Sequence
The sequence has 420 amino acids and a molecular weight of 46032 (UniProt).

Isoforms
There are 9 different isoforms (NCBI AceView).
Of the 9 different isoforms, 6 are considered to be very good quality proteins and 3 are good quality proteins.
The 9 isoforms are:
- aAug 10, predicted protein is 593 aa long and 65,1 kDa, and it has one leucine rich repeat N terminal domain, 3 leucine rich repeat domains, one leucine rich repeat C terminal domian and a transmembrane domain;
- bAug10, predicted protein is 588 aa long and 64,3 kDa and it has has one leucine rich repeat N terminal domain, 3 leucine rich repeat domains, one leucine rich repeat C terminal domain and a transmembrane domain;
- cAug10 518 aa and 56,6 kDa and has one leucine rich repeat N terminal domain, 3 leucine rich repeat domains, one leucine rich repeat C terminal domain and a transmembrane domain;
- dAug10 272 aa and 30,2 kDa and contains 3 leucine rich repeat domains;
- eAug10 229 aa and 23 kDa and contains no protein domain;
- faug10 201 aa and 22,6 kDa and has 2 leucine rich repeat domains;
- gAug10 161 aa and 17 kDa and contains no protein domain;
- hAug10 117 aa and 13,2 kDa and contains no protein domain;
- iAug10 105aa and 11,9 kDa and contains no protein domain.
There are 2 phosphorylation sites that have been identified based on information summarized in Phosphosite Plus.
The first is threonine 99 which was identified by mass spectrometry in the HeLa cervical cancer cell lines (Chen et al., 2009).
The second site of phosphorylation is Serine 418 identified via mass spectrometry in cervical cancer and identified in HeLa cervical cancer cell lines (Olsen et al., 2010).

Drugs and compounds: TroVax
The first study of TroVax in colorectal cancer was in patients who had been previously treated with chemotherapy. In this dose-escalation study, TroVax was given to 22 colorectal cancer patients in an open-label phase I/II trial. Sixteen of 17 immunologically evaluable patients showed a 5T4-specific response. Fourteen patients demonstrated detectable antibody levels following vaccination. There was a positive association between the development of the antibody response and patient survival or time to disease progression (Mulryan et al., 2002).
TroVax has also been studied in combination with systemic chemotherapy in colorectal cancer patients. Two phase 2 studies have studied this combination. In the first study, 12 patients recieved a combination of 5T4 with 5-FU, folinic acid, and irinotecan. Six had a partial response, and 5 had stable disease. Ten patients had 5T4-specific antibody responses (Harrop et al., 2007).
The second study had a total of 11 patients who recived TroVax in combination with 5-FU/folinic acid and irinotecan. Six patients had either a complete response or stable disease, and 10 patients had 5-T4-specific antibody responses (Harrop et al., 2008).
TroVax has been studied as a single agent in patients scheduled for surgical resection of colon cancer. Sixteen patients were enrolled in this phase 2 study. They received 2 vaccinations prior to surgery and 2 vaccinations after surgery. Nine patients had no disease recurrence at 8.4 months, and 13 patients mounted a 5T4-specific antibody response (Elkord et al., 2008).

Drugs and compounds: TroVax
Open-label phase1/2 trial of TroVax administration along with interferon alpha in 11 patients with metastatic RCC. All 11 patients mounted an antibody response to 5T4. The median time to progression was 9 months which was longer than that with interferon alone (Hawkins et al., 2009).
A second open-label, phase 2 trial involved 23 metatstatic RCC patients. TroVax was administered alone or in combination with IFN-alpha. In that study, 96% of patients mounted a 5T4-specific antibody response. One patient in the TroVax/IFN arm achieved a PR; 7 patients in the TroVax/interferon combination arm and 7 patients in the TroVax-alone arm achieved stable disease. The median PFS was 3.8 months, and the median OS was 12.1 months (Amato et al., 2009).
Another phase 2 trial looked at the combination of TroVax with low-dose IL-2 in metastatic RCC patients. Twenty-five patients were enrolled in that study, 21 of whom mounted 5T4-specific antibody response. Two patients demonstrated a complete reponse of >36 months, 1 patient demonstrated a PR of 12 months, and 6 patients demonstrated stable disease for between 6 and 21 months. Median PFS was 3.37 months, and median OS was 12.87 months (Amato et al., 2008b).
There has been only 1 phase 3 trial to date that has studied TroVax in metastatic RCC patients. Amato et al. (2010) enrolled 733 patients in a study to compare TroVax with sunitib, IFN, or IL-2. Immune response was assessed in 590 patients, 56% of whom had a positive 5T4-specific antibody response. A high 5T4 antibody response was associated with longer survival in the TroVax arm.