PIK3CA mutations frequently coexist with RAS and BRAF mutations in patients with advanced cancers

BACKGROUND

Oncogenic mutations of PIK3CA, RAS (KRAS, NRAS), and BRAF have been identified in various malignancies, and activate the PI3K/AKT/mTOR and RAS/RAF/MEK pathways, respectively. Both pathways are critical drivers of tumorigenesis.

METHODS

Tumor tissues from 504 patients with diverse cancers referred to the Clinical Center for Targeted Therapy at MD Anderson Cancer Center starting in October 2008 were analyzed for PIK3CA, RAS (KRAS, NRAS), and BRAF mutations using polymerase chain reaction-based DNA sequencing.

RESULTS

PIK3CA mutations were found in 54 (11%) of 504 patients tested; KRAS in 69 (19%) of 367; NRAS in 19 (8%) of 225; and BRAF in 31 (9%) of 361 patients. PIK3CA mutations were most frequent in squamous cervical (5/14, 36%), uterine (7/28, 25%), breast (6/29, 21%), and colorectal cancers (18/105, 17%); KRAS in pancreatic (5/9, 56%), colorectal (49/97, 51%), and uterine cancers (3/20, 15%); NRAS in melanoma (12/40, 30%), and uterine cancer (2/11, 18%); BRAF in melanoma (23/52, 44%), and colorectal cancer (5/88, 6%). Regardless of histology, KRAS mutations were found in 38% of patients with PIK3CA mutations compared to 16% of patients with wild-type (wt)PIK3CA (p = 0.001). In total, RAS (KRAS, NRAS) or BRAF mutations were found in 47% of patients with PIK3CA mutations vs. 24% of patients wtPIK3CA (p = 0.001). PIK3CA mutations were found in 28% of patients with KRAS mutations compared to 10% with wtKRAS (p = 0.001) and in 20% of patients with RAS (KRAS, NRAS) or BRAF mutations compared to 8% with wtRAS (KRAS, NRAS) or wtBRAF (p = 0.001).

CONCLUSIONS

PIK3CA, RAS (KRAS, NRAS), and BRAF mutations are frequent in diverse tumors. In a wide variety of tumors, PIK3CA mutations coexist with RAS (KRAS, NRAS) and BRAF mutations.

Cardiovascular toxicity profiles of vascular-disrupting agents

BACKGROUND

Vascular-disrupting agents (VDAs) represent a new class of chemotherapeutic agent that targets the existing vasculature in solid tumors. Preclinical and early-phase trials have demonstrated the promising therapeutic benefits of VDAs but have also uncovered a distinctive toxicity profile highlighted by cardiovascular events.

METHODS

We reviewed all preclinical and prospective phase I-III clinical trials published up to August 2010 in MEDLINE and the American Association of Cancer Research and American Society of Clinical Oncology meeting abstracts of small-molecule VDAs, including combretastatin A4 phosphate (CA4P), combretastatin A1 phosphate (CA1P), MPC-6827, ZD6126, AVE8062, and ASA404.

RESULTS

Phase I and II studies of CA1P, ASA404, MPC-6827, and CA4P all reported cardiovascular toxicities, with the most common cardiac events being National Cancer Institute Common Toxicity Criteria (version 3) grade 1-3 hypertension, tachyarrhythmias and bradyarrhythmias, atrial fibrillation, and myocardial infarction. Cardiac events were dose-limiting toxicities in phase I trials with VDA monotherapy and combination therapy.

CONCLUSIONS

Early-phase trials of VDAs have revealed a cardiovascular toxicity profile similar to that of their vascular-targeting counterparts, the angiogenesis inhibitors. As these agents are added to the mainstream chemotherapeutic arsenal, careful identification of baseline cardiovascular risk factors would seem to be a prudent strategy. Close collaboration with cardiology colleagues for early indicators of serious cardiac adverse events will likely minimize toxicity while optimizing the therapeutic potential of VDAs and ultimately enhancing patient outcomes.

Abstract 1279: Loss of PTEN expression in patients treated with PI3K/AKT/mTOR signaling pathway inhibitors

Background: Loss of PTEN function results in increased PI3K/AKT/mTOR signaling and may predict sensitivity to drugs targeting the PI3K/AKT/mTOR pathway.

Methods: Archival tumor samples from patients (N = 202) with diverse cancers referred to the Clinical Center for Targeted Therapy from October 2009 were tested for cytoplasmatic expression of PTEN on immunohistochemistry. Whenever possible, tumor tissue was also analyzed for PIK3CA, RAS (K-, N-), and BRAF mutations using PCR-based DNA sequencing. Consecutive patients with loss of PTEN expression and any tumor type were treated whenever possible with agents targeting the PI3K/AKT/mTOR signaling pathway.

Results: Overall, 49 (24%) of 202 patients had loss of PTEN expression. In specific tumor types with a minimum of five patients tested, the loss of PTEN expression was most frequent in squamous cell cervical (60%, 3/5 patients), non-small-cell lung (50%, 4/8), renal (50%, 3/6), uterine (41%, 7/17), gastroesophageal junction/gastric (38%, 3/8), breast cancers (25%, 2/8), melanomas (22%, 6/27), and colorectal cancers (20%, 6/30). Tumors with PTEN loss had frequencies of simultaneous mutations in PIK3CA, RAS (K-, N-), BRAF that were similar to patients with PTEN expression. Of the 49 patients with PTEN loss, 29 (median number of prior therapies, 3) were treated on a protocol that included a PI3K/AKT/mTOR pathway inhibitor. Six of these 29 patients (20.5%) achieved a partial response (PR) (2 uterine cancers, 1 squamous cell cervical cancer; 1 squamous cell head and neck cancer; 1 melanoma; 1 renal cancer) and 8 (27.5%) had stable disease (SD) for >/ = 4 months (total SD>/ = 4 months + PR = 48%). These 29 treated patients had a median progression-free survival of 4.3 months (95% CI, 3.4-5.2).

Conclusion: Loss of PTEN expression was found in 24% of patients with various solid tumors. Fourteen of 29 heavily-pretreated patients (48%) had a PR or SD >/ = 4 months, when treated with a PI3K/AKT/mTOR axis inhibitor, suggesting that matching patients with these inhibitors based on PTEN loss merits further exploration.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1279. doi:10.1158/1538-7445.AM2011-1279

Abstract 4410: Initiative for Molecular Profile and Advanced Cancer Therapy (IMPACT): A personalized medicine Phase I clinical trials program at MD Anderson Cancer Center

Introduction: Ongoing clinical trials are based on targeting specific pathways in addition to the tumor histology. We examined the results of mutational analyses performed in patients with advanced cancer seen in the Phase I clinic at The University of Texas MD Anderson Cancer Center.

Methods: Mutational analysis was mostly performed in the Clinical Laboratory Improvement Amendments (CLIA)-certified pathology laboratory of MD Anderson. DNA was extracted from microdissected paraffin-embedded tumor samples, and analysis was performed on specific exons, depending on the test ordered, for the following genes: PIK3CA (exon 9: codons 532-554; exon 20: codons 1011-1062); BRAF (exon 15: codons 595 to 600); KRAS and NRAS (codons 12, 13, and 61); EGFR (exons 18 to 21 of the kinase domain); KIT (exons 9, 11, 13, and 17); and RET (exon 10: codons 609, 611, 618, and 620; codon 634 of exon 11; codon 918 of exon 16). The loss of the tumor suppressor nuclear protein, PTEN, was determined using immunohistochemical staining.

Results. Tumor mutational analysis was ordered for 952 patients. Overall, 103 patients did not have adequate tissue. Of the remaining 849 patients, 354 (41.69%) had ≥ 1 mutation and 495 did not have a mutation. More women (45%) than men (38%) had a mutation (p = 0.02), but age was not associated with the presence of mutations (p=0.76). Of the patients with mutations, 313 had 1 mutation, 38 had 2 mutations, and 3 had 3 mutations. The distribution of mutations by diagnosis is shown in the Table. The total distribution of mutations in our patient population was as follows: BRAF, 19.01%; KRAS, 18.74%; PIK3CA, 9.85%; NRAS, 8.17%; EGFR, 3.38%; KIT, 2.13%; and PTEN loss, 21.20%.

Conclusion: Testing for PIK3CA, KRAS, NRAS, BRAF, EGFR, KIT, and RET mutations and PTEN loss in 849 patients with available tissue demonstrated that molecular driver aberrations are common in advanced cancer.

Inhibition of the Ras/Raf/MEK/ERK and RET kinase pathways with the combination of the multikinase inhibitor sorafenib and the farnesyltransferase inhibitor tipifarnib in medullary and differentiated thyroid malignancies

PURPOSE

Ras/Raf/MAPK kinase/ERK and rearranged in transformation (RET) kinase pathways are important in thyroid cancer. We tested sorafenib, a B-Raf, RET, and vascular endothelial growth factor receptor kinase inhibitor, combined with tipifarnib, a farnesyltransferase inhibitor that inactivates Ras and other farnesylated proteins.

PATIENTS AND METHODS

We treated 35 patients with differentiated thyroid cancer (DTC) and medullary thyroid cancer (MTC) in a phase I trial. Sorafenib and tipifarnib were given for 21 d with 7 d rest in each 28-d cycle.

RESULTS

We enrolled 22 patients with metastatic DTC (16 papillary, five follicular, and one poorly differentiated) and 13 patients with MTC, of whom 15 with DTC and 10 with MTC reached first restaging. When tissue was available, eight of 15 DTC patients (53%) had B-Raf mutations; eight of 13 MTC (61.5%) patients had RET mutations. MTC partial response rate was 38% (five of 13) (duration = 9+, 12, 13, 16+, and 34+ months), stable disease of at least 6 months was 31% (four of 13). The DTC partial response rate was 4.5% (one of 22), and stable disease of at least 6 months was 36% (eight of 22). Median progression-free survival for all 35 patients was 18 months (95% confidence interval, 14.6 to not reached months). Median overall survival has not been reached, with a median follow-up of 24 months with 80% overall survival. Grade 1-2 toxicities were mainly rash, fatigue, and diarrhea. The most common grade 3-4 toxicities were rash, rise in amylase/lipase, and fatigue.

CONCLUSIONS

Inhibiting the Ras/Raf/MAPK kinase/ERK and RET kinase pathways with sorafenib and tipifarnib is well tolerated and active against thyroid cancer.

PIK3CA mutations in patients with advanced cancers treated with PI3K/AKT/mTOR axis inhibitors

Preclinical data suggest that PIK3CA mutations predict response to PI3K/AKT/mTOR inhibitors. Concomitant KRAS or BRAF mutations may mediate resistance. Therefore, tumors from patients referred to the phase I program for targeted therapy starting in October 2008 were analyzed for PIK3CA mutations using PCR-based DNA sequencing of exons 9 and 20. Consecutive patients with diverse tumor types and PIK3CA mutation were treated whenever possible with agents targeting the PI3K/AKT/mTOR pathway. Overall, PIK3CA mutations were detected in 25 of 217 patients (11.5%; exon 9, n = 11; exon 20, n = 14). In tumor types with more than 10 patients tested, PIK3CA mutations were most frequent in endometrial (3 of 14, 21%), ovarian (5 of 30, 17%), colorectal (9 of 54, 17%), breast (2 of 14, 14%), cervical (2 of 15, 13%), and squamous cell cancer of the head and neck (1 of 11, 9%). Of the 25 patients with PIK3CA mutations, 17 (68%) were treated on a protocol that included a PI3K/AKT/mTOR pathway inhibitor, and 6 (35%) achieved a partial response. In contrast, only 15 of 241 patients (6%) without documented PIK3CA mutations treated on the same protocols responded (P = 0.001). Of the 17 patients with PIK3CA mutations, 6 (35%) had simultaneous KRAS or BRAF mutations (colorectal, n = 4; ovarian, n = 2). Colorectal cancer patients with PIK3CA and KRAS mutations did not respond to therapy, whereas both ovarian cancer patients with PIK3CA and KRAS or BRAF mutations did. In conclusion, PIK3CA mutations were detected in 11.5% of patients with diverse solid tumors. The response rate was significantly higher for patients with PIK3CA mutations treated with PI3K/AKT/mTOR pathway inhibitors than for those without documented mutations.

Outcomes of patients with advanced non-small cell lung cancer treated in a phase I clinic

BACKGROUND

The outcomes of patients with advanced non-small cell lung cancer (NSCLC) treated in phase I clinical trials have not been systematically analyzed.

METHODS

We reviewed the records of consecutive patients with advanced/metastatic NSCLC who were treated in the Phase I Clinical Trials Program at MD Anderson from August 2004 to May 2009.

RESULTS

Eighty-five patients (51 men, 34 women) treated on various phase I protocols were identified. The median age was 62 years (range, 30-85). The median number of previous systemic therapies was two (range, 0-5). A partial response was observed in eight patients (9.5%) and stable disease lasting >4 months was observed in 16 patients (19%). The median overall survival time was 10.6 months and median progression-free survival (PFS) time was 2.8 months, which was 0.6 months shorter than the median PFS of 3.4 months following prior second-line therapy. Factors predicting longer survival in the univariate analysis were an Eastern Cooperative Oncology Group performance status (PS) score of 0-1, no prior smoking, two or fewer organ systems involved, a hemoglobin level ≥ 12 g/dL, liver metastases, a history of thromboembolism, and a platelets count > 440 × 10(9)/L. In the multivariate analysis, a PS score of 0-1 and history negative for smoking predicted longer survival. Sixty-two (73%) patients had grade ≤ 2 toxicity, and there were no treatment-related deaths.

CONCLUSION

Phase I clinical trials were well tolerated by selected patients with advanced NSCLC treated at M.D. Anderson. Nonsmokers and patients with a good PS survived longer. PFS in our population was shorter in smokers/ex-smokers and patients with a PS score of 2. It is reasonable to refer pretreated patients with a good PS to phase I clinical trials.

Ofatumumab in the treatment of chronic lymphocytic leukemia

Ofatumumab is a type I fully human monoclonal antibody (IgG1) that binds to a unique epitope on the human CD20 molecule expressed on the surface of B cells. It binds specifically to both the small and large extracellular loops of the CD20 molecule. A phase I-II study demonstrated that ofatumumab was well tolerated and resulted in objective responses. In a phase II study of ofatumumab in fludarabine- and alemtuzumab-refractory chronic lymphocytic leukemia (CLL) or fludarabine-refractory CLL with bulky (> 5 cm) lymphadenopathy, the response rates were 58% and 47%, respectively. This study led to accelerated approval of ofatumumab by the U.S. Food and Drug Administration for the treatment of CLL refractory to fludarabine and alemtuzumab. In a phase II study of ofatumumab with fludarabine and cyclophosphamide in untreated CLL, patients were randomized to ofatumumab 500 mg (group A) or 1000 mg (group B) (initial dose, 300 mg, both groups), combined with fludarabine and cyclophosphamide. The higher ofatumumab dose resulted in a higher complete response (CR) rate (50%), compared to the lower-dose ofatumumab group (CR, 32%) (overall response rates, 77% and 73%, respectively). A phase III study of ofatumumab combined with fludarabine and cyclophosphamide versus fludarabine and cyclophosphamide in relapsed CLL are ongoing, as well as several clinical trials of ofatumumab. Ofatumumab has significant antileukemic activity and ongoing clinical trials will determine the role of ofatumumab in CLL.

A phase 1 study of hepatic arterial infusion of oxaliplatin in combination with systemic 5-fluorouracil, leucovorin, and bevacizumab in patients with advanced solid tumors metastatic to the liver

BACKGROUND

Liver metastases in patients with cancer are associated with poor survival. The authors of this report conducted a phase 1 study of hepatic arterial infusion (HAI) oxaliplatin combination therapy in patients with advanced cancer and liver metastases.

METHODS

Treatment consisted of escalating doses of HAI oxaliplatin 60 mg/m(2) to 175 mg/m(2) and intra-arterial heparin 3000 IU (Day 1); leucovorin 200 mg/m(2) intravenously (iv) and 5-fluorouracil 300 mg/m(2) bolus plus 600 mg/m(2) iv (Days 1 and 2); and bevacizumab 10 mg/kg iv (Day 3). A conventional "3 + 3" design was used.

RESULTS

Fifty-seven patients were treated, including 30 women and 27 men. The median age was 57 years, and the patients had received a median of 3 prior therapies (range, 1-7 prior therapies). The most common cancer was colorectal (n = 29). Overall, 204 cycles were administered (median per patient, 2 cycles; range, 1-17 cycles). The maximum tolerated dose (MTD) of HAI oxaliplatin was 140 mg/m(2). Dose-limiting toxicities were grade 4 thrombocytopenia (n = 1) and grade 4 hypokalemia (n = 1) at 150 mg/m(2) (n = 5). Thirty-three patients (58%) had no toxicity greater than grade 1. The most common toxicities were thrombocytopenia (n = 19), fatigue (n = 15), nausea/vomiting (n = 6), constipation (n = 6), and diarrhea (n = 4). Of 55 patients who were evaluable for response (according to Response Evaluation Criteria in Solid Tumors), 4 patients (7%) had a partial response (PR), and 32 patients (58%) had stable disease (SD), including 15 patients (48%) who had SD for >/=4 months. Of 28 patients with colorectal cancer, 3 patients (11%) had a PR, and 9 patients (32%) had SD for >/=4 months.

CONCLUSIONS

HAI oxaliplatin combined with systemic 5-fluorouracil, leucovorin, and bevacizumab had antitumor activity in patients with advanced cancer and liver metastases, and the current results indicated that this combination warrants further study. Cancer 2010. (c) 2010 American Cancer Society.

Progressive multifocal leukoencephalopathy in a patient without apparent immunosuppression

An 80-year-old man with no history of an immune-compromising disorder was diagnosed with progressive multifocal leukoencephalopathy (PML). He presented with dysphagia and left-sided weakness; magnetic resonance imaging demonstrated marked signal abnormality in the subcortical white matter of the left frontal lobe and in the posterior limb of the right internal capsule. Polymerase chain reaction (PCR) analysis of the cerebrospinal fluid (CSF) was negative for John Cunningham (JC) virus. On brain biopsy, foamy macrophages infiltrating the white matter were identified, staining positive for anti-simian virus 40 antibodies. Postoperatively, PCR for JC viral DNA in the CSF was positive, establishing the diagnosis of PML. Extensive investigation for an occult immunocompromising disorder was negative. The patient's neurologic deficits rapidly increased throughout his hospital stay, and he died 3.5 months after his diagnosis.

Clinical outcomes of patients with breast cancer in a phase I clinic: the M. D. Anderson cancer center experience

PURPOSE

Patients with metastatic breast cancer (MBC) refractory to standard therapy have a poor prognosis. We assessed prognostic factors and clinical outcomes for patients with MBC referred to a phase I clinic focused primarily on targeted agents.

PATIENTS AND METHODS

We reviewed the medical records of sequential patients with MBC who presented to our phase I clinic between September 2004 and May 2008 to assess baseline patient characteristics, overall survival (OS), and clinical benefit.

RESULTS

A total of 92 patients were identified, with a median age of 53 years (range, 28-83 years). The median number of previous therapies was 5 (range, 1-16 therapies). Of 92 patients, 78 were eligible for and offered > or = 1 phase I clinical trial. With a median follow-up of 7.4 months, the median OS was 6.7 months (95% CI, 5.2-9.7). In multivariate analysis, independent factors predicting shorter survival were > or = 10 previous treatments (vs. < 10 previous treatments; hazard ratio [HR], 3.27; 95% CI, 1.37-7.81; P = .008), Eastern Cooperative Oncology Group (ECOG) performance status (PS) 2/3 (vs. 0/1; HR, 2.92; 95% CI, 1.28-6.66; P = .01), and albumin level < 3.5 g/dL (vs. > 3.5 g/dL; HR, 2.88; 95% CI, 1.41-5.89; P = .004).

CONCLUSION

Patients with locally advanced or metastatic breast cancer referred for our phase I studies had a median survival of 6.7 months. Heavily pretreated disease, poor ECOG PS, and/or low albumin levels were associated with significantly shorter survival in a multivariate analysis.

Abstract 2771: Clinical outcomes and prognostic factors in 83 patients with pancreatic cancer treated in phase I clinical trials at M.D. Anderson Cancer Center

Introduction. The outcomes of patients with pancreatic cancer treated on early-phase clinical trials have not been systematically analyzed. The purpose of this study was to report the presenting characteristics and outcomes of patients with locally advanced or metastatic pancreatic cancer treated on phase I clinical trials at a single institution.

Patients and Methods. We reviewed the records of consecutive patients with metastatic pancreatic cancer who were treated in the Phase I Clinical Trials Program at The University of Texas M. D. Anderson Cancer Center from November 2004 to March 2009. Data recorded and analyzed included survival, response, and disease characteristics.

Results. Eighty-three patients were identified. The median age was 62 years (range, 39-81). There were 40 men and 43 women. The most common metastatic sites were liver (54% of patients), lung (51%), lymph nodes (37%), and peritoneum and omentum (24%). The median number of prior therapies was 2 (range, 0-7). Thirty-two (39%) patients had a history of pancreatectomy. Sixty-seven (81%) patients had ≥1 comorbidity. Of 78 patients evaluable for response, 2 (3%) had a partial response (PR), and 10 (13%) had stable disease (SD) for ≥4 months. With a median follow-up for survivors of 3.7 months, the median survival from presentation in the Phase I Clinic was 5.0 months (95% CI, 3.3-6.2). The median overall survival from diagnosis was 22.1 months (95% CI, 17.9-26.5). The median time to treatment failure (TTF) was 1.5 months (95% CI, 1.3-1.8). In multivariate analysis, independent factors associated with lower rates of PR or SD were liver metastases (p = 0.001) and PS greater than 0 (p = 0.01) (Table 3). Independent factors associated with shorter survival were liver metastases (p = 0.007), calcium ≤ 8.4 mg/nL (p = 0.015), and elevated serum levels of CEA (&gt;6 ng/mL; p = 0.005). Independent factors associated with shorter TTF were history of smoking (p = 0.009), liver metastases (p = 0.001), serum bilirubin levels &gt;1 mg/dL (p = 0.007), and &gt;1 prior therapy (p = 0.002).

Conclusions. The median survival in the current study (5 months) compares favorably to the median survival reported with best supportive care (3 months). Our results suggest that phase I clinical trials offer a reasonable therapeutic approach for patients with advanced pancreatic cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2771.

Epstein-Barr virus latent membrane protein 1 mRNA is expressed in a significant proportion of patients with chronic lymphocytic leukemia

BACKGROUND

Epstein-Barr virus (EBV) infection has been associated with Richter transformation in patients with chronic lymphocytic leukemia (CLL).

METHODS

A direct isothermal mRNA amplification method was developed for detection of EBV latent membrane protein 1 (LMP1) mRNA transcriptional activity in the peripheral blood of 135 chronic lymphocytic leukemia patients and 98 hematologically healthy control subjects.

RESULTS

EBV LMP1 mRNA transcripts were found in 19 of 135 (14%) of the CLL cases, but only 1% of the healthy controls (P < .0001). In contrast, 23 solid tumor patients tested negative for EBV LMP1 transcripts. In a later cohort of patients after hematopoietic stem cell transplantation, 4 of 7 patients with Hodgkin lymphoma or Burkitt lymphoma had EBV LMP1 detected. In a preliminary analysis, outcome data were available for 88 of the 135 patients with CLL. EBV LMP1 mRNA positivity was associated with a significantly increased degree of histologically demonstrated bone marrow involvement by CLL (P = .003, Mann-Whitney U test).

CONCLUSIONS

EBV LMP1 mRNA transcriptional activity was observed in a significant proportion of CLL patients. Transcription of the EBV LMP1, a late gene with known transforming potential in vitro, suggests that EBV activation plays a role in CLL disease progression. Thus, EBV LMP1 expression in CLL patients may be a factor involved in the genesis of refractory disease.

Abstract B134: PIK3CA mutations in patients with advanced cancers treated in phase I clinical trials

Background: Phosphatidylinositol 3-kinase (PI3K) is thought to play an important role in tumorigenesis. Activating mutations of the p110 subunit of PI3K (PIK3CA) have been identified in a broad spectrum of tumors.

Methods: A mutational analysis (a PCR-based DNA sequencing) of exon 9 (helical domain) and exon 20 (kinase domain) of the PIK3CA was performed using DNA obtained from tumors of patients referred for clinical trials using targeted therapy. Patients with PIK3CA were preferably treated whenever possible with regimens containing PI3K-AKT-mTOR signaling pathway inhibitors.

Results: To date 146 samples from patients with various advanced cancers have been collected. At the time of submission 117 results from mutational analysis were available (ovarian cancer, n=23; colon cancer, n=13; cervical cancer, n=10; endometrial cancer, n=7; breast cancer, n=11; melanoma, n=7; head and neck cancer, n=10; soft tissue sarcoma [not including GIST] n=6; renal cancer, n=4; and other tumor types, n=26). PIK3CA mutations were detected in 14 (12%) patients (3 in exon 9-helical domain, 11 in exon 20-kinase domain). In tumor types with more than 5 patients tested, PIK3CA mutations were most frequent in endometrial cancer (43%, 3 out of 7 patients), ovarian cancer (22%, 5 out of 23 patients), squamous head and neck cancer (14%, 1 out of 7 patients), breast cancer 18% (2 out of 11 patients), and colon cancer (15%, 2 out of 13 patients). No mutations were identified in patients with melanoma or cervical cancer. The small number of patients at this point precludes statistical comparisons. Of the 14 patients with PIK3CA mutations, 10 were treated on a protocol that included a drug targeting the PI3K-AKT-mTOR pathway, and 4 (40%) responded (partial responses). Although numbers are small, in individual disease there were 2 (67%) responses in 3 endometrial cancers, 1 (25%) in 4 ovarian cancers, 1 (100%) in 1 breast cancer, and no response in 1 colorectal cancer patient.

Conclusion: PIK3CA mutations were detected in 12% of patients with various solid tumors. Although numbers are small, response rate appears high (40%) in tumors with PIK3CA mutations treated with PI3K-AKT-mTOR pathway inhibitors.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B134.

Anti-B4 Blocked Ricin Post Chemotherapy in Patients with Chronic Lymphocytic Leukemia--Long-term Follow-up of a Monoclonal Antibody-based Approach to Residual Disease

Anti-B4-blocked ricin is an immunotoxin consisting of anti-B4 murine monoclonal antibody and "blocked ricin" toxin. The anti-B4 monoclonal antibody is directed against the CD19 antigen, which is expressed on B-lymphocytes. A phase II study of anti-B4 blocked ricin toxin in patients with B-cell chronic lymphocytic leukemia (CLL) with residual disease after chemotherapy was conducted. Eleven patients received anti-B4 blocked ricin at 30 microg/kg lean body mass (LBM) daily by continuous infusion for 7 days followed with repeat infusion administered at 14-day intervals. No patient achieved an objective response. The major reasons for failure to respond were the presence of adenopathy and residual marrow disease. Three patients achieved immunophenotypic response in marrow and peripheral blood. Three of 6 patients with rearranged IgH and/or Ig kappa were germline after anti-B4 blocked ricin. The median follow-up of surviving patients is 8.6 years. The median survival is 5.8 years (range, 0.0-8.8). All patients have progressed. The median time to progression was 0.8 years (range, 0.3-3.0). Infusion-related toxicities were all grade 1-2. The most common toxicity was transaminitis. Human antimouse antibody (HAMA) and/or human antiricin antibody (HARA) development was documented in 2 patients. Anti-B4 blocked ricin was well tolerated but had limited activity in patients with residual CLL after chemotherapy.

Dasatinib in chronic myeloid leukemia: a review

Deregulated BCR-ABL tyrosine kinase (TK) activity is the molecular marker for chronic myeloid leukemia (CML), which provides an identifiable target for developing therapeutic agents. Imatinib mesylate, a BCR-ABL TK inhibitor, is the frontline therapy for CML. Despite the stunning efficacy of this agent, a small number of patients develop a suboptimal response or resistance to imatinib. In newly diagnosed patients with chronic phase CML, the rate of resistance to imatinib at 4 years was up to 20%, increasing to 70% to 90% for patients in the accelerated/blastic phase. Resistance to imatinib led to the development of novel TK inhibitors such as dasatinib. Several clinical trials have reported more durable complete hematologic and cytogenetic responses with this agent in patients who are resistant or intolerant to imatinib. Dasatinib is well tolerated and has broad efficacy, resulting in durable responses in patients with any BCR-ABL mutation except for T3151 and mutations in codon 317 – most commonly F317L – including mutations that were highly resistant to imatinib, such as L248, Y253, E255, F359, and H396. Dasatinib is recommended for CML in chronic, blastic or accelerated phase that is resistant or intolerant to imatinib. Dasatinib was approved by the FDA at 100 mg once daily as the starting dose in patients with chronic phase CML and at 70 mg twice daily in patients with accelerated or blastic phase CML. Various clinical trial results provided evidence that resistance to one TK inhibitor can be reversed with the use of a different TK inhibitor (TKI). Other second-generation TKIs with activity in CML include nilotinib, bosutinib and INNO 406. New molecules, such as the inhibitor of Aurora family serine-threonine kinases, MK0457, which has antileukemic activity in CML associated with a T315I mutation, are being investigated. Allogeneic hematopoietic stem cell transplantation remains an option for selected patients.

Survival of patients in a Phase 1 Clinic: the M. D. Anderson Cancer Center experience

BACKGROUND

Patients with advanced malignancies for whom standard therapy is ineffective may participate in phase 1 trials. To gain a better understanding of the clinical features that could influence benefit versus risk, the authors of this report assessed prognostic factors and survival for patients who were referred to a phase 1 clinic focused primarily on targeted agents.

METHODS

The medical records of 200 sequential patients who presented to the Phase 1 Clinic at The University of Texas M. D. Anderson Cancer Center were reviewed, and their characteristics and survival were analyzed.

RESULTS

The median patient age was 58 years (range, 12-85 years), and 57% of patients were men. The median number of prior therapies was 4. Of 200 patients, 182 were treated on at least 1 phase 1 clinical trial. The median follow-up of surviving patients was 21 months, and the median overall survival was 9 months (95% confidence interval [CI], 7.4-10.8). In univariate analysis, the factors that predicted shorter survival were primary tumor in the gastrointestinal tract; a history of thrombosis, liver metastases, and elevated levels of serum lactate dehydrogenase; platelet count; carbohydrate antigen 9 (Ca19-9) and Ca-125 levels; aspartate aminotransferase levels, and alkaline phosphatase levels (P < .05 for each). In multivariate analysis, independent factors that predicted shorter survival were a history of thromboembolism (hazard ratio [HR], 2.38; 95% CI, 1.29-4.39; P = .005), platelets >or=440 x 10(9)/L (HR, 1.72; 95% CI, 1.12-2.65; P = .014), and the presence of liver metastases (HR, 1.51; 95% CI, 1.09-2.09; P = .013).

CONCLUSIONS

Patients who were referred to phase 1 studies had a short median survival (9 months). Patients with thrombocytosis, liver metastases, and a history of thromboembolism had worse outcomes. A prognostic score is proposed.

Relevance of clinical trials in acute myeloid leukaemia

Patients with newly diagnosed acute myeloid leukaemia (AML) are increasingly being enrolled in clinical trials sponsored by pharmaceutical companies or the National Cancer Institute. These trials routinely exclude patients who are less likely to respond (LLTR), e.g. those with Zubrod performance status >2 and levels of bilirubin or creatinine >/=2.0 mg/dL. Here we examine rates of enrollment of LLTR patients in clinical trials over the past 16 years. Overall, 2323 adults with newly diagnosed AML (excluding acute promyelocytic leukaemia) were registered on clinical trials from 1991 to 2006. LLTR patients constituted a significantly smaller proportion of the patients enrolled from 1999 to 2006 than from 1991 to 1998 (p < 0.0001, considering all patients and patients 60 years or older). While 54% of patients considered 'more likely to respond' (MLTR) (i.e. those with performance status <3, bilirubin <2.0 mg/dL and creatinine <2.0 mg/dL) were enrolled in these studies from 1999 to 2006, only 36% of LLTR patients were enrolled during this period (p < 0.0001). Our results suggest that newer clinical trials may be less applicable to LLTR patients than previous trials. There is a need for clinical trials specific to the LLTR population, the group most in need of novel therapies.

Phase I-II Study of Oxaliplatin, Fludarabine, Cytarabine, and Rituximab Combination Therapy in Patients With Richter's Syndrome or Fludarabine-Refractory Chronic Lymphocytic Leukemia

Purpose

Richter's syndrome (RS) and fludarabine-refractory chronic lymphocytic leukemia (CLL) are associated with poor clinical outcomes. We conducted a phase I-II trial of oxaliplatin, fludarabine, cytarabine, and rituximab (OFAR) in these diseases.

Patients and Methods

The OFAR regimen consisted of increasing doses of oxaliplatin (17.5, 20, or 25 mg/m2/d) on days 1 to 4 (phase I), fludarabine 30 mg/m2 on days 2 to 3, cytarabine 1 g/m2 on days 2 to 3, rituximab 375 mg/m2 on day 3 of cycle 1 and day 1 of subsequent cycles, and pegfilgrastim 6 mg on day 6, every 4 weeks for a maximum of six courses. Dose-limiting toxicity (DLT) was defined as any nonhematologic, treatment-related toxicity ≥ grade 3.

Results

Fifty patients were treated (20 patients had RS, and 30 had CLL). The highest tolerated oxaliplatin dose was 25 mg/m2, which was the highest dose tested. DLT was not observed. Pharmacodynamic analyses demonstrated enhanced leukemia cell killing by oxaliplatin in the presence of fludarabine and cytarabine. The overall response rates were 50% in RS and 33% in fludarabine-refractory CLL. The overall response rate in 14 patients with age ≥ 70 years was 50%. Responses were achieved in seven (35%) of 20 patients with 17p deletion, two (29%) of seven patients with 11q deletion, all four patients with trisomy 12, and two (40%) of five patients with 13q deletion. The median response duration was 10 months. Toxicities were mainly hematologic; prolonged myelosuppression was not observed.

Conclusion

The OFAR regimen is highly active in RS and has activity in fludarabine-refractory patients with CLL. This regimen warrants further investigation in the treatment of these disorders.

The natural history of fludarabine-refractory chronic lymphocytic leukemia patients who fail alemtuzumab or have bulky lymphadenopathy

The natural history and outcome of salvage treatment for patients with fludarabine-refractory chronic lymphocytic leukemia who are either refractory to alemtuzumab ("double-refractory") or ineligible for alemtuzumab due to bulky lymphadenopathy ("bulky fludarabine-refractory") have not been described. We present the outcomes of 99 such patients (double-refractory n = 58, bulky fludarabine-refractory n = 41) undergoing their first salvage treatment at our center. Patients received a variety of salvage regimens including monoclonal antibodies (n = 15), single-agent cytotoxic drugs (n = 14), purine analogue combination regimens (n = 21), intensive combination chemotherapy (n = 36), allogeneic stem cell transplantation (SCT; n = 4), or other therapies (n = 9). Overall response to first salvage therapy other than SCT was 23%, with no complete responses. All four patients who underwent SCT as first salvage achieved complete remission. Early death (within 8 weeks of commencing first salvage) occurred in 13% of patients, and 54% of patients experienced a major infection during therapy. Overall survival was 9 months, with hemoglobin < 11 g/dL (hazard ratio 2.3), hepatomegaly (hazard ratio 2.4), and performance status > or = 2 (hazard ratio 1.9) being significant independent predictors of inferior survival.

Assessment of chronic lymphocytic leukemia and small lymphocytic lymphoma by absolute lymphocyte counts in 2,126 patients: 20 years of experience at the University of Texas M.D. Anderson Cancer Center

PURPOSE

Chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) are currently considered the same entity, but controversy remains over whether CLL and SLL should be treated similarly. We assessed whether characteristics of patients with CLL and SLL differ in ways other than the absolute lymphocyte count (ALC) and evaluated treatment outcomes and prognostic factors.

METHODS

We searched the electronic database for patients with CLL or SLL who presented to The University of Texas M.D. Anderson Cancer Center (Houston, TX) between 1985 and 2005. We reviewed patient records to determine presenting characteristics, treatment, and clinical outcomes. Cox models using training and validation sets of patients and resampling methods were used to develop a model predicting survival.

RESULTS

Among 2,126 consecutive CLL/SLL patients, 312 (15%) had ALC less than 5 x 10(9)/L. Patients with ALC less than 5 x 10(9)/L had lower rates of cytogenetic abnormalities (P = .0002) and higher rates of CD38-positive results (P = .0002) and had mutated immunoglobulin heavy-chain variable region gene status (P = .034). Rates of response, survival, and failure-free survival (FFS) were not different among ALC groups. Regimens that included rituximab and a nucleoside analog were associated with superior rates of response and FFS compared with other therapies, irrespective of ALC. Deletion 17p or 6q with or without other cytogenetic abnormalities, age at least 60 years, beta2-microglobulin at least 2 mg/L, albumin less than 3.5 g/dL, and creatinine at least 1.6 mg/dL were each found to independently predict shorter survival and formed the basis of a scoring system.

CONCLUSION

Patients with CLL or SLL can be treated similarly. A new prognostic score is proposed.

Detection of Richter's transformation of chronic lymphocytic leukemia by PET/CT

Our objective was to evaluate the accuracy of PET/CT for the diagnosis of Richter's transformation of chronic lymphocytic leukemia (CLL) to diffuse large cell lymphoma.

METHODS

A retrospective study was performed of 37 patients with CLL who underwent 18F-FDG PET/CT at our institution between March 2003 and July 2005. All PET/CT scans were reviewed in consensus by 2 diagnostic radiologists. Sites of abnormal 18F-FDG uptake with a maximum standardized uptake value (SUVmax) of greater than 5 were considered highly suggestive of Richter's transformation. The PET/CT findings were correlated with histologic findings from bone marrow or lymph node biopsy performed within 6 wk of PET/CT and with clinical follow-up.

RESULTS

The 37 patients (26 men and 11 women; mean age, 61 y, range, 40-82 y) underwent 57 PET/CT scans. In 10 (91%) of 11 patients with Richter's transformation, PET/CT detected sites of abnormal 18F-FDG uptake having an SUVmax of greater than 5. Richter's transformation was missed in 1 patient who had only low-grade 18F-FDG uptake (SUVmax < 5). Nine patients had false-positive PET/CT findings; in 3 of these patients, alternative malignancies were diagnosed (Hodgkin's disease; metastatic neuroendocrine carcinoma; non-small cell lung cancer). In all remaining patients, PET/CT correctly excluded Richter's transformation. For the specific diagnosis of Richter's transformation of CLL to diffuse large B-cell lymphoma, PET/CT had overall sensitivity, specificity, and positive and negative predictive values of 91%, 80%, and 53% and 97%, respectively.

CONCLUSION

PET/CT can detect Richter's transformation of CLL to diffuse large B-cell lymphoma with a high sensitivity and a high negative predictive value.

Outcomes in patients with splenic marginal zone lymphoma and marginal zone lymphoma treated with rituximab with or without chemotherapy or chemotherapy alone

BACKGROUND

The optimal management of patients with splenic marginal zone lymphoma/marginal zone lymphoma (SMZL) is controversial. The objective of this retrospective study was to compare the outcomes of patients with SMZL who received treatment with rituximab, rituximab plus chemotherapy, or chemotherapy alone.

METHODS

The Leukemia Service database was searched for patients with splenic lymphoma who were registered between May 1995 and October 2004. The indications for treatment were the same as those used for patients with chronic lymphocytic leukemia.

RESULTS

SMZL was confirmed in 70 patients. The median age was 64 years. The median number of CD20 molecules per cell was 69 x 10(3). Forty-three patients required systemic therapy; rituximab in 26 patients, chemotherapy plus rituximab in 6 patients, and chemotherapy alone in 11 patients. Ten additional patients underwent splenectomy, and 17 patients were in the observation group. The overall response rates were 88% with rituximab, 83% with rituximab plus chemotherapy, and 55% with chemotherapy alone; the 3-year survival rates were 95%, 100%, and 55%, respectively. The 3-year failure-free survival (FFS) rates were 86%, 100%, and 45% in the rituximab, rituximab plus chemotherapy, and chemotherapy alone groups, respectively. Rituximab treatments resulted in longer survival and FFS compared with chemotherapy. Rituximab alone resulted in disappearance of splenomegaly in 92% of patients and normalization of absolute lymphocyte counts. In univariate analysis, younger age and rituximab-based therapy were predictive of longer FFS.

CONCLUSIONS

Rituximab with or without chemotherapy was found to have major activity in patients with SMZL. These results may be associated with high levels of cellular CD20 antigen sites. Rituximab should be the treatment of choice, at least in older patients with SMZL who have comorbid diseases.

Myeloid sarcoma involving the gynecologic tract: a report of 11 cases and review of the literature

Myeloid sarcoma can involve any anatomic site, but involvement of the gynecologic tract is uncommon. We describe 11 women, 17 to 60 years old, with myeloid sarcoma involving the gynecologic tract, including 5 patients in whom myeloid sarcoma presented as an isolated mass. The uterus was the most frequently involved anatomic site, in 8 patients (5 corpus, 3 cervix). Each neoplasm diffusely infiltrated normal structures, and, cytologically 7 tumors were immature, 3 were differentiated, and 1 was blastic. In 9 cases assessed, immunohistochemical stains showed that all neoplasms were positive for myeloperoxidase and lysozyme; CD117 was positive in 7 of 8 cases, and cytochemical staining for naphthol AS-D chloroacetate was positive in all 6 neoplasms analyzed. Following chemotherapy, complete remission and long-term survival were achieved in a subset of patients, as was particularly true for 2 patients (cases 8 and 10), with complete remission 12.5 and 31 years after diagnosis, respectively.