# CTCAE 6 Pro vs C4 Therapeutics

The clearest difference is in-app purchases: C4 Therapeutics at none against CTCAE 6 Pro's 2. C4 Therapeutics also leads on iOS requirement (12.0 vs 15.6). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. CTCAE 6 Pro sells 2 in-app purchases, starting at $1.99 per month. C4 Therapeutics asks for nothing beyond the download.

CTCAE 6 Pro ships an update monthly, C4 Therapeutics every 2 weeks. The most recent releases landed on October 27, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | CTCAE 6 Pro | C4 Therapeutics |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (10 ratings)](https://appshunter.io/ios/app/ctcae-6-pro/id1625560237/reviews)** | — |
| Number of ratings | **10** | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Monthly | **Every 2 weeks** |
| Monetization | Freemium | — |
| Size | 87 MB | 77 MB |
| Requires iOS | 15.6 | **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 6 Pro

[App page](https://appshunter.io/ios/app/ctcae-6-pro/id1625560237)

Easily review and annotate medical toxicity criteria. Bookmark adverse events, search keywords, and organize entries chronologically. Offers local data storage and optional premium features for advanced note-taking and data export.

**Highlights:** Quick CTCAE 6.0 content access, Unlimited adverse event bookmarking, Keyword search with highlighting, Local data storage, Version comparison (5.0 ⇄ 6.0), Smart notes and timeline management, Spreadsheet to custom list app conversion

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Plan – Monthly | $1.99 | per month |
| Premium Plan – Annual | $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 6 Pro free?

CTCAE 6 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 6 Pro or C4 Therapeutics have ads?

Neither CTCAE 6 Pro nor C4 Therapeutics shows ads.

### Which is updated more often, CTCAE 6 Pro or C4 Therapeutics?

CTCAE 6 Pro ships an update monthly, and C4 Therapeutics every 2 weeks. Most recently, CTCAE 6 Pro was updated on October 27, 2026 and C4 Therapeutics on October 25, 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.*