Biomira Inc. and Merck KGaA of Darmstadt, Germany, announced that the preliminary results from a randomized, open-label Phase IIb trial of BLP25 liposomal vaccine (L-BLP25) in patients with Stage IIIb and IV non-small cell lung cancer (NSCLC) indicate that the median survival of those patients on the vaccine arm was 4.4 months longer than those on the control arm. Although not statistically significant, the overall median survival is 17.4 months for patients on the vaccine arm versus 13 months for the patients on the control arm.
Importantly, the observed two-year survival for patients with locoregional Stage IIIb disease is 60 per cent for the vaccine arm (median survival not yet reached) versus 36.7 per cent for the control arm (median survival of 13.3 months). In the overall patient population the two-year survival is 43.2 per cent for the vaccine arm versus 28.9 per cent for the control arm.
"Our overall survival analysis, is, in our opinion, clinically compelling," said Alex McPherson, MD, PhD, president and CEO of Biomira. "We are very encouraged by these results and are developing plans for further clinical testing of L-BLP25 in lung cancer and possibly other indications. Although not finalized, our plans will likely include a multinational Phase III registration trial."
The controlled, open-label Phase IIb trial enrolled 171 men and women with NSCLC whose disease was stable or who had responded to treatment following completion of their first line standard chemotherapy. Patients were randomized to either L-BLP25 plus best standard of care or to best standard of care alone. Best standard of care includes palliative radiotherapy and/or second line chemotherapy according to current standard clinical practice. The study was designed to document the safety profile of the vaccine and to evaluate efficacy by comparing survival in the two arms.
The results appear to indicate a favourable safety profile. Additional analyses and survival follow-up will be conducted to gather information to assist in the future development of the product.
"Lung cancer is a very aggressive disease and the observation of a 4.4 month improvement in median survival for patients treated with L-BLP25 in this well-controlled trial is a clinically important finding for this serious illness," said Nancy Wysenski, president of EMD Pharmaceuticals, Inc., the U.S subsidiary of Merck KGaA. "We appreciate the participation of the patients and investigators in this study that has yielded this important finding."
Dr. Frances Shepherd, Chairman of the Data Safety Monitoring Board (DSMB) for the Phase IIb trial complimented the Companies saying, "This study was conducted in an exemplary fashion and the high quality data resulting from the trial can now be used in planning the next phase of clinical development."
In preparation for the potential multinational registration trial, Biomira is already scheduling for the manufacture of new vaccine supplies. This will incorporate manufacturing changes intended to secure the future commercial supply of the vaccine. Scheduling these changes now ensures that the resulting pivotal data will be considered representative of the safety and effectiveness of the commercial supply of the vaccine. To assure the successful initiation of a pivotal trial, a comparability plan, which may or may not include clinical data, will be discussed with regulatory authorities.
L-BLP25 is a synthetic MUC1 peptide vaccine. L-BLP25 incorporates a 25-amino acid sequence of the MUC1 cancer mucin, encapsulated in a liposomal delivery system. The liposome enhances recognition of the cancer antigen by the immune system and facilitates better delivery. L-BLP25 is designed to induce an immune response to cancer cells.
Lung cancer is the leading cause of cancer-related mortality for both sexes in North America. In 2004, approximately 174,000 new cases of lung cancer will be diagnosed in the U.S. - 54 per cent of them in men and 46 per cent in women. Approximately 160,000 people will die of this disease in the U.S. alone in 2004. In Canada, the mortality percentages are slightly higher for men - 57 per cent of deaths from lung cancer will occur in men and 43 per cent will be in women. NSCLC accounts for approximately 75 to 80 per cent of all primary lung cancers. At the time of diagnosis, only 25 per cent of patients are potentially curable by surgery.
In addition to the Phase IIb trial for men and women with Stage IIIb and IV NSCLC, in 2002 Biomira also completed enrolment in a second pilot study with L-BLP25 in patients with prostate cancer. A 16-patient L-BLP25 Phase II pilot study in patients with rising prostate specific antigen (PSA) post radical prostatectomy was conducted to determine whether the vaccine could reduce or stabilize PSA levels. L-BLP25 showed a good safety profile, and the dose and schedule were also well accepted by the patients. Preliminary results in this small patient population did not conclusively show a reduction or stabilization of serum PSA levels. However, there appears to be a prolongation of PSA doubling time (PSADT) in just under 40 per cent of the patients. While there has been no commitment to conduct further trials at this time in this indication, the patients continue to be followed for PSA levels for a period of 12 months following their last vaccination.
Biomira and Merck KGaA are also collaborating on the development of Theratope vaccine in the treatment of metastatic breast cancer. The Companies are continuing subset analyses in one pre-stratified subset of more than 300 women who received hormonal treatment following chemotherapy in a Phase III study. In the subset, those women who received Theratope appeared to show a favourable trend toward improvement in survival. A Phase II study of Theratope in metastatic breast cancer is also enrolling patients in the U.S. Women in this trial have a less aggressive disease than those in the Phase III trial, and full enrolment is expected in the first half of 2004. The Companies expect to announce their corporate strategy for Theratope by the end of the second quarter of 2004.