Apostolia M. Tsimberidou

PI3K/AKT/mTOR Inhibitors in Patients With Breast and Gynecologic Malignancies Harboring PIK3CA Mutations

PURPOSE Mutations of the PIK3CA gene may predict response to phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) inhibitors. Concomitant mutations in the mitogen-activated protein kinase (MAPK) pathway may mediate resistance. PATIENTS AND METHODS Tumors from patients with breast, cervical, endometrial, and ovarian cancer referred to the Clinical Center for Targeted Therapy (Phase I Program) were analyzed for PIK3CA, KRAS, NRAS, and BRAF mutations. Patients with PIK3CA mutations were treated, whenever feasible, with agents targeting the PI3K/AKT/mTOR pathway. RESULTS Of 140 patients analyzed, 25 (18%) had PIK3CA mutations, including five of 14 patients with squamous cell cervical, seven of 29 patients with endometrial, six of 29 patients with breast, and seven of 60 patients with ovarian cancers. Of the 25 patients with PIK3CA mutations, 23 (median of two prior therapies) were treated on a protocol that included a PI3K/AKT/mTOR pathway inhibitor. Two (9%) of 23 patients had stable disease for more than 6 months, and seven patients (30%) had a partial response. In comparison, only seven (10%) of 70 patients with the same disease types but with wild-type PIK3CA treated on the same protocols responded (P = .04). Seven patients (30%) with PIK3CA mutations had coexisting MAPK pathway (KRAS, NRAS, BRAF) mutations (ovarian cancer, n = 5; endometrial cancer, n = 2), and two of these patients (ovarian cancer) achieved a response. CONCLUSION PIK3CA mutations were detected in 18% of tested patients. Patients with PIK3CA mutations treated with PI3K/AKT/mTOR inhibitors demonstrated a higher response rate than patients without mutations. A subset of patients with ovarian cancer with simultaneous PIK3CA and MAPK mutations responded to PI3K/AKT/mTOR inhibitors, suggesting that not all patients demonstrate resistance when the MAPK pathway is concomitantly activated.

Personalized Medicine in a Phase I Clinical Trials Program: The MD Anderson Cancer Center Initiative

Purpose: We initiated a personalized medicine program in the context of early clinical trials, using targeted agents matched with tumor molecular aberrations. Herein, we report our observations. Patient and Methods: Patients with advanced cancer were treated in the Clinical Center for Targeted Therapy. Molecular analysis was conducted in the MD Anderson Clinical Laboratory Improvement Amendments (CLIA)–certified laboratory. Patients whose tumors had an aberration were treated with matched targeted therapy, when available. Treatment assignment was not randomized. The clinical outcomes of patients with molecular aberrations treated with matched targeted therapy were compared with those of consecutive patients who were not treated with matched targeted therapy. Results: Of 1,144 patients analyzed, 460 (40.2%) had 1 or more aberration. In patients with 1 molecular aberration, matched therapy (n = 175) compared with treatment without matching (n = 116) was associated with a higher overall response rate (27% vs. 5%; P < 0.0001), longer time-to-treatment failure (TTF; median, 5.2 vs. 2.2 months; P < 0.0001), and longer survival (median, 13.4 vs. 9.0 months; P = 0.017). Matched targeted therapy was associated with longer TTF compared with their prior systemic therapy in patients with 1 mutation (5.2 vs. 3.1 months, respectively; P < 0.0001). In multivariate analysis in patients with 1 molecular aberration, matched therapy was an independent factor predicting response (P = 0.001) and TTF (P = 0.0001). Conclusion: Keeping in mind that the study was not randomized and patients had diverse tumor types and a median of 5 prior therapies, our results suggest that identifying specific molecular abnormalities and choosing therapy based on these abnormalities is relevant in phase I clinical trials. Clin Cancer Res; 18(22); 6373–83. ©2012 AACR.

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. Mol Cancer Ther; 10(3); 558–65. ©2011 AACR.

Richter syndrome: Biology, incidence, and therapeutic strategies

Richters transformation denotes the development of high‐grade non‐Hodgkin lymphoma, prolymphocytic leukemia, Hodgkin disease, or acute leukemia in patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma. A search of published articles in Medline (PubMed) and abstracts from professional meetings was performed. An electronic database search of patients with CLL at The University of Texas M. D. Anderson Cancer Center (Houston, TX) determined the incidence of Richter syndrome (RS) in patients with CLL between 1992 and 2002. RS occurs in approximately 5% of patients with CLL. The large cells of RS may arise through transformation of the original CLL clone or represent a new neoplasm. RS may be triggered by viral infections, such as Epstein–Barr virus. Trisomy 12 and chromosome 11 abnormalities are more frequent in patients with RS than in the overall population of patients with CLL. Multiple genetic defects, such as mutations of the p53 tumor suppressor gene, p16INK4A, and p21, loss of p27 expression, deletion of retinoblastoma, increased copy number of C‐MYC, and decreased expression of the A‐MYB gene, have been described. These abnormalities may cause CLL cells to proliferate and—by facilitating the acquisition of new genetic abnormalities—to transform into RS cells. Therapeutic strategies include intensive chemotherapy, monoclonal antibodies, and stem cell transplantation. The response rates range from 5% to 43% (complete response, 5–38%), and the median survival duration ranges from 5 months to 8 months. In conclusion, RS may be triggered by viral infections or by genetic defects. Current treatments are aggressive, but prognosis is poor. Novel curative treatment strategies are needed. Cancer 2005.

Improvement of Overall and Failure-Free Survival in Stage IV Follicular Lymphoma: 25 Years of Treatment Experience at The University of Texas M.D. Anderson Cancer Center

PURPOSE Advanced-stage follicular lymphoma is considered incurable. The pace of improvements in treatment has been slow. This article analyzes five sequential cohorts of patients with stage IV follicular lymphoma treated between 1972 and 2002. METHODS Five consecutive studies (two were randomized trials) involving 580 patients were analyzed for overall survival (OS), failure-free survival (FFS), and survival after first relapse. A proportional hazards analysis, and subset analyses using the follicular lymphoma international prognostic index (FLIPI) score were performed. Treatment regimens included: cyclophosphamide, doxorubicin, vincristine, prednisone, bleomycin (CHOP-Bleo); CHOP-Bleo followed by interferon alfa (IFN-alpha); a rotation of three regimens (alternating triple therapy), followed by IFN-alpha; fludarabine, mitoxantrone, dexamethasone (FND) followed by IFN-alpha; and FND plus delayed versus concurrent rituximab followed by IFN-alpha. RESULTS Improvements in 5-year OS (from 64% to 95%) and FFS (from 29% to 60%) indicate steady progress, perhaps partly due to more effective salvage therapies, but the FFS data also indicate improved front-line therapies; these observations held true after controlling for differences in prognostic factors among the cohorts. The FLIPI model adds rigor to and facilitates comparisons among the different cohorts. An unexpected finding in this study was a trend toward an apparent FFS plateau. CONCLUSION Evolving therapy, including the incorporation of biologic agents, has led to stepwise significant outcome improvements for patients with advanced-stage follicular lymphoma. The apparent plateau in the FFS curve, starting approximately 8 to 10 years from the beginning of treatment, raises the issue of the potential curability of these patients.

PIK3CA mutation H1047R is associated with response to PI3K/AKT/mTOR signaling pathway inhibitors in early-phase clinical trials.

PIK3CA mutations may predict response to PI3K/AKT/mTOR inhibitors in patients with advanced cancers, but the relevance of mutation subtype has not been investigated. Patients with diverse cancers referred to the Clinical Center for Targeted Therapy were analyzed for PIK3CA and, if possible, KRAS mutations. Patients with PIK3CA mutations were treated, whenever possible, with agents targeting the PI3K/AKT/mTOR pathway. Overall, 105 (10%) of 1,012 patients tested harbored PIK3CA mutations. Sixty-six (median 3 prior therapies) of the 105 PIK3CA-mutant patients, including 16 individuals (of 55 PIK3CA-mutant patients tested) with simultaneous KRAS mutations, were treated on a protocol that included a PI3K/AKT/mTOR pathway inhibitor; 17% (11/66) achieved a partial response (PR). Patients with a PIK3CA H1047R mutation compared with patients who had other PIK3CA mutations or patients with wild-type PIK3CA treated on the same protocols had a higher PR rate (6/16, 38% vs. 5/50; 10% vs. 23/174, 13%, respectively; all P ≤ 0.02). None of the 16 patients with coexisting PIK3CA and KRAS mutations in codon 12 or 13 attained a PR (0/16, 0%). Patients treated with combination therapy versus single-agent therapies had a higher PR rate (11/38, 29% vs. 0/28, 0%; P = 0.002). Multivariate analysis showed that H1047R was the only independent factor predicting response [OR 6.6, 95% confidence interval (CI), 1.02-43.0, P = 0.047). Our data suggest that interaction between PIK3CA mutation H1047R versus other aberrations and response to PI3K/AKT/mTOR axis inhibitors warrants further exploration.

Clinical Outcomes and Prognostic Factors in Patients With Richter's Syndrome Treated With Chemotherapy or Chemoimmunotherapy With or Without Stem-Cell Transplantation

PURPOSE The purpose of this study was to assess the incidence, presenting characteristics, and treatment outcomes of Richters syndrome (RS) and factors predicting response and survival. PATIENTS AND METHODS An electronic database search of patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) who presented at The University of Texas M.D. Anderson Cancer Center (Houston, TX) between January 1975 and June 2005 was performed, and patient medical records were reviewed. RESULTS Of the 3,986 patients with CLL/SLL, 204 patients (5.1%) had possible RS, and 148 patients (3.7%) had biopsy- or fine-needle aspiration-proven RS. Treatment included chemotherapy alone and chemoimmunotherapy with rituximab. The overall response rate for the 130 assessable patients was 39% (chemotherapy, 34%; chemoimmunotherapy, 47%; P = .2). In multivariate analysis, factors predicting prolonged survival were Zubrod performance status 0-1 (P = .006), lactate dehydrogenase < or = 1.5x the upper limit of normal (P = .003), platelet count > or = 100,000 (P = .01), tumor size < or = 5 cm (P = .02), and fewer than two prior therapies (P = .02). The five adverse factors predicting shorter survival were used to design a model to predict an individual patients risk of death: the RS score. A total of 20 patients underwent stem-cell transplantation (SCT). Patients who underwent allogeneic SCT as postremission therapy had longer survival than patients who achieved remission and received no additional therapy or patients who underwent allogeneic or autologous SCT as salvage therapy (P = .019). CONCLUSION A score to predict an individual patients risk of death is proposed. Chemotherapy and rituximab combinations are effective in RS. Patients with available donors may be considered for allogeneic SCT as postremission therapy.

Liposomal vincristine in relapsed non-Hodgkin's lymphomas: Early results of an ongoing phase II trial

OBJECTIVE Vincristine is an active agent in lymphomas, but is often neurotoxic, and the resulting dose reductions have been associated with lower remission and survival rates in Hodgkins disease. Liposomal vincristine (Onco-TCS) has prolonged half-life, reaches higher concentration in tumors and lymph nodes than in nerves, and administered at full doses appears to be less neurotoxic, and more active then free vincristine in mice bearing L-1210 and P-388 leukemias. We therefore explored its activity in relapsed non-Hodgkins lymphomas (NHL) and acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS Eligible patients had histologically proven relapse, age > or = 16 years, normal renal function, neutrophils > 500/microliter, platelets > 50,000/microliter, and no HIV infection, central nervous system disease, or serious neuropathy. Patients were treated with 2.0 mg/m2 of liposomal vincristine i.v. over 60 minutes q 14 days. Responders received up to 12 injections. RESULTS Of the 51 registered patients, 35 are currently evaluable for response. Median age was 62 years (range 19-86), and 21 were male. The median number of prior regimens was 3 (range 1-10) and had included vincristine in all patients, of whom 51% were refractory to their last regimen. Serum LDH was high in 46%, and beta 2-microglobulin > 3.0 mg/l in 63% of patients. Of the 155 administered injections, 138 (89%) were at the 2.0 mg/m2 level. The median injected dose was 3.8 mg (range 2.6-4.8 mg), and median number of injections was 4 (range 1-12). Responses were seen in 14 of 34 (41%) patients with NHL (95% confidence intervals (95% CI) 25%-59%). Response rates were 10% for indolent, 71% for transformed, and 47% for aggressive NHL, but the 95% confidence intervals overlapped. Median progression-free survival was 5.5 months for responders. Grade 3-4 motor or sensory neuropathy was seen in 11, and caused termination of therapy in five patients. All five had prior neuropathy, two had previously received paclitaxel, one platinum, and two paclitaxel and platinum. Fever was detected in three patients, but there were no toxic deaths. CONCLUSIONS Liposomal vincristine is active and well tolerated in this heavily pretreated population with relapsed NHL, but can be neurotoxic in a fraction of patients heavily exposed to prior neurotoxic agents. These data, if confirmed, would suggest a potential role for liposomal vincristine in the combination therapy of previously untreated patients with NHL.

Assessing PIK3CA and PTEN in early-phase trials with PI3K/AKT/mTOR inhibitors

Despite a wealth of preclinical studies, it is unclear whether PIK3CA or phosphatase and tensin homolog (PTEN) gene aberrations are actionable in the clinical setting. Of 1,656 patients with advanced, refractory cancers tested for PIK3CA or PTEN abnormalities, PIK3CA mutations were found in 9% (146/1,589), and PTEN loss and/or mutation was found in 13% (149/1,157). In multicovariable analysis, treatment with a phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) inhibitor was the only independent factor predicting response to therapy in individuals harboring a PIK3CA or PTEN aberration. The rate of stable disease ≥6 months/partial response reached 45% in a subgroup of individuals with H1047R PIK3CA mutations. Aberrations in the PI3K/AKT/mTOR pathway are common and potentially actionable in patients with diverse advanced cancers. This work provides further important clinical validation for continued and accelerated use of biomarker-driven trials incorporating rational drug combinations.

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.