Mesothelioma Patients Hopeful Vaccine for NSCLC Patients Will Benefit Them Too
Few rare diseases have a vaccination available to prevent the disease from developing, or to serve as a treatment for the disease once diagnosed. For scientists researching a vaccine for mesothelioma, a rare disease known to be caused by asbestos exposure, any successes have been fleeting. However, researchers at UC San Diego Moores Cancer Center report that a vaccine tested on non-small cell lung cancer (NSCLC) patients has shown an improved survival.
NSCLC typically presents with distinct, individual tumors, while mesothelioma displays as a large mass of interlocked tumors that blend in with healthy tissue. Both cancers can be extremely aggressive and are difficult to treat. Yet, just 3,000 Americans are diagnosed with mesothelioma each year, and finding a new treatment is challenging for the limited population. However, a discovery for lung cancer can lead to a breakthrough for mesothelioma as well.
In a study presented at the annual meeting of the American Association for Cancer Research, UC San Diego researchers reported that in a follow-up to its phase II trial of belagenpumatucel-L, results “confirmed encouraging survival for patients with stage IIIB/IV [lung cancer] disease.”
Belagenpumatucel-L is a therapeutic vaccine comprised of 4 TGF-β2 (transforming growth factor beta2) antisense gene-modified allogeneic NSCLC cell lines. Other studies have shown that vaccines made from gene-modified tumor cells may help the body build an immune response to kill tumor cells. In their clinical trial, the researchers set out to determine “how well it works compared with a placebo in treating subjects with stage III or stage IV non-small cell lung cancer.”
According to the researchers, the phase II trial was initially reported on in 2006. The recent report provides an updated survival analysis with over 5 years of follow up.
75 patients were enrolled in the trial representing stage II, stage IIIA, stage IIIB, and stage IV of NSCLC. The patients were randomly assigned to three dose cohorts who were followed for a median of 14.5 months, or in the patients with stable disease, were followed for 44 months.
The authors reported median survival for all subjects was 14.5 months; and one-year, two-year and five-year survival were respectively 55%, 35% and 20%.
Patients with stage IIIB and IV NSCLC enrolled into the second and third dose cohorts had one-, two-, and five-year survival rates of 61, 41, and 18 percent, respectively, with median survival of 15.9 months.
Stage IIIB and IV patients with nonprogressive disease following frontline chemotherapy had a median survival of 44.4 months and five-year survival of 50 percent, whereas those who progressed had median survival of 14.1 months and five-year survival of 9.1 percent.
Encouraged by the results, the researchers report the next step is to conduct a phase III trial to evaluate the efficacy of belagenpumatucel-L in a maintenance setting in stage III/IV NSCLC patients who have stable disease or better following frontline chemotherapy. The trial will be conducted with 506 patients – to date 285 have been enrolled.
The authors concluded that similar results in their phase III trial “would provide an important improvement for the treatment of non-small cell lung cancer.”
This study is particularly important for mesothelioma patients who often are not diagnosed until the disease has progressed to stage III or IV. Mesothelioma has an extended incubation period, and by the time symptoms are present, the disease has progressed to a point where limited treatment options are available.