Why event-free survival is better than tumor response or other measures of survival as an endpoint in cancer trials

Autologous dendritic cells loaded with antigens from self-renewing autologous tumor cells as patient-specific therapeutic cancer vaccines

A promising personal immunotherapy is autologous dendritic cells (DC) loaded ex vivo with autologous tumor antigens (ATA) derived from self-renewing autologous cancer cells. DC-ATA are suspended in granulocyte-macrophage colony stimulating factor at the time of each subcutaneous injection. Previously, irradiated autologous tumor cell vaccines have produced encouraging results in 150 cancer patients, but the DC-ATA vaccine demonstrated superiority in single-arm and randomized trials in metastatic melanoma. DC-ATA have been injected into more than 200 patients with melanoma, glioblastoma, and ovarian, hepatocellular, and renal cell cancers. Key observations include: [1] greater than 95% success rates for tumor cell cultures and monocyte collection for dendritic cell production; [2] injections are well-tolerated; [3] the immune response is rapid and includes primarily TH1/TH17 cellular responses; [4] efficacy has been suggested by delayed but durable complete tumor regressions in patients with measurable disease, by progression-free survival in glioblastoma, and by overall survival in melanoma.

Cancer vaccines: can they improve survival?

In patients with metastatic cancer, therapeutic anticancer vaccines are rarely associated with objective antitumor responses; so, many investigators have focused on progression-free survival (PFS) as a key endpoint for clinical trials. However, it is not clear that PFS is a surrogate for overall survival (OS), and OS may be a more appropriate endpoint because of the effects on long-term memory in the adaptive immune system. Recently, reported vaccine trials were reviewed to determine their primary and secondary endpoints and results. Randomized trials testing sipuleucel-T and prostvac-vf in prostate cancer and ipilimumab and eltrapuldencel-T in melanoma were associated with low objective response rates, no improvement in PFS, but statistically significant improvement in OS. Although compared with PFS, it takes longer to get a final result when OS is the primary endpoint; there is increasing evidence that if long-term memory recognition of tumor-associated antigens is the mechanism of action of an investigational product, then OS may be the only valid clinical endpoint for efficacy.

Prognosis, clinical outcomes and quality of life issues in cutaneous T-cell lymphoma

Although the need for a specific QOL index for MF/SS has been recognized, little work has been done in this area. QOL instruments should address general health concepts, as well as specific issues that are relevant to patients who have MF/SS; a combination of two instruments may be appropriate. Confirming the validity, reliability, and responsiveness to change of a combination of QOL instruments, such as SKINDEX-29 and FACT-G, in patients who have MF/SS will be relevant. For patients who have MF/SS, focusing our efforts on improving the disease and their QOL should translate into improvements that are meaningful to them. Thus, our goal should be to incorporate the findings of QOL research into practice and use the results to guide our practices, as they relate to therapy. Some important considerations are: We must be explicit about what will be done with the information that is obtained about an individual's QOL. We should consider what additional knowledge QOL measures provide that we could not otherwise have. We should be ready for unexpected results, as exemplified by instances where aggressive therapy could result in improved QOL. Although challenges exist in moving forward QOL research in CTCL, the words of wisdom of Tannock bring the concept of QOL into perspective: "When cure remains elusive, it is time to start treating the patient, not just the tumor." A final consideration is that we should not forget the dimension of spirituality, which is especially relevant to patients who have advanced MF/SS. Spirituality is characterized by the capacity to seek purpose and meaning, to have faith, to love, to forgive, and to see beyond current circumstances. Spirituality enables a person to rise above suffering. Unfortunately, research on spirituality is scarce, in part, because of the difficulty in assessing spiritual suffering. Nevertheless, physicians who are caring for patients who have advanced MF/SS should acknowledge the spiritual dimension as an integral component of the dying process.

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.

Phase II trial of subcutaneous interleukin-2, subcutaneous interferon-alpha, intravenous combination chemotherapy, and oral tamoxifen in the treatment of metastatic melanoma: final results of cancer biotherapy research group 94-11

BACKGROUND

The treatment of metastatic melanoma remains unsatisfactory despite encouraging results with biotherapy and combination chemotherapy. Combining these two modalities may improve outcomes for such patients.

METHODS

Eligible patients had metastatic melanoma, were in good medical condition, and had not been treated previously for metastatic disease. A 42-day treatment cycle consisted of: tamoxifen 10 mg p.o. b.i.d. days 1-42, carmustine 150 mg/m2 i.v. on day three, dacarbazine 220 mg/m2 and cisplatin 25 mg/m2 i.v. q.d. days 3-5, and 24-26, interferon-alpha 2b 6.0 MU/m2 s.c. days 8-12 and 29-33, and interleukin-2 11 MU/m2 s.c. days 8, 10, 12 and 29, 31, 33. In the absence of tumor progression, patients could receive up to six cycles of alternating treatment. Toxicity and tumor response was assessed following each treatment cycle; survival was determined from the first date of treatment.

RESULTS

The 28 melanoma patients included 21 men and 7 women, with a median age of 55 years with a range of 26-77. Fifty-four percent were asymptomatic when treatment was initiated. Eighty percent had soft tissue metastases, 32% lung, 28% liver, and 8% bone. There were nine patients with significant tumor responses (three complete, six partial) for a response rate of 32% (18-57% 95% CI) based on intent-to-treat analysis, and 38% (18-57%, 95% CI) for the 24 patients who were evaluable for response. The months of duration of survival for responders were 38.9+, 27.2+, 22.8+, 16.3, 13.2, 9.4, 7.5, 6.5+, and 5.8. At a median follow-up of 31 months, the median duration of event-free survival was 4.6 months; median survival was 9.4 months. The survival rate one year from initiating treatment was 42%; 2-year survival was 14%. The most frequent toxicities were 96% nausea/vomiting, 80% fatigue, 73% thrombocytopenia, 60% neutropenia, and 44% fever. Two patients experienced early death that may have been treatment related; one died of cardiovascular complications and the other of a central nervous system event.

CONCLUSION

This outpatient regimen was associated with significant toxicity including a 7% rate of possible treatment-related death. Tumor regression rates and survival were similar to results reported for chemotherapy alone, or inpatient IL-2-based therapy, but did not suggest an improvement in outcome.

Efficacy and safety of docetaxel (Taxotere) in heavily pretreated advanced breast cancer patients: the French compassionate use programme experience

The aim of this investigation was to assess retrospectively docetaxel safety and efficacy in advanced breast cancer patients in a French compassionate use programme. Patients had received > 1 prior chemotherapy regimen for advanced disease, were either anthracycline-resistant (that is progressed within 6 months after anthracycline-based chemotherapy) or had received the maximum cumulative dose. The recommended docetaxel dose was 100 mg/m2/cycle (75 mg/m2 in case of liver function impairment: transaminases > 1.5 x upper limit of normal (ULN), alkaline phosphatases > 3 x ULN). Between August 1993 and December 1995, 889 patients were treated in 67 French centres, of whom 870 were evaluable for safety and 825 were evaluable for patient and treatment characteristics and efficacy. 20.5% (of the 825 patients evaluable for baseline characteristics) had poor performance status (PS > or = 2), 49.3% liver metastasis and 9.6% biological liver dysfunction. 98.4% had been previously treated by anthracyclines, 50.8% had resistant disease and 37.1% had received > 2 prior palliative chemotherapy lines. The most frequent severe toxicity, febrile neutropenia (reported in 223/870 (25.6%) patients evaluable for safety), caused 10 deaths, 6 of these being patients with severe liver impairment before inclusion. Fluid retention syndrome and other common non-haematological toxicities were well tolerated. 3.1% (28/889) of all patients and 11.4% of those with liver dysfunction, died from treatment-related causes. The overall response rate in 825 assessable patients was 22.9% (95% confidence interval (CI): 20.2-26.2%). Median time to treatment failure was 4 months (95% CI: 3.6-4.3) and median survival was 9.8 months (95% CI: 8.8-10.7). This report on the largest series of unselected advanced breast cancer patients treated with docetaxel, supports previous phase II studies, confirming docetaxel's utility in patients relapsing after failing anthracycline-containing palliative chemotherapy.

Clinical experience with autologous tumor cell lines for patient-specific vaccine therapy in metastatic melanoma

Because of their patient specificity and proliferative capacity, tumor cell lines established from autologous metastatic melanoma tumor samples may be an excellent immunogen for patient-specific vaccine therapy. Between October 1990 and July 1996, the Hoag Cancer Center cell biology laboratory received 136 fresh metastatic melanoma samples from 122 different patients. Tumor cell lines were successfully established for 92 of 136 samples (68%), for 87 of 122 patients (71%). Successful cultures were expanded to 10(8) cells (total culture time about 8 weeks), confirmed to be sterile, irradiated, and stored frozen in aliquots of 10(7) cells. Vaccines were prepared from 72 lines, and 62 vaccines were used in 57 different patients. Subcutaneous vaccination took place on weeks 1, 2 and 3, and then monthly for a total of 6 months. A delayed tumor hypersensitivity skin test (DTH) was administered at week zero and week 4. Various adjuvants were co-administered including BCG, alpha- or gamma-interferon, and GM-CSF. Patients were monitored for failure-free survival (FFS) and overall survival (OS) from the date of the first vaccination. Follow-up data is available for 52 patients, 27 who had no evident disease (NED) at the time of vaccination and 25 who had metastatic disease at the time of treatment. There were two partial responses which persisted 11.9 and 39.8+ months among the 25 patients who had detectable metastatic disease whün treatment was initiated (8%, 1 to 26%, 95%-Ci). Twenty patients had negative skin tests at week 0 and week 4; six were positive both times, and 13 converted their DTH from negative to positive, for a conversion rate of 13 of 33 (39%). Patients who received interferon-gamma and/or GM-CSF as an adjuvant had a higher rate of DTH conversion compared to patients who received other adjuvants (13 of 20 v 2 of 13, P = 0.003). For patients who were NED, nine of 19 (47%) converted their DTH test compared to four of 14 (29%) patients with metastatic disease (p = 0.33). For patients whose DTH converted from negative to positive after 3 weeks of vaccination, median FFS and OS were superior compared to patients whose DTH remained negative (19.4 v 4.0 months FFS, p = 0.0052 and 39.6 v 18.3 months OS, p = 0.0602). The autologous cell line approach to active specific immunotherapy is feasible for patients who have resectable foci of metastatic disease. Administration of such patient-specific vaccines improves survival for those patients who are NED at the time of vaccination and convert their DTH skin test, compared to those whose DTH test remains negative.

Conditioning regimens before transplantation in patients with aggressive non-Hodgkin's lymphoma

Substantial progress has been made in understanding the role of autotransplantation in aggressive non-Hodgkin's lymphoma. At present, the clinical indications for high-dose therapy include patients with relapsed or poor prognosis disease. Hematopoietic reconstitution with peripheral stem cells has rendered transplantation less toxic but the optimal preparative regimen remains to be found. It should combine a high antitumor activity with acceptable toxicity to normal tissues. The literature, on combinations of drugs with or without total body irradiation, was reviewed with regard to this objective. BEAM, CBV and ICE, the most common chemotherapy regimens can be considered safe as they cause low transplant-related morbidity. The combination of fractionated TBI and etoposide or cyclophosphamide was not found to be superior. However, it must be kept in mind that comparisons were made on registry data or retrospectively. In every case, relapse of the residual primary disease argue for the need for more effective strategies such as tandem transplantation or sequential high-dose chemotherapy with stem-cell support. To obtain an objective evaluation, these new preparative regimens need to be tested in controlled trials with treatment groups stratified for known prognostic factors.