Background: Telomerase is a necessity for infinite cell division in cancer cells, and high telomerase activity is present in as much as 90 % of human cancers. Hence telomerase has become an attractive target in cancer therapy because it suggests a universal cure for cancer. We summarized research done on the vaccine GV1001 and the telomerase inhibitor Imetelstat in prostate, pancreas and lung cancer. Methods: We reviewed finished and ongoing clinical trials on GV1001 and Imetelstat; and preclinical trials on Imetelstat. Results: Preclinical trials on Imetelstat show that it is a potent inhibitor of cancer growth. It also targets tumor initiating cells (TIC). Clinical trials on GV1001 have shown that it’s a safe treatment. It also induces immune response in majority of patients and phase I/II studies suggest an increased overall survival in the immune responders. Even though one clinical phase III trial on GV1001 has shown negative results, other studies suggest a positive additive effect when combined with chemo and radiotherapy. Conclusion: Therapy targeting telomerase is safe. We believe telomerase-targeted therapy can be an important supplement to other cancer therapy even though it doesn’t seem promising as single treatment.