# CTCAE 5 Pro vs C4 Therapeutics

The clearest difference is in-app purchases: C4 Therapeutics at none against CTCAE 5 Pro's 2. C4 Therapeutics also leads on update cadence (every 2 weeks vs every 5 weeks) and iOS requirement (12.0 vs 15.5). On price, ads and device support there is nothing between them.

Both are free to download. CTCAE 5 Pro sells 2 in-app purchases, starting at $1.99 per month. C4 Therapeutics asks for nothing beyond the download.

CTCAE 5 Pro ships an update every 5 weeks, C4 Therapeutics every 2 weeks. The most recent releases landed on November 12, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | CTCAE 5 Pro | C4 Therapeutics |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (45 ratings)](https://appshunter.io/ios/app/ctcae-5-pro/id1625569535/reviews)** | — |
| Number of ratings | **45** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 5 weeks | **Every 2 weeks** |
| Monetization | Freemium | — |
| Size | 60 MB | 77 MB |
| Requires iOS | 15.5 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 12+ |
| Developer | [Koichiro Watanabe](https://appshunter.io/developer/1077985400) | [ERT, INC](https://appshunter.io/developer/1160214546) |

## What reviewers say

### CTCAE 5 Pro

[App page](https://appshunter.io/ios/app/ctcae-5-pro/id1625569535)

This app provides easy access to CTCAE documentation and supports local data storage for enhanced privacy. Premium features include version comparison, advanced note-taking, custom app creation from spreadsheets, and flexible data backup options.

**Highlights:** Streamlined CTCAE Document Access, Local Data Storage, Version Comparison Tool, Advanced Notes Feature, Custom App Creation, Flexible Backup and Archiving

**Features:** macOS Compatibility, Family Sharing, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly subscription | $1.99 | per month |
| Annual subscription | $9.99 | per year |


### C4 Therapeutics

[App page](https://appshunter.io/ios/app/c4-therapeutics-cft7455-1102/id6757601113)

**In-app purchases:** none


## Frequently asked questions

### Is CTCAE 5 Pro free?

CTCAE 5 Pro is free to download, with in-app purchases available.

### Is C4 Therapeutics free?

C4 Therapeutics is free to download, with no in-app purchases.

### Do CTCAE 5 Pro or C4 Therapeutics have ads?

Neither CTCAE 5 Pro nor C4 Therapeutics shows ads.

### Which is updated more often, CTCAE 5 Pro or C4 Therapeutics?

CTCAE 5 Pro ships an update every 5 weeks, and C4 Therapeutics every 2 weeks. Most recently, CTCAE 5 Pro was updated on November 12, 2026 and C4 Therapeutics on October 31, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*