Human / Clinical Studies
Two additional phase II studies investigated the use of NDV-infected, autologous tumor cell vaccines in patients who had either ovarian cancer or renal cell cancer.[21,23] The ovarian cancer trial enrolled 82 patients, but only 39 were evaluable for response. The published report of this trial, however, described clinical findings for just 24 evaluable patients who had stage III disease; results for the remaining evaluable patients (5 with stage I disease, 5 with stage II disease, and 5 with stage IV disease) were not presented. The patients in this trial were treated with surgery and six courses of chemotherapy in addition to three courses of intradermally administered immunotherapy, but details about the adjuvant treatments (e.g., what constituted a course of immunotherapy or what chemotherapy drugs were used in addition to cisplatin) were very limited. Among the 24 evaluable patients with reported clinical findings, 15 had a complete remission, 8 had a partial remission, and 1 had progressive disease. The median disease-free survival time for the patients who had a complete remission was 30 months. These results were described as very encouraging by the investigators who conducted the study, but the degree of benefit afforded by the immunotherapy in this uncontrolled study cannot be established. In common with other studies of NDV-infected tumor cell vaccines, histologic examination of individual vaccination sites revealed the presence of infiltrates consisting predominantly of helper T cells.
The phase II trial of NDV-infected, autologous tumor cell vaccines in patients with renal cell cancer enrolled 40 individuals whose disease had spread from the kidney to at least 1 other organ. The patients in this trial underwent surgery (i.e., radical nephrectomy) to remove the primary tumor and then were given intradermal injections of NDV-infected tumor cells at 3 weeks and 5 weeks after surgery. The patients were also given subcutaneous injections of low-dose recombinant interleukin-2 and recombinant interferon-alpha. Five patients had a complete response, and six had a partial response. After 4 years of follow-up, overall survival for these 11 responding patients was 100%. Among the remaining 29 patients, 12 had stable disease (median survival = 31 months) and 17 had progressive disease (median survival = 14 months). The researchers also reported a median survival time of 13 months for 36 historical control subjects who were treated with surgery and other types of adjuvant therapy (chemotherapy, radiation therapy, or hormonal therapy). The overall percentage of patients with either a complete response or a partial response in this uncontrolled study (i.e., 28%) is similar to that found in other studies in which comparable patients were treated with cytokine therapy but not vaccine therapy. Therefore, it is not clear whether any of the apparent clinical benefit in this trial can be attributed to vaccination with NDV-infected tumor cells.