Phase I study of PLX4032: Proof of concept for V600E BRAF mutation as a therapeutic target in human cancer

9000

Background: PLX4032 is an oral, selective inhibitor of the oncogenic V600E mutant BRAF kinase with preclinical activity. V600E BRAF is the most common kinase mutation in melanoma (60%), also found in colorectal carcinomas (10%), most anaplastic and papillary thyroid carcinomas, and low-grade serous ovarian carcinomas. Methods: Phase I, dose-escalation study designed to determine maximum tolerated dose (MTD), safety, pharmacokinetic (PK) / pharmacodynamic (PD), and efficacy (RECIST evaluation every 8 wks) of PLX4032 in sequential cohorts of 3 to 6 patients (pts). Plasma PK samples were collected on days 1, 8 and 15. Results: 54 pts have been enrolled: metastatic melanoma (n=49), thyroid (n=3), rectal (n=1), or ovarian carcinoma (n=1). 26 pts received a crystalline formulation (CF) continuously at doses from 100 mg BID to 1600 mg BID with associated exposures below target plasma levels. 28 pts received an optimized formulation with increased bioavailability, predicted to have 10-fold greater bioavailability, at doses from 160 mg BID to 1120 mg BID. AUC was dose-proportional and above target levels at 240 mg BID and higher. There was 1 DLT at 720 mg BID (G4 pancytopenia); treatment was restarted at 360 mg BID without myelosuppression. At 1120 mg BID, 3 of 5 pts had DLT (rash and fatigue). One pt had grade 3 increased ALT at 360 mg BID. 13 melanoma pts (77 %M1C) treated at doses of 240 mg BID or higher of the increased bioavailability formulation have a minimum follow-up of 8 weeks. 5 of the 7 BRAF V600E+ pts treated at ≥ 240 mg BID had tumor regression, up to 83%, with 1 confirmed partial response (PR) and 1 unconfirmed PR (too early); 2 of 4 pts with unknown V600E status had tumor regression, up to 50%, with 1 confirmed PR; 2 BRAF wild-type pts had progressive disease. All 7 pts with tumor regression remain progression-free, ranging from 4 to 14 months. 3 thyroid cancer pts with V600E mutations have tumor regression (range 9–16%) and are progression-free (4–7 months). Conclusions: Dose escalation of PLX4032 reached DLTs at 1120 mg BID. 720 mg BID is the current MTD, but 960 mg BID may be explored. PLX4032 exhibits antitumor activity in V600E BRAF mutant tumors. These observations confirm that V600E BRAF is a valid therapeutic target in human cancer.

[Table: see text]

Survival of patients (pts) with metastatic melanoma treated with the anti-CTLA4 monoclonal antibody (mAb) CP-675,206 in a phase I/II study

8524

Background: The fully human anti-CTLA4 mAb CP-675,206 has demonstrated clinical activity in pts with metastatic melanoma. Prolonged survival was observed in a prior single-dose phase I study, even in pts who did not achieve objective tumor responses. Methods: A multidose phase I/II trial was conducted in pts (N = 119) with histologically confirmed stage IIIc (unresectable) or stage IV recurrent metastatic melanoma and ECOG PS = 1. The study consisted of a phase I, open-label, multidose study (3, 6, and 10 mg/kg) and a phase I expansion cohort for HLA-A2.1+ pts (10 mg/kg monthly [Q1M]), followed by a phase II open-label study of 2 dosing regimens: 10 mg/kg Q1M and 15 mg/kg every 3 months (Q3M). The primary endpoint was safety in phase I, immune monitoring in the expansion cohort, and response in phase II. Survival was analyzed as a secondary endpoint. Results: In the phase I study, Kaplan-Meier estimates of median overall survival were 17.6 months for all dose groups combined (n = 28). In the phase II study, median survival was 10.3 months in the 10 mg/kg arm and 11.0 months in the 15 mg/kg arm. Survival outcomes were favorable, compared with historical median survival of 7 months, independent of whether pts achieved an objective response. Updated survival data will be presented. Conclusions: Patients participating in a multiple dose study of CP-675,206 showed a survival time that was greater than expected on historic controls. These observations support the endpoints of an ongoing randomized phase III study in melanoma to further evaluate survival in the frontline setting.

[Table: see text]

[Table: see text]

Results of a phase II clinical trial of 2 doses and schedules of CP-675,206, an anti-CTLA4 monoclonal antibody, in patients (pts) with advanced melanoma

3000

Background: CP-675,206 has antitumor activity in pts with metastatic melanoma. A 2-stage, 2-arm phase II trial was conducted to choose the optimal dosing regimen for pivotal clinical trial testing. Methods: Eligible pts had measurable melanoma (stage IIIc or IV) progressing on or after prior therapy with ECOG PS = 1. In stage 1, 18 pts per arm were randomized to either 10 mg/kg monthly (10 Q1M) or 15 mg/kg every 3 months (15 Q3M). If 3 or more pts in either arm had CR or PR, then 25 more pts were entered to that arm. Primary endpoint was objective tumor response, and secondary endpoints were safety and survival. Results: 89 pts received at least 1 dose (44 at 10 Q1M, 45 at 15 Q3M), with both study arms moving to stage 2. 96% of pts had stage IV disease, and 57% had elevated LDH. There were no significant differences in age, sex, stage, or baseline LDH levels between study groups. A median of 3 doses (range, 1 to 26) at 10 Q1M and 1 dose (range, 1 to 9) at 15 Q3M were administered with 100% compliance. Dose delays occurred in 30% of pts treated at 10 Q1M and 16% at 15 Q3M. 2 pts at 10 Q1M and 5 pts at 15 Q3M continued on study beyond 12 months (mo). To date, 6 pts at 10 Q1M have been discontinued due to toxicity (3 diarrhea/colitis [1 requiring colectomy], Grave’s ophthalmopathy, pancreatitis, hypersensitivity reaction) and 2 pts at 15 Q3M (colitis and pancreatitis, diarrhea) (P = 0.14). There were no toxic deaths. 15 Q3M was associated with lower incidence of grade 3 or 4 AEs (31% vs 41% at 10 Q1M; P = 0.42). Responses by investigator assessment were 1 CR and 3 PRs at 10 Q1M, and 1 CR and 2 PRs at 15 mg/kg Q3M, including responses in skin, LN, bone, liver, lung, and adrenal glands. To date, only 1 pt with PR at 10 Q1M has relapsed, and the remaining responses are ongoing (18+ to 28+ mo). Median survival is 10.3 mo at 10 Q1M and 11.0 mo at 15 Q3M (P = NS). Conclusions: The 15 mg/kg Q3M regimen was chosen for further clinical testing based on comparable antitumor efficacy and a trend to improved feasibility and safety compared with 10 mg/kg Q1M. CP-675,206 at this dose and schedule is being examined in pivotal phase II and III clinical trials for pts with melanoma, and in early phase II trials in pts with CRC and NSCLC.

No significant financial relationships to disclose.

A multicenter phase II study of erlotinib and bevacizumab in patients with metastatic melanoma

8539

Background: Erlotinib and bevacizumab have demonstrated activity in a number of malignancies by virtue of interrupting interdependent signaling pathways thought important in tumorigenesis. Melanoma may be an appropriate target based on its expression of EGFR and VEGF. We conducted a phase II multi-institutional trial evaluating erlotinib and bevacizumab in advanced melanoma patients. Methods: Eligibility included measurable disease, ECOG PS = 0–1, adequate organ function, no more than one prior therapy for metastatic disease, and CNS metastases were allowed if limited and controlled. Patients received oral erlotinib 150 mg/day and bevacizumab 10 mg/kg IV Q 2 weeks with tumor evaluation every 8 weeks. The primary outcomes were response rate (RR), response duration, and frequency of PFS >6 months. Secondary outcomes included overall survival, safety, and tolerability. A two-stage accrual design was employed ensuring that = 3/21 patients had PFS >6 months before additional patients were accrued. Results: As of Nov 2006, 29 patients with metastatic melanoma were enrolled. A total of 23 patients were evaluable for response. The majority was male 19/29 (65%) and had a median age = 62 yrs (range 35–78 years). Fifteen of the 29 had stage M1c disease (51.7%) and 18/29 (62.1%) had a PS = 1. Ten patients (34%) had prior adjuvant therapy and 6 patients (21%) prior therapy for metastatic disease. There were 2/23 (9%) partial responses lasting < 6 months and 5/23 (22%) had stable disease lasting > 6 months. The median progression free survival of evaluable patients was 96 days (95% CI: 50 - 142 days). A total of 25 grade III toxicities were observed with the most common being rash/pruritis (n=4), pain (n=4), fatigue (n=3), hypertension (n=2) and diarrhea (n=2). Two grade IV toxicities were observed (myocardial infarction and bowel perforation) both thought to be due to bevacizumab. Conclusion: The combination of erlotinib (150 mg/day) and bevacizumab (10 mg/kg) appears potentially active in patients with metastatic melanoma with largely tolerable toxicities. Accrual of a total of 41 patients will be completed shortly.

[Table: see text]

Natural history of diarrhea associated with the anti-CTLA4 monoclonal antibody CP-675,206

3038

Background: Diarrhea resulting from immune activation has been associated with CTLA4 blockade. For example, in patients (pts) with stage IV melanoma receiving ipilimumab (MDX-010), a number of pts developed grade 3/4 autoimmune enterocolitis and severe diarrhea (Attia et al, 2005). In a single-dose phase I trial of CP-675,206 at doses up to 15 mg/kg in pts with solid tumors (n = 39), 9 instances of diarrhea were reported including 3 grade 3 events (Ribas et al, 2005). The incidence and severity of diarrhea was assessed in pts receiving CP- 675,206 in a large phase I/II study. Methods: An open-label phase I/II trial of CP-675,206 was conducted in pts with stage III (unresectable) or stage IV melanoma and an ECOG PS = 1. Diarrhea was assessed in pts treated at the phase II doses: 10 mg/kg monthly (Q1M) in phase I (n = 22), or 10 mg/kg Q1M (n = 44) or 15 mg/kg every 3 months (Q3M, n = 45) in phase II. Results: Medians of 3.5 doses (range, 1 to 18) at 10 mg/kg Q1M in phase I, 3 doses (range, 1 to 26) at 10 mg/kg Q1M in phase II, and 1 dose (range, 1 to 9) at 15 mg/kg Q3M were administered with 100% dose compliance. Treatment-related diarrhea was reported by 43 (39%) of 111 pts, and grade 3 diarrhea occurred in 14 (13%) pts. One patient had grade 4 colitis resulting in a colectomy. Diarrhea (all grades) occurred with similar frequency in each dose group; however, grade 3 treatment-related diarrhea occurred in 8% of pts treated with 15 mg/kg Q3M compared with 18% of pts treated with 10 mg/kg Q1M in phase I and 14% of pts treated with 10 mg/kg Q1M in phase II. Among 9 pts with an objective response, 8 experienced diarrhea (3 of which were grade 3). The majority of cases (65%) were mild to moderate in severity with a median time to onset of 51 days (range, 1 to 583 days) and resolution of 8 days (range, 1 to 182 days). More than half of pts who reported serious events of diarrhea were treated with steroids. Conclusions: Diarrhea associated with CP-675,206 was primarily mild to moderate in severity, transient, and manageable. In addition, 15 mg/kg Q3M may be better tolerated than 10 mg/kg Q1M. Ongoing clinical trials in pts with advanced melanoma will provide further information about the incidence, severity, and optimal management of diarrhea associated with CP-675,206.

No significant financial relationships to disclose.

Safety and outcome after fludarabine-thiotepa-TBI conditioning for allogeneic transplantation: a prospective study of 30 patients with hematologic malignancies

Fludarabine, thiotepa and total body irradiation (TBI) has been used as conditioning in haplo-identical transplantation. We studied this conditioning regimen in adults undergoing matched sibling transplantation and alternative donor transplantation. A total of 30 consecutive patients underwent matched related, haplo-identical related or matched unrelated donor transplantation with fludarabine, thiotepa and TBI conditioning. All but four had advanced hematologic malignancies. For haplo-identical transplant, ATG was added to the regimen. All patients received peripheral blood stem cells; these were T-cell depleted for 2-antigen or 3-antigen mismatched related transplantation. Additional graft-versus-host disease prophylaxis consisted of tacrolimus and mini-methotrexate. One recipient of haplo-identical transplant failed to engraft; all other evaluable patients had prompt engraftment. Four patients died of regimen-related toxicity. In all, 14 additional patients died of regimen-related causes including four from failure to thrive with persistent thrombocytopenia and four from delayed pulmonary toxicity. Six patients relapsed. Progression-free survival at 12 months was 47% (90% CI: 25-69%) for recipients of HLA-identical sibling transplants and 30% (90% CI: 14-46%) for all patients. Five of six long-term survivors have extensive chronic GVHD. As a result of the delayed complications and a relatively high recurrence rate, we abandoned this regimen.

Kidney cancer: the Cytokine Working Group experience (1986-2001): part II. Management of IL-2 toxicity and studies with other cytokines

The Cytokine Working Group (CWG) was initially established in 1986 as the Extramural IL-2/LAK Working Group. With funding from the National Cancer Institute (NCI), the CWG was mandated to confirming data regarding the efficacy of the high-dose interleukin-2 (IL2)/lymphokine-activated killer cell (LAK cell) regimen piloted at the NCI in the treatment of renal cell cancer. Since those initial studies, the CWG has conducted a series of clinical trials, often with correlative immunologic investigations, to evaluate combination immunotherapy in attempts to enhance the efficacy of IL-2 or to reduce toxicity. Subsequently, the CWG conducted trials to demonstrate the activity of lower-dose outpatient combination cytokine regimens to help determine their role in the armamentarium of treatment for metastatic renal cell cancer. This has culminated in a phase III randomized trial comparing the activity of high-dose IL-2 with the activity of outpatient IL-2 plus interferon-alpha. The CWG also has honed the management of both high-dose IL-2 and outpatient IL-2 regimens to make these safer in the hands of experienced clinicians. In addition, the CWG has produced a series of carefully conducted clinical trials of new cytokines, again attempting to define their clinical efficacy as anticancer agents. These include studies of IL-4, IL-6, and IL-12. Currently, the CWG is conducting studies with new approaches to IL-2 therapy, as well as planning trials with new agents for treatment of renal cell cancer. This review describes these efforts conducted over the past 15 yr.

Kidney cancer: the Cytokine Working Group experience (1986-2001): part I. IL-2-based clinical trials

The Cytokine Working Group (CWG) was initially established in 1986 as the Extramural IL-2/LAK Working Group. With funding from the National Cancer Institute (NCI), the CWG was mandated to confirming data regarding the efficacy of the high-dose interleukin-2 (IL2)/lymphokine-activated killer cell (LAK cell) regimen piloted at the NCI in the treatment of renal cell cancer. Since those initial studies, the CWG has conducted a series of clinical trials, often with correlative immunologic investigations, to evaluate combination immunotherapy in attempts to enhance the efficacy of IL-2 or to reduce toxicity. Subsequently, the CWG conducted trials to demonstrate the activity of lower-dose outpatient combination cytokine regimens to help determine their role in the armamentarium of treatment for metastatic renal cell cancer. This has culminated in a phase III randomized trial comparing the activity of high-dose IL-2 with the activity of outpatient IL-2 plus interferon-alpha. The CWG also has honed the management of both high-dose IL-2 and outpatient IL-2 regimens to make these safer in the hands of experienced clinicians. In addition, the CWG has produced a series of carefully conducted clinical trials of new cytokines, again attempting to define their clinical efficacy as anticancer agents. These include studies of IL-4, IL-6, and IL-12. Currently, the CWG is conducting studies with new approaches to IL-2 therapy, as well as planning trials with new agents for treatment of renal cell cancer. This review describes these efforts conducted over the past 15 yr.

Temozolomide and whole brain irradiation in melanoma metastatic to the brain: a phase II trial of the Cytokine Working Group

PURPOSE

To evaluate the antitumor effects and toxicities of whole brain irradiation (WBI) with temozolomide (TMZ) administered by prolonged oral dosing in patients with melanoma metastatic to the brain.

BACKGROUND

Patients with melanoma metastatic to the central nervous system (CNS) have an extremely poor prognosis and appear to benefit little from WBI. TMZ is an alkylating agent chemically similar to dacarbazine (DTIC) with good oral bioavailability and CNS penetration. TMZ has broad preclinical antitumor activity which in melanoma is comparable to that of DTIC. The combination of TMZ and WBI may provide enhanced antitumor activity against CNS metastasis from melanoma.

PATIENTS AND METHODS

Patients with measurable CNS metastases with or without systemic disease were treated with WBI, 30 Gray over ten fractions (days 1-5 and 8-12). TMZ, 75 mg small middle dotm(2 small middle dot)day, was started on day 1, continued daily for 6 weeks and repeated every 10 weeks.

RESULTS

Thirty-one patients were treated. There was one CNS complete response of 4.5 months and two CNS partial responses of 2 months and 7 months duration; the latter patient also had a 4-month complete remission of systemic metastases. Toxicities were limited to a single episode of grade 3 transaminase elevation and two episodes of grade 3 neutropenia, one complicated by fatal sepsis. The median progression-free interval for both CNS and extracranial sites was 2 months (range 1 week-11 months), and median survival 6 months (range 2-12 months).

CONCLUSIONS

WBI has lower than expected activity in CNS metastasis of malignant melanoma. Although TMZ can be safely administered with WBI, the combination has limited anti-tumor activity.

Phase II studies of bryostatin-1 in patients with advanced sarcoma and advanced head and neck cancer

BACKGROUND

Bryostatin 1 is a marine derived macrolactone with antineoplastic activity modulated through protein kinase C, and with good activity in in vitro and in vivo models. There are few drugs that offer palliation for metastatic soft-tissue sarcoma and head and neck cancer, and drugs with new mechanisms of action warrant detailed disease specific study.

PATIENTS AND METHODS

Two phase II studies for patients with incurable soft tissue sarcoma (12), or head and neck cancer (12) were conducted. Patients were treated with bryostatin, 120 mg/m2/72 hours every 2 weeks for 3 cycles prior to re-evaluation. Most patients had received prior chemotherapy.

RESULTS

No patients had objective responses to therapy. Six patients had brief periods of disease stabilization. Toxicity was generally mild, with myalgia being prominent (n=8). Hyponatremia, not previously described, occurred in 5 patients. The mechanism of this toxicity was unclear.

CONCLUSIONS

Bryosytatin 1 given as a single agent for advanced adult soft tissue sarcoma and head and neck cancer is inactive. Myalgia and hyponatremia were the predominant toxicities.

Outpatient biochemotherapy with interleukin-2 and interferon alfa-2b in patients with metastatic malignant melanoma: results of two phase II cytokine working group trials

PURPOSE

The Cytokine Working Group performed a randomized phase II trial of two outpatient biochemotherapy regimens to identify an outpatient regimen with high antitumor activity and less toxicity than inpatient regimens which might be compared with chemotherapy or inpatient biochemotherapy regimens in future phase III trials.

PATIENTS AND METHODS

Eighty-one patients with metastatic malignant melanoma received dacarbazine 250 mg/m(2)/d intravenously (IV) and cisplatin 25 mg/m(2)/d IV on days 1, 2, and 3, plus interferon (IFN) alfa-2b 5 mU/m(2) subcutaneously (SC) on days 6, 8, 10, 13, and 15, given every 28 days. Interleukin-2 (IL-2) was given daily on days 6 to 10 and 13 to 15. In group 1, IV IL-2 was given at 18.0 MU/m(2), and in group 2, SC IL-2 was given at 5.0 mU/m(2).

RESULTS

In group 1 (IV IL-2), there were five complete responses (CRs) and 11 partial responses (PRs) among 44 patients (objective response rate [ORR], 36%; 95% confidence interval [CI], 22% to 51%). In group 2 (SC IL-2), there was one CR and five PRs among the 36 patients (ORR, 17%; 95% CI, 4% to 29%). The median survival was 10.7 months in group 1 and 7.3 months in group 2. Eleven patients in group 1 and four patients in group 2 remain alive as of the last follow-up. Toxicities in both groups were similar. No patient required hospitalization for neutropenic fever.

CONCLUSION

Biochemotherapy has activity in these outpatient regimens with acceptable toxicity. The antitumor activity observed with the IV IL-2 regimen seems similar to that of inpatient biochemotherapy regimens. If inpatient biochemotherapy regimens develop an established role in the management of melanoma, future phase III trial comparisons with this outpatient IV IL-2 regimen would be appropriate.

A phase I study of CNI-1493, an inhibitor of cytokine release, in combination with high-dose interleukin-2 in patients with renal cancer and melanoma

CNI-1493, an inhibitor of proinflammatory cytokines, was studied in a Phase I trial in melanoma and renal cancer patients receiving high-dose interleukin 2 (IL-2). Objectives of the study were to define the maximum tolerated dose (MTD) and toxicity of CNI-1493, to assess its pharmacological effects, and to define its pharmacokinetics. Twenty-four patients were treated in sequential cohorts with CNI-1493 doses from 2 through 32 mg/m2 daily. Patients first received only CNI-1493 daily for 5 days. After a 9-day rest, patients received two 5-day courses of IL-2 of 600,000 IU/kg every 8 h for up to 14 doses/course plus daily CNI-1493; courses were separated by a 9-day rest period. CNI-1493 administered alone was well tolerated at doses through 32 mg/m2; MTD was not reached. The only clinical toxicity attributed to CNI-1493 was occasional injection-site phlebitis. Grade 1 creatinine increases occurred in 1 of 7 patients at 4 mg/m2, in 1 of 1 patients at 25 mg/m2, and in 3 of 6 patients at 32 mg/m2 CNI-1493 alone. In combination with high-dose IL-2, CNI-1493 at > or = 25 mg/m2 seemed to exacerbate IL-2-induced nephrotoxicity: grade 3 or 4 creatinine increases developed in 3 of 6 patients at 25 or 32 mg/m2, as compared with 1 of 16 patients at doses < or = 16 mg/m2. The MTD for CNI-1493 given with high-dose IL-2 was 16 mg/m2. The dose-limiting toxicity of IL-2 was hypotension in 63% of patients; overall tolerance to IL-2 was not improved by CNI-1493. However, relative to changes seen in a reference group receiving high-dose IL-2 alone, at doses > or = 4 mg/m2 CNI-1493 did show evidence of pharmacological activity as an inhibitor of tumor necrosis factor production.

Phase II trial of interleukin 2, interferon alpha, and 5-fluorouracil in metastatic renal cell cancer: a cytokine working group study

The purpose of this study was to evaluate the potential efficacy of alternating two outpatient regimens for the treatment of metastatic renal cell cancer. These regimens consisted of 4 weeks of recombinant interleukin 2 (rIL-2) plus IFN-alpha2B followed by 4 weeks of 5-fluorouracil plus IFN-alpha2B. Fifty patients meeting eligibility criteria of previous Cytokine Working Group studies were treated on an outpatient basis. Patients received s.c. rIL-2 (Proleukin; Chiron, Emeryville, CA) during weeks 1-4 of the 8-week regimen. During weeks 1 and 4, the dosage for rIL-2 was 10 MIU/m2 twice daily on days 3-5, and the dosage for IFN-alpha2B (Intron; Schering Plough, Kenilworth, NJ) was 6 MIU/m2 on day 1. During weeks 2 and 3, the dosage for rIL-2 was 5 MIU/m2 on days 1, 3, and 5, and the dosage for IFN-alpha2B was 6 MIU/m2 on days 1, 3, 5. During weeks 5-8, 5-fluorouracil (750 mg/m2) was administered once weekly by i.v. infusion, and IFN-alpha2B (9 MIU/mZ) was administered as a s.c. injection three times weekly. Throughout the treatment, an assessment of quality of life was made and a symptom-distress scale was evaluated. There were two patients with complete responses (CRs) and seven with partial responses (PRs) for an objective response rate of 18% (95% confidence interval, 10-25). The median response duration was 8 months (range, 3-51+ months). The CRs lasted 5 months and 51+ months and the PRs ranged from 3+ to 18 months. After completing at least one course of treatment, eight patients (three with PR, one with minor response, four with stable disease) became CRs after surgery for remaining metastatic disease. Six remain alive at 43+ to 53+ months, and 5 remain disease-free since surgery. The median survival of the study group is 17.5 months, with a maximal follow-up of 53+ months. The range in survival is 1-53+ months. Toxicity was primarily constitutional. and treatment modifications were designed to maintain toxicity at grade 2/3. The most common toxicities during treatment with IL-2/IFN were fatigue, nausea/vomiting, anorexia, skin reaction, diarrhea, fever, and liver enzyme elevations. One-third had central nervous system toxicity (headache, depression, insomnia). During 5FU/IFN treatment, 49 of 50 patients experienced grade 2/3 myelosuppression during course 1. Eight patients experienced grade 4 toxicities. In conclusion, the activity of this alternating regimen is similar to that of IL-2/IFN alone, given in 4-week cycles. The addition of 5FU/IFN failed to increase the efficacy and added new toxicity (myelosuppression). This report does not confirm the results previously reported for either alternating or simultaneous administration of these three agents. Because 5FU does not appear to add to the antitumor activity of IL-2-based therapy for renal cancer, current efforts are directed toward a Phase III randomized comparison of high-dose i.v. bolus inpatient IL-2 treatment versus treatment with outpatient s.c. injection of IL-2 plus IFN.

Fludarabine-based conditioning for allogeneic transplantation in adults with sickle cell disease

Although allogeneic transplantation can be curative for patients with sickle cell disease, the toxicity of conditioning regimens has precluded its use in adults with significant end-organ damage. Newer conditioning regimens have been developed that are less toxic and that may broaden the applicability of allogeneic transplantation in this disorder. We report two adults with end-stage sickle cell disease, who underwent allogeneic transplantation from an HLA-identical sibling donor after conditioning with fludarabine/melphalan and ATG. Both patients had been extensively transfused and one had multiple RBC antibodies. One of the patients also had end-stage renal disease, and was dialysis dependent. Engraftment occurred promptly in both patients. Both achieved 100% donor chimerism and both were free of pain crises after transplant. The first patient died of a respiratory failure related to chronic graft-versus-host disease (GVHD) on day 335 after transplantation. The second patient developed severe gastro-intestinal GVHD and TTP and died on day 147 after transplantation. Conditioning with fludarabine/melphalan and ATG followed by allogeneic stem cell transplantation resulted in prompt and reliable engraftment in adults with end-stage sickle cell disease. The incidence of severe GVHD was unacceptably high and may be related to the ethnicity of the patients or to the inflammatory state associated with pre-existing sickle cell disease.

Flavopiridol, a novel cyclin-dependent kinase inhibitor, in metastatic renal cancer: a University of Chicago Phase II Consortium study

PURPOSE

Flavopiridol is the first cyclin-dependent kinase (cdk) inhibitor to enter clinical trials. Serum levels of flavopiridol obtained during phase I studies were sufficient to inhibit in vitro cancer cell growth. Because responses were observed in kidney cancer patients in the phase I trials, we performed a phase II trial of flavopiridol in this patient population.

PATIENTS AND METHODS

Thirty-five minimally pretreated patients were accrued using a standard two-step mechanism. Flavopiridol (50 mg/m(2)/d) was administered by continuous infusion for 72 hours every 2 weeks, and response was evaluated every 8 weeks. Peripheral blood mononuclear cells (PBMCs) were collected at baseline, at completion of drug infusion, and on day 7 of the first therapy cycle, and cell cycle parameters after phytohemagglutinin and interleukin-2 stimulation were assessed.

RESULTS

There were two objective responses (response rate = 6%, 95% confidence interval, 1% to 20%). The most common toxicities were asthenia, occurring in 83% of patients (grade 3 or 4 in 9%), and diarrhea, occurring in 77% of patients (grade 3 or 4 in 20%). Also, nine patients (26%) experienced grade 3 or 4 vascular thrombotic events, including one myocardial infarction, two transient neurologic ischemic attacks, four deep venous thrombosis, and two pulmonary emboli. Cell cycle studies did not reveal any effect of flavopiridol on stimulated PBMCs.

CONCLUSION

Flavopiridol, at the dose and schedule administered in this trial, is ineffective in metastatic renal cancer. In addition to the diarrhea observed in phase I studies, we also observed a higher incidence of asthenia and serious vascular thrombotic events than expected.

Multi-institutional study of the angiogenesis inhibitor TNP-470 in metastatic renal carcinoma

PURPOSE

Renal cell carcinoma is resistant to most chemotherapy, and only a minority of patients respond to immunotherapy. Its highly vascular nature suggests that antiangiogenesis therapy might be useful. We thus performed a phase II study of the fumigillin analog TNP-470 in previously treated patients with metastatic renal cell carcinoma.

PATIENTS AND METHODS

Metastatic renal cell carcinoma patients with good organ function were entered onto the study through five separate institutions. There were no exclusion criteria for prior therapy. All patients were treated at a dose of 60 mg/m(2) of TNP-470 infused over 1 hour three times per week.

RESULTS

Thirty-three patients were enrolled. Therapy was generally well tolerated, but asthenia, fatigue, vertigo, dizziness, sense of imbalance, and loss of concentration were common and severe enough to lead to therapy discontinuation in five patients. There was only one partial response of short duration (response rate, 3%, 95% confidence interval, 0% to 16%), but six patients (18%) remained on study for 6 or more months without toxicity or disease progression.

CONCLUSION

Long-term therapy with TNP-470 has manageable toxicities and is feasible in patients with metastatic renal cell carcinoma but does not lead to any significant objective responses. Further studies in this population using TNP-470 schedules that produce more prolonged drug levels and clinical trial end points other than objective tumor regression may be indicated.

A phase II trial of interleukin-2 in myelodysplastic syndromes

Patients with myelodysplastic syndromes (MDS) show a decrease in the number and function of natural killer (NK) cells, including lymphokine activated killer (LAK) cell activity. Interleukin-2 (IL-2) stimulates the proliferation and activity of these lymphocytes. Anecdotal clinical experience has shown haematological and cytogenetic improvement in myelodysplasia by low-dose IL-2 treatment. A total of 10 patients with MDS were treated with 1 million units of IL-2 subcutaneously daily for 12 weeks. Even though improvement in CD16+/CD56+ cell numbers was seen in a majority of the patients, the haematological status and transfusion requirements remained unchanged. There was minimal toxicity from this therapy.

Interleukin-2-based therapy for metastatic renal cell cancer: the Cytokine Working Group experience, 1989-1997

PURPOSE

This article reviews long-term follow-up data from three phase II studies conducted by the Cytokine Working Group from 1989 to 1995 that evaluated various recombinant interleukin-2 (rIL-2) -based regimens in patients with metastatic renal cell cancer. Response rates, long-term response duration, and toxicity are compared.

PATIENTS AND METHODS

The Cytokine Working Group studies reviewed here investigated the safety and efficacy of two high-dose intravenous rIL-2-based regimens and two moderate-dose outpatient subcutaneous rIL-2-based regimens in patients with progressive metastatic renal cell cancer. A randomized phase II study, initiated in 1989, investigated the safety and efficacy of high-dose intravenous rIL-2 alone and high-dose intravenous rIL-2 plus recombinant interferon-alpha (rIFN-alpha). A second phase II study, initiated in 1992, tested the safety and efficacy of moderate-dose subcutaneous rIL-2 plus subcutaneous rIFN-alpha in the outpatient setting. The third trial, initiated in 1995, investigated a regimen consisting of the previous subcutaneous rIL-2 plus rIFN-alpha regimen alternating with intravenous bolus 5-fluorouracil (5-FU) plus subcutaneous rIFN-alpha. Median follow-up for these studies is 72 months, 48 months, and 24 months, respectively.

RESULTS

The overall response rates observed with each of these regimens were similar (17% with high-dose rIL-2 alone, 11% with high-dose rIL-2/rIFN-alpha, 17% with outpatient subcutaneous rIL-2/rIFN-alpha, and 16% with outpatient rIL-2/rIFN-alpha, plus 5-FU/rIFN-alpha). However, the high-dose rIL-2 regimen produced a 7% complete response rate, compared with 0%, 4%, and 4%, respectively, with each of the other regimens. Median response duration was also much longer with high-dose intravenous rIL-2 alone (53 months), compared with 7 months, 12 months, and 9 months, respectively, with each of the other regimens.

CONCLUSION

Complete response rate and response duration appear to favor the high-dose intravenous rIL-2 regimen. This will require verification in a randomized study comparing the best high-dose arm (rIL-2 alone) with the best outpatient regimen (rIL-2/IFN-alpha). The Cytokine Working Group is currently conducting such a study.

Prospective randomized trial of lisofylline for the prevention of toxicities of high-dose interleukin 2 therapy in advanced renal cancer and malignant melanoma

The therapeutic application of high-dose interleukin (IL) 2 in human malignancy is limited by severe multiorgan toxicities that are mediated, in part, by tumor necrosis factor (TNF) and IL-1. CT1501R (lisofylline; LSF) is one of several methyl xanthine congeners that inhibit the effects of TNF by the interruption of specific signal transduction pathways. This randomized, placebo-controlled trial was designed to assess the activity of LSF in reducing the toxicities of high-dose IL-2 therapy. Fifty-three patients with metastatic renal cancer or malignant melanoma were treated with i.v. bolus IL-2, 600, 000 IU/kg every 8 h for 5 days (14 doses), followed by 9 days of rest and another 5-day course of IL-2. Patients were randomly assigned to LSF, 1.5 mg/kg i.v. bolus, or placebo every 6 h during IL-2 therapy. All patients were to be treated to individual maximum tolerance of IL-2 at the intensive care unit level of support. The end points for statistical analysis were the number of IL-2 doses administered during the first cycle of treatment (maximum, 28) and the toxicities experienced by each group after the first 8 planned IL-2 doses. There was no difference between the LSF and placebo groups in the mean number of IL-2 doses tolerated in the entire first cycle of therapy (19.6 +/- 5.4 versus 19.5 +/- 5.8, P = 0.86) or in the first or second 5-day course of IL-2. The only significant difference in toxicities occurring through the eighth dose of IL-2 was in the maximum elevation of serum creatinine (mean, 1.7 +/- 0.8 for placebo versus 1.5 +/- 0.6 mg/dl for LSF, P = 0.013). A Monte Carlo analysis of major toxicities over the first 14-dose course of therapy showed a statistically significant difference favoring the LSF-treated group (P = 0.025). LSF was well tolerated, associated only with mildly increased nausea (P = 0.006 after eight IL-2 doses, but not significant for the entire first cycle). The antitumor activity was comparable in both groups (objective responses, 2 of 28 with LSF versus 4 of 24 with placebo). The mean peak plasma concentrations of LSF on days 1, 5, and 19 were 6.24, 3.83, and 5.04 micromol/liter, respectively. In conclusion, with this dose and schedule, LSF did not alter the toxicities of high-dose i.v. IL-2 sufficiently to impact the overall dose intensity of IL-2. Successful IL-2 toxicity modulation may require the use of higher doses of LSF, the development of agents with more potent anti-TNF activity, and/or combined modulating agents that function via distinct mechanisms to interrupt cytokine-mediated signaling.

High-dose chemotherapy combined with escalating doses of cyclosporin A and an autologous bone marrow transplant for the treatment of drug-resistant solid tumors: a phase I clinical trial

High response rates are seen in patients undergoing dose-intensive chemotherapy and autologous marrow transplantation due to the ability of the therapy to overcome inherent or acquired drug resistance. However, relapse rates are also high because this drug resistance reversal is incomplete. Because both P-glycoprotein- and platinum-induced resistance appear to be clinically important and can be reversed in vitro with a short exposure of cyclosporin A (CSA) at 2000 and 5000 ng/ml, respectively, we undertook a trial of high-dose chemotherapy with carboplatin (1500mg/m2), mitoxantrone (75 mg/m2), and cyclophosphamide (120 mg/kg) over a 5-day period combined with escalating doses of CSA. Thirty-seven patients with primarily breast cancer (61% doxorubicin resistant) and ovarian cancer (85% platinum resistant) were treated with CSA given as a bolus 18 h prior to chemotherapy, followed by a 5-day infusion at doses of 5.0-28.2 mg/kg/day and the chemotherapy. The maximum tolerated dose of CSA was a bolus of 5.5 mg/kg and an infusion of 15. 9 mg/kg/day, which gave a mean serum CSA level of 1544 ng/ml. The dose-limiting toxicity was severe mucositis and enteritis, leading to infectious complications. Nephrotoxicity was seen in 42% and, while usually mild and reversible, was fatal in two patients with pretreatment creatinine clearances h80 ml/min. Grade III-IV isolated hyperbilirubinemia was seen in 39%, but appeared to be of no clinical significance. The overall response rate for the 26 patients with measurable/evaluable disease was 73% and 63% for those with doxorubicin- or platinum-resistant disease. The median overall survival and progression-free survival for the group were 18.1 and 8. 0 months. The overall survival for the nine patients with doxorubicin-resistant breast cancer was 19.3 months. Although we did not achieve CSA levels needed to reverse platinum resistance in vivo, levels approaching those needed to reverse P-glycoprotein resistance were reached at the maximum tolerated dose. The strategy of combining dose intensity with drug resistance reversal deserves further study, especially with the advent of potentially less toxic agents available to reverse P-glycoprotein-mediated resistance.

Severe eosinophilia and hepatocellular carcinoma: an unusual association

Peripheral eosinophilia is an unusual but recognized paraneoplastic manifestation of malignant diseases. We report a case of eosinophilia associated with hepatocellular carcinoma which is the second case described in English literature.

A phase II trial of high-dose mitoxantrone, carboplatin, and cyclophosphamide with autologous bone marrow rescue for recurrent epithelial ovarian carcinoma: analysis of risk factors for clinical outcome

Despite high initial response rates to platinum-based chemotherapy, most patients with advanced ovarian carcinoma die of drug-resistant disease. Drug resistance can be overcome in the hematologic malignancies and lymphomas with high-dose therapy and bone marrow transplantation (BMT) when used early, suggesting that this therapy may also be of value in ovarian carcinoma. As a prelude to the use of high-dose chemotherapy with BMT early in the management of advanced ovarian carcinoma, we evaluated a new high-dose regimen in patients with relapsed/refractory ovarian carcinoma to define toxicities and responses. Thirty patients were treated, of whom 20 were platinum resistant and 22 had > 1 cm maximum diameter disease. They received mitoxantrone (75 mg/m2), carboplatin (1500 mg/m2), and cyclophosphamide (120 mg/kg), followed by an autologous BMT. Overall, 89% responded, with clinical complete responses seen in 88 vs 47% (P = 0.06) of platinum-sensitive vs -resistant disease. There was only one early death (3.3%) due to Aspergillus pneumonia. Median survival for all 30 patients was 29 months, and at 3 years 23% are alive without disease. There was a 10.1- vs 5.1-month progression-free survival for patients with platinum-sensitive versus -resistant disease, and at a median follow-up of 12 months, 80% of the platinum-sensitive patients are alive. This regimen is safe, and for platinum-sensitive disease appears superior to other salvage therapies. Its use should be explored earlier in the management of advanced ovarian carcinoma.

A phase I/II study of sequential interleukin-3 and granulocyte-macrophage colony-stimulating factor in myelodysplastic syndromes

In this phase I/II study, 9 patients with myelodysplastic syndromes (MDS) were treated with interleukin-3 (IL-3) followed by granulocyte-macrophage colony-stimulating factor (GM-CSF). Each treatment cycle was 28 days long and administered as follows: 1 microgram/kg/d IL-3 on days 1 through 7 and 3 micrograms/kg/d GM-CSF for days 8 through 21, followed by a 7-day rest period. IL-3 dose escalations were planned, but the dose of GM-CSF was fixed. Three patients had refractory anemia, 4 had refractory anemia with ringed sideroblasts, and 2 had refractory anemia with excess blasts. Six patients were dependent on red blood cell transfusions, 1 on platelet transfusions, and 2 on both. The absolute neutrophil count improved in 7 (77%) patients and the platelet count improved in 3 (33%) patients during therapy. Hemoglobin levels were unchanged. A clinically relevant response was seen in only 1 patient with thrombocytopenia, and he received five cycles of therapy. The neutrophil count decreased in 2 patients and the platelet count decreased in 4 patients during treatment. The toxicity of the treatment was significant. In the first cohort of 3 patients, 1 patient developed supraventricular tachycardia and congestive heart failure. In the second group, 1 patient developed progressive granulocytopenia and died of gram-negative septicemia. Because of the disparate toxicity, 3 more patients were treated at the same dose level. One of these experienced a high fever and bone pain requiring hospitalization. Because of these adverse effects, the IL-3 dose was not escalated and all patients received 1 microgram/kg/d for 7 days. We believe that sequential therapy with IL-3 and GM-CSF at these dose levels causes unacceptable toxicity in patients with MDS. The major toxic events occurred during weeks 4 and 5 after starting treatment and may have been primarily caused by GM-CSF therapy. Although neutrophil counts improve in most patients, the effect on red blood cells and platelets is minimal. At present, this form of therapy remains problematic and appears to have a limited potential in the management of MDS.

Functional analysis of human T cell subsets defined by monoclonal antibodies. III. Regulation of helper factor production by T cell subsets

In the present report we extended our previous studies demonstrating that obligatory T-T interactions are important in regulating human immune responses in vitro. Functionally distinct human T cell subsets were isolated by complement-mediated lysis using the monoclonal antibodies OKT4 and OKT8. Evidence was obtained that during allogeneic interactions, OKT4+, but not OKT8+, responder T cells are required to generate helper factor(s) capable of polyclonally activating human B cells independent of additional T cell help. Importantly, the alloantigen-induced helper factor(s) production and/or release was found to be suppressed by addition of graded numbers of radiosensitive OKT8+ cells. On the other hand, no evidence was obtained that supernatant derived from alloactivated OKT8+ cells could counterbalance the helper activity generated in the presence of supernatant from alloactivated OKT4+ cells. Furthermore, OKT8+ cells, known to suppress PWM-driven B cell differentiation in the presence of OKT4+ cells, do not suppress B cell differentiation induced by preformed helper factor even in the presence of OKT4+ cells. These data further underscore the importance of functional T-T interactions in immunoregulation in vitro and support the idea that the target of suppression of B cell differentiation, induced either by alloantigen-triggered helper factor or PWM, are OKT4+ cells and not B cells themselves.

Functional analysis of human T cell subsets defined by monoclonal antibodies. III. Regulation of helper factor production by T cell subsets

In the present report we extended our previous studies demonstrating that obligatory T-T interactions are important in regulating human immune responses in vitro. Functionally distinct human T cell subsets were isolated by complement-mediated lysis using the monoclonal antibodies OKT4 and OKT8. Evidence was obtained that during allogeneic interactions, OKT4+, but not OKT8+, responder T cells are required to generate helper factor(s) capable of polyclonally activating human B cells independent of additional T cell help. Importantly, the alloantigen-induced helper factor(s) production and/or release was found to be suppressed by addition of graded numbers of radiosensitive OKT8+ cells. On the other hand, no evidence was obtained that supernatant derived from alloactivated OKT8+ cells could counterbalance the helper activity generated in the presence of supernatant from alloactivated OKT4+ cells. Furthermore, OKT8+ cells, known to suppress PWM-driven B cell differentiation in the presence of OKT4+ cells, do not suppress B cell differentiation induced by preformed helper factor even in the presence of OKT4+ cells. These data further underscore the importance of functional T-T interactions in immunoregulation in vitro and support the idea that the target of suppression of B cell differentiation, induced either by alloantigen-triggered helper factor or PWM, are OKT4+ cells and not B cells themselves.

Functional analysis of human T cell subsets defined by monoclonal antibodies. I. Collaborative T-T interactions in the immunoregulation of B cell differentiation

T-B and T-T interactions involved in the regulation of PWM-triggered human B cell differentiation were studied in vitro. Functionally distinct human T cell subsets were isolated by C-mediated lysis by using the monoclonal antibodies OKT4 and OKT8. Graded numbers of either untreated or irradiated T cell subsets were added to autologous B cells, and total antibody synthesis was measured after 5 to 6 days of culture by using a highly sensitive reverse hemolytic plaque assay. The data indicate that a) the helper activity that is exclusively contained within the OKT4+ population is radiosensitive. Only at high T/B ratios can this radiosensitivity be overcome; b) the OKT8+ population contains radiosensitive cells important in suppressing B cell differentiation, and c) the suppression induced with OKT8+ cells requires the presence of radiosensitive OKT4+ cells. Thus, OKT8+ cells added to cultures containing B cells and irradiated OKT4+ cells do not suppress the PFC response. Addition of unirradiated OKT4+ cells to these cultures permits reexpression of suppression by OKT8+ cells. It is concluded that two radiosensitive cells, one within the OKT4+ population and the other within the OKT8+ population, collaborate to induce suppression. Possible mechanisms for this suppressive interaction including induction of suppressor precursor cells within the OKT4+ population or inhibition of OKT4+ helper cells by OKT8+ cells are discussed.

Functional analysis of human T cell subsets defined by monoclonal antibodies. I. Collaborative T-T interactions in the immunoregulation of B cell differentiation

T-B and T-T interactions involved in the regulation of PWM-triggered human B cell differentiation were studied in vitro. Functionally distinct human T cell subsets were isolated by C-mediated lysis by using the monoclonal antibodies OKT4 and OKT8. Graded numbers of either untreated or irradiated T cell subsets were added to autologous B cells, and total antibody synthesis was measured after 5 to 6 days of culture by using a highly sensitive reverse hemolytic plaque assay. The data indicate that a) the helper activity that is exclusively contained within the OKT4+ population is radiosensitive. Only at high T/B ratios can this radiosensitivity be overcome; b) the OKT8+ population contains radiosensitive cells important in suppressing B cell differentiation, and c) the suppression induced with OKT8+ cells requires the presence of radiosensitive OKT4+ cells. Thus, OKT8+ cells added to cultures containing B cells and irradiated OKT4+ cells do not suppress the PFC response. Addition of unirradiated OKT4+ cells to these cultures permits reexpression of suppression by OKT8+ cells. It is concluded that two radiosensitive cells, one within the OKT4+ population and the other within the OKT8+ population, collaborate to induce suppression. Possible mechanisms for this suppressive interaction including induction of suppressor precursor cells within the OKT4+ population or inhibition of OKT4+ helper cells by OKT8+ cells are discussed.

Enhancement of T cell cytotoxic responses by purified human fibroblast interferon

Purified polyribonucleotide-induced human fibroblast interferon (HFIF) was tested for its effects on proliferative and cytotoxic human T cell responses to alloantigens. The addition of HFIF (100 to 400 IFU/ml) to mixed leukocyte cultures decreased alloantigen-induced lymphocyte proliferative responses as determined by both recovery of responding cells and by 3H-thymidine incorporation into responding cells. However, HFIF, but not the mock interferon preparation, increased the cytotoxic response of T cells to allogeneic cells by 4- to 5-fold when expressed in terms of lytic units. Although fibroblast and leukocyte interferons have different physicochemical and biologic properties, the results reported here are in concert with previous findings concerning the effects of virus-induced leukocyte interferon on human T cell functions.

Decreased H2 histamine response of granulocytes of asthmatic patients

Increased bronchial sensitivity to inhaled histamine in asthma is well known. The mechanism of this increased bronchial sensitivity is not known nor has it been demonstrated that isolated cells respond abnormally to histamine. Polymorpho-nuclear leukocytes (PMNs) provide a homogeneous cell population to study agonist response. Release of granulocyte lysosomal enzymes is inhibited by agonists increasing the PMN cyclic AMP concentration. The release of the lysosomal enzyme beta glucuronidase by serum-activated particles of zymosan was similar in PMNs isolated from normal and asthma subjects. Histamine (100-0.01 muM) inhibited enzyme release. Except at the maximal concentration of histamine (100 muM), the response to histamine was decreased in asthma. The inhibition of enzyme release paralleled an increase in intracellular PMN cyclic AMP. In asthma, the cyclic AMP response to histamine was reduced. The H2 antihistamine metiamide blocked histamine inhibition of lysosomal enzyme release and the increase in cyclic AMP. The effect was maximal at concentrations equimolar to those of histamine. The H1 antihistamine chlorpheniramine had no effect on histamine inhibition of granulocyte lysosomal enzyme release. A decrease in the inhibition of the release of the inflammatory lysosomal enzymes from granulocytes in asthma may contribute to an enhanced bronchial inflammatory reaction.

Histamine inhibition of neutrophil lysosomal enzyme release: an H2 histamine receptor response

Human polymorphonuclear leukocytes treated with cytochalasin B release the lysosomal enzyme beta glucuronidase during contact with serum-activated zymosan particles. Histamine increases intracellular cyclic adenosine monophosphate and inhibits release of this enzyme. The H2 antihistamine metiamide blocks the histamine inhibition of lysosomal enzyme release and the increase in the intracellular adenoisine 3,5'-monophosphate of granulocytes. Chlorpheniramine, an H1 antihistamine, did not block the histamine inhibition of granulocyte lysosomal enzyme release.