has greater activity in younger patients who are less heavily pretreated and have a shorter time since diagnosis. The phase 3 EPIC (Evaluation of Ponatinib vs Imatinib in CML) study is testing the hypothesis that ponatinib is an effective treatment for newly diagnosed chronic phase (CP) CML patients when compared with standard imatinib therapy. Methods: EPIC is a multicenter, international, phase 3, two-arm, open-label trial of ponatinib (45 mg once daily) versus imatinib (400 mg once daily) in patients with newly diagnosed CP-CML. Patients ≥18 years of age with CP-CML (diagnosed within 6 months prior to study entry) and adequate renal, hepatic, and pancreatic function are eligible for enrollment. Enrolled patients are assigned to receive ponatinib or imatinib in a 1:1 fashion, stratified by Sokal Risk score (low vs intermediate vs high). The primary efficacy endpoint for this trial is major molecular response (MMR) rate at 12 months. Secondary endpoints include MMR rate at 5 years, BCR-ABLIS<10% rate at 3 months, CCyR rate at 12 months, progression-free survival, overall survival, and safety. A sample size consisting of 480 patients will provide 90% power to detect a 15% absolute increase in MMR rate at 12 months using an unstratified Fisher exact 2-sided test at an alpha level of 0.05. Assuming a 10% dropout rate, approximately 528 patients will be enrolled. The first patient was enrolled in August 2012. Clinical trial information: NCT01650805.

Safety and durability of ponatinib in patients with Philadelphia chromosome-positive (Ph+) leukemia: Long-term follow-up of an ongoing phase I study

7063

Background: Ponatinib is a potent oral pan–BCR-ABL tyrosine kinase inhibitor (TKI) that is active against native and mutated forms of BCR-ABL. The safety and anti-leukemic activity of ponatinib in patients (pts) with chronic myeloid leukemia (CML) or Ph+ acute lymphoblastic leukemia (ALL) were evaluated in a phase I clinical trial. Methods: Pts (N=81) with resistant/refractory hematologic malignancies were enrolled in this ongoing, open-label, dose escalation, phase I study. Ponatinib was dosed once daily (2–60 mg). 65 pts had Ph+ leukemia and are included in the present analysis (data as of 9 Nov 2012). Median follow-up was 25 (0.5–44) mos. Results: The median age of pts was 55 yrs; median time since diagnosis was 6.5 yrs. Pts were heavily pretreated (94% had received ≥2 prior TKIs, 62% ≥3). 65% had baseline BCR-ABL mutations. 46% (67% chronic phase [CP] CML) of pts remained on study. Progression and adverse events (AEs) were the most common reasons for discontinuation (17% each). The most common treatment-related AEs were rash (42%), thrombocytopenia (34%), arthralgia (20%), and increased lipase (20%). Significant anti-leukemic activity was observed (Table). Responses (major cytogenetic response [MCyR] for CP-CML or major hematologic response [MaHR] for accelerated phase [AP] CML, blast phase [BP] CML, or Ph+ ALL) were observed against the following mutations detected in >1 pt at baseline: 14/19 T315I, 4/7 F317L, 2/4 G250E, 2/2 M244V, 2/2 M35IT, and 1/2 F359V. Among CP-CML pts, 73% with complete cytogenetic response (CCyR) and 63% with major molecular response (MMR) are estimated to maintain response at 2 yrs (Kaplan-Meier). Of 28 CP-CML pts with CCyR, 25 remained on study (19 with continuous CCyR); of 22 pts with MMR, 21 remained on study (15 with continuous MMR). Updated data will be presented. Conclusions: Significant and durable responses were observed in heavily pretreated CP-CML pts, regardless of mutation status, and ponatinib was generally well tolerated. Clinical trial information: NCT00660920. [Table: see text]

Impact of baseline mutations on response to ponatinib and end of treatment mutation analysis in patients with chronic myeloid leukemia

7001

Background: BCR-ABL kinase domain mutations frequently cause tyrosine kinase inhibitor (TKI) failure in chronic myeloid leukemia (CML). Ponatinib, a potent oral pan-BCR-ABL TKI, has shown preclinical activity against all single mutants tested, including T315I. The impact of baseline (BL) mutations on response to ponatinib (45 mg once daily) and end of treatment (EOT) mutations in pts discontinuing treatment were evaluated in the phase II PACE trial. Methods: Heavily pretreated chronic phase (CP) CML pts (93% received ≥2 prior TKIs, 60% ≥3) resistant or intolerant to dasatinib or nilotinib (N=203) or with T315I confirmed at BL (N=64) were enrolled. The primary endpt was major cytogenetic response (MCyR). Min follow up at analysis (9 Nov 2012) was 12 mos (median 15 [0.1-25]). Sanger sequencing was done at one central laboratory. Results: At BL, no mutations were detected in 51% of pts, 1 mutation in 39%, and ≥2 mutations in 10%; 26 unique mutations were observed. Responses were observed regardless of BL mutation status. MCyR rates were: 56% overall, 49% in pts with no mutations, 64% 1 mutation, 62% ≥2 mutations; 57% in pts with mutation(s) other than T315I, 74% T315I only, 57% T315I + other mutation(s). Responses were seen against each of the 15 mutations present in >1 pt at BL, including T315I, E255V, F359V, Y253H. 99 pts discontinued, 56 had EOT mutations assessed. 5 pts lost a mutation, 46 had no change, 5 gained mutations (Table). 11 pts lost MCyR (none with T315I); of the 6 discontinuing, 4 had EOT mutations assessed and no changes from BL were seen. Conclusions: Responses to ponatinib were observed regardless of BL mutation status. No single mutation conferring resistance to ponatinib in CP-CML has been observed to date. Data with a minimum follow up of 18 mos, including pts with advanced disease, will be presented. Clinical trial information: NCT01207440. [Table: see text]

Analysis of the potential effect of ponatinib on the QTc interval in patients with refractory hematological malignancies

Purpose

Cardiac dysfunction, particularly QT interval prolongation, has been observed with tyrosine kinase inhibitors approved to treat chronic myeloid leukemia. This study examines the effects of ponatinib on cardiac repolarization in patients with refractory hematological malignancies enrolled in a phase 1 trial.

Methods

Electrocardiograms (ECGs) were collected at 3 dose levels (30, 45, and 60 mg) at 6 time points. Electrocardiographic parameters, including QTc interval, were measured, and 11 morphological analyses were conducted. Central tendency analyses of ECG parameters were performed using time-point and time-averaged approaches. All patients with at least 2 baseline ECGs and 1 on-treatment ECG were included in the analyses. Patients with paired ECGs and plasma samples were included in the pharmacokinetic/pharmacodynamic analysis to examine the relationship between ponatinib plasma concentration and change from baseline in QT intervals.

Results

Thirty-nine patients at the 30-, 45-, and 60-mg dose levels were included in the central tendency and morphological analyses. There was no significant effect on cardiac repolarization, as evidenced by non-clinically significant mean QTcF changes from baseline of −10.9, −3.6, and −5.0 ms for the 30-, 45-, and 60-mg dose levels, respectively. The morphological analysis revealed 2 patients with atrial fibrillation and 2 with T wave inversion. Seventy-five patients were included in the pharmacokinetic/pharmacodynamic analysis across all dose levels. The slope of the relationship for QTcF versus plasma ponatinib concentration was not positive (−0.0171), indicating no exposure–effect relationship.

Conclusions

Ponatinib is associated with a low risk of QTc prolongation in patients with refractory hematological malignancies.

Ponatinib in refractory Philadelphia chromosome-positive leukemias

BACKGROUND

Resistance to tyrosine kinase inhibitors in patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) is frequently caused by mutations in the BCR-ABL kinase domain. Ponatinib (AP24534) is a potent oral tyrosine kinase inhibitor that blocks native and mutated BCR-ABL, including the gatekeeper mutant T315I, which is uniformly resistant to tyrosine kinase inhibitors.

METHODS

In this phase 1 dose-escalation study, we enrolled 81 patients with resistant hematologic cancers, including 60 with CML and 5 with Ph-positive ALL. Ponatinib was administered once daily at doses ranging from 2 to 60 mg. Median follow-up was 56 weeks (range, 2 to 140).

RESULTS

Dose-limiting toxic effects included elevated lipase or amylase levels and pancreatitis. Common adverse events were rash, myelosuppression, and constitutional symptoms. Among Ph-positive patients, 91% had received two or more approved tyrosine kinase inhibitors, and 51% had received all three approved tyrosine kinase inhibitors. Of 43 patients with chronic-phase CML, 98% had a complete hematologic response, 72% had a major cytogenetic response, and 44% had a major molecular response. Of 12 patients who had chronic-phase CML with the T315I mutation, 100% had a complete hematologic response and 92% had a major cytogenetic response. Of 13 patients with chronic-phase CML without detectable mutations, 100% had a complete hematologic response and 62% had a major cytogenetic response. Responses among patients with chronic-phase CML were durable. Of 22 patients with accelerated-phase or blast-phase CML or Ph-positive ALL, 36% had a major hematologic response and 32% had a major cytogenetic response.

CONCLUSIONS

Ponatinib was highly active in heavily pretreated patients with Ph-positive leukemias with resistance to tyrosine kinase inhibitors, including patients with the BCR-ABL T315I mutation, other mutations, or no mutations. (Funded by Ariad Pharmaceuticals and others; ClinicalTrials.gov number, NCT00660920.).

Alleviating monoterpene toxicity using a two-phase extractive fermentation for the bioproduction of jet fuel mixtures in Saccharomyces cerevisiae

Monoterpenes are a diverse class of compounds with applications as flavors and fragrances, pharmaceuticals and more recently, jet fuels. Engineering biosynthetic pathways for monoterpene production in microbial hosts has received increasing attention. However, monoterpenes are highly toxic to many microorganisms including Saccharomyces cerevisiae, a widely used industrial biocatalyst. In this work, the minimum inhibitory concentration (MIC) for S. cerevisiae was determined for five monoterpenes: β-pinene, limonene, myrcene, γ-terpinene, and terpinolene (1.52, 0.44, 2.12, 0.70, 0.53 mM, respectively). Given the low MIC for all compounds tested, a liquid two-phase solvent extraction system to alleviate toxicity during fermentation was evaluated. Ten solvents were tested for biocompatibility, monoterpene distribution, phase separation, and price. The solvents dioctyl phthalate, dibutyl phthalate, isopropyl myristate, and farnesene showed greater than 100-fold increase in the MIC compared to the monoterpenes in a solvent-free system. In particular, the MIC for limonene in dibutyl phthalate showed a 702-fold (308 mM, 42.1 g L(-1) of limonene) improvement while cell viability was maintained above 90%, demonstrating that extractive fermentation is a suitable tool for the reduction of monoterpene toxicity. Finally, we estimated that a limonane to farnesane ratio of 1:9 has physicochemical properties similar to traditional Jet-A aviation fuel. Since farnesene is currently produced in S. cerevisiae, its use as a co-product and extractant for microbial terpene-based jet fuel production in a two-phase system offers an attractive bioprocessing option.

PACE: A pivotal phase II trial of ponatinib in patients with CML and Ph+ALL resistant or intolerant to dasatinib or nilotinib, or with the T315I mutation

6503

Background: Ponatinib is a potent, oral, pan-BCR-ABL inhibitor active against the native enzyme and all tested resistant mutants, including the uniformly resistant T315I mutation. Methods: The PACE (Ponatinib Ph+ALL and CML Evaluation) trial started Sept 2010. Pts with refractory CML (CP, AP or BP) or Ph+ALL resistant or intolerant (R/I) to dasatinib or nilotinib or with T315I received 45 mg ponatinib once daily. The trial is ongoing; enrollment completed Sept 2011. Data as of 17 Jan 2012 are reported. Results: 449 pts were enrolled, 5 of whom were ineligible (post-imatinib, non-T315I) but treated. Median age was 59 (18-94) yrs; 53% male. Diagnoses were: 271 CP-CML (R/I=207; T315I=64); 79 AP-CML (R/I=60; T315I=19); 94 BP/ALL (R/I=48; T315I=46). Median time from diagnosis to ponatinib was 6 yrs. Prior TKIs included imatinib (96%), dasatinib (85%), nilotinib (66%), bosutinib (7%); 94% failed ≥2 prior TKIs, 59% failed ≥3 prior TKIs. 83% had a history of resistance to dasatinib or nilotinib; 12% were purely intolerant. In CP, best response to most recent dasatinib or nilotinib was MCyR 25%. Frequent mutations confirmed at entry: 29% T315I, 8% F317L, 4% E255K, 4 % F359V, 3% G250E. Median follow-up was 6.6 months. Response rates are presented in the table. Overall, 64% remained on therapy (77% CP). Most frequent reasons for discontinuation were progression (12%) and AE (10%). Most common drug‑related AEs were thrombocytopenia (33%), rash (33%), dry skin (26%). Conclusions: Ponatinib has substantial activity in heavily pretreated pts and those with refractory T315I. Response rates continue to improve with longer follow-up. Multivariate analyses of predictors of outcome will be presented. [Table: see text]

Late effects of therapy for pediatric brain tumor survivors

Approximately 2 of every 3 of all pediatric patients with brain tumors will be long-term survivors. However, there is a steep cost for pediatric brain tumor survivors, and the group as a whole faces significantly more late effects than many other survivors of pediatric cancers. Most of these effects can be attributed to direct neurologic damage to the developing brain caused by the tumor and its removal, the long-term toxicity of chemotherapy, or the effects of irradiation on the central nervous system. The late effects experienced by childhood brain tumor survivors involve multiple domains. This article will review the significant late effects that occur within the medical, neurocognitive, psychosocial, and economic domains of the survivorship experience. We conclude by discussing how the late effects in different domains often coexist and can create a complex set of obstacles that pose significant challenges for a survivor of a pediatric brain tumor on a daily basis.

Medical, psychological, cognitive and educational late-effects in pediatric low-grade glioma survivors treated with surgery only

BACKGROUND

Surgical resection is often the only treatment necessary for pediatric low-grade gliomas (LGGs) and is thought to define a population with an excellent long-term prognosis. The goal of this study was to describe the multidimensional late-effects of pediatric LGG survivors treated exclusively with surgery.

METHODS

A retrospective chart review of "surgery-only" LGG survivors followed at Dana-Farber/Children's Hospital Cancer Care was undertaken. Patients had to be diagnosed with an LGG before the age of 22 years, treated with "surgery-only" and be at least 2 years from diagnosis.

RESULTS

Sixty survivors were eligible with a median age at the time of review of 16.3 years and the median time since diagnosis of 8.4 years. Tumor locations were predominantly posterior fossa (47%) or cortical (33%). Eighty-five percent of patients had at least one ongoing late-effect, and 28% had three or more. The most common late-effects consisted of motor dysfunction (43%), visual problems (32%), anxiety (19%), social difficulties (19%), seizure disorders (17%), depression (15%), poor coordination/ataxia (14%), behavioral problems (13%), and endocrinopathies (10%). Nine patients had a history of suicidal ideation; two with suicide attempts. The mean full-scale IQ was normal, however, the number of survivors scoring one standard deviation below the mean was twice the expected number. Special education services were utilized by more than half of the survivors.

CONCLUSIONS

"Surgery-only" LGG survivors may be more affected by their tumor and its resection than previously appreciated. A prospective study is needed to address this survivor population.

Intensive multimodality treatment for children with newly diagnosed CNS atypical teratoid rhabdoid tumor

PURPOSE

Atypical teratoid rhabdoid tumor (ATRT) of the CNS is a highly malignant neoplasm primarily affecting young children, with a historic median survival ranging from 6 to 11 months. Based on a previous pilot series, a prospective multi-institutional trial was conducted for patients with newly diagnosed CNS ATRT.

PATIENTS AND METHODS

Treatment was divided into five phases: preirradiation, chemoradiation, consolidation, maintenance, and continuation therapy. Intrathecal chemotherapy was administered, alternating intralumbar and intraventricular routes. Radiation therapy (RT) was prescribed, either focal (54 Gy) or craniospinal (36 Gy, plus primary boost), depending on age and extent of disease at diagnosis.

RESULTS

Between 2004 and 2006, 25 patients were enrolled; 20 were eligible for evaluation. Median age at diagnosis was 26 months (range, 2.4 months to 19.5 years). Gross total resection of the primary tumor was achieved in 11 patients. Fourteen patients had M0 disease at diagnosis, one patient had M2 disease, and five patients had M3 disease. Fifteen patients received radiation therapy: 11 focal and four craniospinal. Significant toxicities, in addition to the expected, included radiation recall (n = 2) and transverse myelitis (n = 1). There was one toxic death. Of the 12 patients who were assessable for chemotherapeutic response (pre-RT), the objective response rate was 58%. The objective response rate observed after RT was 38%. The 2-year progression-free and overall survival rates are 53% +/- 13% and 70% +/- 10%, respectively. Median overall survival has not yet been reached.

CONCLUSION

This intensive multimodality regimen has resulted in a significant improvement in time to progression and overall survival for patients with this previously poor-prognosis tumor.

Phase I trial of VNP40101M (Cloretazine) in children with recurrent brain tumors: a pediatric brain tumor consortium study

PURPOSE

VNP40101M (Cloretazine), a novel DNA alkylating agent, was evaluated in a phase I study in children with recurrent brain tumors.

EXPERIMENTAL DESIGN

VNP40101M was given i.v. daily for 5 consecutive days every 6 weeks for up to eight cycles. Dose escalation was done independently in patients stratified based on intensity of prior therapy (moderately pretreated, stratum I; heavily pretreated, stratum II). Correlative studies included pharmacokinetics and measurement of O(6)-alkylguanine-DNA alkyl transferase levels in peripheral blood mononuclear cells before and after treatment.

RESULTS

Forty-one eligible patients (stratum I, 19; stratum II, 22) were enrolled on this study. The dose-limiting toxicity in 35 evaluable patients was myelosuppression, which occurred in 4 of 16 patients in stratum I and 3 of 19 patients in stratum II. Pharmacokinetic studies showed a median terminal half-life of 30 min (range, 14-39.5). The maximum tolerated dose in stratum I and II were 45 and 30 mg/m(2)/d daily for 5 days every 6 weeks, respectively. Peripheral blood mononuclear cells alkylguanine alkyl transferase levels did not decrease significantly after VNP40101M treatment. Central imaging review confirmed that three patients had stable disease for a median of 45 weeks (range, 37-61+) after therapy.

CONCLUSIONS

The recommended dose of VNP40101M for phase II studies in children with brain tumors is 45 mg/m(2)/d in moderately pretreated and 30 mg/m(2)/d in heavily pretreated patients when administered for 5 consecutive days every 6 weeks.

A novel TP53 germline mutation in a family with a history of multiple malignancies: case report and review of the literature

OBJECTIVE

Choroid plexus carcinoma (CPC) has been associated with TP53 germline mutations and Li-Fraumeni syndrome (LFS). We describe our finding of a novel germline mutation in the TP53 gene in a family with multiple malignancies and in association with a child presenting with CPC.

METHOD

An 8-month-old male presented with seizure-like activity; imaging disclosed a 1.5-cm left ventricular mass confirmed to be CPC intra- and postoperatively. Family history was significant for a half-sister who died of a primary CNS sarcoma and a paternal grandmother negative for BRCA1, BRCA2, MLH1, and MSH2 mutations with multiple (>6) LFS spectrum malignancies.

RESULTS

Familial TP53 testing revealed an A-->T substitution at DNA position 13071, creating a deleterious Asn-->Ile substitution at amino acid 131 in exon 5.

CONCLUSION

Physicians treating patients with CPC should be attuned to reviewing family history for risk factors suggestive of genetic cancer syndromes such as LFS. These syndromes markedly influence both the patient and family members and may alter postoperative treatment regimens.

Phase I and pharmacokinetic study of the oral farnesyltransferase inhibitor lonafarnib administered twice daily to pediatric patients with advanced central nervous system tumors using a modified continuous reassessment method: a Pediatric Brain Tumor Consortium Study

PURPOSE

A dose-escalation phase I and pharmacokinetic study of the farnesyltransferase inhibitor lonafarnib (SCH66336) was conducted in children with recurrent or progressive CNS tumors. Primary objectives were to estimate the maximum-tolerated dose (MTD) and to describe the dose-limiting toxicities (DLTs) and pharmacokinetics of lonafarnib. Farnesylation inhibition of HDJ-2 in peripheral blood was also measured.

PATIENTS AND METHODS

Lonafarnib was administered orally twice daily at dose levels of 70, 90, 115, 150, and 200 mg/m2/dose bid. A modified continual reassessment method (CRM) was used to estimate the MTD based on actual dosages of lonafarnib administered and toxicities observed during the initial 4 weeks of treatment.

RESULTS

Fifty-three children with progressive or recurrent brain tumors were enrolled, with a median age of 12.2 years (range, 3.9 to 19.5 years). Dose-limiting pneumonitis or myelosuppression was observed in three of three patients at the 200 mg/m2/dose level. A relatively constant DLT rate at the 70, 90, and 115 mg/m2/dose levels resulted in a recommended phase II dose of 115 mg/m2/dose. Significant diarrhea did not occur with prophylactic loperamide. Both radiographic response (one anaplastic astrocytoma) and stable disease (one medulloblastoma, two high-grade and four low-grade gliomas, one ependymoma, and one sarcoma) were noted, and seven patients remained on treatment for 1 year or longer.

CONCLUSION

Although the estimated MTD by the CRM model was 98.5 mg/m2/dose, because of the relatively constant observed DLT rate at the lower four dose levels, the recommended phase II dose of lonafarnib is 115 mg/m2/dose administered twice daily by mouth with concurrent loperamide.

Moyamoya following cranial irradiation for primary brain tumors in children

OBJECTIVE

To study the risk factors for the development of moyamoya syndrome after cranial irradiation for primary brain tumors in children.

METHODS

We reviewed neuroimaging studies and dosimetry data for 456 children who were treated with radiation for a primary brain tumor and who were prospectively evaluated with serial neuroimaging studies and neurologic evaluations. A total of 345 patients had both adequate neuroimaging and radiation dosimetry data for further analysis. We used survival analysis techniques to examine the relationship of clinically important variables as risk factors for the development of moyamoya over time.

RESULTS

Overall, 12 patients (3.5%) developed evidence of moyamoya. The onset of moyamoya was more rapid for patients with neurofibromatosis type 1 (NF1) (median of 38 vs 55 months) and for patients who received >5,000 cGy of radiation (median of 42 vs 67 months). In a multiple Cox proportional hazards regression analysis controlling for age at start of radiation, each 100-cGy increase in radiation dose increased the rate of moyamoya by 7% (hazard ratio [HR] = 1.07, 95% CI: 1.02 to 1.13, p = 0.01) and the presence of NF1 increased the rate of moyamoya threefold (HR = 3.07, 95% CI: 0.90 to 10.46, p = 0.07).

CONCLUSIONS

Moyamoya syndrome is a potentially serious complication of cranial irradiation in children, particularly for those patients with tumors in close proximity to the circle of Willis, such as optic pathway glioma. Patients who received higher doses of radiation to the circle of Willis and with neurofibromatosis type 1 have increased risk of the development of moyamoya syndrome.

Extracranial metastases of glioblastoma in a child: case report and review of the literature

Glioblastoma (GBM) is the most common adult malignant brain tumor but is notably less common in children. Primary brain tumors rarely metastasize outside the central nervous system and when metastases occur, it is often in patients with diversionary shunting of the cerebrospinal fluid. This report details the case of a 13(1/2)-year-old boy who was diagnosed with GBM. He survived 10 months after diagnosis. At autopsy, the tumor was found to extensively infiltrate the leptomeninges as well as the cranial skin and soft tissue. Further examination disclosed multiple liver and lung metastatic GBM nodules. This pattern of spread is very uncharacteristic of gliomas and emphasizes the importance of adequate metastatic evaluation.

Phase II study of thalidomide and radiation in children with newly diagnosed brain stem gliomas and glioblastoma multiforme

A phase II study was conducted to assess the efficacy of administering daily thalidomide concomitantly with radiation and continuing for up to 1 year following radiation in children with brain stem gliomas (BSG) or glioblastoma multiforme (GBM). Secondary objectives were to obtain preliminary evidence of biologic activity of thalidomide and to evaluate toxicities from chronic administration of thalidomide in this population. Thirteen patients (2-14 years old) with newly diagnosed BSG (12 patients) or GBM (one patient) were enrolled between July 1999 and June 2000. All patients received focal radiotherapy to a total dose of 5,580 cGy. Thalidomide was administered once daily beginning on the first day of radiation and continued for 12 months or until the patient came off study. The starting dose was 12 mg/kg (rounded down to the nearest 50 mg) and was increased by 20% weekly, if tolerated, to 24 mg/kg or 1,000 mg (whichever was lower). Advanced imaging techniques and urine and serum analysis for anti-angiogenic markers were performed in some patients in an attempt to correlate changes with clinical effect of therapy. No patients completed the planned 12 months of thalidomide therapy and all have since died of disease progression. The median duration of therapy was 5 months (range 2-11 months). Nine patients came off study for progressive disease (PD), three patients due to toxicity and one patient withdrew consent. Several patients on this study required more extended courses of high dose steroids than would have been otherwise expected for this population due to significant peritumoral edema and necrosis. No consistent pattern emerged from the biologic correlative studies from 11 patients. However, advanced imaging with techniques such as MR spectroscopy, MR perfusion and 18-fluorodeoxyglucose positron emission tomography (FDG-PET) were helpful in distinguishing growing tumor from treatment effect and necrosis in some patients. The median time to progression (TTP) was 5 months (range 2-11 months) and the median time to death (TTD) was 9 months (range 5-17 months). In this small patient sample adding thalidomide to radiation did not improve TTP or TTD from historical controls, however, toxicity appeared to be increased.

Transverse myelitis after therapy for primitive neuroectodermal tumors

Traditional therapy for malignant primitive neuroectodermal tumors in children includes surgery, multi-agent chemotherapy, and radiation. Given the poor prognosis with conventional therapy alone, newer treatment approaches have incorporated high-dose chemotherapy followed by autologous stem cell rescue. Treatment with chemotherapy and radiation is not without unanticipated and unwanted side effects. Specifically, radiation-induced damage to the central nervous system can occur, though the frequency is thought to be acceptably low. This report describes two cases of treatment-related transverse myelitis in patients who received induction chemotherapy and craniospinal irradiation followed by high-dose chemotherapy with autologous stem cell rescue. Other patients treated with a similar strategy but different sequence and timing of treatment did not experience symptoms of myelitis, suggesting that the specific timing of radiation in relationship to the chemotherapy may be of critical importance.

A feasibility trial of antiangiogenic (metronomic) chemotherapy in pediatric patients with recurrent or progressive cancer

Standard chemotherapeutic drugs, when modified by the frequency and dose of administration, can target angiogenesis. This approach is referred to as antiangiogenic chemotherapy, low-dose chemotherapy, or metronomic chemotherapy. This study evaluated the feasibility of 6 months of metronomic chemotherapy, its toxicity and tolerability, surrogate markers of activity, and preliminary evidence of activity in children with recurrent or progressive cancer. Twenty consecutive children were enrolled and received continuous oral thalidomide and celecoxib with alternating oral etoposide and cyclophosphamide every 21 days for a planned duration of 6 months using antiangiogenic doses of all four drugs. Surrogate markers including bFGF, VEGF, endostatin, and thrombospondin were also evaluated. Therapy was well tolerated in this heavily pretreated population. Toxicities (predominantly reversible bone marrow suppression) responded to dose modifications. Sixty percent of the patients received less than the prescribed 6 months of therapy due to toxicity (one case of deep vein thrombosis), personal choice (1 patient), or disease progression (10 patients). Forty percent of the patients completed the 6 months of therapy, resulting in prolonged or persistent disease-free status. One quarter of all patients continue to be progression free more than 123 weeks from starting therapy. Sixteen percent of patients showed a radiographic partial response. Only elevated thrombospondin-1 levels appeared to correlate with prolonged response. This oral antiangiogenic chemotherapy regimen was well tolerated in this heavily pretreated pediatric population, which showed prolonged or persistent disease-free status, supporting the continued study of antiangiogenic/metronomic chemotherapy in human clinical trials.

Continuous remission of newly diagnosed and relapsed central nervous system atypical teratoid/rhabdoid tumor

Atypical teratoid/rhabdoid tumors (AT/RT) are highly malignant lesions of childhood that carry a very poor prognosis. AT/RT can occur in the central nervous system (CNS AT/RT) and disease in this location carries an even worse prognosis with a median survival of 7 months. In spite of multiple treatment regimens consisting of maximal surgical resection (including second look surgery), radiation therapy (focal and craniospinal), and multi-agent intravenous, oral and intrathecal chemotherapy, with or without high-dose therapy and stem cell rescue, only seven long-term survivors of CNS AT/RT have been reported, all in patients with newly diagnosed disease. For this reason, many centers now direct such patients, particularly those under 5 years of age, or those with recurrent disease, towards comfort care rather than attempt curative therapy. We now report on four children, two with newly diagnosed CNS AT/RT and two with progressive disease after multi-agent chemotherapy who are long term survivors (median follow-up of 37 months) using a combination of surgery, radiation therapy, and intensive chemotherapy. The chemotherapy component was modified from the Intergroup Rhabdomyosarcoma Study Group (IRS III) parameningeal protocol as three of the seven reported survivors in the literature were treated using this type of therapy. Our four patients, when added to the three reported survivors in the literature using this approach, suggest that patients provided this aggressive therapy can significantly alter the course of their disease. More importantly, we report on the first two survivors after relapse with multi-agent intravenous and intrathecal chemotherapy treated with this modified regimen.

Chemotherapy for progressive low-grade gliomas in children older than ten years: the Dana-Farber experience

The purpose of this retrospective study was to examine the clinical and radiographic response rates to and toxicity of chemotherapy for low-grade gliomas in children older than 10 years of age. Between June 1999 and January 2001, seven consecutive children between the ages of 10 and 18 were treated with vincristine and carboplatin +/- thioguanine, procarbazine, CCNU [lomustine], and vincristine (TPCV) for progressive low-grade gliomas. All 7 children completed a 10-week induction course of vincristine and carboplatin; 3 were switched to TPCV during the maintenance phase of therapy after developing an allergic reaction to carboplatin. Overall, 4 patients had a radiographic response to treatment with chemotherapy (3 partial responses and 1 minor response: objective response rate of 57%), and 2 more showed stable disease. One patient progressed while on treatment and 1 patient progressed off treatment, and after 31 months had elapsed. The resulting progression-free survival at the time of this report was 71%. The median duration of follow-up was 32 months (range 25-42 months). Hematologic toxicity was common, but did not result in cessation of therapy. No other significant treatment-related toxicities were observed. The results suggest that the clinical response/disease stabilization rate in children older than 10 years of age does not differ markedly from that observed in younger children. A prospective clinical trial of chemotherapy for progressive low-grade gliomas in children older than 10 years is therefore warranted.