The Cancer Biotherapy Research Group [CBRG], formerly the National Biotherapy Study Group [NBSG]: a 10-year perspective

Should high-dose interleukin-2 still be the preferred treatment for patients with metastatic melanoma?

For more than 20 years interleukin-2 (IL2) was the preferred treatment for medically fit metastatic melanoma patients, but recently two new agents, ipilimumab and vemurafenib, were approved for stage IV disease. Single-institution data were used to determine the long-term survival rate for IL2-treated melanoma patients, and whether use of inpatient IL2 had declined recently. Between May 1987 and April 2010, 150 patients were hospitalized for high-dose, intravenous (i.v.) IL2. The average number of IL2 patients increased from 5.4 per year during 1987-1991 to 5.8 during 1992-1997 after regulatory approval of IL2, to 8.3 during 1998-2006 after a marketing indication in metastatic melanoma was granted, but dropped to 3.0 during 2007-2010. At the time of treatment, median age was 52 years; 27% were 60 years of age or older. At the time of analysis 122 patients were deceased. Median survival from the start date of IL2 treatment was 15.6 months, with a 20% 5-year survival. Among patients enrolled in clinical trials, there were as many nonresponders who survived 5 years as responders, which is consistent with a delayed immunotherapy benefit. In the absence of long-term survival data for these newer agents, IL2 probably should still be the preferred initial treatment for most patients with metastatic melanoma who are medically fit.

Patient-Specific Vaccines Derived from Autologous Tumor Cell Lines as Active Specific Immunotherapy: Results of Exploratory Phase I/II Trials in Patients with Metastatic Melanoma

Seventy-four (74) patients with metastatic melanoma were treated with patient-specific vaccines derived from autologous tumor cell lines. Cryopreserved irradiated tumor cells were injected weekly for 3 weeks, then monthly for 5 months. At a median follow up >6 years, the median event-free survival (EFS) was 4.5 months, with 13 patients alive and progression free 6-12 years later. Median overall survival (OS) was 20.5 months, with 29% 5-year OS. Tumor response rate was 9% among the 35 patients with evaluable disease who received at least 3 injections. Better survival was observed for patients who had minimal rather than clinically evident metastatic disease at the time vaccine therapy was initiated (5-yr OS 47% vs. 13%; p < 0.0001), received granulocyte-macrophage colony-stimulating factor and/or interferon gamma as an adjuvant (5-yr EFS 26% vs. 0%; p < 0.0001) or received an average of <7 million cells for each of the first 3 injections, compared to those who received 7-11.9 million or >12 million cells per injection (5-yr EFS OS 35% vs. 24%; p = 0.041 and p = 0.034). There was a trend toward better EFS for those who had a positive delayed type hypersensitivity (DTH) reaction to an intradermal injection of 1 million irradiated tumor cells at baseline, or converted to positive after 3 injections, compared to those whose DTH remained negative (5-yr EFS 39% vs. 18%; p = 0.159). This treatment approach is feasible, produces minimal toxicity, and is associated with longterm survival in a significant proportion of patients.

Cancer Vaccine Potency: Is There a Dose/Response Relationship for Patient-Specific Vaccines and Clinical Outcomes?

PURPOSE

Determination of potency is a challenging problem for patient-specific products derived from autologous cells. For several years, we have been investigating the safety and therapeutic potential of patient- specific vaccines derived from short-term autologous cell lines. We investigated whether clinical potency of these vaccines could be determined by retrospective correlation between the numbers of cells injected (quantity of tumor antigens) and clinical outcome.

METHODS

The averages and standard deviations of irradiated tumor cells were determined for those patients who received the first 3 weekly injections, and for the subset that had a recording of results from tumor delayed-type hypersensitivity testing (DTH). Correlations were made between the numbers of cells injected and DTH conversion and survival.

RESULTS

One hundred fifty-six patients received the vaccine product, 136 of whom received the first 3 weekly vaccinations. The most common reason for not receiving 3 injections or having a repeat tumor DTH test was rapidly progressive disease. Ninety-nine patients had cell count data for all 3 injections; 73 had a tumor DTH test at baseline and at week 4. The average number of cells injected over 3 weeks, in millions per patient, by quartile were: 6.0 +/- 1.8, 10.2 +/- 1.4, 15.1 +/- 1.4, and 31.2 +/- 9.8, with respective median survivals of 24.7, 25.5, 24.0, and 21.0 months, with the respective number of DTH conversions being 4, 8, 4, and 6. There were no statistical differences in survival or in the number of patients who had a positive tumor DTH test at week 4.

CONCLUSIONS

We were unable to define potency--based on a relationship between the number of tumor cells injected as part of vaccination and survival or the reactivity to pure autologous tumor--in a tumor DTH test, over the range of 2-30 million injected cells over 3 weeks.

Tumor-infiltrating lymphocytes and interleukin-2: dose and schedules of administration in the treatment of metastatic cancer

PURPOSE

The potential for therapeutic use of tumor-infiltrating lymphocytes (TIL), as adoptive cellular therapy has been touted for many years with some encouraging reports in patients with metastatic melanoma.

MATERIALS AND METHODS

We previously described methodologies for TIL production and phenotypic characterization of TIL generated in our laboratory between 1991 and 1995 in semipermeable bags and between 1996 and 2000 in bioreactors. Patients treated in the earlier era were to have received a hybrid bolus and a 12-hour continuous infusion of interleukin (IL)-2 (total, 48 MIU), while in the latter era 4 days of interferon- alpha preceded the TIL and IL-2; which was given by a hybrid schedule that included bolus and 72- hour continuous IL-2 (total, 96 MIU). There were 55 patients, including 23 patients with melanoma, 9 patients with renal cell carcinoma, and 8 patients with colorectal cancer. There was only 1 objective tumor response, which was noted in a patient with renal cell carcinoma. The 55 patients who received these products were grouped in cohorts by treatment era, quantity of TIL received, amount of IL-2 intended, and different combinations of TIL and IL-2.

RESULTS

There was no difference in survival by production method (treatment era), or amount of IL-2 given with TIL, but 33 patients who received an intermediate or higher dose of TIL (mean = 54.4 x 10(9)) had a median survival of 11.8 months, compared to 6.4 months for 22 patients who received 1 low-dose TIL (mean = 6.48 x 10(9)) (p = 0.059, log rank test). The objective response rate in this heterogeneous group of patients was not encouraging. The data suggest there may be a dose/benefit relationship between the total number of TIL infused and survival.

Autologous tumor cell line-derived vaccine for patient-specific treatment of advanced renal cell carcinoma

AIM

We previously reported the laboratory methodology for producing patient-specific irradiated autologous tumor-cell products derived from short-term cultured tumor cells from resected renal cell carcinoma, and described preliminary clinical results. In this study, we report the final clinical results and efforts to define vaccine potency on the basis of clinical outcome for these 25 patients with advanced renal cell carcinoma.

MATERIALS AND METHODS

Approximately 10(8) cells from successful short-term cell lines were irradiated, frozen in aliquots of 10(7) cells, then thawed and administered subcutaneously (s.c.) once a week for 3 weeks, then once a month for 5 months. Patients included 19 men and 6 women, who were 43-82 years of age. Six (6) patients had a large primary lesion, 2 patients had regionally advanced disease, 3 patients had been rendered disease-free by surgical resection of distant metastases, and 14 patients had measurable distant metastatic disease.

RESULTS

The vaccines were well tolerated, and no delayed autoimmune effects were documented. Delayed-type hypersensitivity (DTH) tests of irradiated tumor cells were positive in only 1 of 25 patients at week 0, but converted to positive in 6 of 18 patients of DTH-negative patients who were retested at week 4. Objective response rate in patients who had measurable metastatic disease was 0 of 14 patients. With a median follow-up of greater than 7 years from the date of the first DTH test, median survival is 33.4 months, 5-year survival is 43%, and 10 patients are alive 3-12 years later. The 7 DTH+ patients survived a median of 2.5 years, and 3 patients are alive after 3, 4, and 7 years. There was no correlation between the number of irradiated cells or viable irradiated cells injected and tumor DTH reactivity or survival.

CONCLUSION

This approach is feasible and the therapy is well tolerated, but clinical benefit was not established in this trial. Any further exploration of this product should be limited to the adjuvant setting in a randomized trial.

Phase I/II trial of autologous tumor cell line-derived vaccines for recurrent or metastatic sarcomas

AIM

We previously reported the laboratory methodology for producing patient-specific irradiated autologous tumor-cell products derived from short-term cultured tumor cells. We attempted to determine the feasibility, safety, and clinical effects of autologous tumor vaccine-derived sarcomas.

PATIENTS AND METHODS

Efforts were made to establish tumor cell lines in tissue culture with expansion to 100 million cells for patients who were candidates for therapy. Cells were irradiated and cryopreserved in aliquots of 10 million cells for subcutaneous (s.c.) injections, once a week for 3 weeks, then once a month for 5 months.

RESULTS

Efforts were made to establish short-term tumor cell lines from 86 fresh sarcoma specimens (10 primary, 14 recurrent, and 62 metastatic). Initial growth was successful for 48 patients (56%), and cultures were expanded for 36 patients, with 25 patients treated. There were 23 evaluable patients, including 12 women and 11 men, with a median age of 52 years and a range from 16-79 years. Vaccine therapy was well tolerated. Delayed-type hypersensitivity (DTH) tests to irradiated tumor cells were positive in 0 of 20 patients tested at baseline, but converted to positive after 3 weekly vaccinations in 8 of 16 patients who were retested. Median survival for the 8 DTH converters was 16.6 months versus 8.2 months for the 8 responders whose tumor DTH test remained negative, and 6.0 months for the 7 patients who were not tested. No objective responses were recorded among 12 evaluable patients with measurable disease; 10 patients have survived more than 1 year.

CONCLUSIONS

This approach is feasible, well tolerated, and the resulting DTH conversion rate is of interest. Patients with minimal tumor burden would be preferred for further future testing.

Phase I/II Trial of Melanoma Patient–Specific Vaccine of Proliferating Autologous Tumor Cells, Dendritic Cells, and GM-CSF: Planned Interim Analysis

AIM

The aim of this study was to investigate the feasibility, safety, and clinical efficacy of patient-specific dendritic cell vaccines in patients with metastatic melanoma. A planned interim analysis was conducted on the first 20 patients.

METHODS

Tumor cell lines were established from metastatic tumor, expanded to 200 million cells, and then incubated with interferon-gamma for patients who were candidates for therapy. Cells were irradiated and cryopreserved. Patients underwent leukapheresis to obtain mononuclear cells that were cultured in the presence of IL-4 and GM-CSF to produce dendritic cells, which were incubated with cryopreserved, irradiated tumor cells, and then stored in aliquots of about 20 million cells for subcutaneous (s.c.) injections with GM-CSF once a week for 3 weeks, then once a month for 5 months.

RESULTS

The first 20 eligible patients included 10 men and 10 women, with a median age of 48 years (range, 16-79 years). Three (3) patients had brain metastases, and 13 patients had experienced disease progression after biochemotherapy. At the time of vaccine treatment, 6 patients had evaluable metastatic disease, while 14 patients lacked measurable disease. Vaccine therapy was well tolerated, except for what appeared to be GM-CSF-related allergic reactions in 2 patients. Delayed-type hypersensitivity (DTH) tests to irradiated tumor cells were positive in 0 of 20 patients tested at baseline, but converted to positive in 8 patients (40%). At a median follow-up of 13.8 months, there is a 95% overall survival and a 48% progression-free survival. Four (4) patients have already survived more than 3.0 years since starting the vaccine.

CONCLUSION

Based on tolerability, rate of tumor DTH conversion, and encouraging survival, the trial will continue accrual to at least 19 patients with measurable disease and 40 patients who lack measurable disease at the time of treatment.

Treatment of human solid malignancies with autologous activated lymphocytes and cimetidine: a phase II trial of the cancer biotherapy research group

OBJECTIVE

The Cancer Biotherapy Research Group conducted a clinical trial to verify encouraging reports of antitumor activity of autolymphocyte therapy.

PATIENTS AND METHODS

Patients with a variety of advanced solid malignancies underwent an initial leukapheresis procedure to collect about 5 x 10(9) autologous lymphocytes that were stimulated in vitro for 3 days with anti-CD3 monoclonal antibody in the presence of indomethicin and cis-retinoic acid to obtain media that was frozen in aliquots. This media contained significant amounts of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, interferon-gamma, and IL6, but no IL-2. Subsequently patients underwent up to 6 monthly leukaphereses to collect 2-5 x 10(9) autologous lymphocytes that were incubated in vitro for 6 days in the cryopreserved media containing autologous lymphokines, resulting in a cell population enriched for noncytotoxic T-helper lymphocytes. These were administered intravenously monthly for up to 6 months with daily oral cimetidine at a dose of 600 mg po qid, which was given throughout the treatment period. Tumor response was assessed every 2 months.

RESULTS

There were 47 patients (25 women and 22 men) with a median age of 55 years (range 31-79). One hundred seventy four treatments were delivered and were well tolerated. A mean of 2.05 +/- 1.46 (range 0.82-12.8 x 10(9)) cells were infused. Eighty-five percent received two or more doses; 19% received six doses. Objective tumor responses were observed in 1/15 renal cell, 1/13 colorectal, 0/6 breast, 0/5 lung, 0/2 gastric, 0/2 sarcoma, 0/1 pancreas, 0/1 prostate, 0/1 melanoma, and 0/1 eccrine. Forty-three patients have died. Median survival was 8.8 months, 1-year survival 35%, and 2-year survival 15%.

CONCLUSION

This complex treatment program was feasible. Infusion of these cells was well tolerated. Some antitumor activity was seen in patients with renal cell cancer and colorectal cancer.

Does continuous-infusion interleukin-2 increase survival in metastatic melanoma?

Pharmacy logbooks and clinical trial records were used to identify all 60 patients with metastatic melanoma who were treated as inpatients with intermediate-dose, continuous-infusion interleukin-2 (IL-2) in Hoag Hospital during 1987 to 1998. The hospital tumor registry was used to identify contemporary controls who had not received inpatient IL-2, matched for having distant metastatic melanoma, and by year and stage at original diagnosis, gender, and age. The mean time from original diagnosis to the documentation of distant metastatic disease was similar in both groups, 24 to 26 months. From the date of starting IL-2 therapy, patients had a median survival of 8.8 months, 38% 1-year survival, and 20% 5-year survival, with 8 patients alive beyond 5 years. However, there was no difference in survival from the first date of distant metastatic disease (median 25.8 months for IL-2 versus 31.5 months for controls, with survival rates 5 years after metastatic disease of 26% versus 31%). There was also no difference in overall survival from the date of original diagnosis (60.1 months for the IL-2 group versus 86.3 months for controls, with 5-year survival rates of 51% versus 64%, and 10-year survival rates of 29% versus 33%). This single-institution study failed to establish a survival advantage for patients with metastatic melanoma who received intermediate-dose, continuous-infusion IL-2 administered in the inpatient setting, compared to contemporary, matched-control patients who never received inpatient IL-2 therapy. However, the 5-year survival rates after a diagnosis of distant metastatic disease were a surprisingly high 26% to 31% in both groups. In the absence of a control group, the survival impact of IL-2 has probably been overestimated from single-arm phase II and III trials.

Irradiated cells from autologous tumor cell lines as patient-specific vaccine therapy in 125 patients with metastatic cancer: induction of delayed-type hypersensitivity to autologous tumor is associated with improved survival

OBJECTIVE

We established short-term cultures of pure tumor cells for use as autologous tumor cell vaccines in an effort to study the effects of patients-specific immunotherapy.

PATIENTS AND METHODS

Surgically resected fresh tumor was obtained from patients with metastatic cancer. Successful tumor cell lines (5 x 10(7)) were expanded to 10(8) cells, irradiated, and cryopreserved for clinical use. Following a baseline test of delayed-type hypersensitivity (DTH) to an i.d. injection of 10(6) irradiated autologous tumor cells, patients received 3 weekly s.c. injections of 10(7) cells, had a repeat DTH test at week-4, then received monthly vaccinations for 5 months. A positive DTH test was defined as > or = 10 mm induration; survival was determined from the first DTH test.

RESULTS

Short-term cell lines were successfully established for 299/695 patients (43%). Vaccines were prepared for 231 patients, 142 of whom were treated, and 125 had a baseline DTH test recorded. Median follow up at the time of analysis was greater than 5 years. There was no difference in survival for any of the following: gender, age > 50 years, melanoma histology, anergy to common recall antigens or baseline DTH test result. Only 17 patients had a positive DTH at baseline (14%), but DTH converted from negative to positive in 31/80 (39%) of those who were tested, and in 31/108 (29%) of all patients (intent-to-convert analysis). For the 48 patients who were DTH-positive at entry, or converted to DTH-positive, the median survival was 30.5 months and 5-year survival 41% compared to 11.4 months and 9% 5-year survival for 77 patients whose DTH was never positive (P2 = 0.003). However, survival was even better for patients whose DTH test converted to positive compared to patients who were DTH-positive at baseline (median 37.5 vs 11.9 mos, P2 = 0.066).

CONCLUSION

This patient-specific, cell culture-derived, autologous tumor cell vaccine induced anti-tumor immune reactivity that was associated with improved survival in patients with advanced cancer.

Short-term autologous tumor cell lines for the active specific immunotherapy of patients with metastatic melanoma

We established short-term cell lines for 108/170 (64%) patients with metastatic melanoma. Tumor cell numbers were expanded to 10(8), then cells were irradiated, aliquoted, and cryopreserved for clinical use. Vaccines have been used to treat 69 patients with clinical follow up for 33 who had measurable metastatic disease at the time vaccine therapy was initiated (METS), and 33 who had no evidence of disease (NED) at the time of vaccine therapy following surgical resection of metastases. The protocol called for a baseline test of delayed tumor hypersensitivity (DTH), three weekly injections, a repeat of the DTH test, then monthly injections for an additional 5 months. Objective tumor responses were noted in 3/26 (12%) patients who received a minimum of three vaccinations, one complete, and two partial, with survivals of 36, 46+, and 78+ months. Only 6/64 (9.4%) had a positive DTH (>10 mm) at baseline, including three METS, all of whom progressed within 4 months and died within a year, and three who are still NED after more than 5 years. Conversion of DTH from negative to positive was documented in 18/44 (41%) patients who were tested at week 0 and 4. At a median follow up of greater than 5 years, the median overall survival (OS) was 40 months for "NED" with a 5-year survival rate of 39%, and 8.6 months with a 5-year survival rate of 10% for "METS" The 18 patients who had conversion of their DTH had a median event-free survival (EFS) of 15.8 months and 5-year EFS of 32% compared to 4.2 months and 9% for the 26 non-converters (P=0.012, two-tailed, log-rank test). Among patients who were NED when treatment started, the 12 patients whose DTH converted had a median overall survival of 61.4 months with 5-year survival of 63% compared to 9.7 months and 0% for the 13 non-converters (P=0.0026). This treatment approach is feasible, produces minimal toxicity, and is associated with long-term survival in a significant subset of patients.

Treatment of kidney cancer with autologous tumor cell vaccines of short-term cell lines derived from renal cell carcinoma

BACKGROUND

We established short-term cultures of autologous tumors from patients with renal carcinoma for use as active specific immunotherapy (i.e., autologous vaccine).

METHODS

Between 9/91 and 9/99 the cell biology laboratory of the Hoag Cancer Center received 69 kidney tumor samples that had been surgically excised, including 43 primary tumors and 26 metastatic lesions. Efforts were made to establish short-term tumor cell cultures to use as autologous tumor cell vaccines. Prior to treatment, patients underwent a baseline skin test for delayed tumor hypersensitivity (DTH) and then received s.c. injections of 10 million irradiated tumor cells that were given with various adjuvants weekly x3 and then monthly x5.

RESULTS

Cell lines were established for 55/69 patients (80%) including 36/43 (84%) from primary tumors and 19/26 (73%) from distant metastases. Vaccines were prepared for 41 patients; 27 were treated. At the time of this analysis, follow up data was available for 26 patients with a median follow up > 5 years. Treatment was well-tolerated. Of 10 patients who had no evident disease at the time of treatment, nine were alive 1-8 years later; 5/8 had conversion of their DTH test from negative to positive. For 16 patients with measurable metastatic disease at the time of treatment, there were no objective tumor responses; their median survival was 5.0 months. Among these 16 patients, only 1/8 DTH tests converted, but three had a positive baseline DTH test; one was previously treated with interleukin-2 and tumor infiltrating lymphocytes and two others were previously treated with autolymphocyte therapy.

CONCLUSIONS

Vaccine therapy with short-term cultures of autologous tumor cells is feasible, well-tolerated and associated with conversion of DTH and long-term survival in patients who are free of disease at the time treatment is initiated. However, significant anti-tumor responses were not seen in patients with measurable disease at the time vaccine treatment was initiated.

What to do with IL-2?

It has been 15 years since the first positive clinical reports of Interleukin-2 (IL-2) appeared in the medical literature, ten years since moderate dose continuous infusion IL-2 was approved in Europe, and five years since high-dose bolus IL-2 was approved for general use in the United States. IL-2 is accepted as a standard treatment used alone, or in combination with chemotherapy or biotherapy in the management of metastatic melanoma and metastatic renal cell carcinoma. Various physicians utilize high-dose bolus IL-2, moderate-dose continuous infusion IL-2, and low-dose outpatient intravenous or subcutaneous IL-2. There is still no consensus regarding the best way to deliver IL-2 alone in terms of dose and schedule of administration from a risk-to-benefit standpoint. Despite yielding higher tumor response rates, regimens that combine IL-2 with chemotherapy and/or interferon have not produced better long-term survival.